Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450145114521453145414551456145714581459146014611462146314641465146614671468146914701471147214731474147514761477147814791480148114821483148414851486148714881489149014911492149314941495149614971498149915001501150215031504150515061507150815091510151115121513151415151516151715181519152015211522152315241525152615271528152915301531153215331534153515361537153815391540154115421543154415451546154715481549155015511552155315541555155615571558155915601561156215631564156515661567156815691570157115721573157415751576157715781579158015811582158315841585158615871588158915901591159215931594159515961597159815991600160116021603160416051606160716081609161016111612161316141615161616171618161916201621162216231624162516261627162816291630163116321633163416351636163716381639164016411642164316441645164616471648164916501651165216531654165516561657165816591660166116621663166416651666166716681669167016711672167316741675167616771678167916801681168216831684168516861687168816891690169116921693169416951696169716981699170017011702170317041705170617071708170917101711171217131714171517161717171817191720172117221723172417251726172717281729173017311732173317341735173617371738173917401741174217431744174517461747174817491750175117521753175417551756175717581759176017611762176317641765176617671768176917701771177217731774177517761777177817791780178117821783178417851786178717881789179017911792179317941795179617971798179918001801180218031804180518061807180818091810181118121813181418151816181718181819182018211822182318241825182618271828182918301831183218331834183518361837183818391840184118421843184418451846184718481849185018511852185318541855185618571858185918601861186218631864186518661867186818691870187118721873187418751876187718781879188018811882188318841885188618871888188918901891189218931894189518961897189818991900190119021903190419051906190719081909191019111912191319141915191619171918191919201921192219231924192519261927192819291930193119321933193419351936193719381939194019411942194319441945194619471948194919501951195219531954195519561957195819591960196119621963196419651966196719681969197019711972197319741975197619771978197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044204520462047204820492050205120522053205420552056205720582059206020612062206320642065206620672068206920702071207220732074207520762077207820792080208120822083208420852086208720882089209020912092209320942095209620972098209921002101210221032104210521062107210821092110211121122113211421152116211721182119212021212122212321242125212621272128212921302131213221332134213521362137213821392140214121422143214421452146214721482149215021512152215321542155215621572158215921602161216221632164216521662167216821692170217121722173217421752176217721782179218021812182218321842185218621872188218921902191219221932194219521962197219821992200220122022203220422052206220722082209221022112212221322142215221622172218221922202221222222232224222522262227222822292230223122322233223422352236223722382239224022412242224322442245224622472248224922502251225222532254225522562257225822592260226122622263226422652266226722682269227022712272227322742275227622772278227922802281228222832284228522862287228822892290229122922293229422952296229722982299230023012302230323042305230623072308230923102311231223132314231523162317231823192320232123222323232423252326232723282329233023312332233323342335233623372338233923402341234223432344234523462347234823492350235123522353235423552356235723582359236023612362236323642365236623672368236923702371237223732374237523762377237823792380238123822383238423852386238723882389239023912392239323942395239623972398239924002401240224032404240524062407240824092410241124122413241424152416241724182419242024212422242324242425242624272428242924302431243224332434243524362437243824392440244124422443244424452446244724482449245024512452245324542455245624572458245924602461246224632464246524662467246824692470247124722473247424752476247724782479248024812482248324842485248624872488248924902491249224932494249524962497249824992500250125022503250425052506250725082509251025112512251325142515251625172518251925202521252225232524252525262527252825292530253125322533253425352536253725382539254025412542254325442545254625472548254925502551255225532554255525562557255825592560256125622563256425652566256725682569257025712572257325742575257625772578257925802581258225832584258525862587258825892590259125922593259425952596259725982599260026012602260326042605260626072608260926102611261226132614261526162617261826192620262126222623262426252626262726282629263026312632263326342635263626372638263926402641264226432644264526462647264826492650265126522653265426552656265726582659266026612662266326642665266626672668266926702671267226732674267526762677267826792680268126822683268426852686268726882689269026912692269326942695269626972698269927002701270227032704270527062707270827092710271127122713271427152716271727182719272027212722272327242725272627272728272927302731273227332734273527362737273827392740274127422743274427452746274727482749275027512752275327542755275627572758275927602761276227632764276527662767276827692770277127722773277427752776277727782779278027812782278327842785278627872788278927902791279227932794279527962797279827992800280128022803280428052806280728082809281028112812281328142815281628172818281928202821282228232824282528262827282828292830283128322833283428352836283728382839284028412842284328442845284628472848284928502851285228532854285528562857285828592860286128622863286428652866286728682869287028712872287328742875287628772878287928802881288228832884288528862887288828892890289128922893289428952896289728982899290029012902290329042905290629072908290929102911291229132914291529162917291829192920292129222923292429252926292729282929293029312932293329342935293629372938293929402941294229432944294529462947294829492950295129522953295429552956295729582959296029612962296329642965296629672968296929702971297229732974297529762977297829792980298129822983298429852986298729882989299029912992299329942995299629972998299930003001300230033004300530063007300830093010301130123013301430153016301730183019302030213022302330243025302630273028302930303031303230333034303530363037303830393040304130423043304430453046304730483049305030513052305330543055305630573058305930603061306230633064306530663067306830693070307130723073307430753076307730783079308030813082308330843085308630873088308930903091309230933094309530963097309830993100310131023103310431053106310731083109311031113112311331143115311631173118311931203121312231233124312531263127312831293130313131323133313431353136313731383139314031413142314331443145314631473148314931503151315231533154315531563157315831593160316131623163316431653166316731683169317031713172317331743175317631773178317931803181318231833184318531863187318831893190319131923193319431953196319731983199320032013202320332043205320632073208320932103211321232133214321532163217321832193220322132223223322432253226322732283229323032313232323332343235323632373238323932403241324232433244324532463247324832493250325132523253325432553256325732583259326032613262326332643265326632673268326932703271327232733274327532763277327832793280328132823283328432853286328732883289329032913292329332943295329632973298329933003301330233033304330533063307330833093310331133123313331433153316331733183319332033213322332333243325332633273328332933303331333233333334333533363337333833393340334133423343334433453346334733483349335033513352335333543355335633573358335933603361336233633364336533663367336833693370337133723373337433753376337733783379338033813382338333843385338633873388338933903391339233933394339533963397339833993400340134023403340434053406340734083409341034113412341334143415341634173418341934203421342234233424342534263427342834293430343134323433343434353436343734383439344034413442344334443445344634473448344934503451345234533454345534563457345834593460346134623463346434653466346734683469347034713472347334743475347634773478347934803481348234833484348534863487348834893490349134923493349434953496349734983499350035013502350335043505350635073508350935103511351235133514351535163517351835193520352135223523352435253526352735283529353035313532353335343535353635373538353935403541354235433544354535463547354835493550355135523553355435553556355735583559356035613562356335643565356635673568356935703571357235733574357535763577357835793580358135823583358435853586358735883589359035913592359335943595359635973598359936003601360236033604360536063607360836093610361136123613361436153616361736183619362036213622362336243625362636273628362936303631363236333634363536363637363836393640364136423643364436453646364736483649365036513652365336543655365636573658365936603661366236633664366536663667366836693670367136723673367436753676367736783679368036813682368336843685368636873688368936903691369236933694369536963697369836993700370137023703370437053706370737083709371037113712371337143715371637173718371937203721372237233724372537263727372837293730373137323733373437353736373737383739374037413742374337443745374637473748374937503751375237533754375537563757375837593760376137623763376437653766376737683769377037713772377337743775377637773778377937803781378237833784378537863787378837893790379137923793379437953796379737983799380038013802380338043805380638073808380938103811381238133814381538163817381838193820382138223823382438253826382738283829383038313832383338343835383638373838383938403841384238433844384538463847384838493850385138523853385438553856385738583859386038613862386338643865386638673868386938703871387238733874387538763877387838793880388138823883388438853886388738883889389038913892389338943895389638973898389939003901390239033904390539063907390839093910391139123913391439153916391739183919392039213922392339243925392639273928392939303931393239333934393539363937393839393940394139423943394439453946394739483949395039513952395339543955395639573958395939603961396239633964396539663967396839693970397139723973397439753976397739783979398039813982398339843985398639873988398939903991399239933994399539963997399839994000400140024003400440054006400740084009401040114012401340144015401640174018401940204021402240234024402540264027402840294030403140324033403440354036403740384039404040414042404340444045404640474048404940504051405240534054405540564057405840594060406140624063406440654066406740684069407040714072407340744075407640774078407940804081408240834084408540864087408840894090409140924093409440954096409740984099410041014102410341044105410641074108410941104111411241134114411541164117411841194120412141224123412441254126412741284129413041314132413341344135413641374138413941404141414241434144414541464147414841494150415141524153415441554156415741584159416041614162416341644165416641674168416941704171417241734174417541764177417841794180418141824183418441854186418741884189419041914192419341944195419641974198419942004201420242034204420542064207420842094210421142124213421442154216421742184219422042214222422342244225422642274228422942304231423242334234423542364237423842394240424142424243424442454246424742484249425042514252425342544255425642574258425942604261426242634264426542664267426842694270427142724273427442754276427742784279428042814282428342844285428642874288428942904291429242934294429542964297429842994300430143024303430443054306430743084309431043114312431343144315431643174318431943204321432243234324432543264327432843294330433143324333433443354336433743384339434043414342434343444345434643474348434943504351435243534354435543564357435843594360436143624363436443654366436743684369437043714372437343744375437643774378437943804381438243834384438543864387438843894390439143924393439443954396439743984399440044014402440344044405440644074408440944104411441244134414441544164417441844194420442144224423442444254426442744284429443044314432443344344435443644374438443944404441444244434444444544464447444844494450445144524453445444554456445744584459446044614462446344644465446644674468446944704471447244734474447544764477447844794480448144824483448444854486448744884489449044914492449344944495449644974498449945004501450245034504450545064507450845094510451145124513451445154516451745184519452045214522452345244525452645274528452945304531453245334534453545364537453845394540454145424543454445454546454745484549455045514552455345544555455645574558455945604561456245634564456545664567456845694570457145724573457445754576457745784579458045814582458345844585458645874588458945904591459245934594459545964597459845994600460146024603460446054606460746084609461046114612461346144615461646174618461946204621462246234624462546264627462846294630463146324633463446354636463746384639464046414642464346444645464646474648464946504651465246534654465546564657465846594660466146624663466446654666466746684669467046714672467346744675467646774678467946804681468246834684468546864687468846894690469146924693469446954696469746984699470047014702470347044705470647074708470947104711471247134714471547164717471847194720472147224723472447254726472747284729473047314732473347344735473647374738473947404741474247434744474547464747474847494750475147524753475447554756475747584759476047614762476347644765476647674768476947704771477247734774477547764777477847794780478147824783478447854786478747884789479047914792479347944795479647974798479948004801480248034804480548064807480848094810481148124813481448154816481748184819482048214822482348244825482648274828482948304831483248334834483548364837483848394840484148424843484448454846484748484849485048514852485348544855485648574858485948604861486248634864486548664867486848694870487148724873487448754876487748784879488048814882488348844885488648874888488948904891489248934894489548964897489848994900490149024903490449054906490749084909491049114912491349144915491649174918491949204921492249234924492549264927492849294930493149324933493449354936493749384939494049414942494349444945494649474948494949504951495249534954495549564957495849594960496149624963496449654966496749684969497049714972497349744975497649774978497949804981498249834984498549864987498849894990499149924993499449954996499749984999500050015002500350045005500650075008500950105011501250135014501550165017501850195020502150225023502450255026502750285029503050315032503350345035503650375038503950405041504250435044504550465047504850495050505150525053505450555056505750585059506050615062506350645065506650675068506950705071507250735074507550765077507850795080508150825083508450855086508750885089509050915092509350945095509650975098509951005101510251035104510551065107510851095110511151125113511451155116511751185119512051215122512351245125512651275128512951305131513251335134513551365137513851395140514151425143514451455146514751485149515051515152515351545155515651575158515951605161516251635164516551665167516851695170517151725173517451755176517751785179518051815182518351845185518651875188518951905191519251935194519551965197519851995200520152025203520452055206520752085209521052115212521352145215521652175218521952205221522252235224522552265227522852295230523152325233523452355236523752385239524052415242524352445245524652475248524952505251525252535254525552565257525852595260526152625263526452655266526752685269527052715272527352745275527652775278527952805281528252835284528552865287528852895290529152925293529452955296529752985299530053015302530353045305530653075308530953105311531253135314531553165317531853195320532153225323532453255326532753285329533053315332533353345335533653375338533953405341534253435344534553465347534853495350535153525353535453555356535753585359536053615362536353645365536653675368536953705371537253735374537553765377537853795380538153825383538453855386538753885389539053915392539353945395539653975398539954005401540254035404540554065407540854095410541154125413541454155416541754185419542054215422542354245425542654275428542954305431543254335434543554365437543854395440544154425443544454455446544754485449545054515452545354545455545654575458545954605461546254635464546554665467546854695470547154725473547454755476547754785479548054815482548354845485548654875488548954905491549254935494549554965497549854995500550155025503550455055506550755085509551055115512551355145515551655175518551955205521552255235524552555265527552855295530553155325533553455355536553755385539554055415542554355445545554655475548554955505551555255535554555555565557555855595560556155625563556455655566556755685569557055715572557355745575557655775578557955805581558255835584558555865587558855895590559155925593559455955596559755985599560056015602560356045605560656075608560956105611561256135614561556165617561856195620562156225623562456255626562756285629563056315632563356345635563656375638563956405641564256435644564556465647564856495650565156525653565456555656565756585659566056615662566356645665566656675668566956705671567256735674567556765677567856795680568156825683568456855686568756885689569056915692569356945695569656975698569957005701570257035704570557065707570857095710571157125713571457155716571757185719572057215722572357245725572657275728572957305731573257335734573557365737573857395740574157425743574457455746574757485749575057515752575357545755575657575758575957605761576257635764576557665767576857695770577157725773577457755776577757785779578057815782578357845785578657875788578957905791579257935794579557965797579857995800580158025803580458055806580758085809581058115812581358145815581658175818581958205821582258235824582558265827582858295830583158325833583458355836583758385839584058415842584358445845584658475848584958505851585258535854585558565857585858595860586158625863586458655866586758685869587058715872587358745875587658775878587958805881588258835884588558865887588858895890589158925893589458955896589758985899590059015902590359045905590659075908590959105911591259135914591559165917591859195920592159225923592459255926592759285929593059315932593359345935593659375938593959405941594259435944594559465947594859495950595159525953595459555956595759585959596059615962596359645965596659675968596959705971597259735974597559765977597859795980598159825983598459855986598759885989599059915992599359945995599659975998599960006001600260036004600560066007600860096010601160126013601460156016601760186019602060216022602360246025602660276028602960306031603260336034603560366037603860396040604160426043604460456046604760486049605060516052605360546055605660576058605960606061606260636064606560666067606860696070607160726073607460756076607760786079608060816082608360846085608660876088608960906091609260936094609560966097609860996100610161026103610461056106610761086109611061116112611361146115611661176118611961206121612261236124612561266127612861296130613161326133613461356136613761386139614061416142614361446145614661476148614961506151615261536154615561566157615861596160616161626163616461656166616761686169617061716172617361746175617661776178617961806181618261836184618561866187618861896190619161926193619461956196619761986199620062016202620362046205620662076208620962106211621262136214621562166217621862196220622162226223622462256226622762286229623062316232623362346235623662376238623962406241624262436244624562466247624862496250625162526253625462556256625762586259626062616262626362646265626662676268626962706271627262736274627562766277627862796280628162826283628462856286628762886289629062916292629362946295629662976298629963006301630263036304630563066307630863096310631163126313631463156316631763186319632063216322632363246325632663276328632963306331633263336334633563366337633863396340634163426343634463456346634763486349635063516352635363546355635663576358635963606361636263636364636563666367636863696370637163726373637463756376637763786379638063816382638363846385638663876388638963906391639263936394639563966397639863996400640164026403640464056406640764086409641064116412641364146415641664176418641964206421642264236424642564266427642864296430643164326433643464356436643764386439644064416442644364446445644664476448644964506451645264536454645564566457645864596460646164626463646464656466646764686469647064716472647364746475647664776478647964806481648264836484648564866487648864896490649164926493649464956496649764986499650065016502650365046505650665076508650965106511651265136514651565166517651865196520652165226523652465256526652765286529653065316532653365346535653665376538653965406541654265436544654565466547654865496550655165526553655465556556655765586559656065616562656365646565656665676568656965706571657265736574657565766577657865796580658165826583658465856586658765886589659065916592659365946595659665976598659966006601660266036604660566066607660866096610661166126613661466156616661766186619662066216622662366246625662666276628662966306631663266336634663566366637663866396640664166426643664466456646664766486649665066516652665366546655665666576658665966606661666266636664666566666667666866696670667166726673667466756676667766786679668066816682668366846685668666876688668966906691669266936694669566966697669866996700670167026703670467056706670767086709671067116712671367146715671667176718671967206721672267236724672567266727672867296730673167326733673467356736673767386739674067416742674367446745674667476748674967506751675267536754675567566757675867596760676167626763676467656766676767686769677067716772677367746775677667776778677967806781678267836784678567866787678867896790679167926793679467956796679767986799680068016802680368046805680668076808680968106811681268136814681568166817681868196820682168226823682468256826682768286829683068316832683368346835683668376838683968406841684268436844684568466847684868496850685168526853685468556856685768586859686068616862686368646865686668676868686968706871687268736874687568766877687868796880688168826883688468856886688768886889689068916892689368946895689668976898689969006901690269036904690569066907690869096910691169126913691469156916691769186919692069216922692369246925692669276928692969306931693269336934693569366937693869396940694169426943694469456946694769486949695069516952695369546955695669576958695969606961696269636964696569666967696869696970697169726973697469756976697769786979698069816982698369846985698669876988698969906991699269936994699569966997699869997000700170027003700470057006700770087009701070117012701370147015701670177018701970207021702270237024702570267027702870297030703170327033703470357036703770387039704070417042704370447045704670477048704970507051705270537054705570567057705870597060706170627063706470657066706770687069707070717072707370747075707670777078707970807081708270837084708570867087708870897090709170927093709470957096709770987099710071017102710371047105710671077108710971107111711271137114711571167117711871197120712171227123712471257126712771287129713071317132713371347135713671377138713971407141714271437144714571467147714871497150715171527153715471557156715771587159716071617162716371647165716671677168716971707171717271737174717571767177717871797180718171827183718471857186718771887189719071917192719371947195719671977198719972007201720272037204720572067207720872097210721172127213721472157216721772187219722072217222722372247225722672277228722972307231723272337234723572367237723872397240724172427243724472457246724772487249725072517252725372547255725672577258725972607261726272637264726572667267726872697270727172727273727472757276727772787279728072817282728372847285728672877288728972907291729272937294729572967297729872997300730173027303730473057306730773087309731073117312731373147315731673177318731973207321732273237324732573267327732873297330733173327333733473357336733773387339734073417342734373447345734673477348734973507351735273537354735573567357735873597360736173627363736473657366736773687369737073717372737373747375737673777378737973807381738273837384738573867387738873897390739173927393739473957396739773987399740074017402740374047405740674077408740974107411741274137414741574167417741874197420742174227423742474257426742774287429743074317432743374347435743674377438743974407441744274437444744574467447744874497450745174527453745474557456745774587459746074617462746374647465746674677468746974707471747274737474747574767477747874797480748174827483748474857486748774887489749074917492749374947495749674977498749975007501750275037504750575067507750875097510751175127513751475157516751775187519752075217522752375247525752675277528752975307531753275337534753575367537753875397540754175427543754475457546754775487549755075517552755375547555755675577558755975607561756275637564756575667567756875697570757175727573757475757576757775787579758075817582758375847585758675877588758975907591759275937594759575967597759875997600760176027603760476057606760776087609761076117612761376147615761676177618761976207621762276237624762576267627762876297630763176327633763476357636763776387639764076417642764376447645764676477648764976507651765276537654765576567657765876597660766176627663766476657666766776687669767076717672767376747675767676777678767976807681768276837684768576867687768876897690769176927693769476957696769776987699770077017702770377047705770677077708770977107711771277137714771577167717771877197720772177227723772477257726772777287729773077317732773377347735773677377738773977407741774277437744774577467747774877497750775177527753775477557756775777587759776077617762776377647765776677677768776977707771777277737774777577767777777877797780778177827783778477857786778777887789779077917792779377947795779677977798779978007801780278037804780578067807780878097810781178127813781478157816781778187819782078217822782378247825782678277828782978307831783278337834783578367837783878397840784178427843784478457846784778487849785078517852785378547855785678577858785978607861786278637864786578667867786878697870787178727873787478757876787778787879788078817882788378847885788678877888788978907891789278937894789578967897789878997900790179027903790479057906790779087909791079117912791379147915791679177918791979207921792279237924792579267927792879297930793179327933793479357936793779387939794079417942794379447945794679477948794979507951795279537954795579567957795879597960796179627963796479657966796779687969797079717972797379747975797679777978797979807981798279837984798579867987798879897990799179927993799479957996799779987999800080018002800380048005800680078008800980108011801280138014801580168017801880198020802180228023802480258026802780288029803080318032803380348035803680378038803980408041804280438044804580468047804880498050805180528053805480558056805780588059806080618062806380648065806680678068806980708071807280738074807580768077807880798080808180828083808480858086808780888089809080918092809380948095809680978098809981008101810281038104810581068107810881098110811181128113811481158116811781188119812081218122812381248125812681278128812981308131813281338134813581368137813881398140814181428143814481458146814781488149815081518152815381548155815681578158815981608161816281638164816581668167816881698170817181728173817481758176817781788179818081818182818381848185818681878188818981908191819281938194819581968197819881998200820182028203820482058206820782088209821082118212821382148215821682178218821982208221822282238224822582268227822882298230823182328233823482358236823782388239824082418242824382448245824682478248824982508251825282538254825582568257825882598260826182628263826482658266826782688269827082718272827382748275827682778278827982808281828282838284828582868287828882898290829182928293829482958296829782988299830083018302830383048305830683078308830983108311831283138314831583168317831883198320832183228323832483258326832783288329833083318332833383348335833683378338833983408341834283438344834583468347834883498350835183528353835483558356835783588359836083618362836383648365836683678368836983708371837283738374837583768377837883798380838183828383838483858386838783888389839083918392839383948395839683978398839984008401840284038404840584068407840884098410841184128413841484158416841784188419842084218422842384248425842684278428842984308431843284338434843584368437843884398440844184428443844484458446844784488449845084518452845384548455845684578458845984608461846284638464846584668467846884698470847184728473847484758476847784788479848084818482848384848485848684878488848984908491849284938494849584968497849884998500850185028503850485058506850785088509851085118512851385148515851685178518851985208521852285238524852585268527852885298530853185328533853485358536853785388539854085418542854385448545854685478548854985508551855285538554855585568557855885598560856185628563856485658566856785688569857085718572857385748575857685778578857985808581858285838584858585868587858885898590859185928593859485958596859785988599860086018602860386048605860686078608860986108611861286138614861586168617861886198620862186228623862486258626862786288629863086318632863386348635863686378638863986408641864286438644864586468647864886498650865186528653865486558656865786588659866086618662866386648665866686678668866986708671867286738674867586768677867886798680868186828683868486858686868786888689869086918692869386948695869686978698869987008701870287038704870587068707870887098710871187128713871487158716871787188719872087218722872387248725872687278728872987308731873287338734873587368737873887398740874187428743874487458746874787488749875087518752875387548755875687578758875987608761876287638764876587668767876887698770877187728773877487758776877787788779878087818782878387848785878687878788878987908791879287938794879587968797879887998800880188028803880488058806880788088809881088118812881388148815881688178818881988208821882288238824882588268827882888298830883188328833883488358836883788388839884088418842884388448845884688478848884988508851885288538854885588568857885888598860886188628863886488658866886788688869887088718872887388748875887688778878887988808881888288838884888588868887888888898890889188928893889488958896889788988899890089018902890389048905890689078908890989108911891289138914891589168917891889198920892189228923892489258926892789288929893089318932893389348935893689378938893989408941894289438944894589468947894889498950895189528953895489558956895789588959896089618962896389648965896689678968896989708971897289738974897589768977897889798980898189828983898489858986898789888989899089918992899389948995899689978998899990009001900290039004900590069007900890099010901190129013901490159016901790189019902090219022902390249025902690279028902990309031903290339034903590369037903890399040904190429043904490459046904790489049905090519052905390549055905690579058905990609061906290639064906590669067906890699070907190729073907490759076907790789079908090819082908390849085908690879088908990909091909290939094909590969097909890999100910191029103910491059106910791089109911091119112911391149115911691179118911991209121912291239124912591269127912891299130913191329133913491359136913791389139914091419142914391449145914691479148914991509151915291539154915591569157915891599160916191629163916491659166916791689169917091719172917391749175917691779178917991809181918291839184918591869187918891899190919191929193919491959196919791989199920092019202920392049205920692079208920992109211921292139214921592169217921892199220922192229223922492259226922792289229923092319232923392349235923692379238923992409241924292439244924592469247924892499250925192529253925492559256925792589259926092619262926392649265926692679268926992709271927292739274927592769277927892799280928192829283928492859286928792889289929092919292929392949295929692979298929993009301930293039304930593069307930893099310931193129313931493159316931793189319932093219322932393249325932693279328932993309331933293339334933593369337933893399340934193429343934493459346934793489349935093519352935393549355935693579358935993609361936293639364936593669367936893699370937193729373937493759376937793789379938093819382938393849385938693879388938993909391939293939394939593969397939893999400940194029403940494059406940794089409941094119412941394149415941694179418941994209421942294239424942594269427942894299430943194329433943494359436943794389439944094419442944394449445944694479448944994509451945294539454945594569457945894599460946194629463946494659466946794689469947094719472947394749475947694779478947994809481948294839484948594869487948894899490949194929493949494959496949794989499950095019502950395049505950695079508950995109511951295139514951595169517951895199520952195229523952495259526952795289529953095319532953395349535953695379538953995409541954295439544954595469547954895499550955195529553955495559556955795589559956095619562956395649565956695679568956995709571957295739574957595769577957895799580958195829583958495859586958795889589959095919592959395949595959695979598959996009601960296039604960596069607960896099610961196129613961496159616961796189619962096219622962396249625962696279628962996309631963296339634963596369637963896399640964196429643964496459646964796489649965096519652965396549655965696579658965996609661966296639664966596669667966896699670967196729673967496759676967796789679968096819682968396849685968696879688968996909691969296939694969596969697969896999700970197029703970497059706970797089709971097119712971397149715971697179718971997209721972297239724972597269727972897299730973197329733973497359736973797389739974097419742974397449745974697479748974997509751975297539754975597569757975897599760976197629763976497659766976797689769977097719772977397749775977697779778977997809781978297839784978597869787978897899790979197929793979497959796979797989799980098019802980398049805980698079808980998109811981298139814981598169817981898199820982198229823982498259826982798289829983098319832983398349835983698379838983998409841984298439844984598469847984898499850985198529853985498559856985798589859986098619862986398649865986698679868986998709871987298739874987598769877987898799880988198829883988498859886988798889889989098919892989398949895989698979898989999009901990299039904990599069907990899099910991199129913991499159916991799189919992099219922992399249925992699279928992999309931993299339934993599369937993899399940994199429943994499459946994799489949995099519952995399549955995699579958995999609961996299639964996599669967996899699970997199729973997499759976997799789979998099819982998399849985998699879988998999909991999299939994999599969997999899991000010001100021000310004100051000610007100081000910010100111001210013100141001510016100171001810019100201002110022100231002410025100261002710028100291003010031100321003310034100351003610037100381003910040100411004210043100441004510046100471004810049100501005110052100531005410055100561005710058100591006010061100621006310064100651006610067100681006910070100711007210073100741007510076100771007810079100801008110082100831008410085100861008710088100891009010091100921009310094100951009610097100981009910100101011010210103101041010510106101071010810109101101011110112101131011410115101161011710118101191012010121101221012310124101251012610127101281012910130101311013210133101341013510136101371013810139101401014110142101431014410145101461014710148101491015010151101521015310154101551015610157101581015910160101611016210163101641016510166101671016810169101701017110172101731017410175101761017710178101791018010181101821018310184101851018610187101881018910190101911019210193101941019510196101971019810199102001020110202102031020410205102061020710208102091021010211102121021310214102151021610217102181021910220102211022210223102241022510226102271022810229102301023110232102331023410235102361023710238102391024010241102421024310244102451024610247102481024910250102511025210253102541025510256102571025810259102601026110262102631026410265102661026710268102691027010271102721027310274102751027610277102781027910280102811028210283102841028510286102871028810289102901029110292102931029410295102961029710298102991030010301103021030310304103051030610307103081030910310103111031210313103141031510316103171031810319103201032110322103231032410325103261032710328103291033010331103321033310334103351033610337103381033910340103411034210343103441034510346103471034810349103501035110352103531035410355103561035710358103591036010361103621036310364103651036610367103681036910370103711037210373103741037510376103771037810379103801038110382103831038410385103861038710388103891039010391103921039310394103951039610397103981039910400104011040210403104041040510406104071040810409104101041110412104131041410415104161041710418104191042010421104221042310424104251042610427104281042910430104311043210433104341043510436104371043810439104401044110442104431044410445104461044710448104491045010451104521045310454104551045610457104581045910460104611046210463104641046510466104671046810469104701047110472104731047410475104761047710478104791048010481104821048310484104851048610487104881048910490104911049210493104941049510496104971049810499105001050110502105031050410505105061050710508105091051010511105121051310514105151051610517105181051910520105211052210523105241052510526105271052810529105301053110532105331053410535105361053710538105391054010541105421054310544105451054610547105481054910550105511055210553105541055510556105571055810559105601056110562105631056410565105661056710568105691057010571105721057310574105751057610577105781057910580105811058210583105841058510586105871058810589105901059110592105931059410595105961059710598105991060010601106021060310604106051060610607106081060910610106111061210613106141061510616106171061810619106201062110622106231062410625106261062710628106291063010631106321063310634106351063610637106381063910640106411064210643106441064510646106471064810649106501065110652106531065410655106561065710658106591066010661106621066310664106651066610667106681066910670106711067210673106741067510676106771067810679106801068110682106831068410685106861068710688106891069010691106921069310694106951069610697106981069910700107011070210703107041070510706107071070810709107101071110712107131071410715107161071710718107191072010721107221072310724107251072610727107281072910730107311073210733107341073510736107371073810739107401074110742107431074410745107461074710748107491075010751107521075310754107551075610757107581075910760107611076210763107641076510766107671076810769107701077110772107731077410775107761077710778107791078010781107821078310784107851078610787107881078910790107911079210793107941079510796107971079810799108001080110802108031080410805108061080710808108091081010811108121081310814108151081610817108181081910820108211082210823108241082510826108271082810829108301083110832108331083410835108361083710838108391084010841108421084310844108451084610847108481084910850108511085210853108541085510856108571085810859108601086110862108631086410865108661086710868108691087010871108721087310874108751087610877108781087910880108811088210883108841088510886108871088810889108901089110892108931089410895108961089710898108991090010901109021090310904109051090610907109081090910910109111091210913109141091510916109171091810919109201092110922109231092410925109261092710928109291093010931109321093310934109351093610937109381093910940109411094210943109441094510946109471094810949109501095110952109531095410955109561095710958109591096010961109621096310964109651096610967109681096910970109711097210973109741097510976109771097810979109801098110982109831098410985109861098710988109891099010991109921099310994109951099610997109981099911000110011100211003110041100511006110071100811009110101101111012110131101411015110161101711018110191102011021110221102311024110251102611027110281102911030110311103211033110341103511036110371103811039110401104111042110431104411045110461104711048110491105011051110521105311054110551105611057110581105911060110611106211063110641106511066110671106811069110701107111072110731107411075110761107711078110791108011081110821108311084110851108611087110881108911090110911109211093110941109511096110971109811099111001110111102111031110411105111061110711108111091111011111111121111311114111151111611117111181111911120111211112211123111241112511126111271112811129111301113111132111331113411135111361113711138111391114011141111421114311144111451114611147111481114911150111511115211153111541115511156111571115811159111601116111162111631116411165111661116711168111691117011171111721117311174111751117611177111781117911180111811118211183111841118511186111871118811189111901119111192111931119411195111961119711198111991120011201112021120311204112051120611207112081120911210112111121211213112141121511216112171121811219112201122111222112231122411225112261122711228112291123011231112321123311234112351123611237112381123911240112411124211243112441124511246112471124811249112501125111252112531125411255112561125711258112591126011261112621126311264112651126611267112681126911270112711127211273112741127511276112771127811279112801128111282112831128411285112861128711288112891129011291112921129311294112951129611297112981129911300113011130211303113041130511306113071130811309113101131111312113131131411315113161131711318113191132011321113221132311324113251132611327113281132911330113311133211333113341133511336113371133811339113401134111342113431134411345113461134711348113491135011351113521135311354113551135611357113581135911360113611136211363113641136511366113671136811369113701137111372113731137411375113761137711378113791138011381113821138311384113851138611387113881138911390113911139211393113941139511396113971139811399114001140111402114031140411405114061140711408114091141011411114121141311414114151141611417114181141911420114211142211423114241142511426114271142811429114301143111432114331143411435114361143711438114391144011441114421144311444114451144611447114481144911450114511145211453114541145511456114571145811459114601146111462114631146411465114661146711468114691147011471114721147311474114751147611477114781147911480114811148211483114841148511486114871148811489114901149111492114931149411495114961149711498114991150011501115021150311504115051150611507115081150911510115111151211513115141151511516115171151811519115201152111522115231152411525115261152711528115291153011531115321153311534115351153611537115381153911540115411154211543115441154511546115471154811549115501155111552115531155411555115561155711558115591156011561115621156311564115651156611567115681156911570115711157211573115741157511576115771157811579115801158111582115831158411585115861158711588115891159011591115921159311594115951159611597115981159911600116011160211603116041160511606116071160811609116101161111612116131161411615116161161711618116191162011621116221162311624116251162611627116281162911630116311163211633116341163511636116371163811639116401164111642116431164411645116461164711648116491165011651116521165311654116551165611657116581165911660116611166211663116641166511666116671166811669116701167111672116731167411675116761167711678116791168011681116821168311684116851168611687116881168911690116911169211693116941169511696116971169811699117001170111702117031170411705117061170711708117091171011711117121171311714117151171611717117181171911720117211172211723117241172511726117271172811729117301173111732117331173411735117361173711738117391174011741117421174311744117451174611747117481174911750117511175211753117541175511756117571175811759117601176111762117631176411765117661176711768117691177011771117721177311774117751177611777117781177911780117811178211783117841178511786117871178811789117901179111792117931179411795117961179711798117991180011801118021180311804118051180611807118081180911810118111181211813118141181511816118171181811819118201182111822118231182411825118261182711828118291183011831118321183311834118351183611837118381183911840118411184211843118441184511846118471184811849118501185111852118531185411855118561185711858118591186011861118621186311864118651186611867118681186911870118711187211873118741187511876118771187811879118801188111882118831188411885118861188711888118891189011891118921189311894118951189611897118981189911900119011190211903119041190511906119071190811909119101191111912119131191411915119161191711918119191192011921119221192311924119251192611927119281192911930119311193211933119341193511936119371193811939119401194111942119431194411945119461194711948119491195011951119521195311954119551195611957119581195911960119611196211963119641196511966119671196811969119701197111972119731197411975119761197711978119791198011981119821198311984119851198611987119881198911990119911199211993119941199511996119971199811999120001200112002120031200412005120061200712008120091201012011120121201312014120151201612017120181201912020120211202212023120241202512026120271202812029120301203112032120331203412035120361203712038120391204012041120421204312044120451204612047120481204912050120511205212053120541205512056120571205812059120601206112062120631206412065120661206712068120691207012071120721207312074120751207612077120781207912080120811208212083120841208512086120871208812089120901209112092120931209412095120961209712098120991210012101121021210312104121051210612107121081210912110121111211212113121141211512116121171211812119121201212112122121231212412125121261212712128121291213012131121321213312134121351213612137121381213912140121411214212143121441214512146121471214812149121501215112152121531215412155121561215712158121591216012161121621216312164121651216612167121681216912170121711217212173121741217512176121771217812179121801218112182121831218412185121861218712188121891219012191121921219312194121951219612197121981219912200122011220212203122041220512206122071220812209122101221112212122131221412215122161221712218122191222012221122221222312224122251222612227122281222912230122311223212233122341223512236122371223812239122401224112242122431224412245122461224712248122491225012251122521225312254122551225612257122581225912260122611226212263122641226512266122671226812269122701227112272122731227412275122761227712278122791228012281122821228312284122851228612287122881228912290122911229212293122941229512296122971229812299123001230112302123031230412305123061230712308123091231012311123121231312314123151231612317123181231912320123211232212323123241232512326123271232812329123301233112332123331233412335123361233712338123391234012341123421234312344123451234612347123481234912350123511235212353123541235512356123571235812359123601236112362123631236412365123661236712368123691237012371123721237312374123751237612377123781237912380123811238212383123841238512386123871238812389123901239112392123931239412395123961239712398123991240012401124021240312404124051240612407124081240912410124111241212413124141241512416124171241812419124201242112422124231242412425124261242712428124291243012431124321243312434124351243612437124381243912440124411244212443124441244512446124471244812449124501245112452124531245412455124561245712458124591246012461124621246312464124651246612467124681246912470124711247212473124741247512476124771247812479124801248112482124831248412485124861248712488124891249012491124921249312494124951249612497124981249912500125011250212503125041250512506125071250812509125101251112512125131251412515125161251712518125191252012521125221252312524125251252612527125281252912530125311253212533125341253512536125371253812539125401254112542125431254412545125461254712548125491255012551125521255312554125551255612557125581255912560125611256212563125641256512566125671256812569125701257112572125731257412575125761257712578125791258012581125821258312584125851258612587125881258912590125911259212593125941259512596125971259812599126001260112602126031260412605126061260712608126091261012611126121261312614126151261612617126181261912620126211262212623126241262512626126271262812629126301263112632126331263412635126361263712638126391264012641126421264312644126451264612647126481264912650126511265212653126541265512656126571265812659126601266112662126631266412665126661266712668126691267012671126721267312674126751267612677126781267912680126811268212683126841268512686126871268812689126901269112692126931269412695126961269712698126991270012701127021270312704127051270612707127081270912710127111271212713127141271512716127171271812719127201272112722127231272412725127261272712728127291273012731127321273312734127351273612737127381273912740127411274212743127441274512746127471274812749127501275112752127531275412755127561275712758127591276012761127621276312764127651276612767127681276912770127711277212773127741277512776127771277812779127801278112782127831278412785127861278712788127891279012791127921279312794127951279612797127981279912800128011280212803128041280512806128071280812809128101281112812128131281412815128161281712818128191282012821128221282312824128251282612827128281282912830128311283212833128341283512836128371283812839128401284112842128431284412845128461284712848128491285012851128521285312854128551285612857128581285912860128611286212863128641286512866128671286812869128701287112872128731287412875128761287712878128791288012881128821288312884128851288612887128881288912890128911289212893128941289512896128971289812899129001290112902129031290412905129061290712908129091291012911129121291312914129151291612917129181291912920129211292212923129241292512926129271292812929129301293112932129331293412935129361293712938129391294012941129421294312944129451294612947129481294912950129511295212953129541295512956129571295812959129601296112962129631296412965129661296712968129691297012971129721297312974129751297612977129781297912980129811298212983129841298512986129871298812989129901299112992129931299412995129961299712998129991300013001130021300313004130051300613007130081300913010130111301213013130141301513016130171301813019130201302113022130231302413025130261302713028130291303013031130321303313034130351303613037130381303913040130411304213043130441304513046130471304813049130501305113052130531305413055130561305713058130591306013061130621306313064130651306613067130681306913070130711307213073130741307513076130771307813079130801308113082130831308413085130861308713088130891309013091130921309313094130951309613097130981309913100131011310213103131041310513106131071310813109131101311113112131131311413115131161311713118131191312013121131221312313124131251312613127131281312913130131311313213133131341313513136131371313813139131401314113142131431314413145131461314713148131491315013151131521315313154131551315613157131581315913160131611316213163131641316513166131671316813169131701317113172131731317413175131761317713178131791318013181131821318313184131851318613187131881318913190131911319213193131941319513196131971319813199132001320113202132031320413205132061320713208132091321013211132121321313214132151321613217132181321913220132211322213223132241322513226132271322813229132301323113232132331323413235132361323713238132391324013241132421324313244132451324613247132481324913250132511325213253132541325513256132571325813259132601326113262132631326413265132661326713268132691327013271132721327313274132751327613277132781327913280132811328213283132841328513286132871328813289132901329113292132931329413295132961329713298132991330013301133021330313304133051330613307133081330913310133111331213313133141331513316133171331813319133201332113322133231332413325133261332713328133291333013331133321333313334133351333613337133381333913340133411334213343133441334513346133471334813349133501335113352133531335413355133561335713358133591336013361133621336313364133651336613367133681336913370133711337213373133741337513376133771337813379133801338113382133831338413385133861338713388133891339013391133921339313394133951339613397133981339913400134011340213403134041340513406134071340813409134101341113412134131341413415134161341713418134191342013421134221342313424134251342613427134281342913430134311343213433134341343513436134371343813439134401344113442134431344413445134461344713448134491345013451134521345313454134551345613457134581345913460134611346213463134641346513466134671346813469134701347113472134731347413475134761347713478134791348013481134821348313484134851348613487134881348913490134911349213493134941349513496134971349813499135001350113502135031350413505135061350713508135091351013511135121351313514135151351613517135181351913520135211352213523135241352513526135271352813529135301353113532135331353413535135361353713538135391354013541135421354313544135451354613547135481354913550135511355213553135541355513556135571355813559135601356113562135631356413565135661356713568135691357013571135721357313574135751357613577135781357913580135811358213583135841358513586135871358813589135901359113592135931359413595135961359713598135991360013601136021360313604136051360613607136081360913610136111361213613136141361513616136171361813619136201362113622136231362413625136261362713628136291363013631136321363313634136351363613637136381363913640136411364213643136441364513646136471364813649136501365113652136531365413655136561365713658136591366013661136621366313664136651366613667136681366913670136711367213673136741367513676136771367813679136801368113682136831368413685136861368713688136891369013691136921369313694136951369613697136981369913700137011370213703137041370513706137071370813709137101371113712137131371413715137161371713718137191372013721137221372313724137251372613727137281372913730137311373213733137341373513736137371373813739137401374113742137431374413745137461374713748137491375013751137521375313754137551375613757137581375913760137611376213763137641376513766137671376813769137701377113772137731377413775137761377713778137791378013781137821378313784137851378613787137881378913790137911379213793137941379513796137971379813799138001380113802138031380413805138061380713808138091381013811138121381313814138151381613817138181381913820138211382213823138241382513826138271382813829138301383113832138331383413835138361383713838138391384013841138421384313844138451384613847138481384913850138511385213853138541385513856138571385813859138601386113862138631386413865138661386713868138691387013871138721387313874138751387613877138781387913880138811388213883138841388513886138871388813889138901389113892138931389413895138961389713898138991390013901139021390313904139051390613907139081390913910139111391213913139141391513916139171391813919139201392113922139231392413925139261392713928139291393013931139321393313934139351393613937139381393913940139411394213943139441394513946139471394813949139501395113952139531395413955139561395713958139591396013961139621396313964139651396613967139681396913970139711397213973139741397513976139771397813979139801398113982139831398413985139861398713988139891399013991139921399313994139951399613997139981399914000140011400214003140041400514006140071400814009140101401114012140131401414015140161401714018140191402014021140221402314024140251402614027140281402914030140311403214033140341403514036140371403814039140401404114042140431404414045140461404714048140491405014051140521405314054140551405614057140581405914060140611406214063140641406514066140671406814069140701407114072140731407414075140761407714078140791408014081140821408314084140851408614087140881408914090140911409214093140941409514096140971409814099141001410114102141031410414105141061410714108141091411014111141121411314114141151411614117141181411914120141211412214123141241412514126141271412814129141301413114132141331413414135141361413714138141391414014141141421414314144141451414614147141481414914150141511415214153141541415514156141571415814159141601416114162141631416414165141661416714168141691417014171141721417314174141751417614177141781417914180141811418214183141841418514186141871418814189141901419114192141931419414195141961419714198141991420014201142021420314204142051420614207142081420914210142111421214213142141421514216142171421814219142201422114222142231422414225142261422714228142291423014231142321423314234142351423614237142381423914240142411424214243142441424514246142471424814249142501425114252142531425414255142561425714258142591426014261142621426314264142651426614267142681426914270142711427214273142741427514276142771427814279142801428114282142831428414285142861428714288142891429014291142921429314294142951429614297142981429914300143011430214303143041430514306143071430814309143101431114312143131431414315143161431714318143191432014321143221432314324143251432614327143281432914330143311433214333143341433514336143371433814339143401434114342143431434414345143461434714348143491435014351143521435314354143551435614357143581435914360143611436214363143641436514366143671436814369143701437114372143731437414375143761437714378143791438014381143821438314384143851438614387143881438914390143911439214393143941439514396143971439814399144001440114402144031440414405144061440714408144091441014411144121441314414144151441614417144181441914420144211442214423144241442514426144271442814429144301443114432144331443414435144361443714438144391444014441144421444314444144451444614447144481444914450144511445214453144541445514456144571445814459144601446114462144631446414465144661446714468144691447014471144721447314474144751447614477144781447914480144811448214483144841448514486144871448814489144901449114492144931449414495144961449714498144991450014501145021450314504145051450614507145081450914510145111451214513145141451514516145171451814519145201452114522145231452414525145261452714528145291453014531145321453314534145351453614537145381453914540145411454214543145441454514546145471454814549145501455114552145531455414555145561455714558145591456014561145621456314564145651456614567145681456914570145711457214573145741457514576145771457814579145801458114582145831458414585145861458714588145891459014591145921459314594145951459614597145981459914600146011460214603146041460514606146071460814609146101461114612146131461414615146161461714618146191462014621146221462314624146251462614627146281462914630146311463214633146341463514636146371463814639146401464114642146431464414645146461464714648146491465014651146521465314654146551465614657146581465914660146611466214663146641466514666146671466814669146701467114672146731467414675146761467714678146791468014681146821468314684146851468614687146881468914690146911469214693146941469514696146971469814699147001470114702147031470414705147061470714708147091471014711147121471314714147151471614717147181471914720147211472214723147241472514726147271472814729147301473114732147331473414735147361473714738147391474014741147421474314744147451474614747147481474914750147511475214753147541475514756147571475814759147601476114762147631476414765147661476714768147691477014771147721477314774147751477614777147781477914780147811478214783147841478514786147871478814789147901479114792147931479414795147961479714798147991480014801148021480314804148051480614807148081480914810148111481214813148141481514816148171481814819148201482114822148231482414825148261482714828148291483014831148321483314834148351483614837148381483914840148411484214843148441484514846148471484814849148501485114852148531485414855148561485714858148591486014861148621486314864148651486614867148681486914870148711487214873148741487514876148771487814879148801488114882148831488414885148861488714888148891489014891148921489314894148951489614897148981489914900149011490214903149041490514906149071490814909149101491114912149131491414915149161491714918149191492014921149221492314924149251492614927149281492914930149311493214933149341493514936149371493814939149401494114942149431494414945149461494714948149491495014951149521495314954149551495614957149581495914960149611496214963149641496514966149671496814969149701497114972149731497414975149761497714978149791498014981149821498314984149851498614987149881498914990149911499214993149941499514996149971499814999150001500115002150031500415005150061500715008150091501015011150121501315014150151501615017150181501915020150211502215023150241502515026150271502815029150301503115032150331503415035150361503715038150391504015041150421504315044150451504615047150481504915050150511505215053150541505515056150571505815059150601506115062150631506415065150661506715068150691507015071150721507315074150751507615077150781507915080150811508215083150841508515086150871508815089150901509115092150931509415095150961509715098150991510015101151021510315104151051510615107151081510915110151111511215113151141511515116151171511815119151201512115122151231512415125151261512715128151291513015131151321513315134151351513615137151381513915140151411514215143151441514515146151471514815149151501515115152151531515415155151561515715158151591516015161151621516315164151651516615167151681516915170151711517215173// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* * Common eBPF ELF object loading operations. * * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> * Copyright (C) 2015 Huawei Inc. * Copyright (C) 2017 Nicira, Inc. * Copyright (C) 2019 Isovalent, Inc. */
#ifndef _GNU_SOURCE#define _GNU_SOURCE#endif#include <stdlib.h>#include <stdio.h>#include <stdarg.h>#include <libgen.h>#include <inttypes.h>#include <limits.h>#include <string.h>#include <unistd.h>#include <endian.h>#include <fcntl.h>#include <errno.h>#include <ctype.h>#include <asm/unistd.h>#include <linux/err.h>#include <linux/kernel.h>#include <linux/bpf.h>#include <linux/btf.h>#include <linux/filter.h>#include <linux/limits.h>#include <linux/perf_event.h>#include <linux/bpf_perf_event.h>#include <linux/ring_buffer.h>#include <sys/epoll.h>#include <sys/ioctl.h>#include <sys/mman.h>#include <sys/stat.h>#include <sys/types.h>#include <sys/vfs.h>#include <sys/utsname.h>#include <sys/resource.h>#include <libelf.h>#include <gelf.h>#include <zlib.h>
#include "libbpf.h"#include "bpf.h"#include "btf.h"#include "libbpf_internal.h"#include "hashmap.h"#include "bpf_gen_internal.h"#include "zip.h"
#ifndef BPF_FS_MAGIC#define BPF_FS_MAGIC 0xcafe4a11#endif
#define MAX_EVENT_NAME_LEN 64
#define BPF_FS_DEFAULT_PATH "/sys/fs/bpf"
#define BPF_INSN_SZ (sizeof(struct bpf_insn))
/* vsprintf() in __base_pr() uses nonliteral format string. It may break * compilation if user enables corresponding warning. Disable it explicitly. */#pragma GCC diagnostic ignored "-Wformat-nonliteral"
#define __printf(a, b) __attribute__((format(printf, a, b)))
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog);static int map_set_def_max_entries(struct bpf_map *map);
static const char * const attach_type_name[] = { [BPF_CGROUP_INET_INGRESS] = "cgroup_inet_ingress", [BPF_CGROUP_INET_EGRESS] = "cgroup_inet_egress", [BPF_CGROUP_INET_SOCK_CREATE] = "cgroup_inet_sock_create", [BPF_CGROUP_INET_SOCK_RELEASE] = "cgroup_inet_sock_release", [BPF_CGROUP_SOCK_OPS] = "cgroup_sock_ops", [BPF_CGROUP_DEVICE] = "cgroup_device", [BPF_CGROUP_INET4_BIND] = "cgroup_inet4_bind", [BPF_CGROUP_INET6_BIND] = "cgroup_inet6_bind", [BPF_CGROUP_INET4_CONNECT] = "cgroup_inet4_connect", [BPF_CGROUP_INET6_CONNECT] = "cgroup_inet6_connect", [BPF_CGROUP_UNIX_CONNECT] = "cgroup_unix_connect", [BPF_CGROUP_INET4_POST_BIND] = "cgroup_inet4_post_bind", [BPF_CGROUP_INET6_POST_BIND] = "cgroup_inet6_post_bind", [BPF_CGROUP_INET4_GETPEERNAME] = "cgroup_inet4_getpeername", [BPF_CGROUP_INET6_GETPEERNAME] = "cgroup_inet6_getpeername", [BPF_CGROUP_UNIX_GETPEERNAME] = "cgroup_unix_getpeername", [BPF_CGROUP_INET4_GETSOCKNAME] = "cgroup_inet4_getsockname", [BPF_CGROUP_INET6_GETSOCKNAME] = "cgroup_inet6_getsockname", [BPF_CGROUP_UNIX_GETSOCKNAME] = "cgroup_unix_getsockname", [BPF_CGROUP_UDP4_SENDMSG] = "cgroup_udp4_sendmsg", [BPF_CGROUP_UDP6_SENDMSG] = "cgroup_udp6_sendmsg", [BPF_CGROUP_UNIX_SENDMSG] = "cgroup_unix_sendmsg", [BPF_CGROUP_SYSCTL] = "cgroup_sysctl", [BPF_CGROUP_UDP4_RECVMSG] = "cgroup_udp4_recvmsg", [BPF_CGROUP_UDP6_RECVMSG] = "cgroup_udp6_recvmsg", [BPF_CGROUP_UNIX_RECVMSG] = "cgroup_unix_recvmsg", [BPF_CGROUP_GETSOCKOPT] = "cgroup_getsockopt", [BPF_CGROUP_SETSOCKOPT] = "cgroup_setsockopt", [BPF_SK_SKB_STREAM_PARSER] = "sk_skb_stream_parser", [BPF_SK_SKB_STREAM_VERDICT] = "sk_skb_stream_verdict", [BPF_SK_SKB_VERDICT] = "sk_skb_verdict", [BPF_SK_MSG_VERDICT] = "sk_msg_verdict", [BPF_LIRC_MODE2] = "lirc_mode2", [BPF_FLOW_DISSECTOR] = "flow_dissector", [BPF_TRACE_RAW_TP] = "trace_raw_tp", [BPF_TRACE_FENTRY] = "trace_fentry", [BPF_TRACE_FEXIT] = "trace_fexit", [BPF_MODIFY_RETURN] = "modify_return", [BPF_TRACE_FSESSION] = "trace_fsession", [BPF_LSM_MAC] = "lsm_mac", [BPF_LSM_CGROUP] = "lsm_cgroup", [BPF_SK_LOOKUP] = "sk_lookup", [BPF_TRACE_ITER] = "trace_iter", [BPF_XDP_DEVMAP] = "xdp_devmap", [BPF_XDP_CPUMAP] = "xdp_cpumap", [BPF_XDP] = "xdp", [BPF_SK_REUSEPORT_SELECT] = "sk_reuseport_select", [BPF_SK_REUSEPORT_SELECT_OR_MIGRATE] = "sk_reuseport_select_or_migrate", [BPF_PERF_EVENT] = "perf_event", [BPF_TRACE_KPROBE_MULTI] = "trace_kprobe_multi", [BPF_STRUCT_OPS] = "struct_ops", [BPF_NETFILTER] = "netfilter", [BPF_TCX_INGRESS] = "tcx_ingress", [BPF_TCX_EGRESS] = "tcx_egress", [BPF_TRACE_UPROBE_MULTI] = "trace_uprobe_multi", [BPF_NETKIT_PRIMARY] = "netkit_primary", [BPF_NETKIT_PEER] = "netkit_peer", [BPF_TRACE_KPROBE_SESSION] = "trace_kprobe_session", [BPF_TRACE_UPROBE_SESSION] = "trace_uprobe_session", [BPF_TRACE_FENTRY_MULTI] = "trace_fentry_multi", [BPF_TRACE_FEXIT_MULTI] = "trace_fexit_multi", [BPF_TRACE_FSESSION_MULTI] = "trace_fsession_multi",};
static const char * const link_type_name[] = { [BPF_LINK_TYPE_UNSPEC] = "unspec", [BPF_LINK_TYPE_RAW_TRACEPOINT] = "raw_tracepoint", [BPF_LINK_TYPE_TRACING] = "tracing", [BPF_LINK_TYPE_CGROUP] = "cgroup", [BPF_LINK_TYPE_ITER] = "iter", [BPF_LINK_TYPE_NETNS] = "netns", [BPF_LINK_TYPE_XDP] = "xdp", [BPF_LINK_TYPE_PERF_EVENT] = "perf_event", [BPF_LINK_TYPE_KPROBE_MULTI] = "kprobe_multi", [BPF_LINK_TYPE_STRUCT_OPS] = "struct_ops", [BPF_LINK_TYPE_NETFILTER] = "netfilter", [BPF_LINK_TYPE_TCX] = "tcx", [BPF_LINK_TYPE_UPROBE_MULTI] = "uprobe_multi", [BPF_LINK_TYPE_NETKIT] = "netkit", [BPF_LINK_TYPE_SOCKMAP] = "sockmap", [BPF_LINK_TYPE_TRACING_MULTI] = "tracing_multi",};
static const char * const map_type_name[] = { [BPF_MAP_TYPE_UNSPEC] = "unspec", [BPF_MAP_TYPE_HASH] = "hash", [BPF_MAP_TYPE_ARRAY] = "array", [BPF_MAP_TYPE_PROG_ARRAY] = "prog_array", [BPF_MAP_TYPE_PERF_EVENT_ARRAY] = "perf_event_array", [BPF_MAP_TYPE_PERCPU_HASH] = "percpu_hash", [BPF_MAP_TYPE_PERCPU_ARRAY] = "percpu_array", [BPF_MAP_TYPE_STACK_TRACE] = "stack_trace", [BPF_MAP_TYPE_CGROUP_ARRAY] = "cgroup_array", [BPF_MAP_TYPE_LRU_HASH] = "lru_hash", [BPF_MAP_TYPE_LRU_PERCPU_HASH] = "lru_percpu_hash", [BPF_MAP_TYPE_LPM_TRIE] = "lpm_trie", [BPF_MAP_TYPE_ARRAY_OF_MAPS] = "array_of_maps", [BPF_MAP_TYPE_HASH_OF_MAPS] = "hash_of_maps", [BPF_MAP_TYPE_DEVMAP] = "devmap", [BPF_MAP_TYPE_DEVMAP_HASH] = "devmap_hash", [BPF_MAP_TYPE_SOCKMAP] = "sockmap", [BPF_MAP_TYPE_CPUMAP] = "cpumap", [BPF_MAP_TYPE_XSKMAP] = "xskmap", [BPF_MAP_TYPE_SOCKHASH] = "sockhash", [BPF_MAP_TYPE_CGROUP_STORAGE] = "cgroup_storage", [BPF_MAP_TYPE_REUSEPORT_SOCKARRAY] = "reuseport_sockarray", [BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE] = "percpu_cgroup_storage", [BPF_MAP_TYPE_QUEUE] = "queue", [BPF_MAP_TYPE_STACK] = "stack", [BPF_MAP_TYPE_SK_STORAGE] = "sk_storage", [BPF_MAP_TYPE_STRUCT_OPS] = "struct_ops", [BPF_MAP_TYPE_RINGBUF] = "ringbuf", [BPF_MAP_TYPE_INODE_STORAGE] = "inode_storage", [BPF_MAP_TYPE_TASK_STORAGE] = "task_storage", [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", [BPF_MAP_TYPE_ARENA] = "arena", [BPF_MAP_TYPE_INSN_ARRAY] = "insn_array", [BPF_MAP_TYPE_RHASH] = "rhash",};
static const char * const prog_type_name[] = { [BPF_PROG_TYPE_UNSPEC] = "unspec", [BPF_PROG_TYPE_SOCKET_FILTER] = "socket_filter", [BPF_PROG_TYPE_KPROBE] = "kprobe", [BPF_PROG_TYPE_SCHED_CLS] = "sched_cls", [BPF_PROG_TYPE_SCHED_ACT] = "sched_act", [BPF_PROG_TYPE_TRACEPOINT] = "tracepoint", [BPF_PROG_TYPE_XDP] = "xdp", [BPF_PROG_TYPE_PERF_EVENT] = "perf_event", [BPF_PROG_TYPE_CGROUP_SKB] = "cgroup_skb", [BPF_PROG_TYPE_CGROUP_SOCK] = "cgroup_sock", [BPF_PROG_TYPE_LWT_IN] = "lwt_in", [BPF_PROG_TYPE_LWT_OUT] = "lwt_out", [BPF_PROG_TYPE_LWT_XMIT] = "lwt_xmit", [BPF_PROG_TYPE_SOCK_OPS] = "sock_ops", [BPF_PROG_TYPE_SK_SKB] = "sk_skb", [BPF_PROG_TYPE_CGROUP_DEVICE] = "cgroup_device", [BPF_PROG_TYPE_SK_MSG] = "sk_msg", [BPF_PROG_TYPE_RAW_TRACEPOINT] = "raw_tracepoint", [BPF_PROG_TYPE_CGROUP_SOCK_ADDR] = "cgroup_sock_addr", [BPF_PROG_TYPE_LWT_SEG6LOCAL] = "lwt_seg6local", [BPF_PROG_TYPE_LIRC_MODE2] = "lirc_mode2", [BPF_PROG_TYPE_SK_REUSEPORT] = "sk_reuseport", [BPF_PROG_TYPE_FLOW_DISSECTOR] = "flow_dissector", [BPF_PROG_TYPE_CGROUP_SYSCTL] = "cgroup_sysctl", [BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE] = "raw_tracepoint_writable", [BPF_PROG_TYPE_CGROUP_SOCKOPT] = "cgroup_sockopt", [BPF_PROG_TYPE_TRACING] = "tracing", [BPF_PROG_TYPE_STRUCT_OPS] = "struct_ops", [BPF_PROG_TYPE_EXT] = "ext", [BPF_PROG_TYPE_LSM] = "lsm", [BPF_PROG_TYPE_SK_LOOKUP] = "sk_lookup", [BPF_PROG_TYPE_SYSCALL] = "syscall", [BPF_PROG_TYPE_NETFILTER] = "netfilter",};
static int __base_pr(enum libbpf_print_level level, const char *format, va_list args){ const char *env_var = "LIBBPF_LOG_LEVEL"; static enum libbpf_print_level min_level = LIBBPF_INFO; static bool initialized;
if (!initialized) { char *verbosity;
initialized = true; verbosity = getenv(env_var); if (verbosity) { if (strcasecmp(verbosity, "warn") == 0) min_level = LIBBPF_WARN; else if (strcasecmp(verbosity, "debug") == 0) min_level = LIBBPF_DEBUG; else if (strcasecmp(verbosity, "info") == 0) min_level = LIBBPF_INFO; else fprintf(stderr, "libbpf: unrecognized '%s' envvar value: '%s', should be one of 'warn', 'debug', or 'info'.\n", env_var, verbosity); } }
/* if too verbose, skip logging */ if (level > min_level) return 0;
return vfprintf(stderr, format, args);}
static libbpf_print_fn_t __libbpf_pr = __base_pr;
libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn){ libbpf_print_fn_t old_print_fn;
old_print_fn = __atomic_exchange_n(&__libbpf_pr, fn, __ATOMIC_RELAXED);
return old_print_fn;}
__printf(2, 3)void libbpf_print(enum libbpf_print_level level, const char *format, ...){ va_list args; int old_errno; libbpf_print_fn_t print_fn;
print_fn = __atomic_load_n(&__libbpf_pr, __ATOMIC_RELAXED); if (!print_fn) return;
old_errno = errno;
va_start(args, format); print_fn(level, format, args); va_end(args);
errno = old_errno;}
static void pr_perm_msg(int err){ struct rlimit limit; char buf[100];
if (err != -EPERM || geteuid() != 0) return;
err = getrlimit(RLIMIT_MEMLOCK, &limit); if (err) return;
if (limit.rlim_cur == RLIM_INFINITY) return;
if (limit.rlim_cur < 1024) snprintf(buf, sizeof(buf), "%zu bytes", (size_t)limit.rlim_cur); else if (limit.rlim_cur < 1024*1024) snprintf(buf, sizeof(buf), "%.1f KiB", (double)limit.rlim_cur / 1024); else snprintf(buf, sizeof(buf), "%.1f MiB", (double)limit.rlim_cur / (1024*1024));
pr_warn("permission error while running as root; try raising 'ulimit -l'? current value: %s\n", buf);}
/* Copied from tools/perf/util/util.h */#ifndef zfree# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })#endif
#ifndef zclose# define zclose(fd) ({ \ int ___err = 0; \ if ((fd) >= 0) \ ___err = close((fd)); \ fd = -1; \ ___err; })#endif
static inline __u64 ptr_to_u64(const void *ptr){ return (__u64) (unsigned long) ptr;}
int libbpf_set_strict_mode(enum libbpf_strict_mode mode){ /* as of v1.0 libbpf_set_strict_mode() is a no-op */ return 0;}
__u32 libbpf_major_version(void){ return LIBBPF_MAJOR_VERSION;}
__u32 libbpf_minor_version(void){ return LIBBPF_MINOR_VERSION;}
const char *libbpf_version_string(void){#define __S(X) #X#define _S(X) __S(X) return "v" _S(LIBBPF_MAJOR_VERSION) "." _S(LIBBPF_MINOR_VERSION);#undef _S#undef __S}
enum reloc_type { RELO_LD64, RELO_CALL, RELO_DATA, RELO_EXTERN_LD64, RELO_EXTERN_CALL, RELO_SUBPROG_ADDR, RELO_CORE, RELO_INSN_ARRAY,};
struct reloc_desc { enum reloc_type type; int insn_idx; union { const struct bpf_core_relo *core_relo; /* used when type == RELO_CORE */ struct { int map_idx; unsigned int sym_off; /* * The following two fields can be unionized, as the * ext_idx field is used for extern symbols, and the * sym_size is used for jump tables, which are never * extern */ union { int ext_idx; int sym_size; }; }; };};
/* stored as sec_def->cookie for all libbpf-supported SEC()s */enum sec_def_flags { SEC_NONE = 0, /* expected_attach_type is optional, if kernel doesn't support that */ SEC_EXP_ATTACH_OPT = 1, /* legacy, only used by libbpf_get_type_names() and * libbpf_attach_type_by_name(), not used by libbpf itself at all. * This used to be associated with cgroup (and few other) BPF programs * that were attachable through BPF_PROG_ATTACH command. Pretty * meaningless nowadays, though. */ SEC_ATTACHABLE = 2, SEC_ATTACHABLE_OPT = SEC_ATTACHABLE | SEC_EXP_ATTACH_OPT, /* attachment target is specified through BTF ID in either kernel or * other BPF program's BTF object */ SEC_ATTACH_BTF = 4, /* BPF program type allows sleeping/blocking in kernel */ SEC_SLEEPABLE = 8, /* BPF program support non-linear XDP buffer */ SEC_XDP_FRAGS = 16, /* Setup proper attach type for usdt probes. */ SEC_USDT = 32,};
struct bpf_sec_def { char *sec; enum bpf_prog_type prog_type; enum bpf_attach_type expected_attach_type; long cookie; int handler_id;
libbpf_prog_setup_fn_t prog_setup_fn; libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; libbpf_prog_attach_fn_t prog_attach_fn;};
struct bpf_light_subprog { __u32 sec_insn_off; __u32 sub_insn_off;};
/* * bpf_prog should be a better name but it has been used in * linux/filter.h. */struct bpf_program { char *name; char *sec_name; size_t sec_idx; const struct bpf_sec_def *sec_def; /* this program's instruction offset (in number of instructions) * within its containing ELF section */ size_t sec_insn_off; /* number of original instructions in ELF section belonging to this * program, not taking into account subprogram instructions possible * appended later during relocation */ size_t sec_insn_cnt; /* Offset (in number of instructions) of the start of instruction * belonging to this BPF program within its containing main BPF * program. For the entry-point (main) BPF program, this is always * zero. For a sub-program, this gets reset before each of main BPF * programs are processed and relocated and is used to determined * whether sub-program was already appended to the main program, and * if yes, at which instruction offset. */ size_t sub_insn_off;
/* instructions that belong to BPF program; insns[0] is located at * sec_insn_off instruction within its ELF section in ELF file, so * when mapping ELF file instruction index to the local instruction, * one needs to subtract sec_insn_off; and vice versa. */ struct bpf_insn *insns; /* actual number of instruction in this BPF program's image; for * entry-point BPF programs this includes the size of main program * itself plus all the used sub-programs, appended at the end */ size_t insns_cnt;
struct reloc_desc *reloc_desc; int nr_reloc;
/* BPF verifier log settings */ char *log_buf; size_t log_size; __u32 log_level;
struct bpf_object *obj;
int fd; bool autoload; bool autoattach; bool sym_global; bool mark_btf_static; enum bpf_prog_type type; enum bpf_attach_type expected_attach_type; int exception_cb_idx;
int prog_ifindex; __u32 attach_btf_obj_fd; __u32 attach_btf_id; __u32 attach_prog_fd;
void *func_info; __u32 func_info_rec_size; __u32 func_info_cnt;
void *line_info; __u32 line_info_rec_size; __u32 line_info_cnt; __u32 prog_flags; __u8 hash[SHA256_DIGEST_LENGTH];
struct bpf_light_subprog *subprogs; __u32 subprog_cnt;};
struct bpf_struct_ops { struct bpf_program **progs; __u32 *kern_func_off; /* e.g. struct tcp_congestion_ops in bpf_prog's btf format */ void *data; /* e.g. struct bpf_struct_ops_tcp_congestion_ops in * btf_vmlinux's format. * struct bpf_struct_ops_tcp_congestion_ops { * [... some other kernel fields ...] * struct tcp_congestion_ops data; * } * kern_vdata-size == sizeof(struct bpf_struct_ops_tcp_congestion_ops) * bpf_map__init_kern_struct_ops() will populate the "kern_vdata" * from "data". */ void *kern_vdata; __u32 type_id;};
#define DATA_SEC ".data"#define BSS_SEC ".bss"#define RODATA_SEC ".rodata"#define KCONFIG_SEC ".kconfig"#define KSYMS_SEC ".ksyms"#define STRUCT_OPS_SEC ".struct_ops"#define STRUCT_OPS_LINK_SEC ".struct_ops.link"#define ARENA_SEC ".addr_space.1"
enum libbpf_map_type { LIBBPF_MAP_UNSPEC, LIBBPF_MAP_DATA, LIBBPF_MAP_BSS, LIBBPF_MAP_RODATA, LIBBPF_MAP_KCONFIG,};
struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; unsigned int map_flags;};
struct bpf_map { struct bpf_object *obj; char *name; /* real_name is defined for special internal maps (.rodata*, * .data*, .bss, .kconfig) and preserves their original ELF section * name. This is important to be able to find corresponding BTF * DATASEC information. */ char *real_name; int fd; int sec_idx; size_t sec_offset; int map_ifindex; int inner_map_fd; struct bpf_map_def def; __u32 numa_node; __u32 btf_var_idx; int mod_btf_fd; __u32 btf_key_type_id; __u32 btf_value_type_id; __u32 btf_vmlinux_value_type_id; enum libbpf_map_type libbpf_type; void *mmaped; struct bpf_struct_ops *st_ops; struct bpf_map *inner_map; void **init_slots; int init_slots_sz; char *pin_path; bool pinned; bool reused; bool autocreate; bool autoattach; __u64 map_extra; struct bpf_program *excl_prog;};
enum extern_type { EXT_UNKNOWN, EXT_KCFG, EXT_KSYM,};
enum kcfg_type { KCFG_UNKNOWN, KCFG_CHAR, KCFG_BOOL, KCFG_INT, KCFG_TRISTATE, KCFG_CHAR_ARR,};
struct extern_desc { enum extern_type type; int sym_idx; int btf_id; int sec_btf_id; char *name; char *essent_name; bool is_set; bool is_weak; union { struct { enum kcfg_type type; int sz; int align; int data_off; bool is_signed; } kcfg; struct { unsigned long long addr;
/* target btf_id of the corresponding kernel var. */ int kernel_btf_obj_fd; int kernel_btf_id;
/* local btf_id of the ksym extern's type. */ __u32 type_id; /* BTF fd index to be patched in for insn->off, this is * 0 for vmlinux BTF, index in obj->fd_array for module * BTF */ __s16 btf_fd_idx; } ksym; };};
struct module_btf { struct btf *btf; char *name; __u32 id; int fd; int fd_array_idx;};
enum sec_type { SEC_UNUSED = 0, SEC_RELO, SEC_BSS, SEC_DATA, SEC_RODATA, SEC_ST_OPS,};
struct elf_sec_desc { enum sec_type sec_type; Elf64_Shdr *shdr; Elf_Data *data;};
struct elf_state { int fd; const void *obj_buf; size_t obj_buf_sz; Elf *elf; Elf64_Ehdr *ehdr; Elf_Data *symbols; Elf_Data *arena_data; size_t shstrndx; /* section index for section name strings */ size_t strtabidx; struct elf_sec_desc *secs; size_t sec_cnt; int btf_maps_shndx; __u32 btf_maps_sec_btf_id; int text_shndx; int symbols_shndx; bool has_st_ops; int arena_data_shndx; int jumptables_data_shndx;};
struct usdt_manager;
enum bpf_object_state { OBJ_OPEN, OBJ_PREPARED, OBJ_LOADED,};
struct bpf_object { char name[BPF_OBJ_NAME_LEN]; char license[64]; __u32 kern_version;
enum bpf_object_state state; struct bpf_program *programs; size_t nr_programs; struct bpf_map *maps; size_t nr_maps; size_t maps_cap;
char *kconfig; struct extern_desc *externs; int nr_extern; int kconfig_map_idx;
bool has_subcalls; bool has_rodata;
struct bpf_gen *gen_loader;
/* Information when doing ELF related work. Only valid if efile.elf is not NULL */ struct elf_state efile;
unsigned char byteorder;
struct btf *btf; struct btf_ext *btf_ext;
/* Parse and load BTF vmlinux if any of the programs in the object need * it at load time. */ struct btf *btf_vmlinux; /* Path to the custom BTF to be used for BPF CO-RE relocations as an * override for vmlinux BTF. */ char *btf_custom_path; /* vmlinux BTF override for CO-RE relocations */ struct btf *btf_vmlinux_override; /* Lazily initialized kernel module BTFs */ struct module_btf *btf_modules; bool btf_modules_loaded; size_t btf_module_cnt; size_t btf_module_cap;
/* optional log settings passed to BPF_BTF_LOAD and BPF_PROG_LOAD commands */ char *log_buf; size_t log_size; __u32 log_level;
int *fd_array; size_t fd_array_cap; size_t fd_array_cnt;
struct usdt_manager *usdt_man;
int arena_map_idx; void *arena_data; size_t arena_data_sz; size_t arena_data_off;
void *jumptables_data; size_t jumptables_data_sz;
struct { struct bpf_program *prog; unsigned int sym_off; int fd; } *jumptable_maps; size_t jumptable_map_cnt;
struct kern_feature_cache *feat_cache; char *token_path; int token_fd;
char path[];};
static const char *elf_sym_str(const struct bpf_object *obj, size_t off);static const char *elf_sec_str(const struct bpf_object *obj, size_t off);static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx);static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name);static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn);static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn);static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn);static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx);static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx);
void bpf_program__unload(struct bpf_program *prog){ if (!prog) return;
zclose(prog->fd);
zfree(&prog->func_info); zfree(&prog->line_info); zfree(&prog->subprogs);}
static void bpf_program__exit(struct bpf_program *prog){ if (!prog) return;
bpf_program__unload(prog); zfree(&prog->name); zfree(&prog->sec_name); zfree(&prog->insns); zfree(&prog->reloc_desc);
prog->nr_reloc = 0; prog->insns_cnt = 0; prog->sec_idx = -1;}
static bool insn_is_subprog_call(const struct bpf_insn *insn){ return BPF_CLASS(insn->code) == BPF_JMP && BPF_OP(insn->code) == BPF_CALL && BPF_SRC(insn->code) == BPF_K && insn->src_reg == BPF_PSEUDO_CALL && insn->dst_reg == 0 && insn->off == 0;}
static bool is_call_insn(const struct bpf_insn *insn){ return insn->code == (BPF_JMP | BPF_CALL);}
static bool insn_is_pseudo_func(struct bpf_insn *insn){ return is_ldimm64_insn(insn) && insn->src_reg == BPF_PSEUDO_FUNC;}
static intbpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, const char *name, size_t sec_idx, const char *sec_name, size_t sec_off, void *insn_data, size_t insn_data_sz){ if (insn_data_sz == 0 || insn_data_sz % BPF_INSN_SZ || sec_off % BPF_INSN_SZ) { pr_warn("sec '%s': corrupted program '%s', offset %zu, size %zu\n", sec_name, name, sec_off, insn_data_sz); return -EINVAL; }
memset(prog, 0, sizeof(*prog)); prog->obj = obj;
prog->sec_idx = sec_idx; prog->sec_insn_off = sec_off / BPF_INSN_SZ; prog->sec_insn_cnt = insn_data_sz / BPF_INSN_SZ; /* insns_cnt can later be increased by appending used subprograms */ prog->insns_cnt = prog->sec_insn_cnt;
prog->type = BPF_PROG_TYPE_UNSPEC; prog->fd = -1; prog->exception_cb_idx = -1;
/* libbpf's convention for SEC("?abc...") is that it's just like * SEC("abc...") but the corresponding bpf_program starts out with * autoload set to false. */ if (sec_name[0] == '?') { prog->autoload = false; /* from now on forget there was ? in section name */ sec_name++; } else { prog->autoload = true; }
prog->autoattach = true;
/* inherit object's log_level */ prog->log_level = obj->log_level;
prog->sec_name = strdup(sec_name); if (!prog->sec_name) goto errout;
prog->name = strdup(name); if (!prog->name) goto errout;
prog->insns = malloc(insn_data_sz); if (!prog->insns) goto errout; memcpy(prog->insns, insn_data, insn_data_sz);
return 0;errout: pr_warn("sec '%s': failed to allocate memory for prog '%s'\n", sec_name, name); bpf_program__exit(prog); return -ENOMEM;}
static intbpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data, const char *sec_name, int sec_idx){ Elf_Data *symbols = obj->efile.symbols; struct bpf_program *prog, *progs; void *data = sec_data->d_buf; size_t sec_sz = sec_data->d_size, sec_off, prog_sz, nr_syms; int nr_progs, err, i; const char *name; Elf64_Sym *sym;
progs = obj->programs; nr_progs = obj->nr_programs; nr_syms = symbols->d_size / sizeof(Elf64_Sym);
for (i = 0; i < nr_syms; i++) { sym = elf_sym_by_idx(obj, i);
if (sym->st_shndx != sec_idx) continue; if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC) continue;
prog_sz = sym->st_size; sec_off = sym->st_value;
name = elf_sym_str(obj, sym->st_name); if (!name) { pr_warn("sec '%s': failed to get symbol name for offset %zu\n", sec_name, sec_off); return -LIBBPF_ERRNO__FORMAT; }
if (sec_off + prog_sz > sec_sz || sec_off + prog_sz < sec_off) { pr_warn("sec '%s': program at offset %zu crosses section boundary\n", sec_name, sec_off); return -LIBBPF_ERRNO__FORMAT; }
if (sec_idx != obj->efile.text_shndx && ELF64_ST_BIND(sym->st_info) == STB_LOCAL) { pr_warn("sec '%s': program '%s' is static and not supported\n", sec_name, name); return -ENOTSUP; }
pr_debug("sec '%s': found program '%s' at insn offset %zu (%zu bytes), code size %zu insns (%zu bytes)\n", sec_name, name, sec_off / BPF_INSN_SZ, sec_off, prog_sz / BPF_INSN_SZ, prog_sz);
progs = libbpf_reallocarray(progs, nr_progs + 1, sizeof(*progs)); if (!progs) { /* * In this case the original obj->programs * is still valid, so don't need special treat for * bpf_close_object(). */ pr_warn("sec '%s': failed to alloc memory for new program '%s'\n", sec_name, name); return -ENOMEM; } obj->programs = progs;
prog = &progs[nr_progs];
err = bpf_object__init_prog(obj, prog, name, sec_idx, sec_name, sec_off, data + sec_off, prog_sz); if (err) return err;
if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL) prog->sym_global = true;
/* if function is a global/weak symbol, but has restricted * (STV_HIDDEN or STV_INTERNAL) visibility, mark its BTF FUNC * as static to enable more permissive BPF verification mode * with more outside context available to BPF verifier */ if (prog->sym_global && (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN || ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL)) prog->mark_btf_static = true;
nr_progs++; obj->nr_programs = nr_progs; }
return 0;}
static void bpf_object_bswap_progs(struct bpf_object *obj){ struct bpf_program *prog = obj->programs; struct bpf_insn *insn; int p, i;
for (p = 0; p < obj->nr_programs; p++, prog++) { insn = prog->insns; for (i = 0; i < prog->insns_cnt; i++, insn++) bpf_insn_bswap(insn); } pr_debug("converted %zu BPF programs to native byte order\n", obj->nr_programs);}
static const struct btf_member *find_member_by_offset(const struct btf_type *t, __u32 bit_offset){ struct btf_member *m; int i;
for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) { if (btf_member_bit_offset(t, i) == bit_offset) return m; }
return NULL;}
static const struct btf_member *find_member_by_name(const struct btf *btf, const struct btf_type *t, const char *name){ struct btf_member *m; int i;
for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) { if (!strcmp(btf__name_by_offset(btf, m->name_off), name)) return m; }
return NULL;}
static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, __u16 kind, struct btf **res_btf, struct module_btf **res_mod_btf);
#define STRUCT_OPS_VALUE_PREFIX "bpf_struct_ops_"static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix, const char *name, __u32 kind);
static intfind_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw, struct module_btf **mod_btf, const struct btf_type **type, __u32 *type_id, const struct btf_type **vtype, __u32 *vtype_id, const struct btf_member **data_member){ const struct btf_type *kern_type, *kern_vtype; const struct btf_member *kern_data_member; struct btf *btf = NULL; __s32 kern_vtype_id, kern_type_id; char tname[192], stname[256]; __u32 i;
snprintf(tname, sizeof(tname), "%.*s", (int)bpf_core_essential_name_len(tname_raw), tname_raw);
snprintf(stname, sizeof(stname), "%s%s", STRUCT_OPS_VALUE_PREFIX, tname);
/* Look for the corresponding "map_value" type that will be used * in map_update(BPF_MAP_TYPE_STRUCT_OPS) first, figure out the btf * and the mod_btf. * For example, find "struct bpf_struct_ops_tcp_congestion_ops". */ kern_vtype_id = find_ksym_btf_id(obj, stname, BTF_KIND_STRUCT, &btf, mod_btf); if (kern_vtype_id < 0) { pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n", stname); return kern_vtype_id; } kern_vtype = btf__type_by_id(btf, kern_vtype_id);
kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT); if (kern_type_id < 0) { pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n", tname); return kern_type_id; } kern_type = btf__type_by_id(btf, kern_type_id);
/* Find "struct tcp_congestion_ops" from * struct bpf_struct_ops_tcp_congestion_ops { * [ ... ] * struct tcp_congestion_ops data; * } */ kern_data_member = btf_members(kern_vtype); for (i = 0; i < btf_vlen(kern_vtype); i++, kern_data_member++) { if (kern_data_member->type == kern_type_id) break; } if (i == btf_vlen(kern_vtype)) { pr_warn("struct_ops init_kern: struct %s data is not found in struct %s\n", tname, stname); return -EINVAL; }
*type = kern_type; *type_id = kern_type_id; *vtype = kern_vtype; *vtype_id = kern_vtype_id; *data_member = kern_data_member;
return 0;}
static bool bpf_map__is_struct_ops(const struct bpf_map *map){ return map->def.type == BPF_MAP_TYPE_STRUCT_OPS;}
static bool is_valid_st_ops_program(struct bpf_object *obj, const struct bpf_program *prog){ int i;
for (i = 0; i < obj->nr_programs; i++) { if (&obj->programs[i] == prog) return prog->type == BPF_PROG_TYPE_STRUCT_OPS; }
return false;}
/* For each struct_ops program P, referenced from some struct_ops map M, * enable P.autoload if there are Ms for which M.autocreate is true, * disable P.autoload if for all Ms M.autocreate is false. * Don't change P.autoload for programs that are not referenced from any maps. */static int bpf_object_adjust_struct_ops_autoload(struct bpf_object *obj){ struct bpf_program *prog, *slot_prog; struct bpf_map *map; int i, j, k, vlen;
for (i = 0; i < obj->nr_programs; ++i) { int should_load = false; int use_cnt = 0;
prog = &obj->programs[i]; if (prog->type != BPF_PROG_TYPE_STRUCT_OPS) continue;
for (j = 0; j < obj->nr_maps; ++j) { const struct btf_type *type;
map = &obj->maps[j]; if (!bpf_map__is_struct_ops(map)) continue;
type = btf__type_by_id(obj->btf, map->st_ops->type_id); vlen = btf_vlen(type); for (k = 0; k < vlen; ++k) { slot_prog = map->st_ops->progs[k]; if (prog != slot_prog) continue;
use_cnt++; if (map->autocreate) should_load = true; } } if (use_cnt) prog->autoload = should_load; }
return 0;}
/* Init the map's fields that depend on kern_btf */static int bpf_map__init_kern_struct_ops(struct bpf_map *map){ const struct btf_member *member, *kern_member, *kern_data_member; const struct btf_type *type, *kern_type, *kern_vtype; __u32 i, kern_type_id, kern_vtype_id, kern_data_off; struct bpf_object *obj = map->obj; const struct btf *btf = obj->btf; struct bpf_struct_ops *st_ops; const struct btf *kern_btf; struct module_btf *mod_btf = NULL; void *data, *kern_data; const char *tname; int err;
st_ops = map->st_ops; type = btf__type_by_id(btf, st_ops->type_id); tname = btf__name_by_offset(btf, type->name_off); err = find_struct_ops_kern_types(obj, tname, &mod_btf, &kern_type, &kern_type_id, &kern_vtype, &kern_vtype_id, &kern_data_member); if (err) return err;
kern_btf = mod_btf ? mod_btf->btf : obj->btf_vmlinux;
pr_debug("struct_ops init_kern %s: type_id:%u kern_type_id:%u kern_vtype_id:%u\n", map->name, st_ops->type_id, kern_type_id, kern_vtype_id);
map->mod_btf_fd = mod_btf ? mod_btf->fd : -1; map->def.value_size = kern_vtype->size; map->btf_vmlinux_value_type_id = kern_vtype_id;
st_ops->kern_vdata = calloc(1, kern_vtype->size); if (!st_ops->kern_vdata) return -ENOMEM;
data = st_ops->data; kern_data_off = kern_data_member->offset / 8; kern_data = st_ops->kern_vdata + kern_data_off;
member = btf_members(type); for (i = 0; i < btf_vlen(type); i++, member++) { const struct btf_type *mtype, *kern_mtype; __u32 mtype_id, kern_mtype_id; void *mdata, *kern_mdata; struct bpf_program *prog; __s64 msize, kern_msize; __u32 moff, kern_moff; __u32 kern_member_idx; const char *mname;
mname = btf__name_by_offset(btf, member->name_off); moff = member->offset / 8; mdata = data + moff; msize = btf__resolve_size(btf, member->type); if (msize < 0) { pr_warn("struct_ops init_kern %s: failed to resolve the size of member %s\n", map->name, mname); return msize; }
kern_member = find_member_by_name(kern_btf, kern_type, mname); if (!kern_member) { if (!libbpf_is_mem_zeroed(mdata, msize)) { pr_warn("struct_ops init_kern %s: Cannot find member %s in kernel BTF\n", map->name, mname); return -ENOTSUP; }
if (st_ops->progs[i]) { /* If we had declaratively set struct_ops callback, we need to * force its autoload to false, because it doesn't have * a chance of succeeding from POV of the current struct_ops map. * If this program is still referenced somewhere else, though, * then bpf_object_adjust_struct_ops_autoload() will update its * autoload accordingly. */ st_ops->progs[i]->autoload = false; st_ops->progs[i] = NULL; }
/* Skip all-zero/NULL fields if they are not present in the kernel BTF */ pr_info("struct_ops %s: member %s not found in kernel, skipping it as it's set to zero\n", map->name, mname); continue; }
kern_member_idx = kern_member - btf_members(kern_type); if (btf_member_bitfield_size(type, i) || btf_member_bitfield_size(kern_type, kern_member_idx)) { pr_warn("struct_ops init_kern %s: bitfield %s is not supported\n", map->name, mname); return -ENOTSUP; }
kern_moff = kern_member->offset / 8; kern_mdata = kern_data + kern_moff;
mtype = skip_mods_and_typedefs(btf, member->type, &mtype_id); kern_mtype = skip_mods_and_typedefs(kern_btf, kern_member->type, &kern_mtype_id); if (BTF_INFO_KIND(mtype->info) != BTF_INFO_KIND(kern_mtype->info)) { pr_warn("struct_ops init_kern %s: Unmatched member type %s %u != %u(kernel)\n", map->name, mname, BTF_INFO_KIND(mtype->info), BTF_INFO_KIND(kern_mtype->info)); return -ENOTSUP; }
if (btf_is_ptr(mtype)) { prog = *(void **)mdata; /* just like for !kern_member case above, reset declaratively * set (at compile time) program's autload to false, * if user replaced it with another program or NULL */ if (st_ops->progs[i] && st_ops->progs[i] != prog) st_ops->progs[i]->autoload = false;
/* Update the value from the shadow type */ st_ops->progs[i] = prog; if (!prog) continue;
if (!is_valid_st_ops_program(obj, prog)) { pr_warn("struct_ops init_kern %s: member %s is not a struct_ops program\n", map->name, mname); return -ENOTSUP; }
kern_mtype = skip_mods_and_typedefs(kern_btf, kern_mtype->type, &kern_mtype_id);
/* mtype->type must be a func_proto which was * guaranteed in bpf_object__collect_st_ops_relos(), * so only check kern_mtype for func_proto here. */ if (!btf_is_func_proto(kern_mtype)) { pr_warn("struct_ops init_kern %s: kernel member %s is not a func ptr\n", map->name, mname); return -ENOTSUP; }
if (mod_btf) prog->attach_btf_obj_fd = mod_btf->fd;
/* if we haven't yet processed this BPF program, record proper * attach_btf_id and member_idx */ if (!prog->attach_btf_id) { prog->attach_btf_id = kern_type_id; prog->expected_attach_type = kern_member_idx; }
/* struct_ops BPF prog can be re-used between multiple * .struct_ops & .struct_ops.link as long as it's the * same struct_ops struct definition and the same * function pointer field */ if (prog->attach_btf_id != kern_type_id) { pr_warn("struct_ops init_kern %s func ptr %s: invalid reuse of prog %s in sec %s with type %u: attach_btf_id %u != kern_type_id %u\n", map->name, mname, prog->name, prog->sec_name, prog->type, prog->attach_btf_id, kern_type_id); return -EINVAL; } if (prog->expected_attach_type != kern_member_idx) { pr_warn("struct_ops init_kern %s func ptr %s: invalid reuse of prog %s in sec %s with type %u: expected_attach_type %u != kern_member_idx %u\n", map->name, mname, prog->name, prog->sec_name, prog->type, prog->expected_attach_type, kern_member_idx); return -EINVAL; }
st_ops->kern_func_off[i] = kern_data_off + kern_moff;
pr_debug("struct_ops init_kern %s: func ptr %s is set to prog %s from data(+%u) to kern_data(+%u)\n", map->name, mname, prog->name, moff, kern_moff);
continue; }
kern_msize = btf__resolve_size(kern_btf, kern_mtype_id); if (kern_msize < 0 || msize != kern_msize) { pr_warn("struct_ops init_kern %s: Error in size of member %s: %zd != %zd(kernel)\n", map->name, mname, (ssize_t)msize, (ssize_t)kern_msize); return -ENOTSUP; }
pr_debug("struct_ops init_kern %s: copy %s %u bytes from data(+%u) to kern_data(+%u)\n", map->name, mname, (unsigned int)msize, moff, kern_moff); memcpy(kern_mdata, mdata, msize); }
return 0;}
static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj){ struct bpf_map *map; size_t i; int err;
for (i = 0; i < obj->nr_maps; i++) { map = &obj->maps[i];
if (!bpf_map__is_struct_ops(map)) continue;
if (!map->autocreate) continue;
err = bpf_map__init_kern_struct_ops(map); if (err) return err; }
return 0;}
static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name, int shndx, Elf_Data *data){ const struct btf_type *type, *datasec; const struct btf_var_secinfo *vsi; struct bpf_struct_ops *st_ops; const char *tname, *var_name; __s32 type_id, datasec_id; const struct btf *btf; struct bpf_map *map; __u32 i;
if (shndx == -1) return 0;
btf = obj->btf; datasec_id = btf__find_by_name_kind(btf, sec_name, BTF_KIND_DATASEC); if (datasec_id < 0) { pr_warn("struct_ops init: DATASEC %s not found\n", sec_name); return -EINVAL; }
datasec = btf__type_by_id(btf, datasec_id); vsi = btf_var_secinfos(datasec); for (i = 0; i < btf_vlen(datasec); i++, vsi++) { type = btf__type_by_id(obj->btf, vsi->type); var_name = btf__name_by_offset(obj->btf, type->name_off);
type_id = btf__resolve_type(obj->btf, vsi->type); if (type_id < 0) { pr_warn("struct_ops init: Cannot resolve var type_id %u in DATASEC %s\n", vsi->type, sec_name); return -EINVAL; }
type = btf__type_by_id(obj->btf, type_id); tname = btf__name_by_offset(obj->btf, type->name_off); if (!tname[0]) { pr_warn("struct_ops init: anonymous type is not supported\n"); return -ENOTSUP; } if (!btf_is_struct(type)) { pr_warn("struct_ops init: %s is not a struct\n", tname); return -EINVAL; }
map = bpf_object__add_map(obj); if (IS_ERR(map)) return PTR_ERR(map);
map->sec_idx = shndx; map->sec_offset = vsi->offset; map->name = strdup(var_name); if (!map->name) return -ENOMEM; map->btf_value_type_id = type_id;
/* Follow same convention as for programs autoload: * SEC("?.struct_ops") means map is not created by default. */ if (sec_name[0] == '?') { map->autocreate = false; /* from now on forget there was ? in section name */ sec_name++; }
map->def.type = BPF_MAP_TYPE_STRUCT_OPS; map->def.key_size = sizeof(int); map->def.value_size = type->size; map->def.max_entries = 1; map->def.map_flags = strcmp(sec_name, STRUCT_OPS_LINK_SEC) == 0 ? BPF_F_LINK : 0; map->autoattach = true;
map->st_ops = calloc(1, sizeof(*map->st_ops)); if (!map->st_ops) return -ENOMEM; st_ops = map->st_ops; st_ops->data = malloc(type->size); st_ops->progs = calloc(btf_vlen(type), sizeof(*st_ops->progs)); st_ops->kern_func_off = malloc(btf_vlen(type) * sizeof(*st_ops->kern_func_off)); if (!st_ops->data || !st_ops->progs || !st_ops->kern_func_off) return -ENOMEM;
if (vsi->offset + type->size > data->d_size) { pr_warn("struct_ops init: var %s is beyond the end of DATASEC %s\n", var_name, sec_name); return -EINVAL; }
memcpy(st_ops->data, data->d_buf + vsi->offset, type->size); st_ops->type_id = type_id;
pr_debug("struct_ops init: struct %s(type_id=%u) %s found at offset %u\n", tname, type_id, var_name, vsi->offset); }
return 0;}
static int bpf_object_init_struct_ops(struct bpf_object *obj){ const char *sec_name; int sec_idx, err;
for (sec_idx = 0; sec_idx < obj->efile.sec_cnt; ++sec_idx) { struct elf_sec_desc *desc = &obj->efile.secs[sec_idx];
if (desc->sec_type != SEC_ST_OPS) continue;
sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); if (!sec_name) return -LIBBPF_ERRNO__FORMAT;
err = init_struct_ops_maps(obj, sec_name, sec_idx, desc->data); if (err) return err; }
return 0;}
static struct bpf_object *bpf_object__new(const char *path, const void *obj_buf, size_t obj_buf_sz, const char *obj_name){ struct bpf_object *obj; char *end;
obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1); if (!obj) { pr_warn("alloc memory failed for %s\n", path); return ERR_PTR(-ENOMEM); }
strcpy(obj->path, path); if (obj_name) { libbpf_strlcpy(obj->name, obj_name, sizeof(obj->name)); } else { /* Using basename() GNU version which doesn't modify arg. */ libbpf_strlcpy(obj->name, basename((void *)path), sizeof(obj->name)); end = strchr(obj->name, '.'); if (end) *end = 0; }
obj->efile.fd = -1; /* * Caller of this function should also call * bpf_object__elf_finish() after data collection to return * obj_buf to user. If not, we should duplicate the buffer to * avoid user freeing them before elf finish. */ obj->efile.obj_buf = obj_buf; obj->efile.obj_buf_sz = obj_buf_sz; obj->efile.btf_maps_shndx = -1; obj->kconfig_map_idx = -1; obj->arena_map_idx = -1;
obj->kern_version = get_kernel_version(); obj->state = OBJ_OPEN;
return obj;}
static void bpf_object__elf_finish(struct bpf_object *obj){ if (!obj->efile.elf) return;
elf_end(obj->efile.elf); obj->efile.elf = NULL; obj->efile.ehdr = NULL; obj->efile.symbols = NULL; obj->efile.arena_data = NULL;
zfree(&obj->efile.secs); obj->efile.sec_cnt = 0; zclose(obj->efile.fd); obj->efile.obj_buf = NULL; obj->efile.obj_buf_sz = 0;}
static int bpf_object__elf_init(struct bpf_object *obj){ Elf64_Ehdr *ehdr; int err = 0; Elf *elf;
if (obj->efile.elf) { pr_warn("elf: init internal error\n"); return -LIBBPF_ERRNO__LIBELF; }
if (obj->efile.obj_buf_sz > 0) { /* obj_buf should have been validated by bpf_object__open_mem(). */ elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz); } else { obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC); if (obj->efile.fd < 0) { err = -errno; pr_warn("elf: failed to open %s: %s\n", obj->path, errstr(err)); return err; }
elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL); }
if (!elf) { pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__LIBELF; goto errout; }
obj->efile.elf = elf;
if (elf_kind(elf) != ELF_K_ELF) { err = -LIBBPF_ERRNO__FORMAT; pr_warn("elf: '%s' is not a proper ELF object\n", obj->path); goto errout; }
if (gelf_getclass(elf) != ELFCLASS64) { err = -LIBBPF_ERRNO__FORMAT; pr_warn("elf: '%s' is not a 64-bit ELF object\n", obj->path); goto errout; }
obj->efile.ehdr = ehdr = elf64_getehdr(elf); if (!obj->efile.ehdr) { pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__FORMAT; goto errout; }
/* Validate ELF object endianness... */ if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB && ehdr->e_ident[EI_DATA] != ELFDATA2MSB) { err = -LIBBPF_ERRNO__ENDIAN; pr_warn("elf: '%s' has unknown byte order\n", obj->path); goto errout; } /* and save after bpf_object_open() frees ELF data */ obj->byteorder = ehdr->e_ident[EI_DATA];
if (elf_getshdrstrndx(elf, &obj->efile.shstrndx)) { pr_warn("elf: failed to get section names section index for %s: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__FORMAT; goto errout; }
/* ELF is corrupted/truncated, avoid calling elf_strptr. */ if (!elf_rawdata(elf_getscn(elf, obj->efile.shstrndx), NULL)) { pr_warn("elf: failed to get section names strings from %s: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__FORMAT; goto errout; }
/* Old LLVM set e_machine to EM_NONE */ if (ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF)) { pr_warn("elf: %s is not a valid eBPF object file\n", obj->path); err = -LIBBPF_ERRNO__FORMAT; goto errout; }
return 0;errout: bpf_object__elf_finish(obj); return err;}
static bool is_native_endianness(struct bpf_object *obj){#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ return obj->byteorder == ELFDATA2LSB;#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ return obj->byteorder == ELFDATA2MSB;#else# error "Unrecognized __BYTE_ORDER__"#endif}
static intbpf_object__init_license(struct bpf_object *obj, void *data, size_t size){ if (!data) { pr_warn("invalid license section in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } /* libbpf_strlcpy() only copies first N - 1 bytes, so size + 1 won't * go over allowed ELF data section buffer */ libbpf_strlcpy(obj->license, data, min(size + 1, sizeof(obj->license))); pr_debug("license of %s is %s\n", obj->path, obj->license); return 0;}
static intbpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size){ __u32 kver;
if (!data || size != sizeof(kver)) { pr_warn("invalid kver section in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } memcpy(&kver, data, sizeof(kver)); obj->kern_version = kver; pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version); return 0;}
static bool bpf_map_type__is_map_in_map(enum bpf_map_type type){ if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS || type == BPF_MAP_TYPE_HASH_OF_MAPS) return true; return false;}
static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size){ Elf_Data *data; Elf_Scn *scn;
if (!name) return -EINVAL;
scn = elf_sec_by_name(obj, name); data = elf_sec_data(obj, scn); if (data) { *size = data->d_size; return 0; /* found it */ }
return -ENOENT;}
static Elf64_Sym *find_elf_var_sym(const struct bpf_object *obj, const char *name){ Elf_Data *symbols = obj->efile.symbols; const char *sname; size_t si;
for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) { Elf64_Sym *sym = elf_sym_by_idx(obj, si);
if (ELF64_ST_TYPE(sym->st_info) != STT_OBJECT) continue;
if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL && ELF64_ST_BIND(sym->st_info) != STB_WEAK) continue;
sname = elf_sym_str(obj, sym->st_name); if (!sname) { pr_warn("failed to get sym name string for var %s\n", name); return ERR_PTR(-EIO); } if (strcmp(name, sname) == 0) return sym; }
return ERR_PTR(-ENOENT);}
#ifndef MFD_CLOEXEC#define MFD_CLOEXEC 0x0001U#endif#ifndef MFD_NOEXEC_SEAL#define MFD_NOEXEC_SEAL 0x0008U#endif
static int create_placeholder_fd(void){ unsigned int flags = MFD_CLOEXEC | MFD_NOEXEC_SEAL; const char *name = "libbpf-placeholder-fd"; int fd;
fd = ensure_good_fd(sys_memfd_create(name, flags)); if (fd >= 0) return fd; else if (errno != EINVAL) return -errno;
/* Possibly running on kernel without MFD_NOEXEC_SEAL */ fd = ensure_good_fd(sys_memfd_create(name, flags & ~MFD_NOEXEC_SEAL)); if (fd < 0) return -errno; return fd;}
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj){ struct bpf_map *map; int err;
err = libbpf_ensure_mem((void **)&obj->maps, &obj->maps_cap, sizeof(*obj->maps), obj->nr_maps + 1); if (err) return ERR_PTR(err);
map = &obj->maps[obj->nr_maps++]; map->obj = obj; /* Preallocate map FD without actually creating BPF map just yet. * These map FD "placeholders" will be reused later without changing * FD value when map is actually created in the kernel. * * This is useful to be able to perform BPF program relocations * without having to create BPF maps before that step. This allows us * to finalize and load BTF very late in BPF object's loading phase, * right before BPF maps have to be created and BPF programs have to * be loaded. By having these map FD placeholders we can perform all * the sanitizations, relocations, and any other adjustments before we * start creating actual BPF kernel objects (BTF, maps, progs). */ map->fd = create_placeholder_fd(); if (map->fd < 0) return ERR_PTR(map->fd); map->inner_map_fd = -1; map->autocreate = true;
return map;}
static size_t array_map_mmap_sz(unsigned int value_sz, unsigned int max_entries){ const long page_sz = sysconf(_SC_PAGE_SIZE); size_t map_sz;
map_sz = (size_t)roundup(value_sz, 8) * max_entries; map_sz = roundup(map_sz, page_sz); return map_sz;}
static size_t bpf_map_mmap_sz(const struct bpf_map *map){ const long page_sz = sysconf(_SC_PAGE_SIZE);
switch (map->def.type) { case BPF_MAP_TYPE_ARRAY: return array_map_mmap_sz(map->def.value_size, map->def.max_entries); case BPF_MAP_TYPE_ARENA: return page_sz * map->def.max_entries; default: return 0; /* not supported */ }}
static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz){ void *mmaped;
if (!map->mmaped) return -EINVAL;
if (old_sz == new_sz) return 0;
mmaped = mmap(NULL, new_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); if (mmaped == MAP_FAILED) return -errno;
memcpy(mmaped, map->mmaped, min(old_sz, new_sz)); munmap(map->mmaped, old_sz); map->mmaped = mmaped; return 0;}
static char *internal_map_name(struct bpf_object *obj, const char *real_name){ char map_name[BPF_OBJ_NAME_LEN], *p; int pfx_len, sfx_len = max((size_t)7, strlen(real_name));
/* This is one of the more confusing parts of libbpf for various * reasons, some of which are historical. The original idea for naming * internal names was to include as much of BPF object name prefix as * possible, so that it can be distinguished from similar internal * maps of a different BPF object. * As an example, let's say we have bpf_object named 'my_object_name' * and internal map corresponding to '.rodata' ELF section. The final * map name advertised to user and to the kernel will be * 'my_objec.rodata', taking first 8 characters of object name and * entire 7 characters of '.rodata'. * Somewhat confusingly, if internal map ELF section name is shorter * than 7 characters, e.g., '.bss', we still reserve 7 characters * for the suffix, even though we only have 4 actual characters, and * resulting map will be called 'my_objec.bss', not even using all 15 * characters allowed by the kernel. Oh well, at least the truncated * object name is somewhat consistent in this case. But if the map * name is '.kconfig', we'll still have entirety of '.kconfig' added * (8 chars) and thus will be left with only first 7 characters of the * object name ('my_obje'). Happy guessing, user, that the final map * name will be "my_obje.kconfig". * Now, with libbpf starting to support arbitrarily named .rodata.* * and .data.* data sections, it's possible that ELF section name is * longer than allowed 15 chars, so we now need to be careful to take * only up to 15 first characters of ELF name, taking no BPF object * name characters at all. So '.rodata.abracadabra' will result in * '.rodata.abracad' kernel and user-visible name. * We need to keep this convoluted logic intact for .data, .bss and * .rodata maps, but for new custom .data.custom and .rodata.custom * maps we use their ELF names as is, not prepending bpf_object name * in front. We still need to truncate them to 15 characters for the * kernel. Full name can be recovered for such maps by using DATASEC * BTF type associated with such map's value type, though. */ if (sfx_len >= BPF_OBJ_NAME_LEN) sfx_len = BPF_OBJ_NAME_LEN - 1;
/* if there are two or more dots in map name, it's a custom dot map */ if (strchr(real_name + 1, '.') != NULL) pfx_len = 0; else pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1, strlen(obj->name));
snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name, sfx_len, real_name);
/* sanities map name to characters allowed by kernel */ for (p = map_name; *p && p < map_name + sizeof(map_name); p++) if (!isalnum(*p) && *p != '_' && *p != '.') *p = '_';
return strdup(map_name);}
static intmap_fill_btf_type_info(struct bpf_object *obj, struct bpf_map *map);
/* Internal BPF map is mmap()'able only if at least one of corresponding * DATASEC's VARs are to be exposed through BPF skeleton. I.e., it's a GLOBAL * variable and it's not marked as __hidden (which turns it into, effectively, * a STATIC variable). */static bool map_is_mmapable(struct bpf_object *obj, struct bpf_map *map){ const struct btf_type *t, *vt; struct btf_var_secinfo *vsi; int i, n;
if (!map->btf_value_type_id) return false;
t = btf__type_by_id(obj->btf, map->btf_value_type_id); if (!btf_is_datasec(t)) return false;
vsi = btf_var_secinfos(t); for (i = 0, n = btf_vlen(t); i < n; i++, vsi++) { vt = btf__type_by_id(obj->btf, vsi->type); if (!btf_is_var(vt)) continue;
if (btf_var(vt)->linkage != BTF_VAR_STATIC) return true; }
return false;}
static intbpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, const char *real_name, int sec_idx, void *data, size_t data_sz){ struct bpf_map_def *def; struct bpf_map *map; size_t mmap_sz; int err;
map = bpf_object__add_map(obj); if (IS_ERR(map)) return PTR_ERR(map);
map->libbpf_type = type; map->sec_idx = sec_idx; map->sec_offset = 0; map->real_name = strdup(real_name); map->name = internal_map_name(obj, real_name); if (!map->real_name || !map->name) { zfree(&map->real_name); zfree(&map->name); return -ENOMEM; }
def = &map->def; def->type = BPF_MAP_TYPE_ARRAY; def->key_size = sizeof(int); def->value_size = data_sz; def->max_entries = 1; def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG ? BPF_F_RDONLY_PROG : 0;
/* failures are fine because of maps like .rodata.str1.1 */ (void) map_fill_btf_type_info(obj, map);
if (map_is_mmapable(obj, map)) def->map_flags |= BPF_F_MMAPABLE;
pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", map->name, map->sec_idx, map->sec_offset, def->map_flags);
mmap_sz = bpf_map_mmap_sz(map); map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); if (map->mmaped == MAP_FAILED) { err = -errno; map->mmaped = NULL; pr_warn("failed to alloc map '%s' content buffer: %s\n", map->name, errstr(err)); zfree(&map->real_name); zfree(&map->name); return err; }
if (data) memcpy(map->mmaped, data, data_sz);
pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name); return 0;}
static int bpf_object__init_global_data_maps(struct bpf_object *obj){ struct elf_sec_desc *sec_desc; const char *sec_name; int err = 0, sec_idx;
/* * Populate obj->maps with libbpf internal maps. */ for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) { sec_desc = &obj->efile.secs[sec_idx];
/* Skip recognized sections with size 0. */ if (!sec_desc->data || sec_desc->data->d_size == 0) continue;
switch (sec_desc->sec_type) { case SEC_DATA: sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA, sec_name, sec_idx, sec_desc->data->d_buf, sec_desc->data->d_size); break; case SEC_RODATA: obj->has_rodata = true; sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA, sec_name, sec_idx, sec_desc->data->d_buf, sec_desc->data->d_size); break; case SEC_BSS: sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS, sec_name, sec_idx, NULL, sec_desc->data->d_size); break; default: /* skip */ break; } if (err) return err; } return 0;}
static struct extern_desc *find_extern_by_name(const struct bpf_object *obj, const void *name){ int i;
for (i = 0; i < obj->nr_extern; i++) { if (strcmp(obj->externs[i].name, name) == 0) return &obj->externs[i]; } return NULL;}
static struct extern_desc *find_extern_by_name_with_len(const struct bpf_object *obj, const void *name, int len){ const char *ext_name; int i;
for (i = 0; i < obj->nr_extern; i++) { ext_name = obj->externs[i].name; if (strlen(ext_name) == len && strncmp(ext_name, name, len) == 0) return &obj->externs[i]; } return NULL;}
static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, char value){ switch (ext->kcfg.type) { case KCFG_BOOL: if (value == 'm') { pr_warn("extern (kcfg) '%s': value '%c' implies tristate or char type\n", ext->name, value); return -EINVAL; } *(bool *)ext_val = value == 'y' ? true : false; break; case KCFG_TRISTATE: if (value == 'y') *(enum libbpf_tristate *)ext_val = TRI_YES; else if (value == 'm') *(enum libbpf_tristate *)ext_val = TRI_MODULE; else /* value == 'n' */ *(enum libbpf_tristate *)ext_val = TRI_NO; break; case KCFG_CHAR: *(char *)ext_val = value; break; case KCFG_UNKNOWN: case KCFG_INT: case KCFG_CHAR_ARR: default: pr_warn("extern (kcfg) '%s': value '%c' implies bool, tristate, or char type\n", ext->name, value); return -EINVAL; } ext->is_set = true; return 0;}
static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, const char *value){ size_t len;
if (ext->kcfg.type != KCFG_CHAR_ARR) { pr_warn("extern (kcfg) '%s': value '%s' implies char array type\n", ext->name, value); return -EINVAL; }
len = strlen(value); if (len < 2 || value[len - 1] != '"') { pr_warn("extern (kcfg) '%s': invalid string config '%s'\n", ext->name, value); return -EINVAL; }
/* strip quotes */ len -= 2; if (len >= ext->kcfg.sz) { pr_warn("extern (kcfg) '%s': long string '%s' of (%zu bytes) truncated to %d bytes\n", ext->name, value, len, ext->kcfg.sz - 1); len = ext->kcfg.sz - 1; } memcpy(ext_val, value + 1, len); ext_val[len] = '\0'; ext->is_set = true; return 0;}
static int parse_u64(const char *value, __u64 *res){ char *value_end; int err;
errno = 0; *res = strtoull(value, &value_end, 0); if (errno) { err = -errno; pr_warn("failed to parse '%s': %s\n", value, errstr(err)); return err; } if (*value_end) { pr_warn("failed to parse '%s' as integer completely\n", value); return -EINVAL; } return 0;}
static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v){ int bit_sz = ext->kcfg.sz * 8;
if (ext->kcfg.sz == 8) return true;
/* Validate that value stored in u64 fits in integer of `ext->sz` * bytes size without any loss of information. If the target integer * is signed, we rely on the following limits of integer type of * Y bits and subsequent transformation: * * -2^(Y-1) <= X <= 2^(Y-1) - 1 * 0 <= X + 2^(Y-1) <= 2^Y - 1 * 0 <= X + 2^(Y-1) < 2^Y * * For unsigned target integer, check that all the (64 - Y) bits are * zero. */ if (ext->kcfg.is_signed) return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz); else return (v >> bit_sz) == 0;}
static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val, __u64 value){ if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR && ext->kcfg.type != KCFG_BOOL) { pr_warn("extern (kcfg) '%s': value '%llu' implies integer, char, or boolean type\n", ext->name, (unsigned long long)value); return -EINVAL; } if (ext->kcfg.type == KCFG_BOOL && value > 1) { pr_warn("extern (kcfg) '%s': value '%llu' isn't boolean compatible\n", ext->name, (unsigned long long)value); return -EINVAL;
} if (!is_kcfg_value_in_range(ext, value)) { pr_warn("extern (kcfg) '%s': value '%llu' doesn't fit in %d bytes\n", ext->name, (unsigned long long)value, ext->kcfg.sz); return -ERANGE; } switch (ext->kcfg.sz) { case 1: *(__u8 *)ext_val = value; break; case 2: *(__u16 *)ext_val = value; break; case 4: *(__u32 *)ext_val = value; break; case 8: *(__u64 *)ext_val = value; break; default: return -EINVAL; } ext->is_set = true; return 0;}
static int bpf_object__process_kconfig_line(struct bpf_object *obj, char *buf, void *data){ struct extern_desc *ext; char *sep, *value; int len, err = 0; void *ext_val; __u64 num;
if (!str_has_pfx(buf, "CONFIG_")) return 0;
sep = strchr(buf, '='); if (!sep) { pr_warn("failed to parse '%s': no separator\n", buf); return -EINVAL; }
/* Trim ending '\n' */ len = strlen(buf); if (buf[len - 1] == '\n') buf[len - 1] = '\0'; /* Split on '=' and ensure that a value is present. */ *sep = '\0'; if (!sep[1]) { *sep = '='; pr_warn("failed to parse '%s': no value\n", buf); return -EINVAL; }
ext = find_extern_by_name(obj, buf); if (!ext || ext->is_set) return 0;
ext_val = data + ext->kcfg.data_off; value = sep + 1;
switch (*value) { case 'y': case 'n': case 'm': err = set_kcfg_value_tri(ext, ext_val, *value); break; case '"': err = set_kcfg_value_str(ext, ext_val, value); break; default: /* assume integer */ err = parse_u64(value, &num); if (err) { pr_warn("extern (kcfg) '%s': value '%s' isn't a valid integer\n", ext->name, value); return err; } if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { pr_warn("extern (kcfg) '%s': value '%s' implies integer type\n", ext->name, value); return -EINVAL; } err = set_kcfg_value_num(ext, ext_val, num); break; } if (err) return err; pr_debug("extern (kcfg) '%s': set to %s\n", ext->name, value); return 0;}
static int bpf_object__read_kconfig_file(struct bpf_object *obj, void *data){ char buf[PATH_MAX]; struct utsname uts; int len, err = 0; gzFile file;
uname(&uts); len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release); if (len < 0) return -EINVAL; else if (len >= PATH_MAX) return -ENAMETOOLONG;
/* gzopen also accepts uncompressed files. */ file = gzopen(buf, "re"); if (!file) file = gzopen("/proc/config.gz", "re");
if (!file) { pr_warn("failed to open system Kconfig\n"); return -ENOENT; }
while (gzgets(file, buf, sizeof(buf))) { err = bpf_object__process_kconfig_line(obj, buf, data); if (err) { pr_warn("error parsing system Kconfig line '%s': %s\n", buf, errstr(err)); goto out; } }
out: gzclose(file); return err;}
static int bpf_object__read_kconfig_mem(struct bpf_object *obj, const char *config, void *data){ char buf[PATH_MAX]; int err = 0; FILE *file;
file = fmemopen((void *)config, strlen(config), "r"); if (!file) { err = -errno; pr_warn("failed to open in-memory Kconfig: %s\n", errstr(err)); return err; }
while (fgets(buf, sizeof(buf), file)) { err = bpf_object__process_kconfig_line(obj, buf, data); if (err) { pr_warn("error parsing in-memory Kconfig line '%s': %s\n", buf, errstr(err)); break; } }
fclose(file); return err;}
static int bpf_object__init_kconfig_map(struct bpf_object *obj){ struct extern_desc *last_ext = NULL, *ext; size_t map_sz; int i, err;
for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; if (ext->type == EXT_KCFG) last_ext = ext; }
if (!last_ext) return 0;
map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz; err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG, ".kconfig", obj->efile.symbols_shndx, NULL, map_sz); if (err) return err;
obj->kconfig_map_idx = obj->nr_maps - 1;
return 0;}
const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id){ const struct btf_type *t = btf__type_by_id(btf, id);
if (res_id) *res_id = id;
while (btf_is_mod(t) || btf_is_typedef(t)) { if (res_id) *res_id = t->type; t = btf__type_by_id(btf, t->type); }
return t;}
static const struct btf_type *resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id){ const struct btf_type *t;
t = skip_mods_and_typedefs(btf, id, NULL); if (!btf_is_ptr(t)) return NULL;
t = skip_mods_and_typedefs(btf, t->type, res_id);
return btf_is_func_proto(t) ? t : NULL;}
static const char *__btf_kind_str(__u16 kind){ switch (kind) { case BTF_KIND_UNKN: return "void"; case BTF_KIND_INT: return "int"; case BTF_KIND_PTR: return "ptr"; case BTF_KIND_ARRAY: return "array"; case BTF_KIND_STRUCT: return "struct"; case BTF_KIND_UNION: return "union"; case BTF_KIND_ENUM: return "enum"; case BTF_KIND_FWD: return "fwd"; case BTF_KIND_TYPEDEF: return "typedef"; case BTF_KIND_VOLATILE: return "volatile"; case BTF_KIND_CONST: return "const"; case BTF_KIND_RESTRICT: return "restrict"; case BTF_KIND_FUNC: return "func"; case BTF_KIND_FUNC_PROTO: return "func_proto"; case BTF_KIND_VAR: return "var"; case BTF_KIND_DATASEC: return "datasec"; case BTF_KIND_FLOAT: return "float"; case BTF_KIND_DECL_TAG: return "decl_tag"; case BTF_KIND_TYPE_TAG: return "type_tag"; case BTF_KIND_ENUM64: return "enum64"; default: return "unknown"; }}
const char *btf_kind_str(const struct btf_type *t){ return __btf_kind_str(btf_kind(t));}
/* * Fetch integer attribute of BTF map definition. Such attributes are * represented using a pointer to an array, in which dimensionality of array * encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY]; * encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF * type definition, while using only sizeof(void *) space in ELF data section. */static bool get_map_field_int(const char *map_name, const struct btf *btf, const struct btf_member *m, __u32 *res){ const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL); const char *name = btf__name_by_offset(btf, m->name_off); const struct btf_array *arr_info; const struct btf_type *arr_t;
if (!btf_is_ptr(t)) { pr_warn("map '%s': attr '%s': expected PTR, got %s.\n", map_name, name, btf_kind_str(t)); return false; }
arr_t = btf__type_by_id(btf, t->type); if (!arr_t) { pr_warn("map '%s': attr '%s': type [%u] not found.\n", map_name, name, t->type); return false; } if (!btf_is_array(arr_t)) { pr_warn("map '%s': attr '%s': expected ARRAY, got %s.\n", map_name, name, btf_kind_str(arr_t)); return false; } arr_info = btf_array(arr_t); *res = arr_info->nelems; return true;}
static bool get_map_field_long(const char *map_name, const struct btf *btf, const struct btf_member *m, __u64 *res){ const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL); const char *name = btf__name_by_offset(btf, m->name_off);
if (btf_is_ptr(t)) { __u32 res32; bool ret;
ret = get_map_field_int(map_name, btf, m, &res32); if (ret) *res = (__u64)res32; return ret; }
if (!btf_is_enum(t) && !btf_is_enum64(t)) { pr_warn("map '%s': attr '%s': expected ENUM or ENUM64, got %s.\n", map_name, name, btf_kind_str(t)); return false; }
if (btf_vlen(t) != 1) { pr_warn("map '%s': attr '%s': invalid __ulong\n", map_name, name); return false; }
if (btf_is_enum(t)) { const struct btf_enum *e = btf_enum(t);
*res = e->val; } else { const struct btf_enum64 *e = btf_enum64(t);
*res = btf_enum64_value(e); } return true;}
static int pathname_concat(char *buf, size_t buf_sz, const char *path, const char *name){ int len;
len = snprintf(buf, buf_sz, "%s/%s", path, name); if (len < 0) return -EINVAL; if (len >= buf_sz) return -ENAMETOOLONG;
return 0;}
static int build_map_pin_path(struct bpf_map *map, const char *path){ char buf[PATH_MAX]; int err;
if (!path) path = BPF_FS_DEFAULT_PATH;
err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); if (err) return err;
return bpf_map__set_pin_path(map, buf);}
/* should match definition in bpf_helpers.h */enum libbpf_pin_type { LIBBPF_PIN_NONE, /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */ LIBBPF_PIN_BY_NAME,};
int parse_btf_map_def(const char *map_name, struct btf *btf, const struct btf_type *def_t, bool strict, struct btf_map_def *map_def, struct btf_map_def *inner_def){ const struct btf_type *t; const struct btf_member *m; bool is_inner = inner_def == NULL; int vlen, i;
vlen = btf_vlen(def_t); m = btf_members(def_t); for (i = 0; i < vlen; i++, m++) { const char *name = btf__name_by_offset(btf, m->name_off);
if (!name) { pr_warn("map '%s': invalid field #%d.\n", map_name, i); return -EINVAL; } if (strcmp(name, "type") == 0) { if (!get_map_field_int(map_name, btf, m, &map_def->map_type)) return -EINVAL; map_def->parts |= MAP_DEF_MAP_TYPE; } else if (strcmp(name, "max_entries") == 0) { if (!get_map_field_int(map_name, btf, m, &map_def->max_entries)) return -EINVAL; map_def->parts |= MAP_DEF_MAX_ENTRIES; } else if (strcmp(name, "map_flags") == 0) { if (!get_map_field_int(map_name, btf, m, &map_def->map_flags)) return -EINVAL; map_def->parts |= MAP_DEF_MAP_FLAGS; } else if (strcmp(name, "numa_node") == 0) { if (!get_map_field_int(map_name, btf, m, &map_def->numa_node)) return -EINVAL; map_def->parts |= MAP_DEF_NUMA_NODE; } else if (strcmp(name, "key_size") == 0) { __u32 sz;
if (!get_map_field_int(map_name, btf, m, &sz)) return -EINVAL; if (map_def->key_size && map_def->key_size != sz) { pr_warn("map '%s': conflicting key size %u != %u.\n", map_name, map_def->key_size, sz); return -EINVAL; } map_def->key_size = sz; map_def->parts |= MAP_DEF_KEY_SIZE; } else if (strcmp(name, "key") == 0) { __s64 sz;
t = btf__type_by_id(btf, m->type); if (!t) { pr_warn("map '%s': key type [%d] not found.\n", map_name, m->type); return -EINVAL; } if (!btf_is_ptr(t)) { pr_warn("map '%s': key spec is not PTR: %s.\n", map_name, btf_kind_str(t)); return -EINVAL; } sz = btf__resolve_size(btf, t->type); if (sz < 0) { pr_warn("map '%s': can't determine key size for type [%u]: %zd.\n", map_name, t->type, (ssize_t)sz); return sz; } if (map_def->key_size && map_def->key_size != sz) { pr_warn("map '%s': conflicting key size %u != %zd.\n", map_name, map_def->key_size, (ssize_t)sz); return -EINVAL; } map_def->key_size = sz; map_def->key_type_id = t->type; map_def->parts |= MAP_DEF_KEY_SIZE | MAP_DEF_KEY_TYPE; } else if (strcmp(name, "value_size") == 0) { __u32 sz;
if (!get_map_field_int(map_name, btf, m, &sz)) return -EINVAL; if (map_def->value_size && map_def->value_size != sz) { pr_warn("map '%s': conflicting value size %u != %u.\n", map_name, map_def->value_size, sz); return -EINVAL; } map_def->value_size = sz; map_def->parts |= MAP_DEF_VALUE_SIZE; } else if (strcmp(name, "value") == 0) { __s64 sz;
t = btf__type_by_id(btf, m->type); if (!t) { pr_warn("map '%s': value type [%d] not found.\n", map_name, m->type); return -EINVAL; } if (!btf_is_ptr(t)) { pr_warn("map '%s': value spec is not PTR: %s.\n", map_name, btf_kind_str(t)); return -EINVAL; } sz = btf__resolve_size(btf, t->type); if (sz < 0) { pr_warn("map '%s': can't determine value size for type [%u]: %zd.\n", map_name, t->type, (ssize_t)sz); return sz; } if (map_def->value_size && map_def->value_size != sz) { pr_warn("map '%s': conflicting value size %u != %zd.\n", map_name, map_def->value_size, (ssize_t)sz); return -EINVAL; } map_def->value_size = sz; map_def->value_type_id = t->type; map_def->parts |= MAP_DEF_VALUE_SIZE | MAP_DEF_VALUE_TYPE; } else if (strcmp(name, "values") == 0) { bool is_map_in_map = bpf_map_type__is_map_in_map(map_def->map_type); bool is_prog_array = map_def->map_type == BPF_MAP_TYPE_PROG_ARRAY; const char *desc = is_map_in_map ? "map-in-map inner" : "prog-array value"; char inner_map_name[128]; int err;
if (is_inner) { pr_warn("map '%s': multi-level inner maps not supported.\n", map_name); return -ENOTSUP; } if (i != vlen - 1) { pr_warn("map '%s': '%s' member should be last.\n", map_name, name); return -EINVAL; } if (!is_map_in_map && !is_prog_array) { pr_warn("map '%s': should be map-in-map or prog-array.\n", map_name); return -ENOTSUP; } if (map_def->value_size && map_def->value_size != 4) { pr_warn("map '%s': conflicting value size %u != 4.\n", map_name, map_def->value_size); return -EINVAL; } map_def->value_size = 4; t = btf__type_by_id(btf, m->type); if (!t) { pr_warn("map '%s': %s type [%d] not found.\n", map_name, desc, m->type); return -EINVAL; } if (!btf_is_array(t) || btf_array(t)->nelems) { pr_warn("map '%s': %s spec is not a zero-sized array.\n", map_name, desc); return -EINVAL; } t = skip_mods_and_typedefs(btf, btf_array(t)->type, NULL); if (!btf_is_ptr(t)) { pr_warn("map '%s': %s def is of unexpected kind %s.\n", map_name, desc, btf_kind_str(t)); return -EINVAL; } t = skip_mods_and_typedefs(btf, t->type, NULL); if (is_prog_array) { if (!btf_is_func_proto(t)) { pr_warn("map '%s': prog-array value def is of unexpected kind %s.\n", map_name, btf_kind_str(t)); return -EINVAL; } continue; } if (!btf_is_struct(t)) { pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n", map_name, btf_kind_str(t)); return -EINVAL; }
snprintf(inner_map_name, sizeof(inner_map_name), "%s.inner", map_name); err = parse_btf_map_def(inner_map_name, btf, t, strict, inner_def, NULL); if (err) return err;
map_def->parts |= MAP_DEF_INNER_MAP; } else if (strcmp(name, "pinning") == 0) { __u32 val;
if (is_inner) { pr_warn("map '%s': inner def can't be pinned.\n", map_name); return -EINVAL; } if (!get_map_field_int(map_name, btf, m, &val)) return -EINVAL; if (val != LIBBPF_PIN_NONE && val != LIBBPF_PIN_BY_NAME) { pr_warn("map '%s': invalid pinning value %u.\n", map_name, val); return -EINVAL; } map_def->pinning = val; map_def->parts |= MAP_DEF_PINNING; } else if (strcmp(name, "map_extra") == 0) { __u64 map_extra;
if (!get_map_field_long(map_name, btf, m, &map_extra)) return -EINVAL; map_def->map_extra = map_extra; map_def->parts |= MAP_DEF_MAP_EXTRA; } else { if (strict) { pr_warn("map '%s': unknown field '%s'.\n", map_name, name); return -ENOTSUP; } pr_debug("map '%s': ignoring unknown field '%s'.\n", map_name, name); } }
if (map_def->map_type == BPF_MAP_TYPE_UNSPEC) { pr_warn("map '%s': map type isn't specified.\n", map_name); return -EINVAL; }
return 0;}
static size_t adjust_ringbuf_sz(size_t sz){ __u32 page_sz = sysconf(_SC_PAGE_SIZE); __u32 mul;
/* if user forgot to set any size, make sure they see error */ if (sz == 0) return 0; /* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be * a power-of-2 multiple of kernel's page size. If user diligently * satisified these conditions, pass the size through. */ if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz)) return sz;
/* Otherwise find closest (page_sz * power_of_2) product bigger than * user-set size to satisfy both user size request and kernel * requirements and substitute correct max_entries for map creation. */ for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) { if (mul * page_sz > sz) return mul * page_sz; }
/* if it's impossible to satisfy the conditions (i.e., user size is * very close to UINT_MAX but is not a power-of-2 multiple of * page_size) then just return original size and let kernel reject it */ return sz;}
static bool map_is_ringbuf(const struct bpf_map *map){ return map->def.type == BPF_MAP_TYPE_RINGBUF || map->def.type == BPF_MAP_TYPE_USER_RINGBUF;}
static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def){ map->def.type = def->map_type; map->def.key_size = def->key_size; map->def.value_size = def->value_size; map->def.max_entries = def->max_entries; map->def.map_flags = def->map_flags; map->map_extra = def->map_extra;
map->numa_node = def->numa_node; map->btf_key_type_id = def->key_type_id; map->btf_value_type_id = def->value_type_id;
/* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ if (map_is_ringbuf(map)) map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries);
if (def->parts & MAP_DEF_MAP_TYPE) pr_debug("map '%s': found type = %u.\n", map->name, def->map_type);
if (def->parts & MAP_DEF_KEY_TYPE) pr_debug("map '%s': found key [%u], sz = %u.\n", map->name, def->key_type_id, def->key_size); else if (def->parts & MAP_DEF_KEY_SIZE) pr_debug("map '%s': found key_size = %u.\n", map->name, def->key_size);
if (def->parts & MAP_DEF_VALUE_TYPE) pr_debug("map '%s': found value [%u], sz = %u.\n", map->name, def->value_type_id, def->value_size); else if (def->parts & MAP_DEF_VALUE_SIZE) pr_debug("map '%s': found value_size = %u.\n", map->name, def->value_size);
if (def->parts & MAP_DEF_MAX_ENTRIES) pr_debug("map '%s': found max_entries = %u.\n", map->name, def->max_entries); if (def->parts & MAP_DEF_MAP_FLAGS) pr_debug("map '%s': found map_flags = 0x%x.\n", map->name, def->map_flags); if (def->parts & MAP_DEF_MAP_EXTRA) pr_debug("map '%s': found map_extra = 0x%llx.\n", map->name, (unsigned long long)def->map_extra); if (def->parts & MAP_DEF_PINNING) pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning); if (def->parts & MAP_DEF_NUMA_NODE) pr_debug("map '%s': found numa_node = %u.\n", map->name, def->numa_node);
if (def->parts & MAP_DEF_INNER_MAP) pr_debug("map '%s': found inner map definition.\n", map->name);}
static const char *btf_var_linkage_str(__u32 linkage){ switch (linkage) { case BTF_VAR_STATIC: return "static"; case BTF_VAR_GLOBAL_ALLOCATED: return "global"; case BTF_VAR_GLOBAL_EXTERN: return "extern"; default: return "unknown"; }}
static int bpf_object__init_user_btf_map(struct bpf_object *obj, const struct btf_type *sec, int var_idx, int sec_idx, const Elf_Data *data, bool strict, const char *pin_root_path){ struct btf_map_def map_def = {}, inner_def = {}; const struct btf_type *var, *def; const struct btf_var_secinfo *vi; const struct btf_var *var_extra; const char *map_name; struct bpf_map *map; int err;
vi = btf_var_secinfos(sec) + var_idx; var = btf__type_by_id(obj->btf, vi->type); var_extra = btf_var(var); map_name = btf__name_by_offset(obj->btf, var->name_off);
if (str_is_empty(map_name)) { pr_warn("map #%d: empty name.\n", var_idx); return -EINVAL; } if ((__u64)vi->offset + vi->size > data->d_size) { pr_warn("map '%s' BTF data is corrupted.\n", map_name); return -EINVAL; } if (!btf_is_var(var)) { pr_warn("map '%s': unexpected var kind %s.\n", map_name, btf_kind_str(var)); return -EINVAL; } if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED) { pr_warn("map '%s': unsupported map linkage %s.\n", map_name, btf_var_linkage_str(var_extra->linkage)); return -EOPNOTSUPP; }
def = skip_mods_and_typedefs(obj->btf, var->type, NULL); if (!btf_is_struct(def)) { pr_warn("map '%s': unexpected def kind %s.\n", map_name, btf_kind_str(var)); return -EINVAL; } if (def->size > vi->size) { pr_warn("map '%s': invalid def size.\n", map_name); return -EINVAL; }
map = bpf_object__add_map(obj); if (IS_ERR(map)) return PTR_ERR(map); map->name = strdup(map_name); if (!map->name) { pr_warn("map '%s': failed to alloc map name.\n", map_name); return -ENOMEM; } map->libbpf_type = LIBBPF_MAP_UNSPEC; map->def.type = BPF_MAP_TYPE_UNSPEC; map->sec_idx = sec_idx; map->sec_offset = vi->offset; map->btf_var_idx = var_idx; pr_debug("map '%s': at sec_idx %d, offset %zu.\n", map_name, map->sec_idx, map->sec_offset);
err = parse_btf_map_def(map->name, obj->btf, def, strict, &map_def, &inner_def); if (err) return err;
fill_map_from_def(map, &map_def);
if (map_def.pinning == LIBBPF_PIN_BY_NAME) { err = build_map_pin_path(map, pin_root_path); if (err) { pr_warn("map '%s': couldn't build pin path.\n", map->name); return err; } }
if (map_def.parts & MAP_DEF_INNER_MAP) { map->inner_map = calloc(1, sizeof(*map->inner_map)); if (!map->inner_map) return -ENOMEM; map->inner_map->fd = create_placeholder_fd(); if (map->inner_map->fd < 0) return map->inner_map->fd; map->inner_map->sec_idx = sec_idx; map->inner_map->name = malloc(strlen(map_name) + sizeof(".inner") + 1); if (!map->inner_map->name) return -ENOMEM; sprintf(map->inner_map->name, "%s.inner", map_name);
fill_map_from_def(map->inner_map, &inner_def); }
err = map_fill_btf_type_info(obj, map); if (err) return err;
return 0;}
static int init_arena_map_data(struct bpf_object *obj, struct bpf_map *map, const char *sec_name, int sec_idx, void *data, size_t data_sz){ const long page_sz = sysconf(_SC_PAGE_SIZE); const size_t data_alloc_sz = roundup(data_sz, page_sz); size_t mmap_sz;
mmap_sz = bpf_map_mmap_sz(map); if (data_alloc_sz > mmap_sz) { pr_warn("elf: sec '%s': declared ARENA map size (%zu) is too small to hold global __arena variables of size %zu\n", sec_name, mmap_sz, data_sz); return -E2BIG; }
obj->arena_data = malloc(data_sz); if (!obj->arena_data) return -ENOMEM; memcpy(obj->arena_data, data, data_sz); obj->arena_data_sz = data_sz;
/* make bpf_map__init_value() work for ARENA maps */ map->mmaped = obj->arena_data;
return 0;}
static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, const char *pin_root_path){ const struct btf_type *sec = NULL; int nr_types, i, vlen, err; const struct btf_type *t; const char *name; Elf_Data *data; Elf_Scn *scn;
if (obj->efile.btf_maps_shndx < 0) return 0;
scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx); data = elf_sec_data(obj, scn); if (!data) { pr_warn("elf: failed to get %s map definitions for %s\n", MAPS_ELF_SEC, obj->path); return -EINVAL; }
nr_types = btf__type_cnt(obj->btf); for (i = 1; i < nr_types; i++) { t = btf__type_by_id(obj->btf, i); if (!btf_is_datasec(t)) continue; name = btf__name_by_offset(obj->btf, t->name_off); if (strcmp(name, MAPS_ELF_SEC) == 0) { sec = t; obj->efile.btf_maps_sec_btf_id = i; break; } }
if (!sec) { pr_warn("DATASEC '%s' not found.\n", MAPS_ELF_SEC); return -ENOENT; }
vlen = btf_vlen(sec); for (i = 0; i < vlen; i++) { err = bpf_object__init_user_btf_map(obj, sec, i, obj->efile.btf_maps_shndx, data, strict, pin_root_path); if (err) return err; }
for (i = 0; i < obj->nr_maps; i++) { struct bpf_map *map = &obj->maps[i];
if (map->def.type != BPF_MAP_TYPE_ARENA) continue;
if (obj->arena_map_idx >= 0) { pr_warn("map '%s': only single ARENA map is supported (map '%s' is also ARENA)\n", map->name, obj->maps[obj->arena_map_idx].name); return -EINVAL; } obj->arena_map_idx = i;
if (obj->efile.arena_data) { err = init_arena_map_data(obj, map, ARENA_SEC, obj->efile.arena_data_shndx, obj->efile.arena_data->d_buf, obj->efile.arena_data->d_size); if (err) return err; } } if (obj->efile.arena_data && obj->arena_map_idx < 0) { pr_warn("elf: sec '%s': to use global __arena variables the ARENA map should be explicitly declared in SEC(\".maps\")\n", ARENA_SEC); return -ENOENT; }
return 0;}
static int bpf_object__init_maps(struct bpf_object *obj, const struct bpf_object_open_opts *opts){ const char *pin_root_path; bool strict; int err = 0;
strict = !OPTS_GET(opts, relaxed_maps, false); pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
err = bpf_object__init_user_btf_maps(obj, strict, pin_root_path); err = err ?: bpf_object__init_global_data_maps(obj); err = err ?: bpf_object__init_kconfig_map(obj); err = err ?: bpf_object_init_struct_ops(obj);
return err;}
static bool section_have_execinstr(struct bpf_object *obj, int idx){ Elf64_Shdr *sh;
sh = elf_sec_hdr(obj, elf_sec_by_idx(obj, idx)); if (!sh) return false;
return sh->sh_flags & SHF_EXECINSTR;}
static bool starts_with_qmark(const char *s){ return s && s[0] == '?';}
static bool btf_needs_sanitization(struct bpf_object *obj){ bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC); bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC); bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT); bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG); bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64); bool has_qmark_datasec = kernel_supports(obj, FEAT_BTF_QMARK_DATASEC); bool has_layout = kernel_supports(obj, FEAT_BTF_LAYOUT);
return !has_func || !has_datasec || !has_func_global || !has_float || !has_decl_tag || !has_type_tag || !has_enum64 || !has_qmark_datasec || !has_layout;}
struct btf *bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *orig_btf){ bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC); bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC); bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT); bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG); bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64); bool has_qmark_datasec = kernel_supports(obj, FEAT_BTF_QMARK_DATASEC); bool has_layout = kernel_supports(obj, FEAT_BTF_LAYOUT); int enum64_placeholder_id = 0; const struct btf_header *hdr; struct btf *btf = NULL; const void *raw_data; struct btf_type *t; int i, j, vlen; __u32 sz; int err;
/* clone BTF to sanitize a copy and leave the original intact */ raw_data = btf__raw_data(orig_btf, &sz); if (!raw_data) return ERR_PTR(-ENOMEM); /* btf_header() gives us endian-safe header info */ hdr = btf_header(orig_btf);
if (!has_layout && hdr->hdr_len >= sizeof(struct btf_header) && (hdr->layout_len != 0 || hdr->layout_off != 0)) { const struct btf_header *old_hdr = raw_data; struct btf_header *new_hdr; void *new_raw_data; __u32 new_str_off;
/* * Need to rewrite BTF to exclude layout information and * move string section to immediately after types. */ new_raw_data = malloc(sz); if (!new_raw_data) return ERR_PTR(-ENOMEM);
memcpy(new_raw_data, raw_data, sz); new_hdr = new_raw_data; new_hdr->layout_off = 0; new_hdr->layout_len = 0; new_str_off = hdr->type_off + hdr->type_len; /* Handle swapped endian case */ if (old_hdr->magic != hdr->magic) new_hdr->str_off = bswap_32(new_str_off); else new_hdr->str_off = new_str_off;
memmove(new_raw_data + hdr->hdr_len + new_str_off, new_raw_data + hdr->hdr_len + hdr->str_off, hdr->str_len); sz = hdr->hdr_len + hdr->type_off + hdr->type_len + hdr->str_len; btf = btf__new(new_raw_data, sz); free(new_raw_data); } else { btf = btf__new(raw_data, sz); } err = libbpf_get_error(btf); if (err) return ERR_PTR(err);
/* enforce 8-byte pointers for BPF-targeted BTFs */ btf__set_pointer_size(btf, 8);
for (i = 1; i < btf__type_cnt(btf); i++) { t = (struct btf_type *)btf__type_by_id(btf, i);
if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) { /* replace VAR/DECL_TAG with INT */ t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0); /* * using size = 1 is the safest choice, 4 will be too * big and cause kernel BTF validation failure if * original variable took less than 4 bytes */ t->size = 1; *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8); } else if (!has_datasec && btf_is_datasec(t)) { /* replace DATASEC with STRUCT */ const struct btf_var_secinfo *v = btf_var_secinfos(t); struct btf_member *m = btf_members(t); struct btf_type *vt; char *name;
name = (char *)btf__name_by_offset(btf, t->name_off); while (*name) { if (*name == '.' || *name == '?') *name = '_'; name++; }
vlen = btf_vlen(t); t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen); for (j = 0; j < vlen; j++, v++, m++) { /* order of field assignments is important */ m->offset = v->offset * 8; m->type = v->type; /* preserve variable name as member name */ vt = (void *)btf__type_by_id(btf, v->type); m->name_off = vt->name_off; } } else if (!has_qmark_datasec && btf_is_datasec(t) && starts_with_qmark(btf__name_by_offset(btf, t->name_off))) { /* replace '?' prefix with '_' for DATASEC names */ char *name;
name = (char *)btf__name_by_offset(btf, t->name_off); if (name[0] == '?') name[0] = '_'; } else if (!has_func && btf_is_func_proto(t)) { /* replace FUNC_PROTO with ENUM */ vlen = btf_vlen(t); t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen); t->size = sizeof(__u32); /* kernel enforced */ } else if (!has_func && btf_is_func(t)) { /* replace FUNC with TYPEDEF */ t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0); } else if (!has_func_global && btf_is_func(t)) { /* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */ t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0); } else if (!has_float && btf_is_float(t)) { /* replace FLOAT with an equally-sized empty STRUCT; * since C compilers do not accept e.g. "float" as a * valid struct name, make it anonymous */ t->name_off = 0; t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 0); } else if (!has_type_tag && btf_is_type_tag(t)) { /* replace TYPE_TAG with a CONST */ t->name_off = 0; t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0); } else if (!has_enum64 && btf_is_enum(t)) { /* clear the kflag */ t->info = btf_type_info(btf_kind(t), btf_vlen(t), false); } else if (!has_enum64 && btf_is_enum64(t)) { /* replace ENUM64 with a union */ struct btf_member *m;
if (enum64_placeholder_id == 0) { enum64_placeholder_id = btf__add_int(btf, "enum64_placeholder", 1, 0); if (enum64_placeholder_id < 0) { btf__free(btf); return ERR_PTR(enum64_placeholder_id); } t = (struct btf_type *)btf__type_by_id(btf, i); }
m = btf_members(t); vlen = btf_vlen(t); t->info = BTF_INFO_ENC(BTF_KIND_UNION, 0, vlen); for (j = 0; j < vlen; j++, m++) { m->type = enum64_placeholder_id; m->offset = 0; } } }
return btf;}
static bool libbpf_needs_btf(const struct bpf_object *obj){ return obj->efile.btf_maps_shndx >= 0 || obj->efile.has_st_ops || obj->nr_extern > 0;}
static bool kernel_needs_btf(const struct bpf_object *obj){ return obj->efile.has_st_ops;}
static int bpf_object__init_btf(struct bpf_object *obj, Elf_Data *btf_data, Elf_Data *btf_ext_data){ int err = -ENOENT;
if (btf_data) { obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); err = libbpf_get_error(obj->btf); if (err) { obj->btf = NULL; pr_warn("Error loading ELF section %s: %s.\n", BTF_ELF_SEC, errstr(err)); goto out; } /* enforce 8-byte pointers for BPF-targeted BTFs */ btf__set_pointer_size(obj->btf, 8); } if (btf_ext_data) { struct btf_ext_info *ext_segs[3]; int seg_num, sec_num;
if (!obj->btf) { pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", BTF_EXT_ELF_SEC, BTF_ELF_SEC); goto out; } obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, btf_ext_data->d_size); err = libbpf_get_error(obj->btf_ext); if (err) { pr_warn("Error loading ELF section %s: %s. Ignored and continue.\n", BTF_EXT_ELF_SEC, errstr(err)); obj->btf_ext = NULL; goto out; }
/* setup .BTF.ext to ELF section mapping */ ext_segs[0] = &obj->btf_ext->func_info; ext_segs[1] = &obj->btf_ext->line_info; ext_segs[2] = &obj->btf_ext->core_relo_info; for (seg_num = 0; seg_num < ARRAY_SIZE(ext_segs); seg_num++) { struct btf_ext_info *seg = ext_segs[seg_num]; const struct btf_ext_info_sec *sec; const char *sec_name; Elf_Scn *scn;
if (seg->sec_cnt == 0) continue;
seg->sec_idxs = calloc(seg->sec_cnt, sizeof(*seg->sec_idxs)); if (!seg->sec_idxs) { err = -ENOMEM; goto out; }
sec_num = 0; for_each_btf_ext_sec(seg, sec) { /* preventively increment index to avoid doing * this before every continue below */ sec_num++;
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); if (str_is_empty(sec_name)) continue; scn = elf_sec_by_name(obj, sec_name); if (!scn) continue;
seg->sec_idxs[sec_num - 1] = elf_ndxscn(scn); } } }out: if (err && libbpf_needs_btf(obj)) { pr_warn("BTF is required, but is missing or corrupted.\n"); return err; } return 0;}
static int compare_vsi_off(const void *_a, const void *_b){ const struct btf_var_secinfo *a = _a; const struct btf_var_secinfo *b = _b;
return a->offset - b->offset;}
static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf, struct btf_type *t){ __u32 size = 0, i, vars = btf_vlen(t); const char *sec_name = btf__name_by_offset(btf, t->name_off); struct btf_var_secinfo *vsi; bool fixup_offsets = false; int err;
if (!sec_name) { pr_debug("No name found in string section for DATASEC kind.\n"); return -ENOENT; }
/* Extern-backing datasecs (.ksyms, .kconfig) have their size and * variable offsets set at the previous step. Further, not every * extern BTF VAR has corresponding ELF symbol preserved, so we skip * all fixups altogether for such sections and go straight to sorting * VARs within their DATASEC. */ if (strcmp(sec_name, KCONFIG_SEC) == 0 || strcmp(sec_name, KSYMS_SEC) == 0) goto sort_vars;
/* Clang leaves DATASEC size and VAR offsets as zeroes, so we need to * fix this up. But BPF static linker already fixes this up and fills * all the sizes and offsets during static linking. So this step has * to be optional. But the STV_HIDDEN handling is non-optional for any * non-extern DATASEC, so the variable fixup loop below handles both * functions at the same time, paying the cost of BTF VAR <-> ELF * symbol matching just once. */ if (t->size == 0) { err = find_elf_sec_sz(obj, sec_name, &size); if (err || !size) { pr_debug("sec '%s': failed to determine size from ELF: size %u, err %s\n", sec_name, size, errstr(err)); return -ENOENT; }
t->size = size; fixup_offsets = true; }
for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) { const struct btf_type *t_var; struct btf_var *var; const char *var_name; Elf64_Sym *sym;
t_var = btf__type_by_id(btf, vsi->type); if (!t_var || !btf_is_var(t_var)) { pr_debug("sec '%s': unexpected non-VAR type found\n", sec_name); return -EINVAL; }
var = btf_var(t_var); if (var->linkage == BTF_VAR_STATIC || var->linkage == BTF_VAR_GLOBAL_EXTERN) continue;
var_name = btf__name_by_offset(btf, t_var->name_off); if (!var_name) { pr_debug("sec '%s': failed to find name of DATASEC's member #%d\n", sec_name, i); return -ENOENT; }
sym = find_elf_var_sym(obj, var_name); if (IS_ERR(sym)) { pr_debug("sec '%s': failed to find ELF symbol for VAR '%s'\n", sec_name, var_name); return -ENOENT; }
if (fixup_offsets) vsi->offset = sym->st_value;
/* if variable is a global/weak symbol, but has restricted * (STV_HIDDEN or STV_INTERNAL) visibility, mark its BTF VAR * as static. This follows similar logic for functions (BPF * subprogs) and influences libbpf's further decisions about * whether to make global data BPF array maps as * BPF_F_MMAPABLE. */ if (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN || ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL) var->linkage = BTF_VAR_STATIC; }
sort_vars: qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off); return 0;}
static int bpf_object_fixup_btf(struct bpf_object *obj){ int i, n, err = 0;
if (!obj->btf) return 0;
n = btf__type_cnt(obj->btf); for (i = 1; i < n; i++) { struct btf_type *t = btf_type_by_id(obj->btf, i);
/* Loader needs to fix up some of the things compiler * couldn't get its hands on while emitting BTF. This * is section size and global variable offset. We use * the info from the ELF itself for this purpose. */ if (btf_is_datasec(t)) { err = btf_fixup_datasec(obj, obj->btf, t); if (err) return err; } }
return 0;}
static bool prog_needs_vmlinux_btf(struct bpf_program *prog){ if (prog->type == BPF_PROG_TYPE_STRUCT_OPS || prog->type == BPF_PROG_TYPE_LSM) return true;
/* BPF_PROG_TYPE_TRACING programs which do not attach to other programs * also need vmlinux BTF */ if (prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd) return true;
return false;}
static bool map_needs_vmlinux_btf(struct bpf_map *map){ return bpf_map__is_struct_ops(map);}
static bool obj_needs_vmlinux_btf(const struct bpf_object *obj){ struct bpf_program *prog; struct bpf_map *map; int i;
/* CO-RE relocations need kernel BTF, only when btf_custom_path * is not specified */ if (obj->btf_ext && obj->btf_ext->core_relo_info.len && !obj->btf_custom_path) return true;
/* Support for typed ksyms needs kernel BTF */ for (i = 0; i < obj->nr_extern; i++) { const struct extern_desc *ext;
ext = &obj->externs[i]; if (ext->type == EXT_KSYM && ext->ksym.type_id) return true; }
bpf_object__for_each_program(prog, obj) { if (!prog->autoload) continue; if (prog_needs_vmlinux_btf(prog)) return true; }
bpf_object__for_each_map(map, obj) { if (map_needs_vmlinux_btf(map)) return true; }
return false;}
static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force){ int err;
/* btf_vmlinux could be loaded earlier */ if (obj->btf_vmlinux || obj->gen_loader) return 0;
if (!force && !obj_needs_vmlinux_btf(obj)) return 0;
obj->btf_vmlinux = btf__load_vmlinux_btf(); err = libbpf_get_error(obj->btf_vmlinux); if (err) { pr_warn("Error loading vmlinux BTF: %s\n", errstr(err)); obj->btf_vmlinux = NULL; return err; } return 0;}
static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj){ struct btf *kern_btf = obj->btf; bool btf_mandatory, sanitize; int i, err = 0;
if (!obj->btf) return 0;
if (!kernel_supports(obj, FEAT_BTF)) { if (kernel_needs_btf(obj)) { err = -EOPNOTSUPP; goto report; } pr_debug("Kernel doesn't support BTF, skipping uploading it.\n"); return 0; }
/* Even though some subprogs are global/weak, user might prefer more * permissive BPF verification process that BPF verifier performs for * static functions, taking into account more context from the caller * functions. In such case, they need to mark such subprogs with * __attribute__((visibility("hidden"))) and libbpf will adjust * corresponding FUNC BTF type to be marked as static and trigger more * involved BPF verification process. */ for (i = 0; i < obj->nr_programs; i++) { struct bpf_program *prog = &obj->programs[i]; struct btf_type *t; const char *name; int j, n;
if (!prog->mark_btf_static || !prog_is_subprog(obj, prog)) continue;
n = btf__type_cnt(obj->btf); for (j = 1; j < n; j++) { t = btf_type_by_id(obj->btf, j); if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL) continue;
name = btf__str_by_offset(obj->btf, t->name_off); if (strcmp(name, prog->name) != 0) continue;
t->info = btf_type_info(BTF_KIND_FUNC, BTF_FUNC_STATIC, 0); break; } }
sanitize = btf_needs_sanitization(obj); if (sanitize) { kern_btf = bpf_object__sanitize_btf(obj, obj->btf); if (IS_ERR(kern_btf)) return PTR_ERR(kern_btf); }
if (obj->gen_loader) { __u32 raw_size = 0; const void *raw_data = btf__raw_data(kern_btf, &raw_size);
if (!raw_data) return -ENOMEM; bpf_gen__load_btf(obj->gen_loader, raw_data, raw_size); /* Pretend to have valid FD to pass various fd >= 0 checks. * This fd == 0 will not be used with any syscall and will be reset to -1 eventually. */ btf__set_fd(kern_btf, 0); } else { /* currently BPF_BTF_LOAD only supports log_level 1 */ err = btf_load_into_kernel(kern_btf, obj->log_buf, obj->log_size, obj->log_level ? 1 : 0, obj->token_fd); } if (sanitize) { if (!err) { /* move fd to libbpf's BTF */ btf__set_fd(obj->btf, btf__fd(kern_btf)); btf__set_fd(kern_btf, -1); } btf__free(kern_btf); }report: if (err) { btf_mandatory = kernel_needs_btf(obj); if (btf_mandatory) { pr_warn("Error loading .BTF into kernel: %s. BTF is mandatory, can't proceed.\n", errstr(err)); } else { pr_info("Error loading .BTF into kernel: %s. BTF is optional, ignoring.\n", errstr(err)); err = 0; } } return err;}
static const char *elf_sym_str(const struct bpf_object *obj, size_t off){ const char *name;
name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, off); if (!name) { pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n", off, obj->path, elf_errmsg(-1)); return NULL; }
return name;}
static const char *elf_sec_str(const struct bpf_object *obj, size_t off){ const char *name;
name = elf_strptr(obj->efile.elf, obj->efile.shstrndx, off); if (!name) { pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n", off, obj->path, elf_errmsg(-1)); return NULL; }
return name;}
static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx){ Elf_Scn *scn;
scn = elf_getscn(obj->efile.elf, idx); if (!scn) { pr_warn("elf: failed to get section(%zu) from %s: %s\n", idx, obj->path, elf_errmsg(-1)); return NULL; } return scn;}
static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name){ Elf_Scn *scn = NULL; Elf *elf = obj->efile.elf; const char *sec_name;
while ((scn = elf_nextscn(elf, scn)) != NULL) { sec_name = elf_sec_name(obj, scn); if (!sec_name) return NULL;
if (strcmp(sec_name, name) != 0) continue;
return scn; } return NULL;}
static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn){ Elf64_Shdr *shdr;
if (!scn) return NULL;
shdr = elf64_getshdr(scn); if (!shdr) { pr_warn("elf: failed to get section(%zu) header from %s: %s\n", elf_ndxscn(scn), obj->path, elf_errmsg(-1)); return NULL; }
return shdr;}
static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn){ const char *name; Elf64_Shdr *sh;
if (!scn) return NULL;
sh = elf_sec_hdr(obj, scn); if (!sh) return NULL;
name = elf_sec_str(obj, sh->sh_name); if (!name) { pr_warn("elf: failed to get section(%zu) name from %s: %s\n", elf_ndxscn(scn), obj->path, elf_errmsg(-1)); return NULL; }
return name;}
static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn){ Elf_Data *data;
if (!scn) return NULL;
data = elf_getdata(scn, 0); if (!data) { pr_warn("elf: failed to get section(%zu) %s data from %s: %s\n", elf_ndxscn(scn), elf_sec_name(obj, scn) ?: "<?>", obj->path, elf_errmsg(-1)); return NULL; }
return data;}
static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx){ if (idx >= obj->efile.symbols->d_size / sizeof(Elf64_Sym)) return NULL;
return (Elf64_Sym *)obj->efile.symbols->d_buf + idx;}
static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx){ if (idx >= data->d_size / sizeof(Elf64_Rel)) return NULL;
return (Elf64_Rel *)data->d_buf + idx;}
static bool is_sec_name_dwarf(const char *name){ /* approximation, but the actual list is too long */ return str_has_pfx(name, ".debug_");}
static bool ignore_elf_section(Elf64_Shdr *hdr, const char *name){ /* no special handling of .strtab */ if (hdr->sh_type == SHT_STRTAB) return true;
/* ignore .llvm_addrsig section as well */ if (hdr->sh_type == SHT_LLVM_ADDRSIG) return true;
/* no subprograms will lead to an empty .text section, ignore it */ if (hdr->sh_type == SHT_PROGBITS && hdr->sh_size == 0 && strcmp(name, ".text") == 0) return true;
/* DWARF sections */ if (is_sec_name_dwarf(name)) return true;
if (str_has_pfx(name, ".rel")) { name += sizeof(".rel") - 1; /* DWARF section relocations */ if (is_sec_name_dwarf(name)) return true;
/* .BTF and .BTF.ext don't need relocations */ if (strcmp(name, BTF_ELF_SEC) == 0 || strcmp(name, BTF_EXT_ELF_SEC) == 0) return true; }
return false;}
static int cmp_progs(const void *_a, const void *_b){ const struct bpf_program *a = _a; const struct bpf_program *b = _b;
if (a->sec_idx != b->sec_idx) return a->sec_idx < b->sec_idx ? -1 : 1;
/* sec_insn_off can't be the same within the section */ return a->sec_insn_off < b->sec_insn_off ? -1 : 1;}
static int bpf_object__elf_collect(struct bpf_object *obj){ struct elf_sec_desc *sec_desc; Elf *elf = obj->efile.elf; Elf_Data *btf_ext_data = NULL; Elf_Data *btf_data = NULL; int idx = 0, err = 0; const char *name; Elf_Data *data; Elf_Scn *scn; Elf64_Shdr *sh;
/* ELF section indices are 0-based, but sec #0 is special "invalid" * section. Since section count retrieved by elf_getshdrnum() does * include sec #0, it is already the necessary size of an array to keep * all the sections. */ if (elf_getshdrnum(obj->efile.elf, &obj->efile.sec_cnt)) { pr_warn("elf: failed to get the number of sections for %s: %s\n", obj->path, elf_errmsg(-1)); return -LIBBPF_ERRNO__FORMAT; } obj->efile.secs = calloc(obj->efile.sec_cnt, sizeof(*obj->efile.secs)); if (!obj->efile.secs) return -ENOMEM;
/* a bunch of ELF parsing functionality depends on processing symbols, * so do the first pass and find the symbol table */ scn = NULL; while ((scn = elf_nextscn(elf, scn)) != NULL) { sh = elf_sec_hdr(obj, scn); if (!sh) return -LIBBPF_ERRNO__FORMAT;
if (sh->sh_type == SHT_SYMTAB) { if (obj->efile.symbols) { pr_warn("elf: multiple symbol tables in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; }
data = elf_sec_data(obj, scn); if (!data) return -LIBBPF_ERRNO__FORMAT;
idx = elf_ndxscn(scn);
obj->efile.symbols = data; obj->efile.symbols_shndx = idx; obj->efile.strtabidx = sh->sh_link; } }
if (!obj->efile.symbols) { pr_warn("elf: couldn't find symbol table in %s, stripped object file?\n", obj->path); return -ENOENT; }
scn = NULL; while ((scn = elf_nextscn(elf, scn)) != NULL) { idx = elf_ndxscn(scn); sec_desc = &obj->efile.secs[idx];
sh = elf_sec_hdr(obj, scn); if (!sh) return -LIBBPF_ERRNO__FORMAT;
name = elf_sec_str(obj, sh->sh_name); if (!name) return -LIBBPF_ERRNO__FORMAT;
if (ignore_elf_section(sh, name)) continue;
data = elf_sec_data(obj, scn); if (!data) return -LIBBPF_ERRNO__FORMAT;
pr_debug("elf: section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", idx, name, (unsigned long)data->d_size, (int)sh->sh_link, (unsigned long)sh->sh_flags, (int)sh->sh_type);
if (strcmp(name, "license") == 0) { err = bpf_object__init_license(obj, data->d_buf, data->d_size); if (err) return err; } else if (strcmp(name, "version") == 0) { err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); if (err) return err; } else if (strcmp(name, "maps") == 0) { pr_warn("elf: legacy map definitions in 'maps' section are not supported by libbpf v1.0+\n"); return -ENOTSUP; } else if (strcmp(name, MAPS_ELF_SEC) == 0) { obj->efile.btf_maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { if (sh->sh_type != SHT_PROGBITS) return -LIBBPF_ERRNO__FORMAT; btf_data = data; } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { if (sh->sh_type != SHT_PROGBITS) return -LIBBPF_ERRNO__FORMAT; btf_ext_data = data; } else if (sh->sh_type == SHT_SYMTAB) { /* already processed during the first pass above */ } else if (sh->sh_type == SHT_PROGBITS && data->d_size > 0) { if (sh->sh_flags & SHF_EXECINSTR) { if (strcmp(name, ".text") == 0) obj->efile.text_shndx = idx; err = bpf_object__add_programs(obj, data, name, idx); if (err) return err; } else if (strcmp(name, DATA_SEC) == 0 || str_has_pfx(name, DATA_SEC ".")) { sec_desc->sec_type = SEC_DATA; sec_desc->shdr = sh; sec_desc->data = data; } else if (strcmp(name, RODATA_SEC) == 0 || str_has_pfx(name, RODATA_SEC ".")) { sec_desc->sec_type = SEC_RODATA; sec_desc->shdr = sh; sec_desc->data = data; } else if (strcmp(name, STRUCT_OPS_SEC) == 0 || strcmp(name, STRUCT_OPS_LINK_SEC) == 0 || strcmp(name, "?" STRUCT_OPS_SEC) == 0 || strcmp(name, "?" STRUCT_OPS_LINK_SEC) == 0) { sec_desc->sec_type = SEC_ST_OPS; sec_desc->shdr = sh; sec_desc->data = data; obj->efile.has_st_ops = true; } else if (strcmp(name, ARENA_SEC) == 0) { obj->efile.arena_data = data; obj->efile.arena_data_shndx = idx; } else if (strcmp(name, JUMPTABLES_SEC) == 0) { obj->jumptables_data = malloc(data->d_size); if (!obj->jumptables_data) return -ENOMEM; memcpy(obj->jumptables_data, data->d_buf, data->d_size); obj->jumptables_data_sz = data->d_size; obj->efile.jumptables_data_shndx = idx; } else { pr_info("elf: skipping unrecognized data section(%d) %s\n", idx, name); } } else if (sh->sh_type == SHT_REL) { int targ_sec_idx = sh->sh_info; /* points to other section */
if (sh->sh_entsize != sizeof(Elf64_Rel) || targ_sec_idx >= obj->efile.sec_cnt) return -LIBBPF_ERRNO__FORMAT;
/* Only do relo for section with exec instructions */ if (!section_have_execinstr(obj, targ_sec_idx) && strcmp(name, ".rel" STRUCT_OPS_SEC) && strcmp(name, ".rel" STRUCT_OPS_LINK_SEC) && strcmp(name, ".rel?" STRUCT_OPS_SEC) && strcmp(name, ".rel?" STRUCT_OPS_LINK_SEC) && strcmp(name, ".rel" MAPS_ELF_SEC)) { pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n", idx, name, targ_sec_idx, elf_sec_name(obj, elf_sec_by_idx(obj, targ_sec_idx)) ?: "<?>"); continue; }
sec_desc->sec_type = SEC_RELO; sec_desc->shdr = sh; sec_desc->data = data; } else if (sh->sh_type == SHT_NOBITS && (strcmp(name, BSS_SEC) == 0 || str_has_pfx(name, BSS_SEC "."))) { sec_desc->sec_type = SEC_BSS; sec_desc->shdr = sh; sec_desc->data = data; } else { pr_info("elf: skipping section(%d) %s (size %zu)\n", idx, name, (size_t)sh->sh_size); } }
if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) { pr_warn("elf: symbol strings section missing or invalid in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; }
/* change BPF program insns to native endianness for introspection */ if (!is_native_endianness(obj)) bpf_object_bswap_progs(obj);
/* sort BPF programs by section name and in-section instruction offset * for faster search */ if (obj->nr_programs) qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
return bpf_object__init_btf(obj, btf_data, btf_ext_data);}
static bool sym_is_extern(const Elf64_Sym *sym){ int bind = ELF64_ST_BIND(sym->st_info); /* externs are symbols w/ type=NOTYPE, bind=GLOBAL|WEAK, section=UND */ return sym->st_shndx == SHN_UNDEF && (bind == STB_GLOBAL || bind == STB_WEAK) && ELF64_ST_TYPE(sym->st_info) == STT_NOTYPE;}
static bool sym_is_subprog(const Elf64_Sym *sym, int text_shndx){ int bind = ELF64_ST_BIND(sym->st_info); int type = ELF64_ST_TYPE(sym->st_info);
/* in .text section */ if (sym->st_shndx != text_shndx) return false;
/* local function */ if (bind == STB_LOCAL && type == STT_SECTION) return true;
/* global function */ return (bind == STB_GLOBAL || bind == STB_WEAK) && type == STT_FUNC;}
static int find_extern_btf_id(const struct btf *btf, const char *ext_name){ const struct btf_type *t; const char *tname; int i, n;
if (!btf) return -ESRCH;
n = btf__type_cnt(btf); for (i = 1; i < n; i++) { t = btf__type_by_id(btf, i);
if (!btf_is_var(t) && !btf_is_func(t)) continue;
tname = btf__name_by_offset(btf, t->name_off); if (strcmp(tname, ext_name)) continue;
if (btf_is_var(t) && btf_var(t)->linkage != BTF_VAR_GLOBAL_EXTERN) return -EINVAL;
if (btf_is_func(t) && btf_func_linkage(t) != BTF_FUNC_EXTERN) return -EINVAL;
return i; }
return -ENOENT;}
static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) { const struct btf_var_secinfo *vs; const struct btf_type *t; int i, j, n;
if (!btf) return -ESRCH;
n = btf__type_cnt(btf); for (i = 1; i < n; i++) { t = btf__type_by_id(btf, i);
if (!btf_is_datasec(t)) continue;
vs = btf_var_secinfos(t); for (j = 0; j < btf_vlen(t); j++, vs++) { if (vs->type == ext_btf_id) return i; } }
return -ENOENT;}
static enum kcfg_type find_kcfg_type(const struct btf *btf, int id, bool *is_signed){ const struct btf_type *t; const char *name;
t = skip_mods_and_typedefs(btf, id, NULL); name = btf__name_by_offset(btf, t->name_off);
if (is_signed) *is_signed = false; switch (btf_kind(t)) { case BTF_KIND_INT: { int enc = btf_int_encoding(t);
if (enc & BTF_INT_BOOL) return t->size == 1 ? KCFG_BOOL : KCFG_UNKNOWN; if (is_signed) *is_signed = enc & BTF_INT_SIGNED; if (t->size == 1) return KCFG_CHAR; if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1))) return KCFG_UNKNOWN; return KCFG_INT; } case BTF_KIND_ENUM: if (t->size != 4) return KCFG_UNKNOWN; if (strcmp(name, "libbpf_tristate")) return KCFG_UNKNOWN; return KCFG_TRISTATE; case BTF_KIND_ENUM64: if (strcmp(name, "libbpf_tristate")) return KCFG_UNKNOWN; return KCFG_TRISTATE; case BTF_KIND_ARRAY: if (btf_array(t)->nelems == 0) return KCFG_UNKNOWN; if (find_kcfg_type(btf, btf_array(t)->type, NULL) != KCFG_CHAR) return KCFG_UNKNOWN; return KCFG_CHAR_ARR; default: return KCFG_UNKNOWN; }}
static int cmp_externs(const void *_a, const void *_b){ const struct extern_desc *a = _a; const struct extern_desc *b = _b;
if (a->type != b->type) return a->type < b->type ? -1 : 1;
if (a->type == EXT_KCFG) { /* descending order by alignment requirements */ if (a->kcfg.align != b->kcfg.align) return a->kcfg.align > b->kcfg.align ? -1 : 1; /* ascending order by size, within same alignment class */ if (a->kcfg.sz != b->kcfg.sz) return a->kcfg.sz < b->kcfg.sz ? -1 : 1; }
/* resolve ties by name */ return strcmp(a->name, b->name);}
static int find_int_btf_id(const struct btf *btf){ const struct btf_type *t; int i, n;
n = btf__type_cnt(btf); for (i = 1; i < n; i++) { t = btf__type_by_id(btf, i);
if (btf_is_int(t) && btf_int_bits(t) == 32) return i; }
return 0;}
static int add_dummy_ksym_var(struct btf *btf){ int i, int_btf_id, sec_btf_id, dummy_var_btf_id; const struct btf_var_secinfo *vs; const struct btf_type *sec;
if (!btf) return 0;
sec_btf_id = btf__find_by_name_kind(btf, KSYMS_SEC, BTF_KIND_DATASEC); if (sec_btf_id < 0) return 0;
sec = btf__type_by_id(btf, sec_btf_id); vs = btf_var_secinfos(sec); for (i = 0; i < btf_vlen(sec); i++, vs++) { const struct btf_type *vt;
vt = btf__type_by_id(btf, vs->type); if (btf_is_func(vt)) break; }
/* No func in ksyms sec. No need to add dummy var. */ if (i == btf_vlen(sec)) return 0;
int_btf_id = find_int_btf_id(btf); dummy_var_btf_id = btf__add_var(btf, "dummy_ksym", BTF_VAR_GLOBAL_ALLOCATED, int_btf_id); if (dummy_var_btf_id < 0) pr_warn("cannot create a dummy_ksym var\n");
return dummy_var_btf_id;}
static int bpf_object__collect_externs(struct bpf_object *obj){ struct btf_type *sec, *kcfg_sec = NULL, *ksym_sec = NULL; const struct btf_type *t; struct extern_desc *ext; int i, n, off, dummy_var_btf_id; const char *ext_name, *sec_name; size_t ext_essent_len; Elf_Scn *scn; Elf64_Shdr *sh;
if (!obj->efile.symbols) return 0;
scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx); sh = elf_sec_hdr(obj, scn); if (!sh || sh->sh_entsize != sizeof(Elf64_Sym)) return -LIBBPF_ERRNO__FORMAT;
dummy_var_btf_id = add_dummy_ksym_var(obj->btf); if (dummy_var_btf_id < 0) return dummy_var_btf_id;
n = sh->sh_size / sh->sh_entsize; pr_debug("looking for externs among %d symbols...\n", n);
for (i = 0; i < n; i++) { Elf64_Sym *sym = elf_sym_by_idx(obj, i);
if (!sym) return -LIBBPF_ERRNO__FORMAT; if (!sym_is_extern(sym)) continue; ext_name = elf_sym_str(obj, sym->st_name); if (str_is_empty(ext_name)) continue;
ext = obj->externs; ext = libbpf_reallocarray(ext, obj->nr_extern + 1, sizeof(*ext)); if (!ext) return -ENOMEM; obj->externs = ext; ext = &ext[obj->nr_extern]; memset(ext, 0, sizeof(*ext)); obj->nr_extern++;
ext->btf_id = find_extern_btf_id(obj->btf, ext_name); if (ext->btf_id <= 0) { pr_warn("failed to find BTF for extern '%s': %d\n", ext_name, ext->btf_id); return ext->btf_id; } t = btf__type_by_id(obj->btf, ext->btf_id); ext->name = strdup(btf__name_by_offset(obj->btf, t->name_off)); if (!ext->name) return -ENOMEM; ext->sym_idx = i; ext->is_weak = ELF64_ST_BIND(sym->st_info) == STB_WEAK;
ext_essent_len = bpf_core_essential_name_len(ext->name); ext->essent_name = NULL; if (ext_essent_len != strlen(ext->name)) { ext->essent_name = strndup(ext->name, ext_essent_len); if (!ext->essent_name) return -ENOMEM; }
ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id); if (ext->sec_btf_id <= 0) { pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n", ext_name, ext->btf_id, ext->sec_btf_id); return ext->sec_btf_id; } sec = (void *)btf__type_by_id(obj->btf, ext->sec_btf_id); sec_name = btf__name_by_offset(obj->btf, sec->name_off);
if (strcmp(sec_name, KCONFIG_SEC) == 0) { if (btf_is_func(t)) { pr_warn("extern function %s is unsupported under %s section\n", ext->name, KCONFIG_SEC); return -ENOTSUP; } kcfg_sec = sec; ext->type = EXT_KCFG; ext->kcfg.sz = btf__resolve_size(obj->btf, t->type); if (ext->kcfg.sz <= 0) { pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n", ext_name, ext->kcfg.sz); return ext->kcfg.sz; } ext->kcfg.align = btf__align_of(obj->btf, t->type); if (ext->kcfg.align <= 0) { pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n", ext_name, ext->kcfg.align); return -EINVAL; } ext->kcfg.type = find_kcfg_type(obj->btf, t->type, &ext->kcfg.is_signed); if (ext->kcfg.type == KCFG_UNKNOWN) { pr_warn("extern (kcfg) '%s': type is unsupported\n", ext_name); return -ENOTSUP; } } else if (strcmp(sec_name, KSYMS_SEC) == 0) { ksym_sec = sec; ext->type = EXT_KSYM; skip_mods_and_typedefs(obj->btf, t->type, &ext->ksym.type_id); } else { pr_warn("unrecognized extern section '%s'\n", sec_name); return -ENOTSUP; } } pr_debug("collected %d externs total\n", obj->nr_extern);
if (!obj->nr_extern) return 0;
/* sort externs by type, for kcfg ones also by (align, size, name) */ qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs);
/* for .ksyms section, we need to turn all externs into allocated * variables in BTF to pass kernel verification; we do this by * pretending that each extern is a 8-byte variable */ if (ksym_sec) { /* find existing 4-byte integer type in BTF to use for fake * extern variables in DATASEC */ int int_btf_id = find_int_btf_id(obj->btf); /* For extern function, a dummy_var added earlier * will be used to replace the vs->type and * its name string will be used to refill * the missing param's name. */ const struct btf_type *dummy_var;
dummy_var = btf__type_by_id(obj->btf, dummy_var_btf_id); for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; if (ext->type != EXT_KSYM) continue; pr_debug("extern (ksym) #%d: symbol %d, name %s\n", i, ext->sym_idx, ext->name); }
sec = ksym_sec; n = btf_vlen(sec); for (i = 0, off = 0; i < n; i++, off += sizeof(int)) { struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; struct btf_type *vt;
vt = (void *)btf__type_by_id(obj->btf, vs->type); ext_name = btf__name_by_offset(obj->btf, vt->name_off); ext = find_extern_by_name(obj, ext_name); if (!ext) { pr_warn("failed to find extern definition for BTF %s '%s'\n", btf_kind_str(vt), ext_name); return -ESRCH; } if (btf_is_func(vt)) { const struct btf_type *func_proto; struct btf_param *param; int j;
func_proto = btf__type_by_id(obj->btf, vt->type); param = btf_params(func_proto); /* Reuse the dummy_var string if the * func proto does not have param name. */ for (j = 0; j < btf_vlen(func_proto); j++) if (param[j].type && !param[j].name_off) param[j].name_off = dummy_var->name_off; vs->type = dummy_var_btf_id; vt->info &= ~0xffff; vt->info |= BTF_FUNC_GLOBAL; } else { btf_var(vt)->linkage = BTF_VAR_GLOBAL_ALLOCATED; vt->type = int_btf_id; } vs->offset = off; vs->size = sizeof(int); } sec->size = off; }
if (kcfg_sec) { sec = kcfg_sec; /* for kcfg externs calculate their offsets within a .kconfig map */ off = 0; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; if (ext->type != EXT_KCFG) continue;
ext->kcfg.data_off = roundup(off, ext->kcfg.align); off = ext->kcfg.data_off + ext->kcfg.sz; pr_debug("extern (kcfg) #%d: symbol %d, off %u, name %s\n", i, ext->sym_idx, ext->kcfg.data_off, ext->name); } sec->size = off; n = btf_vlen(sec); for (i = 0; i < n; i++) { struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
t = btf__type_by_id(obj->btf, vs->type); ext_name = btf__name_by_offset(obj->btf, t->name_off); ext = find_extern_by_name(obj, ext_name); if (!ext) { pr_warn("failed to find extern definition for BTF var '%s'\n", ext_name); return -ESRCH; } btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; vs->offset = ext->kcfg.data_off; } } return 0;}
static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog){ return prog->sec_idx == obj->efile.text_shndx;}
struct bpf_program *bpf_object__find_program_by_name(const struct bpf_object *obj, const char *name){ struct bpf_program *prog;
bpf_object__for_each_program(prog, obj) { if (prog_is_subprog(obj, prog)) continue; if (!strcmp(prog->name, name)) return prog; } return errno = ENOENT, NULL;}
static bool bpf_object__shndx_is_data(const struct bpf_object *obj, int shndx){ switch (obj->efile.secs[shndx].sec_type) { case SEC_BSS: case SEC_DATA: case SEC_RODATA: return true; default: return false; }}
static bool bpf_object__shndx_is_maps(const struct bpf_object *obj, int shndx){ return shndx == obj->efile.btf_maps_shndx;}
static enum libbpf_map_typebpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx){ if (shndx == obj->efile.symbols_shndx) return LIBBPF_MAP_KCONFIG;
switch (obj->efile.secs[shndx].sec_type) { case SEC_BSS: return LIBBPF_MAP_BSS; case SEC_DATA: return LIBBPF_MAP_DATA; case SEC_RODATA: return LIBBPF_MAP_RODATA; default: return LIBBPF_MAP_UNSPEC; }}
static int bpf_prog_compute_hash(struct bpf_program *prog){ struct bpf_insn *purged; int i, err = 0;
purged = calloc(prog->insns_cnt, BPF_INSN_SZ); if (!purged) return -ENOMEM;
/* If relocations have been done, the map_fd needs to be * discarded for the digest calculation. */ for (i = 0; i < prog->insns_cnt; i++) { purged[i] = prog->insns[i]; if (purged[i].code == (BPF_LD | BPF_IMM | BPF_DW) && (purged[i].src_reg == BPF_PSEUDO_MAP_FD || purged[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { purged[i].imm = 0; i++; if (i >= prog->insns_cnt || prog->insns[i].code != 0 || prog->insns[i].dst_reg != 0 || prog->insns[i].src_reg != 0 || prog->insns[i].off != 0) { err = -EINVAL; goto out; } purged[i] = prog->insns[i]; purged[i].imm = 0; } } libbpf_sha256(purged, prog->insns_cnt * sizeof(struct bpf_insn), prog->hash);out: free(purged); return err;}
static int bpf_program__record_reloc(struct bpf_program *prog, struct reloc_desc *reloc_desc, __u32 insn_idx, const char *sym_name, const Elf64_Sym *sym, const Elf64_Rel *rel){ struct bpf_insn *insn = &prog->insns[insn_idx]; size_t map_idx, nr_maps = prog->obj->nr_maps; struct bpf_object *obj = prog->obj; __u32 shdr_idx = sym->st_shndx; enum libbpf_map_type type; const char *sym_sec_name; struct bpf_map *map;
if (!is_call_insn(insn) && !is_ldimm64_insn(insn)) { pr_warn("prog '%s': invalid relo against '%s' for insns[%d].code 0x%x\n", prog->name, sym_name, insn_idx, insn->code); return -LIBBPF_ERRNO__RELOC; }
if (sym_is_extern(sym)) { int sym_idx = ELF64_R_SYM(rel->r_info); int i, n = obj->nr_extern; struct extern_desc *ext;
for (i = 0; i < n; i++) { ext = &obj->externs[i]; if (ext->sym_idx == sym_idx) break; } if (i >= n) { pr_warn("prog '%s': extern relo failed to find extern for '%s' (%d)\n", prog->name, sym_name, sym_idx); return -LIBBPF_ERRNO__RELOC; } pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n", prog->name, i, ext->name, ext->sym_idx, insn_idx); if (insn->code == (BPF_JMP | BPF_CALL)) reloc_desc->type = RELO_EXTERN_CALL; else reloc_desc->type = RELO_EXTERN_LD64; reloc_desc->insn_idx = insn_idx; reloc_desc->ext_idx = i; return 0; }
/* sub-program call relocation */ if (is_call_insn(insn)) { if (insn->src_reg != BPF_PSEUDO_CALL) { pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name); return -LIBBPF_ERRNO__RELOC; } /* text_shndx can be 0, if no default "main" program exists */ if (!shdr_idx || shdr_idx != obj->efile.text_shndx) { sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx)); pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n", prog->name, sym_name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } if (sym->st_value % BPF_INSN_SZ) { pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n", prog->name, sym_name, (size_t)sym->st_value); return -LIBBPF_ERRNO__RELOC; } reloc_desc->type = RELO_CALL; reloc_desc->insn_idx = insn_idx; reloc_desc->sym_off = sym->st_value; return 0; }
if (!shdr_idx || shdr_idx >= SHN_LORESERVE) { pr_warn("prog '%s': invalid relo against '%s' in special section 0x%x; forgot to initialize global var?..\n", prog->name, sym_name, shdr_idx); return -LIBBPF_ERRNO__RELOC; }
/* loading subprog addresses */ if (sym_is_subprog(sym, obj->efile.text_shndx)) { /* global_func: sym->st_value = offset in the section, insn->imm = 0. * local_func: sym->st_value = 0, insn->imm = offset in the section. */ if ((sym->st_value % BPF_INSN_SZ) || (insn->imm % BPF_INSN_SZ)) { pr_warn("prog '%s': bad subprog addr relo against '%s' at offset %zu+%d\n", prog->name, sym_name, (size_t)sym->st_value, insn->imm); return -LIBBPF_ERRNO__RELOC; }
reloc_desc->type = RELO_SUBPROG_ADDR; reloc_desc->insn_idx = insn_idx; reloc_desc->sym_off = sym->st_value; return 0; }
type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx); sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
/* arena data relocation */ if (shdr_idx == obj->efile.arena_data_shndx) { if (obj->arena_map_idx < 0) { pr_warn("prog '%s': bad arena data relocation at insn %u, no arena maps defined\n", prog->name, insn_idx); return -LIBBPF_ERRNO__RELOC; } reloc_desc->type = RELO_DATA; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = obj->arena_map_idx; reloc_desc->sym_off = sym->st_value;
map = &obj->maps[obj->arena_map_idx]; pr_debug("prog '%s': found arena map %d (%s, sec %d, off %zu) for insn %u\n", prog->name, obj->arena_map_idx, map->name, map->sec_idx, map->sec_offset, insn_idx); return 0; }
/* jump table data relocation */ if (shdr_idx == obj->efile.jumptables_data_shndx) { reloc_desc->type = RELO_INSN_ARRAY; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = -1; reloc_desc->sym_off = sym->st_value; reloc_desc->sym_size = sym->st_size; return 0; }
/* generic map reference relocation */ if (type == LIBBPF_MAP_UNSPEC) { if (!bpf_object__shndx_is_maps(obj, shdr_idx)) { pr_warn("prog '%s': bad map relo against '%s' in section '%s'\n", prog->name, sym_name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } for (map_idx = 0; map_idx < nr_maps; map_idx++) { map = &obj->maps[map_idx]; if (map->libbpf_type != type || map->sec_idx != sym->st_shndx || map->sec_offset != sym->st_value) continue; pr_debug("prog '%s': found map %zd (%s, sec %d, off %zu) for insn #%u\n", prog->name, map_idx, map->name, map->sec_idx, map->sec_offset, insn_idx); break; } if (map_idx >= nr_maps) { pr_warn("prog '%s': map relo failed to find map for section '%s', off %zu\n", prog->name, sym_sec_name, (size_t)sym->st_value); return -LIBBPF_ERRNO__RELOC; } reloc_desc->type = RELO_LD64; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = map_idx; reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */ return 0; }
/* global data map relocation */ if (!bpf_object__shndx_is_data(obj, shdr_idx)) { pr_warn("prog '%s': bad data relo against section '%s'\n", prog->name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } for (map_idx = 0; map_idx < nr_maps; map_idx++) { map = &obj->maps[map_idx]; if (map->libbpf_type != type || map->sec_idx != sym->st_shndx) continue; pr_debug("prog '%s': found data map %zd (%s, sec %d, off %zu) for insn %u\n", prog->name, map_idx, map->name, map->sec_idx, map->sec_offset, insn_idx); break; } if (map_idx >= nr_maps) { pr_warn("prog '%s': data relo failed to find map for section '%s'\n", prog->name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; }
reloc_desc->type = RELO_DATA; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = map_idx; reloc_desc->sym_off = sym->st_value; return 0;}
static bool prog_contains_insn(const struct bpf_program *prog, size_t insn_idx){ return insn_idx >= prog->sec_insn_off && insn_idx < prog->sec_insn_off + prog->sec_insn_cnt;}
static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj, size_t sec_idx, size_t insn_idx){ int l = 0, r = obj->nr_programs - 1, m; struct bpf_program *prog;
if (!obj->nr_programs) return NULL;
while (l < r) { m = l + (r - l + 1) / 2; prog = &obj->programs[m];
if (prog->sec_idx < sec_idx || (prog->sec_idx == sec_idx && prog->sec_insn_off <= insn_idx)) l = m; else r = m - 1; } /* matching program could be at index l, but it still might be the * wrong one, so we need to double check conditions for the last time */ prog = &obj->programs[l]; if (prog->sec_idx == sec_idx && prog_contains_insn(prog, insn_idx)) return prog; return NULL;}
static intbpf_object__collect_prog_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data){ const char *relo_sec_name, *sec_name; size_t sec_idx = shdr->sh_info, sym_idx; struct bpf_program *prog; struct reloc_desc *relos; int err, i, nrels; const char *sym_name; __u32 insn_idx; Elf_Scn *scn; Elf_Data *scn_data; Elf64_Sym *sym; Elf64_Rel *rel;
if (sec_idx >= obj->efile.sec_cnt) return -EINVAL;
scn = elf_sec_by_idx(obj, sec_idx); scn_data = elf_sec_data(obj, scn); if (!scn_data) return -LIBBPF_ERRNO__FORMAT;
relo_sec_name = elf_sec_str(obj, shdr->sh_name); sec_name = elf_sec_name(obj, scn); if (!relo_sec_name || !sec_name) return -EINVAL;
pr_debug("sec '%s': collecting relocation for section(%zu) '%s'\n", relo_sec_name, sec_idx, sec_name); nrels = shdr->sh_size / shdr->sh_entsize;
for (i = 0; i < nrels; i++) { rel = elf_rel_by_idx(data, i); if (!rel) { pr_warn("sec '%s': failed to get relo #%d\n", relo_sec_name, i); return -LIBBPF_ERRNO__FORMAT; }
sym_idx = ELF64_R_SYM(rel->r_info); sym = elf_sym_by_idx(obj, sym_idx); if (!sym) { pr_warn("sec '%s': symbol #%zu not found for relo #%d\n", relo_sec_name, sym_idx, i); return -LIBBPF_ERRNO__FORMAT; }
if (sym->st_shndx >= obj->efile.sec_cnt) { pr_warn("sec '%s': corrupted symbol #%zu pointing to invalid section #%zu for relo #%d\n", relo_sec_name, sym_idx, (size_t)sym->st_shndx, i); return -LIBBPF_ERRNO__FORMAT; }
if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) { pr_warn("sec '%s': invalid offset 0x%zx for relo #%d\n", relo_sec_name, (size_t)rel->r_offset, i); return -LIBBPF_ERRNO__FORMAT; }
insn_idx = rel->r_offset / BPF_INSN_SZ; /* relocations against static functions are recorded as * relocations against the section that contains a function; * in such case, symbol will be STT_SECTION and sym.st_name * will point to empty string (0), so fetch section name * instead */ if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION && sym->st_name == 0) sym_name = elf_sec_name(obj, elf_sec_by_idx(obj, sym->st_shndx)); else sym_name = elf_sym_str(obj, sym->st_name); sym_name = sym_name ?: "<?";
pr_debug("sec '%s': relo #%d: insn #%u against '%s'\n", relo_sec_name, i, insn_idx, sym_name);
prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx); if (!prog) { pr_debug("sec '%s': relo #%d: couldn't find program in section '%s' for insn #%u, probably overridden weak function, skipping...\n", relo_sec_name, i, sec_name, insn_idx); continue; }
relos = libbpf_reallocarray(prog->reloc_desc, prog->nr_reloc + 1, sizeof(*relos)); if (!relos) return -ENOMEM; prog->reloc_desc = relos;
/* adjust insn_idx to local BPF program frame of reference */ insn_idx -= prog->sec_insn_off; err = bpf_program__record_reloc(prog, &relos[prog->nr_reloc], insn_idx, sym_name, sym, rel); if (err) return err;
prog->nr_reloc++; } return 0;}
static int map_fill_btf_type_info(struct bpf_object *obj, struct bpf_map *map){ int id;
if (!obj->btf) return -ENOENT;
/* if it's BTF-defined map, we don't need to search for type IDs. * For struct_ops map, it does not need btf_key_type_id and * btf_value_type_id. */ if (map->sec_idx == obj->efile.btf_maps_shndx || bpf_map__is_struct_ops(map)) return 0;
/* * LLVM annotates global data differently in BTF, that is, * only as '.data', '.bss' or '.rodata'. */ if (!bpf_map__is_internal(map)) return -ENOENT;
id = btf__find_by_name(obj->btf, map->real_name); if (id < 0) return id;
map->btf_key_type_id = 0; map->btf_value_type_id = id; return 0;}
static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info){ char file[PATH_MAX], buff[4096]; FILE *fp; __u32 val; int err;
snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd); memset(info, 0, sizeof(*info));
fp = fopen(file, "re"); if (!fp) { err = -errno; pr_warn("failed to open %s: %s. No procfs support?\n", file, errstr(err)); return err; }
while (fgets(buff, sizeof(buff), fp)) { if (sscanf(buff, "map_type:\t%u", &val) == 1) info->type = val; else if (sscanf(buff, "key_size:\t%u", &val) == 1) info->key_size = val; else if (sscanf(buff, "value_size:\t%u", &val) == 1) info->value_size = val; else if (sscanf(buff, "max_entries:\t%u", &val) == 1) info->max_entries = val; else if (sscanf(buff, "map_flags:\t%i", &val) == 1) info->map_flags = val; }
fclose(fp);
return 0;}
static bool map_is_created(const struct bpf_map *map){ return map->obj->state >= OBJ_PREPARED || map->reused;}
bool bpf_map__autocreate(const struct bpf_map *map){ return map->autocreate;}
int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate){ if (map_is_created(map)) return libbpf_err(-EBUSY);
map->autocreate = autocreate; return 0;}
int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach){ if (!bpf_map__is_struct_ops(map)) return libbpf_err(-EINVAL);
map->autoattach = autoattach; return 0;}
bool bpf_map__autoattach(const struct bpf_map *map){ return map->autoattach;}
int bpf_map__reuse_fd(struct bpf_map *map, int fd){ struct bpf_map_info info; __u32 len = sizeof(info), name_len; int new_fd, err; char *new_name;
memset(&info, 0, len); err = bpf_map_get_info_by_fd(fd, &info, &len); if (err && errno == EINVAL) err = bpf_get_map_info_from_fdinfo(fd, &info); if (err) return libbpf_err(err);
name_len = strlen(info.name); if (name_len == BPF_OBJ_NAME_LEN - 1 && strncmp(map->name, info.name, name_len) == 0) new_name = strdup(map->name); else new_name = strdup(info.name);
if (!new_name) return libbpf_err(-errno);
/* * Like dup(), but make sure new FD is >= 3 and has O_CLOEXEC set. * This is similar to what we do in ensure_good_fd(), but without * closing original FD. */ new_fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); if (new_fd < 0) { err = -errno; goto err_free_new_name; }
err = reuse_fd(map->fd, new_fd); if (err) goto err_free_new_name;
free(map->name);
map->name = new_name; map->def.type = info.type; map->def.key_size = info.key_size; map->def.value_size = info.value_size; map->def.max_entries = info.max_entries; map->def.map_flags = info.map_flags; map->btf_key_type_id = info.btf_key_type_id; map->btf_value_type_id = info.btf_value_type_id; map->reused = true; map->map_extra = info.map_extra;
return 0;
err_free_new_name: free(new_name); return libbpf_err(err);}
__u32 bpf_map__max_entries(const struct bpf_map *map){ return map->def.max_entries;}
struct bpf_map *bpf_map__inner_map(struct bpf_map *map){ if (!bpf_map_type__is_map_in_map(map->def.type)) return errno = EINVAL, NULL;
return map->inner_map;}
int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries){ if (map_is_created(map)) return libbpf_err(-EBUSY);
map->def.max_entries = max_entries;
/* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ if (map_is_ringbuf(map)) map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries);
return 0;}
static int bpf_object_prepare_token(struct bpf_object *obj){ const char *bpffs_path; int bpffs_fd = -1, token_fd, err; bool mandatory; enum libbpf_print_level level;
/* token is explicitly prevented */ if (obj->token_path && obj->token_path[0] == '\0') { pr_debug("object '%s': token is prevented, skipping...\n", obj->name); return 0; }
mandatory = obj->token_path != NULL; level = mandatory ? LIBBPF_WARN : LIBBPF_DEBUG;
bpffs_path = obj->token_path ?: BPF_FS_DEFAULT_PATH; bpffs_fd = open(bpffs_path, O_DIRECTORY, O_RDWR); if (bpffs_fd < 0) { err = -errno; __pr(level, "object '%s': failed (%s) to open BPF FS mount at '%s'%s\n", obj->name, errstr(err), bpffs_path, mandatory ? "" : ", skipping optional step..."); return mandatory ? err : 0; }
token_fd = bpf_token_create(bpffs_fd, 0); close(bpffs_fd); if (token_fd < 0) { if (!mandatory && token_fd == -ENOENT) { pr_debug("object '%s': BPF FS at '%s' doesn't have BPF token delegation set up, skipping...\n", obj->name, bpffs_path); return 0; } __pr(level, "object '%s': failed (%d) to create BPF token from '%s'%s\n", obj->name, token_fd, bpffs_path, mandatory ? "" : ", skipping optional step..."); return mandatory ? token_fd : 0; }
obj->feat_cache = calloc(1, sizeof(*obj->feat_cache)); if (!obj->feat_cache) { close(token_fd); return -ENOMEM; }
obj->token_fd = token_fd; obj->feat_cache->token_fd = token_fd;
return 0;}
static intbpf_object__probe_loading(struct bpf_object *obj){ struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }; int ret, insn_cnt = ARRAY_SIZE(insns); LIBBPF_OPTS(bpf_prog_load_opts, opts, .token_fd = obj->token_fd, .prog_flags = obj->token_fd ? BPF_F_TOKEN_FD : 0, );
if (obj->gen_loader) return 0;
ret = bump_rlimit_memlock(); if (ret) pr_warn("Failed to bump RLIMIT_MEMLOCK (err = %s), you might need to do it explicitly!\n", errstr(ret));
/* make sure basic loading works */ ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, &opts); if (ret < 0) ret = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, &opts); if (ret < 0) { ret = errno; pr_warn("Error in %s(): %s. Couldn't load trivial BPF program. Make sure your kernel supports BPF (CONFIG_BPF_SYSCALL=y) and/or that RLIMIT_MEMLOCK is set to big enough value.\n", __func__, errstr(ret)); return -ret; } close(ret);
return 0;}
bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id){ if (obj->gen_loader) /* To generate loader program assume the latest kernel * to avoid doing extra prog_load, map_create syscalls. */ return true;
if (obj->feat_cache) return feat_supported(obj->feat_cache, feat_id);
return feat_supported(NULL, feat_id);}
/* Used in testing to simulate missing features. */void bpf_object_set_feat_cache(struct bpf_object *obj, struct kern_feature_cache *cache){ if (obj->feat_cache) free(obj->feat_cache); obj->feat_cache = cache;}
static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd){ struct bpf_map_info map_info; __u32 map_info_len = sizeof(map_info); int err;
memset(&map_info, 0, map_info_len); err = bpf_map_get_info_by_fd(map_fd, &map_info, &map_info_len); if (err && errno == EINVAL) err = bpf_get_map_info_from_fdinfo(map_fd, &map_info); if (err) { pr_warn("failed to get map info for map FD %d: %s\n", map_fd, errstr(err)); return false; }
/* * bpf_get_map_info_by_fd() for DEVMAP will always return flags with * BPF_F_RDONLY_PROG set, but it generally is not set at map creation time. * Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from * bpf_get_map_info_by_fd() when checking for compatibility with an * existing DEVMAP. */ if (map->def.type == BPF_MAP_TYPE_DEVMAP || map->def.type == BPF_MAP_TYPE_DEVMAP_HASH) map_info.map_flags &= ~BPF_F_RDONLY_PROG;
return (map_info.type == map->def.type && map_info.key_size == map->def.key_size && map_info.value_size == map->def.value_size && map_info.max_entries == map->def.max_entries && map_info.map_flags == map->def.map_flags && map_info.map_extra == map->map_extra);}
static intbpf_object__reuse_map(struct bpf_map *map){ int err, pin_fd;
pin_fd = bpf_obj_get(map->pin_path); if (pin_fd < 0) { err = -errno; if (err == -ENOENT) { pr_debug("found no pinned map to reuse at '%s'\n", map->pin_path); return 0; }
pr_warn("couldn't retrieve pinned map '%s': %s\n", map->pin_path, errstr(err)); return err; }
if (!map_is_reuse_compat(map, pin_fd)) { pr_warn("couldn't reuse pinned map at '%s': parameter mismatch\n", map->pin_path); close(pin_fd); return -EINVAL; }
err = bpf_map__reuse_fd(map, pin_fd); close(pin_fd); if (err) return err;
map->pinned = true; pr_debug("reused pinned map at '%s'\n", map->pin_path);
return 0;}
static intbpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map){ enum libbpf_map_type map_type = map->libbpf_type; int err, zero = 0; size_t mmap_sz;
if (obj->gen_loader) { bpf_gen__map_update_elem(obj->gen_loader, map - obj->maps, map->mmaped, map->def.value_size); if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) bpf_gen__map_freeze(obj->gen_loader, map - obj->maps); return 0; }
err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0); if (err) { err = -errno; pr_warn("map '%s': failed to set initial contents: %s\n", bpf_map__name(map), errstr(err)); return err; }
/* Freeze .rodata and .kconfig map as read-only from syscall side. */ if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) { err = bpf_map_freeze(map->fd); if (err) { err = -errno; pr_warn("map '%s': failed to freeze as read-only: %s\n", bpf_map__name(map), errstr(err)); return err; } }
/* Remap anonymous mmap()-ed "map initialization image" as * a BPF map-backed mmap()-ed memory, but preserving the same * memory address. This will cause kernel to change process' * page table to point to a different piece of kernel memory, * but from userspace point of view memory address (and its * contents, being identical at this point) will stay the * same. This mapping will be released by bpf_object__close() * as per normal clean up procedure. */ mmap_sz = bpf_map_mmap_sz(map); if (map->def.map_flags & BPF_F_MMAPABLE) { void *mmaped; int prot;
if (map->def.map_flags & BPF_F_RDONLY_PROG) prot = PROT_READ; else prot = PROT_READ | PROT_WRITE; mmaped = mmap(map->mmaped, mmap_sz, prot, MAP_SHARED | MAP_FIXED, map->fd, 0); if (mmaped == MAP_FAILED) { err = -errno; pr_warn("map '%s': failed to re-mmap() contents: %s\n", bpf_map__name(map), errstr(err)); return err; } map->mmaped = mmaped; } else if (map->mmaped) { munmap(map->mmaped, mmap_sz); map->mmaped = NULL; }
return 0;}
static void bpf_map__destroy(struct bpf_map *map);
static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner){ LIBBPF_OPTS(bpf_map_create_opts, create_attr); struct bpf_map_def *def = &map->def; const char *map_name = NULL; int err = 0, map_fd;
if (kernel_supports(obj, FEAT_PROG_NAME)) map_name = map->name; create_attr.map_ifindex = map->map_ifindex; create_attr.map_flags = def->map_flags; create_attr.numa_node = map->numa_node; create_attr.map_extra = map->map_extra; create_attr.token_fd = obj->token_fd; if (obj->token_fd) create_attr.map_flags |= BPF_F_TOKEN_FD; if (map->excl_prog) { err = bpf_prog_compute_hash(map->excl_prog); if (err) return err;
create_attr.excl_prog_hash = map->excl_prog->hash; create_attr.excl_prog_hash_size = SHA256_DIGEST_LENGTH; }
if (bpf_map__is_struct_ops(map)) { create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; if (map->mod_btf_fd >= 0) { create_attr.value_type_btf_obj_fd = map->mod_btf_fd; create_attr.map_flags |= BPF_F_VTYPE_BTF_OBJ_FD; } }
if (obj->btf && btf__fd(obj->btf) >= 0) { create_attr.btf_fd = btf__fd(obj->btf); create_attr.btf_key_type_id = map->btf_key_type_id; create_attr.btf_value_type_id = map->btf_value_type_id; }
if (bpf_map_type__is_map_in_map(def->type)) { if (map->inner_map) { err = map_set_def_max_entries(map->inner_map); if (err) return err; err = bpf_object__create_map(obj, map->inner_map, true); if (err) { pr_warn("map '%s': failed to create inner map: %s\n", map->name, errstr(err)); return err; } map->inner_map_fd = map->inner_map->fd; } if (map->inner_map_fd >= 0) create_attr.inner_map_fd = map->inner_map_fd; }
switch (def->type) { case BPF_MAP_TYPE_PERF_EVENT_ARRAY: case BPF_MAP_TYPE_CGROUP_ARRAY: case BPF_MAP_TYPE_STACK_TRACE: case BPF_MAP_TYPE_ARRAY_OF_MAPS: case BPF_MAP_TYPE_HASH_OF_MAPS: case BPF_MAP_TYPE_DEVMAP: case BPF_MAP_TYPE_DEVMAP_HASH: case BPF_MAP_TYPE_CPUMAP: case BPF_MAP_TYPE_XSKMAP: case BPF_MAP_TYPE_SOCKMAP: case BPF_MAP_TYPE_SOCKHASH: case BPF_MAP_TYPE_QUEUE: case BPF_MAP_TYPE_STACK: case BPF_MAP_TYPE_ARENA: create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; map->btf_key_type_id = 0; map->btf_value_type_id = 0; break; case BPF_MAP_TYPE_STRUCT_OPS: create_attr.btf_value_type_id = 0; break; default: break; }
if (obj->gen_loader) { bpf_gen__map_create(obj->gen_loader, def->type, map_name, def->key_size, def->value_size, def->max_entries, &create_attr, is_inner ? -1 : map - obj->maps); /* We keep pretenting we have valid FD to pass various fd >= 0 * checks by just keeping original placeholder FDs in place. * See bpf_object__add_map() comment. * This placeholder fd will not be used with any syscall and * will be reset to -1 eventually. */ map_fd = map->fd; } else { map_fd = bpf_map_create(def->type, map_name, def->key_size, def->value_size, def->max_entries, &create_attr); } if (map_fd < 0 && (create_attr.btf_key_type_id || create_attr.btf_value_type_id)) { err = -errno; pr_warn("Error in bpf_create_map_xattr(%s): %s. Retrying without BTF.\n", map->name, errstr(err)); create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; map->btf_key_type_id = 0; map->btf_value_type_id = 0; map_fd = bpf_map_create(def->type, map_name, def->key_size, def->value_size, def->max_entries, &create_attr); }
if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) { if (obj->gen_loader) map->inner_map->fd = -1; bpf_map__destroy(map->inner_map); zfree(&map->inner_map); }
if (map_fd < 0) return map_fd;
/* obj->gen_loader case, prevent reuse_fd() from closing map_fd */ if (map->fd == map_fd) return 0;
/* Keep placeholder FD value but now point it to the BPF map object. * This way everything that relied on this map's FD (e.g., relocated * ldimm64 instructions) will stay valid and won't need adjustments. * map->fd stays valid but now point to what map_fd points to. */ return reuse_fd(map->fd, map_fd);}
static int init_map_in_map_slots(struct bpf_object *obj, struct bpf_map *map){ const struct bpf_map *targ_map; unsigned int i; int fd, err = 0;
for (i = 0; i < map->init_slots_sz; i++) { if (!map->init_slots[i]) continue;
targ_map = map->init_slots[i]; fd = targ_map->fd;
if (obj->gen_loader) { bpf_gen__populate_outer_map(obj->gen_loader, map - obj->maps, i, targ_map - obj->maps); } else { err = bpf_map_update_elem(map->fd, &i, &fd, 0); } if (err) { err = -errno; pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %s\n", map->name, i, targ_map->name, fd, errstr(err)); return err; } pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n", map->name, i, targ_map->name, fd); }
zfree(&map->init_slots); map->init_slots_sz = 0;
return 0;}
static int init_prog_array_slots(struct bpf_object *obj, struct bpf_map *map){ const struct bpf_program *targ_prog; unsigned int i; int fd, err;
if (obj->gen_loader) return -ENOTSUP;
for (i = 0; i < map->init_slots_sz; i++) { if (!map->init_slots[i]) continue;
targ_prog = map->init_slots[i]; fd = bpf_program__fd(targ_prog);
err = bpf_map_update_elem(map->fd, &i, &fd, 0); if (err) { err = -errno; pr_warn("map '%s': failed to initialize slot [%d] to prog '%s' fd=%d: %s\n", map->name, i, targ_prog->name, fd, errstr(err)); return err; } pr_debug("map '%s': slot [%d] set to prog '%s' fd=%d\n", map->name, i, targ_prog->name, fd); }
zfree(&map->init_slots); map->init_slots_sz = 0;
return 0;}
static int bpf_object_init_prog_arrays(struct bpf_object *obj){ struct bpf_map *map; int i, err;
for (i = 0; i < obj->nr_maps; i++) { map = &obj->maps[i];
if (!map->init_slots_sz || map->def.type != BPF_MAP_TYPE_PROG_ARRAY) continue;
err = init_prog_array_slots(obj, map); if (err < 0) return err; } return 0;}
static int map_set_def_max_entries(struct bpf_map *map){ if (map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !map->def.max_entries) { int nr_cpus;
nr_cpus = libbpf_num_possible_cpus(); if (nr_cpus < 0) { pr_warn("map '%s': failed to determine number of system CPUs: %d\n", map->name, nr_cpus); return nr_cpus; } pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus); map->def.max_entries = nr_cpus; }
return 0;}
static intbpf_object__create_maps(struct bpf_object *obj){ struct bpf_map *map; unsigned int i, j; int err; bool retried;
for (i = 0; i < obj->nr_maps; i++) { map = &obj->maps[i];
/* To support old kernels, we skip creating global data maps * (.rodata, .data, .kconfig, etc); later on, during program * loading, if we detect that at least one of the to-be-loaded * programs is referencing any global data map, we'll error * out with program name and relocation index logged. * This approach allows to accommodate Clang emitting * unnecessary .rodata.str1.1 sections for string literals, * but also it allows to have CO-RE applications that use * global variables in some of BPF programs, but not others. * If those global variable-using programs are not loaded at * runtime due to bpf_program__set_autoload(prog, false), * bpf_object loading will succeed just fine even on old * kernels. */ if (bpf_map__is_internal(map) && !kernel_supports(obj, FEAT_GLOBAL_DATA)) map->autocreate = false;
if (!map->autocreate) { pr_debug("map '%s': skipped auto-creating...\n", map->name); continue; }
err = map_set_def_max_entries(map); if (err) goto err_out;
retried = false;retry: if (map->pin_path) { err = bpf_object__reuse_map(map); if (err) { pr_warn("map '%s': error reusing pinned map\n", map->name); goto err_out; } if (retried && map->fd < 0) { pr_warn("map '%s': cannot find pinned map\n", map->name); err = -ENOENT; goto err_out; } }
if (map->reused) { pr_debug("map '%s': skipping creation (preset fd=%d)\n", map->name, map->fd); } else { err = bpf_object__create_map(obj, map, false); if (err) goto err_out;
pr_debug("map '%s': created successfully, fd=%d\n", map->name, map->fd);
if (bpf_map__is_internal(map)) { err = bpf_object__populate_internal_map(obj, map); if (err < 0) goto err_out; } else if (map->def.type == BPF_MAP_TYPE_ARENA) { map->mmaped = mmap((void *)(long)map->map_extra, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE, map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED, map->fd, 0); if (map->mmaped == MAP_FAILED) { err = -errno; map->mmaped = NULL; pr_warn("map '%s': failed to mmap arena: %s\n", map->name, errstr(err)); return err; } if (obj->arena_data) { memcpy(map->mmaped + obj->arena_data_off, obj->arena_data, obj->arena_data_sz); zfree(&obj->arena_data); } } if (map->init_slots_sz && map->def.type != BPF_MAP_TYPE_PROG_ARRAY) { err = init_map_in_map_slots(obj, map); if (err < 0) goto err_out; } }
if (map->pin_path && !map->pinned) { err = bpf_map__pin(map, NULL); if (err) { if (!retried && err == -EEXIST) { retried = true; goto retry; } pr_warn("map '%s': failed to auto-pin at '%s': %s\n", map->name, map->pin_path, errstr(err)); goto err_out; } } }
return 0;
err_out: pr_warn("map '%s': failed to create: %s\n", map->name, errstr(err)); pr_perm_msg(err); for (j = 0; j < i; j++) zclose(obj->maps[j].fd); return err;}
static bool bpf_core_is_flavor_sep(const char *s){ /* check X___Y name pattern, where X and Y are not underscores */ return s[0] != '_' && /* X */ s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ s[4] != '_'; /* Y */}
/* Given 'some_struct_name___with_flavor' return the length of a name prefix * before last triple underscore. Struct name part after last triple * underscore is ignored by BPF CO-RE relocation during relocation matching. */size_t bpf_core_essential_name_len(const char *name){ size_t n = strlen(name); int i;
for (i = n - 5; i >= 0; i--) { if (bpf_core_is_flavor_sep(name + i)) return i + 1; } return n;}
void bpf_core_free_cands(struct bpf_core_cand_list *cands){ if (!cands) return;
free(cands->cands); free(cands);}
int bpf_core_add_cands(struct bpf_core_cand *local_cand, size_t local_essent_len, const struct btf *targ_btf, const char *targ_btf_name, int targ_start_id, struct bpf_core_cand_list *cands){ struct bpf_core_cand *new_cands, *cand; const struct btf_type *t, *local_t; const char *targ_name, *local_name; size_t targ_essent_len; int n, i;
local_t = btf__type_by_id(local_cand->btf, local_cand->id); local_name = btf__str_by_offset(local_cand->btf, local_t->name_off);
n = btf__type_cnt(targ_btf); for (i = targ_start_id; i < n; i++) { t = btf__type_by_id(targ_btf, i); if (!btf_kind_core_compat(t, local_t)) continue;
targ_name = btf__name_by_offset(targ_btf, t->name_off); if (str_is_empty(targ_name)) continue;
targ_essent_len = bpf_core_essential_name_len(targ_name); if (targ_essent_len != local_essent_len) continue;
if (strncmp(local_name, targ_name, local_essent_len) != 0) continue;
pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s in [%s]\n", local_cand->id, btf_kind_str(local_t), local_name, i, btf_kind_str(t), targ_name, targ_btf_name); new_cands = libbpf_reallocarray(cands->cands, cands->len + 1, sizeof(*cands->cands)); if (!new_cands) return -ENOMEM;
cand = &new_cands[cands->len]; cand->btf = targ_btf; cand->id = i;
cands->cands = new_cands; cands->len++; } return 0;}
static int load_module_btfs(struct bpf_object *obj){ struct bpf_btf_info info; struct module_btf *mod_btf; struct btf *btf; char name[64]; __u32 id = 0, len; int err, fd;
if (obj->btf_modules_loaded) return 0;
if (obj->gen_loader) return 0;
/* don't do this again, even if we find no module BTFs */ obj->btf_modules_loaded = true;
/* kernel too old to support module BTFs */ if (!kernel_supports(obj, FEAT_MODULE_BTF)) return 0;
while (true) { err = bpf_btf_get_next_id(id, &id); if (err && errno == ENOENT) return 0; if (err && errno == EPERM) { pr_debug("skipping module BTFs loading, missing privileges\n"); return 0; } if (err) { err = -errno; pr_warn("failed to iterate BTF objects: %s\n", errstr(err)); return err; }
fd = bpf_btf_get_fd_by_id(id); if (fd < 0) { if (errno == ENOENT) continue; /* expected race: BTF was unloaded */ err = -errno; pr_warn("failed to get BTF object #%d FD: %s\n", id, errstr(err)); return err; }
len = sizeof(info); memset(&info, 0, sizeof(info)); info.name = ptr_to_u64(name); info.name_len = sizeof(name);
btf = NULL; err = bpf_btf_get_info_by_fd(fd, &info, &len); if (err) { err = -errno; pr_warn("failed to get BTF object #%d info: %s\n", id, errstr(err)); break; }
/* ignore non-module BTFs */ if (!info.kernel_btf || strcmp(name, "vmlinux") == 0) { close(fd); continue; }
btf = btf_get_from_fd(fd, obj->btf_vmlinux); err = libbpf_get_error(btf); if (err) { pr_warn("failed to load module [%s]'s BTF object #%d: %s\n", name, id, errstr(err)); break; }
err = libbpf_ensure_mem((void **)&obj->btf_modules, &obj->btf_module_cap, sizeof(*obj->btf_modules), obj->btf_module_cnt + 1); if (err) break;
mod_btf = &obj->btf_modules[obj->btf_module_cnt];
mod_btf->btf = btf; mod_btf->id = id; mod_btf->fd = fd; mod_btf->name = strdup(name); if (!mod_btf->name) { err = -ENOMEM; break; } obj->btf_module_cnt++; }
if (err) { btf__free(btf); close(fd); } return err;}
static struct bpf_core_cand_list *bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 local_type_id){ struct bpf_core_cand local_cand = {}; struct bpf_core_cand_list *cands; const struct btf *main_btf; const struct btf_type *local_t; const char *local_name; size_t local_essent_len; int err, i;
local_cand.btf = local_btf; local_cand.id = local_type_id; local_t = btf__type_by_id(local_btf, local_type_id); if (!local_t) return ERR_PTR(-EINVAL);
local_name = btf__name_by_offset(local_btf, local_t->name_off); if (str_is_empty(local_name)) return ERR_PTR(-EINVAL); local_essent_len = bpf_core_essential_name_len(local_name);
cands = calloc(1, sizeof(*cands)); if (!cands) return ERR_PTR(-ENOMEM);
/* Attempt to find target candidates in vmlinux BTF first */ main_btf = obj->btf_vmlinux_override ?: obj->btf_vmlinux; err = bpf_core_add_cands(&local_cand, local_essent_len, main_btf, "vmlinux", 1, cands); if (err) goto err_out;
/* if vmlinux BTF has any candidate, don't got for module BTFs */ if (cands->len) return cands;
/* if vmlinux BTF was overridden, don't attempt to load module BTFs */ if (obj->btf_vmlinux_override) return cands;
/* now look through module BTFs, trying to still find candidates */ err = load_module_btfs(obj); if (err) goto err_out;
for (i = 0; i < obj->btf_module_cnt; i++) { err = bpf_core_add_cands(&local_cand, local_essent_len, obj->btf_modules[i].btf, obj->btf_modules[i].name, btf__type_cnt(obj->btf_vmlinux), cands); if (err) goto err_out; }
return cands;err_out: bpf_core_free_cands(cands); return ERR_PTR(err);}
/* Check local and target types for compatibility. This check is used for * type-based CO-RE relocations and follow slightly different rules than * field-based relocations. This function assumes that root types were already * checked for name match. Beyond that initial root-level name check, names * are completely ignored. Compatibility rules are as follows: * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but * kind should match for local and target types (i.e., STRUCT is not * compatible with UNION); * - for ENUMs, the size is ignored; * - for INT, size and signedness are ignored; * - for ARRAY, dimensionality is ignored, element types are checked for * compatibility recursively; * - CONST/VOLATILE/RESTRICT modifiers are ignored; * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; * - FUNC_PROTOs are compatible if they have compatible signature: same * number of input args and compatible return and argument types. * These rules are not set in stone and probably will be adjusted as we get * more experience with using BPF CO-RE relocations. */int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id){ return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, 32);}
int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id){ return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, 32);}
static size_t bpf_core_hash_fn(const long key, void *ctx){ return key;}
static bool bpf_core_equal_fn(const long k1, const long k2, void *ctx){ return k1 == k2;}
static int record_relo_core(struct bpf_program *prog, const struct bpf_core_relo *core_relo, int insn_idx){ struct reloc_desc *relos, *relo;
relos = libbpf_reallocarray(prog->reloc_desc, prog->nr_reloc + 1, sizeof(*relos)); if (!relos) return -ENOMEM; relo = &relos[prog->nr_reloc]; relo->type = RELO_CORE; relo->insn_idx = insn_idx; relo->core_relo = core_relo; prog->reloc_desc = relos; prog->nr_reloc++; return 0;}
static const struct bpf_core_relo *find_relo_core(struct bpf_program *prog, int insn_idx){ struct reloc_desc *relo; int i;
for (i = 0; i < prog->nr_reloc; i++) { relo = &prog->reloc_desc[i]; if (relo->type != RELO_CORE || relo->insn_idx != insn_idx) continue;
return relo->core_relo; }
return NULL;}
static int bpf_core_resolve_relo(struct bpf_program *prog, const struct bpf_core_relo *relo, int relo_idx, const struct btf *local_btf, struct hashmap *cand_cache, struct bpf_core_relo_res *targ_res){ struct bpf_core_spec specs_scratch[3] = {}; struct bpf_core_cand_list *cands = NULL; const char *prog_name = prog->name; const struct btf_type *local_type; const char *local_name; __u32 local_id = relo->type_id; int err;
local_type = btf__type_by_id(local_btf, local_id); if (!local_type) return -EINVAL;
local_name = btf__name_by_offset(local_btf, local_type->name_off); if (!local_name) return -EINVAL;
if (relo->kind != BPF_CORE_TYPE_ID_LOCAL && !hashmap__find(cand_cache, local_id, &cands)) { cands = bpf_core_find_cands(prog->obj, local_btf, local_id); if (IS_ERR(cands)) { pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld\n", prog_name, relo_idx, local_id, btf_kind_str(local_type), local_name, PTR_ERR(cands)); return PTR_ERR(cands); } err = hashmap__set(cand_cache, local_id, cands, NULL, NULL); if (err) { bpf_core_free_cands(cands); return err; } }
return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch, targ_res);}
static intbpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path){ const struct btf_ext_info_sec *sec; struct bpf_core_relo_res targ_res; const struct bpf_core_relo *rec; const struct btf_ext_info *seg; struct hashmap_entry *entry; struct hashmap *cand_cache = NULL; struct bpf_program *prog; struct bpf_insn *insn; const char *sec_name; int i, err = 0, insn_idx, sec_idx, sec_num;
if (obj->btf_ext->core_relo_info.len == 0) return 0;
if (targ_btf_path) { obj->btf_vmlinux_override = btf__parse(targ_btf_path, NULL); err = libbpf_get_error(obj->btf_vmlinux_override); if (err) { pr_warn("failed to parse target BTF: %s\n", errstr(err)); return err; } }
cand_cache = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL); if (IS_ERR(cand_cache)) { err = PTR_ERR(cand_cache); goto out; }
seg = &obj->btf_ext->core_relo_info; sec_num = 0; for_each_btf_ext_sec(seg, sec) { sec_idx = seg->sec_idxs[sec_num]; sec_num++;
sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); if (str_is_empty(sec_name)) { err = -EINVAL; goto out; }
pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) { if (rec->insn_off % BPF_INSN_SZ) return -EINVAL; insn_idx = rec->insn_off / BPF_INSN_SZ; prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx); if (!prog) { /* When __weak subprog is "overridden" by another instance * of the subprog from a different object file, linker still * appends all the .BTF.ext info that used to belong to that * eliminated subprogram. * This is similar to what x86-64 linker does for relocations. * So just ignore such relocations just like we ignore * subprog instructions when discovering subprograms. */ pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n", sec_name, i, insn_idx); continue; } /* no need to apply CO-RE relocation if the program is * not going to be loaded */ if (!prog->autoload) continue;
/* adjust insn_idx from section frame of reference to the local * program's frame of reference; (sub-)program code is not yet * relocated, so it's enough to just subtract in-section offset */ insn_idx = insn_idx - prog->sec_insn_off; if (insn_idx >= prog->insns_cnt) return -EINVAL; insn = &prog->insns[insn_idx];
err = record_relo_core(prog, rec, insn_idx); if (err) { pr_warn("prog '%s': relo #%d: failed to record relocation: %s\n", prog->name, i, errstr(err)); goto out; }
if (prog->obj->gen_loader) continue;
err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %s\n", prog->name, i, errstr(err)); goto out; }
err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res); if (err) { pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %s\n", prog->name, i, insn_idx, errstr(err)); goto out; } } }
out: /* obj->btf_vmlinux and module BTFs are freed after object load */ btf__free(obj->btf_vmlinux_override); obj->btf_vmlinux_override = NULL;
if (!IS_ERR_OR_NULL(cand_cache)) { hashmap__for_each_entry(cand_cache, entry, i) { bpf_core_free_cands(entry->pvalue); } hashmap__free(cand_cache); } return err;}
/* base map load ldimm64 special constant, used also for log fixup logic */#define POISON_LDIMM64_MAP_BASE 2001000000#define POISON_LDIMM64_MAP_PFX "200100"
static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx, int insn_idx, struct bpf_insn *insn, int map_idx, const struct bpf_map *map){ int i;
pr_debug("prog '%s': relo #%d: poisoning insn #%d that loads map #%d '%s'\n", prog->name, relo_idx, insn_idx, map_idx, map->name);
/* we turn single ldimm64 into two identical invalid calls */ for (i = 0; i < 2; i++) { insn->code = BPF_JMP | BPF_CALL; insn->dst_reg = 0; insn->src_reg = 0; insn->off = 0; /* if this instruction is reachable (not a dead code), * verifier will complain with something like: * invalid func unknown#2001000123 * where lower 123 is map index into obj->maps[] array */ insn->imm = POISON_LDIMM64_MAP_BASE + map_idx;
insn++; }}
/* unresolved kfunc call special constant, used also for log fixup logic */#define POISON_CALL_KFUNC_BASE 2002000000#define POISON_CALL_KFUNC_PFX "2002"
static void poison_kfunc_call(struct bpf_program *prog, int relo_idx, int insn_idx, struct bpf_insn *insn, int ext_idx, const struct extern_desc *ext){ pr_debug("prog '%s': relo #%d: poisoning insn #%d that calls kfunc '%s'\n", prog->name, relo_idx, insn_idx, ext->name);
/* we turn kfunc call into invalid helper call with identifiable constant */ insn->code = BPF_JMP | BPF_CALL; insn->dst_reg = 0; insn->src_reg = 0; insn->off = 0; /* if this instruction is reachable (not a dead code), * verifier will complain with something like: * invalid func unknown#2001000123 * where lower 123 is extern index into obj->externs[] array */ insn->imm = POISON_CALL_KFUNC_BASE + ext_idx;}
static int find_jt_map(struct bpf_object *obj, struct bpf_program *prog, unsigned int sym_off){ size_t i;
for (i = 0; i < obj->jumptable_map_cnt; i++) { /* * This might happen that same offset is used for two different * programs (as jump tables can be the same). However, for * different programs different maps should be created. */ if (obj->jumptable_maps[i].sym_off == sym_off && obj->jumptable_maps[i].prog == prog) return obj->jumptable_maps[i].fd; }
return -ENOENT;}
static int add_jt_map(struct bpf_object *obj, struct bpf_program *prog, unsigned int sym_off, int map_fd){ size_t cnt = obj->jumptable_map_cnt; size_t size = sizeof(obj->jumptable_maps[0]); void *tmp;
tmp = libbpf_reallocarray(obj->jumptable_maps, cnt + 1, size); if (!tmp) return -ENOMEM;
obj->jumptable_maps = tmp; obj->jumptable_maps[cnt].prog = prog; obj->jumptable_maps[cnt].sym_off = sym_off; obj->jumptable_maps[cnt].fd = map_fd; obj->jumptable_map_cnt++;
return 0;}
static int find_subprog_idx(struct bpf_program *prog, int insn_idx){ int i;
for (i = prog->subprog_cnt - 1; i >= 0; i--) { if (insn_idx >= prog->subprogs[i].sub_insn_off) return i; }
return -1;}
static int create_jt_map(struct bpf_object *obj, struct bpf_program *prog, struct reloc_desc *relo){ const __u32 jt_entry_size = 8; unsigned int sym_off = relo->sym_off; int jt_size = relo->sym_size; __u32 max_entries = jt_size / jt_entry_size; __u32 value_size = sizeof(struct bpf_insn_array_value); struct bpf_insn_array_value val = {}; int subprog_idx; int map_fd, err; __u64 insn_off; __u64 *jt; __u32 i;
map_fd = find_jt_map(obj, prog, sym_off); if (map_fd >= 0) return map_fd;
if (sym_off % jt_entry_size) { pr_warn("map '.jumptables': jumptable start %u should be multiple of %u\n", sym_off, jt_entry_size); return -EINVAL; }
if (jt_size % jt_entry_size) { pr_warn("map '.jumptables': jumptable size %d should be multiple of %u\n", jt_size, jt_entry_size); return -EINVAL; }
map_fd = bpf_map_create(BPF_MAP_TYPE_INSN_ARRAY, ".jumptables", 4, value_size, max_entries, NULL); if (map_fd < 0) return map_fd;
if (!obj->jumptables_data) { pr_warn("map '.jumptables': ELF file is missing jump table data\n"); err = -EINVAL; goto err_close; } if (sym_off + jt_size > obj->jumptables_data_sz) { pr_warn("map '.jumptables': jumptables_data size is %zd, trying to access %d\n", obj->jumptables_data_sz, sym_off + jt_size); err = -EINVAL; goto err_close; }
subprog_idx = -1; /* main program */ if (relo->insn_idx < 0 || relo->insn_idx >= prog->insns_cnt) { pr_warn("map '.jumptables': invalid instruction index %d\n", relo->insn_idx); err = -EINVAL; goto err_close; } if (prog->subprogs) subprog_idx = find_subprog_idx(prog, relo->insn_idx);
jt = (__u64 *)(obj->jumptables_data + sym_off); for (i = 0; i < max_entries; i++) { /* * The offset should be made to be relative to the beginning of * the main function, not the subfunction. */ insn_off = jt[i]/sizeof(struct bpf_insn); if (subprog_idx >= 0) { insn_off -= prog->subprogs[subprog_idx].sec_insn_off; insn_off += prog->subprogs[subprog_idx].sub_insn_off; } else { insn_off -= prog->sec_insn_off; }
/* * LLVM-generated jump tables contain u64 records, however * should contain values that fit in u32. */ if (insn_off > UINT32_MAX) { pr_warn("map '.jumptables': invalid jump table value 0x%llx at offset %u\n", (long long)jt[i], sym_off + i * jt_entry_size); err = -EINVAL; goto err_close; }
val.orig_off = insn_off; err = bpf_map_update_elem(map_fd, &i, &val, 0); if (err) goto err_close; }
err = bpf_map_freeze(map_fd); if (err) goto err_close;
err = add_jt_map(obj, prog, sym_off, map_fd); if (err) goto err_close;
return map_fd;
err_close: close(map_fd); return err;}
/* Relocate data references within program code: * - map references; * - global variable references; * - extern references. */static intbpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog){ int i;
for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct bpf_insn *insn = &prog->insns[relo->insn_idx]; const struct bpf_map *map; struct extern_desc *ext;
switch (relo->type) { case RELO_LD64: map = &obj->maps[relo->map_idx]; if (obj->gen_loader) { insn[0].src_reg = BPF_PSEUDO_MAP_IDX; insn[0].imm = relo->map_idx; } else if (map->autocreate) { insn[0].src_reg = BPF_PSEUDO_MAP_FD; insn[0].imm = map->fd; } else { poison_map_ldimm64(prog, i, relo->insn_idx, insn, relo->map_idx, map); } break; case RELO_DATA: map = &obj->maps[relo->map_idx]; insn[1].imm = insn[0].imm + relo->sym_off;
if (relo->map_idx == obj->arena_map_idx) insn[1].imm += obj->arena_data_off;
if (obj->gen_loader) { insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE; insn[0].imm = relo->map_idx; } else if (map->autocreate) { insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; insn[0].imm = map->fd; } else { poison_map_ldimm64(prog, i, relo->insn_idx, insn, relo->map_idx, map); } break; case RELO_EXTERN_LD64: ext = &obj->externs[relo->ext_idx]; if (ext->type == EXT_KCFG) { if (obj->gen_loader) { insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE; insn[0].imm = obj->kconfig_map_idx; } else { insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; insn[0].imm = obj->maps[obj->kconfig_map_idx].fd; } insn[1].imm = ext->kcfg.data_off; } else /* EXT_KSYM */ { if (ext->ksym.type_id && ext->is_set) { /* typed ksyms */ insn[0].src_reg = BPF_PSEUDO_BTF_ID; insn[0].imm = ext->ksym.kernel_btf_id; insn[1].imm = ext->ksym.kernel_btf_obj_fd; } else { /* typeless ksyms or unresolved typed ksyms */ insn[0].imm = (__u32)ext->ksym.addr; insn[1].imm = ext->ksym.addr >> 32; } } break; case RELO_EXTERN_CALL: ext = &obj->externs[relo->ext_idx]; insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL; if (ext->is_set) { insn[0].imm = ext->ksym.kernel_btf_id; insn[0].off = ext->ksym.btf_fd_idx; } else { /* unresolved weak kfunc call */ poison_kfunc_call(prog, i, relo->insn_idx, insn, relo->ext_idx, ext); } break; case RELO_SUBPROG_ADDR: if (insn[0].src_reg != BPF_PSEUDO_FUNC) { pr_warn("prog '%s': relo #%d: bad insn\n", prog->name, i); return -EINVAL; } /* handled already */ break; case RELO_CALL: /* handled already */ break; case RELO_CORE: /* will be handled by bpf_program_record_relos() */ break; case RELO_INSN_ARRAY: { int map_fd;
map_fd = create_jt_map(obj, prog, relo); if (map_fd < 0) { pr_warn("prog '%s': relo #%d: can't create jump table: sym_off %u\n", prog->name, i, relo->sym_off); return map_fd; } insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; insn->imm = map_fd; insn->off = 0; } break; default: pr_warn("prog '%s': relo #%d: bad relo type %d\n", prog->name, i, relo->type); return -EINVAL; } }
return 0;}
static int adjust_prog_btf_ext_info(const struct bpf_object *obj, const struct bpf_program *prog, const struct btf_ext_info *ext_info, void **prog_info, __u32 *prog_rec_cnt, __u32 *prog_rec_sz){ void *copy_start = NULL, *copy_end = NULL; void *rec, *rec_end, *new_prog_info; const struct btf_ext_info_sec *sec; size_t old_sz, new_sz; int i, sec_num, sec_idx, off_adj;
sec_num = 0; for_each_btf_ext_sec(ext_info, sec) { sec_idx = ext_info->sec_idxs[sec_num]; sec_num++; if (prog->sec_idx != sec_idx) continue;
for_each_btf_ext_rec(ext_info, sec, i, rec) { __u32 insn_off = *(__u32 *)rec / BPF_INSN_SZ;
if (insn_off < prog->sec_insn_off) continue; if (insn_off >= prog->sec_insn_off + prog->sec_insn_cnt) break;
if (!copy_start) copy_start = rec; copy_end = rec + ext_info->rec_size; }
if (!copy_start) return -ENOENT;
/* append func/line info of a given (sub-)program to the main * program func/line info */ old_sz = (size_t)(*prog_rec_cnt) * ext_info->rec_size; new_sz = old_sz + (copy_end - copy_start); new_prog_info = realloc(*prog_info, new_sz); if (!new_prog_info) return -ENOMEM; *prog_info = new_prog_info; *prog_rec_cnt = new_sz / ext_info->rec_size; memcpy(new_prog_info + old_sz, copy_start, copy_end - copy_start);
/* Kernel instruction offsets are in units of 8-byte * instructions, while .BTF.ext instruction offsets generated * by Clang are in units of bytes. So convert Clang offsets * into kernel offsets and adjust offset according to program * relocated position. */ off_adj = prog->sub_insn_off - prog->sec_insn_off; rec = new_prog_info + old_sz; rec_end = new_prog_info + new_sz; for (; rec < rec_end; rec += ext_info->rec_size) { __u32 *insn_off = rec;
*insn_off = *insn_off / BPF_INSN_SZ + off_adj; } *prog_rec_sz = ext_info->rec_size; return 0; }
return -ENOENT;}
static intreloc_prog_func_and_line_info(const struct bpf_object *obj, struct bpf_program *main_prog, const struct bpf_program *prog){ int err;
/* no .BTF.ext relocation if .BTF.ext is missing or kernel doesn't * support func/line info */ if (!obj->btf_ext || !kernel_supports(obj, FEAT_BTF_FUNC)) return 0;
/* only attempt func info relocation if main program's func_info * relocation was successful */ if (main_prog != prog && !main_prog->func_info) goto line_info;
err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->func_info, &main_prog->func_info, &main_prog->func_info_cnt, &main_prog->func_info_rec_size); if (err) { if (err != -ENOENT) { pr_warn("prog '%s': error relocating .BTF.ext function info: %s\n", prog->name, errstr(err)); return err; } if (main_prog->func_info) { /* * Some info has already been found but has problem * in the last btf_ext reloc. Must have to error out. */ pr_warn("prog '%s': missing .BTF.ext function info.\n", prog->name); return err; } /* Have problem loading the very first info. Ignore the rest. */ pr_warn("prog '%s': missing .BTF.ext function info for the main program, skipping all of .BTF.ext func info.\n", prog->name); }
line_info: /* don't relocate line info if main program's relocation failed */ if (main_prog != prog && !main_prog->line_info) return 0;
err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->line_info, &main_prog->line_info, &main_prog->line_info_cnt, &main_prog->line_info_rec_size); if (err) { if (err != -ENOENT) { pr_warn("prog '%s': error relocating .BTF.ext line info: %s\n", prog->name, errstr(err)); return err; } if (main_prog->line_info) { /* * Some info has already been found but has problem * in the last btf_ext reloc. Must have to error out. */ pr_warn("prog '%s': missing .BTF.ext line info.\n", prog->name); return err; } /* Have problem loading the very first info. Ignore the rest. */ pr_warn("prog '%s': missing .BTF.ext line info for the main program, skipping all of .BTF.ext line info.\n", prog->name); } return 0;}
static int cmp_relo_by_insn_idx(const void *key, const void *elem){ size_t insn_idx = *(const size_t *)key; const struct reloc_desc *relo = elem;
if (insn_idx == relo->insn_idx) return 0; return insn_idx < relo->insn_idx ? -1 : 1;}
static struct reloc_desc *find_prog_insn_relo(const struct bpf_program *prog, size_t insn_idx){ if (!prog->nr_reloc) return NULL; return bsearch(&insn_idx, prog->reloc_desc, prog->nr_reloc, sizeof(*prog->reloc_desc), cmp_relo_by_insn_idx);}
static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_program *subprog){ int new_cnt = main_prog->nr_reloc + subprog->nr_reloc; struct reloc_desc *relos; int i;
if (main_prog == subprog) return 0; relos = libbpf_reallocarray(main_prog->reloc_desc, new_cnt, sizeof(*relos)); /* if new count is zero, reallocarray can return a valid NULL result; * in this case the previous pointer will be freed, so we *have to* * reassign old pointer to the new value (even if it's NULL) */ if (!relos && new_cnt) return -ENOMEM; if (subprog->nr_reloc) memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc, sizeof(*relos) * subprog->nr_reloc);
for (i = main_prog->nr_reloc; i < new_cnt; i++) relos[i].insn_idx += subprog->sub_insn_off; /* After insn_idx adjustment the 'relos' array is still sorted * by insn_idx and doesn't break bsearch. */ main_prog->reloc_desc = relos; main_prog->nr_reloc = new_cnt; return 0;}
static int save_subprog_offsets(struct bpf_program *main_prog, struct bpf_program *subprog){ size_t size = sizeof(main_prog->subprogs[0]); int cnt = main_prog->subprog_cnt; void *tmp;
tmp = libbpf_reallocarray(main_prog->subprogs, cnt + 1, size); if (!tmp) return -ENOMEM;
main_prog->subprogs = tmp; main_prog->subprogs[cnt].sec_insn_off = subprog->sec_insn_off; main_prog->subprogs[cnt].sub_insn_off = subprog->sub_insn_off; main_prog->subprog_cnt++;
return 0;}
static intbpf_object__append_subprog_code(struct bpf_object *obj, struct bpf_program *main_prog, struct bpf_program *subprog){ struct bpf_insn *insns; size_t new_cnt; int err;
subprog->sub_insn_off = main_prog->insns_cnt;
new_cnt = main_prog->insns_cnt + subprog->insns_cnt; insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns)); if (!insns) { pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name); return -ENOMEM; } main_prog->insns = insns; main_prog->insns_cnt = new_cnt;
memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns, subprog->insns_cnt * sizeof(*insns));
pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n", main_prog->name, subprog->insns_cnt, subprog->name);
/* The subprog insns are now appended. Append its relos too. */ err = append_subprog_relos(main_prog, subprog); if (err) return err;
err = save_subprog_offsets(main_prog, subprog); if (err) { pr_warn("prog '%s': failed to add subprog offsets: %s\n", main_prog->name, errstr(err)); return err; }
return 0;}
static intbpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog, struct bpf_program *prog){ size_t sub_insn_idx, insn_idx; struct bpf_program *subprog; struct reloc_desc *relo; struct bpf_insn *insn; int err;
err = reloc_prog_func_and_line_info(obj, main_prog, prog); if (err) return err;
for (insn_idx = 0; insn_idx < prog->sec_insn_cnt; insn_idx++) { insn = &main_prog->insns[prog->sub_insn_off + insn_idx]; if (!insn_is_subprog_call(insn) && !insn_is_pseudo_func(insn)) continue;
relo = find_prog_insn_relo(prog, insn_idx); if (relo && relo->type == RELO_EXTERN_CALL) /* kfunc relocations will be handled later * in bpf_object__relocate_data() */ continue; if (relo && relo->type != RELO_CALL && relo->type != RELO_SUBPROG_ADDR) { pr_warn("prog '%s': unexpected relo for insn #%zu, type %d\n", prog->name, insn_idx, relo->type); return -LIBBPF_ERRNO__RELOC; } if (relo) { /* sub-program instruction index is a combination of * an offset of a symbol pointed to by relocation and * call instruction's imm field; for global functions, * call always has imm = -1, but for static functions * relocation is against STT_SECTION and insn->imm * points to a start of a static function * * for subprog addr relocation, the relo->sym_off + insn->imm is * the byte offset in the corresponding section. */ if (relo->type == RELO_CALL) sub_insn_idx = relo->sym_off / BPF_INSN_SZ + insn->imm + 1; else sub_insn_idx = (relo->sym_off + insn->imm) / BPF_INSN_SZ; } else if (insn_is_pseudo_func(insn)) { /* * RELO_SUBPROG_ADDR relo is always emitted even if both * functions are in the same section, so it shouldn't reach here. */ pr_warn("prog '%s': missing subprog addr relo for insn #%zu\n", prog->name, insn_idx); return -LIBBPF_ERRNO__RELOC; } else { /* if subprogram call is to a static function within * the same ELF section, there won't be any relocation * emitted, but it also means there is no additional * offset necessary, insns->imm is relative to * instruction's original position within the section */ sub_insn_idx = prog->sec_insn_off + insn_idx + insn->imm + 1; }
/* we enforce that sub-programs should be in .text section */ subprog = find_prog_by_sec_insn(obj, obj->efile.text_shndx, sub_insn_idx); if (!subprog) { pr_warn("prog '%s': no .text section found yet sub-program call exists\n", prog->name); return -LIBBPF_ERRNO__RELOC; }
/* if it's the first call instruction calling into this * subprogram (meaning this subprog hasn't been processed * yet) within the context of current main program: * - append it at the end of main program's instructions blog; * - process is recursively, while current program is put on hold; * - if that subprogram calls some other not yet processes * subprogram, same thing will happen recursively until * there are no more unprocesses subprograms left to append * and relocate. */ if (subprog->sub_insn_off == 0) { err = bpf_object__append_subprog_code(obj, main_prog, subprog); if (err) return err; err = bpf_object__reloc_code(obj, main_prog, subprog); if (err) return err; }
/* main_prog->insns memory could have been re-allocated, so * calculate pointer again */ insn = &main_prog->insns[prog->sub_insn_off + insn_idx]; /* calculate correct instruction position within current main * prog; each main prog can have a different set of * subprograms appended (potentially in different order as * well), so position of any subprog can be different for * different main programs */ insn->imm = subprog->sub_insn_off - (prog->sub_insn_off + insn_idx) - 1;
pr_debug("prog '%s': insn #%zu relocated, imm %d points to subprog '%s' (now at %zu offset)\n", prog->name, insn_idx, insn->imm, subprog->name, subprog->sub_insn_off); }
return 0;}
/* * Relocate sub-program calls. * * Algorithm operates as follows. Each entry-point BPF program (referred to as * main prog) is processed separately. For each subprog (non-entry functions, * that can be called from either entry progs or other subprogs) gets their * sub_insn_off reset to zero. This serves as indicator that this subprogram * hasn't been yet appended and relocated within current main prog. Once its * relocated, sub_insn_off will point at the position within current main prog * where given subprog was appended. This will further be used to relocate all * the call instructions jumping into this subprog. * * We start with main program and process all call instructions. If the call * is into a subprog that hasn't been processed (i.e., subprog->sub_insn_off * is zero), subprog instructions are appended at the end of main program's * instruction array. Then main program is "put on hold" while we recursively * process newly appended subprogram. If that subprogram calls into another * subprogram that hasn't been appended, new subprogram is appended again to * the *main* prog's instructions (subprog's instructions are always left * untouched, as they need to be in unmodified state for subsequent main progs * and subprog instructions are always sent only as part of a main prog) and * the process continues recursively. Once all the subprogs called from a main * prog or any of its subprogs are appended (and relocated), all their * positions within finalized instructions array are known, so it's easy to * rewrite call instructions with correct relative offsets, corresponding to * desired target subprog. * * Its important to realize that some subprogs might not be called from some * main prog and any of its called/used subprogs. Those will keep their * subprog->sub_insn_off as zero at all times and won't be appended to current * main prog and won't be relocated within the context of current main prog. * They might still be used from other main progs later. * * Visually this process can be shown as below. Suppose we have two main * programs mainA and mainB and BPF object contains three subprogs: subA, * subB, and subC. mainA calls only subA, mainB calls only subC, but subA and * subC both call subB: * * +--------+ +-------+ * | v v | * +--+---+ +--+-+-+ +---+--+ * | subA | | subB | | subC | * +--+---+ +------+ +---+--+ * ^ ^ * | | * +---+-------+ +------+----+ * | mainA | | mainB | * +-----------+ +-----------+ * * We'll start relocating mainA, will find subA, append it and start * processing sub A recursively: * * +-----------+------+ * | mainA | subA | * +-----------+------+ * * At this point we notice that subB is used from subA, so we append it and * relocate (there are no further subcalls from subB): * * +-----------+------+------+ * | mainA | subA | subB | * +-----------+------+------+ * * At this point, we relocate subA calls, then go one level up and finish with * relocatin mainA calls. mainA is done. * * For mainB process is similar but results in different order. We start with * mainB and skip subA and subB, as mainB never calls them (at least * directly), but we see subC is needed, so we append and start processing it: * * +-----------+------+ * | mainB | subC | * +-----------+------+ * Now we see subC needs subB, so we go back to it, append and relocate it: * * +-----------+------+------+ * | mainB | subC | subB | * +-----------+------+------+ * * At this point we unwind recursion, relocate calls in subC, then in mainB. */static intbpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog){ struct bpf_program *subprog; int i, err;
/* mark all subprogs as not relocated (yet) within the context of * current main program */ for (i = 0; i < obj->nr_programs; i++) { subprog = &obj->programs[i]; if (!prog_is_subprog(obj, subprog)) continue;
subprog->sub_insn_off = 0; }
err = bpf_object__reloc_code(obj, prog, prog); if (err) return err;
return 0;}
static voidbpf_object__free_relocs(struct bpf_object *obj){ struct bpf_program *prog; int i;
/* free up relocation descriptors */ for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; zfree(&prog->reloc_desc); prog->nr_reloc = 0; }}
static int cmp_relocs(const void *_a, const void *_b){ const struct reloc_desc *a = _a; const struct reloc_desc *b = _b;
if (a->insn_idx != b->insn_idx) return a->insn_idx < b->insn_idx ? -1 : 1;
/* no two relocations should have the same insn_idx, but ... */ if (a->type != b->type) return a->type < b->type ? -1 : 1;
return 0;}
static void bpf_object__sort_relos(struct bpf_object *obj){ int i;
for (i = 0; i < obj->nr_programs; i++) { struct bpf_program *p = &obj->programs[i];
if (!p->nr_reloc) continue;
qsort(p->reloc_desc, p->nr_reloc, sizeof(*p->reloc_desc), cmp_relocs); }}
static int bpf_prog_assign_exc_cb(struct bpf_object *obj, struct bpf_program *prog){ const char *str = "exception_callback:"; size_t pfx_len = strlen(str); int i, j, n;
if (!obj->btf || !kernel_supports(obj, FEAT_BTF_DECL_TAG)) return 0;
n = btf__type_cnt(obj->btf); for (i = 1; i < n; i++) { const char *name; struct btf_type *t;
t = btf_type_by_id(obj->btf, i); if (!btf_is_decl_tag(t) || btf_decl_tag(t)->component_idx != -1) continue;
name = btf__str_by_offset(obj->btf, t->name_off); if (strncmp(name, str, pfx_len) != 0) continue;
t = btf_type_by_id(obj->btf, t->type); if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL) { pr_warn("prog '%s': exception_callback:<value> decl tag not applied to the main program\n", prog->name); return -EINVAL; } if (strcmp(prog->name, btf__str_by_offset(obj->btf, t->name_off)) != 0) continue; /* Multiple callbacks are specified for the same prog, * the verifier will eventually return an error for this * case, hence simply skip appending a subprog. */ if (prog->exception_cb_idx >= 0) { prog->exception_cb_idx = -1; break; }
name += pfx_len; if (str_is_empty(name)) { pr_warn("prog '%s': exception_callback:<value> decl tag contains empty value\n", prog->name); return -EINVAL; }
for (j = 0; j < obj->nr_programs; j++) { struct bpf_program *subprog = &obj->programs[j];
if (!prog_is_subprog(obj, subprog)) continue; if (strcmp(name, subprog->name) != 0) continue; /* Enforce non-hidden, as from verifier point of * view it expects global functions, whereas the * mark_btf_static fixes up linkage as static. */ if (!subprog->sym_global || subprog->mark_btf_static) { pr_warn("prog '%s': exception callback %s must be a global non-hidden function\n", prog->name, subprog->name); return -EINVAL; } /* Let's see if we already saw a static exception callback with the same name */ if (prog->exception_cb_idx >= 0) { pr_warn("prog '%s': multiple subprogs with same name as exception callback '%s'\n", prog->name, subprog->name); return -EINVAL; } prog->exception_cb_idx = j; break; }
if (prog->exception_cb_idx >= 0) continue;
pr_warn("prog '%s': cannot find exception callback '%s'\n", prog->name, name); return -ENOENT; }
return 0;}
static struct { enum bpf_prog_type prog_type; const char *ctx_name;} global_ctx_map[] = { { BPF_PROG_TYPE_CGROUP_DEVICE, "bpf_cgroup_dev_ctx" }, { BPF_PROG_TYPE_CGROUP_SKB, "__sk_buff" }, { BPF_PROG_TYPE_CGROUP_SOCK, "bpf_sock" }, { BPF_PROG_TYPE_CGROUP_SOCK_ADDR, "bpf_sock_addr" }, { BPF_PROG_TYPE_CGROUP_SOCKOPT, "bpf_sockopt" }, { BPF_PROG_TYPE_CGROUP_SYSCTL, "bpf_sysctl" }, { BPF_PROG_TYPE_FLOW_DISSECTOR, "__sk_buff" }, { BPF_PROG_TYPE_KPROBE, "bpf_user_pt_regs_t" }, { BPF_PROG_TYPE_LWT_IN, "__sk_buff" }, { BPF_PROG_TYPE_LWT_OUT, "__sk_buff" }, { BPF_PROG_TYPE_LWT_SEG6LOCAL, "__sk_buff" }, { BPF_PROG_TYPE_LWT_XMIT, "__sk_buff" }, { BPF_PROG_TYPE_NETFILTER, "bpf_nf_ctx" }, { BPF_PROG_TYPE_PERF_EVENT, "bpf_perf_event_data" }, { BPF_PROG_TYPE_RAW_TRACEPOINT, "bpf_raw_tracepoint_args" }, { BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, "bpf_raw_tracepoint_args" }, { BPF_PROG_TYPE_SCHED_ACT, "__sk_buff" }, { BPF_PROG_TYPE_SCHED_CLS, "__sk_buff" }, { BPF_PROG_TYPE_SK_LOOKUP, "bpf_sk_lookup" }, { BPF_PROG_TYPE_SK_MSG, "sk_msg_md" }, { BPF_PROG_TYPE_SK_REUSEPORT, "sk_reuseport_md" }, { BPF_PROG_TYPE_SK_SKB, "__sk_buff" }, { BPF_PROG_TYPE_SOCK_OPS, "bpf_sock_ops" }, { BPF_PROG_TYPE_SOCKET_FILTER, "__sk_buff" }, { BPF_PROG_TYPE_XDP, "xdp_md" }, /* all other program types don't have "named" context structs */};
/* forward declarations for arch-specific underlying types of bpf_user_pt_regs_t typedef, * for below __builtin_types_compatible_p() checks; * with this approach we don't need any extra arch-specific #ifdef guards */struct pt_regs;struct user_pt_regs;struct user_regs_struct;
static bool need_func_arg_type_fixup(const struct btf *btf, const struct bpf_program *prog, const char *subprog_name, int arg_idx, int arg_type_id, const char *ctx_name){ const struct btf_type *t; const char *tname;
/* check if existing parameter already matches verifier expectations */ t = skip_mods_and_typedefs(btf, arg_type_id, NULL); if (!btf_is_ptr(t)) goto out_warn;
/* typedef bpf_user_pt_regs_t is a special PITA case, valid for kprobe * and perf_event programs, so check this case early on and forget * about it for subsequent checks */ while (btf_is_mod(t)) t = btf__type_by_id(btf, t->type); if (btf_is_typedef(t) && (prog->type == BPF_PROG_TYPE_KPROBE || prog->type == BPF_PROG_TYPE_PERF_EVENT)) { tname = btf__str_by_offset(btf, t->name_off) ?: "<anon>"; if (strcmp(tname, "bpf_user_pt_regs_t") == 0) return false; /* canonical type for kprobe/perf_event */ }
/* now we can ignore typedefs moving forward */ t = skip_mods_and_typedefs(btf, t->type, NULL);
/* if it's `void *`, definitely fix up BTF info */ if (btf_is_void(t)) return true;
/* if it's already proper canonical type, no need to fix up */ tname = btf__str_by_offset(btf, t->name_off) ?: "<anon>"; if (btf_is_struct(t) && strcmp(tname, ctx_name) == 0) return false;
/* special cases */ switch (prog->type) { case BPF_PROG_TYPE_KPROBE: /* `struct pt_regs *` is expected, but we need to fix up */ if (btf_is_struct(t) && strcmp(tname, "pt_regs") == 0) return true; break; case BPF_PROG_TYPE_PERF_EVENT: if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct pt_regs) && btf_is_struct(t) && strcmp(tname, "pt_regs") == 0) return true; if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_pt_regs) && btf_is_struct(t) && strcmp(tname, "user_pt_regs") == 0) return true; if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_regs_struct) && btf_is_struct(t) && strcmp(tname, "user_regs_struct") == 0) return true; break; case BPF_PROG_TYPE_RAW_TRACEPOINT: case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: /* allow u64* as ctx */ if (btf_is_int(t) && t->size == 8) return true; break; default: break; }
out_warn: pr_warn("prog '%s': subprog '%s' arg#%d is expected to be of `struct %s *` type\n", prog->name, subprog_name, arg_idx, ctx_name); return false;}
static int clone_func_btf_info(struct btf *btf, int orig_fn_id, struct bpf_program *prog){ int fn_id, fn_proto_id, ret_type_id, orig_proto_id; int i, err, arg_cnt, fn_name_off, linkage; struct btf_type *fn_t, *fn_proto_t, *t; struct btf_param *p;
/* caller already validated FUNC -> FUNC_PROTO validity */ fn_t = btf_type_by_id(btf, orig_fn_id); fn_proto_t = btf_type_by_id(btf, fn_t->type);
/* Note that each btf__add_xxx() operation invalidates * all btf_type and string pointers, so we need to be * very careful when cloning BTF types. BTF type * pointers have to be always refetched. And to avoid * problems with invalidated string pointers, we * add empty strings initially, then just fix up * name_off offsets in place. Offsets are stable for * existing strings, so that works out. */ fn_name_off = fn_t->name_off; /* we are about to invalidate fn_t */ linkage = btf_func_linkage(fn_t); orig_proto_id = fn_t->type; /* original FUNC_PROTO ID */ ret_type_id = fn_proto_t->type; /* fn_proto_t will be invalidated */ arg_cnt = btf_vlen(fn_proto_t);
/* clone FUNC_PROTO and its params */ fn_proto_id = btf__add_func_proto(btf, ret_type_id); if (fn_proto_id < 0) return -EINVAL;
for (i = 0; i < arg_cnt; i++) { int name_off;
/* copy original parameter data */ t = btf_type_by_id(btf, orig_proto_id); p = &btf_params(t)[i]; name_off = p->name_off;
err = btf__add_func_param(btf, "", p->type); if (err) return err;
fn_proto_t = btf_type_by_id(btf, fn_proto_id); p = &btf_params(fn_proto_t)[i]; p->name_off = name_off; /* use remembered str offset */ }
/* clone FUNC now, btf__add_func() enforces non-empty name, so use * entry program's name as a placeholder, which we replace immediately * with original name_off */ fn_id = btf__add_func(btf, prog->name, linkage, fn_proto_id); if (fn_id < 0) return -EINVAL;
fn_t = btf_type_by_id(btf, fn_id); fn_t->name_off = fn_name_off; /* reuse original string */
return fn_id;}
/* Check if main program or global subprog's function prototype has `arg:ctx` * argument tags, and, if necessary, substitute correct type to match what BPF * verifier would expect, taking into account specific program type. This * allows to support __arg_ctx tag transparently on old kernels that don't yet * have a native support for it in the verifier, making user's life much * easier. */static int bpf_program_fixup_func_info(struct bpf_object *obj, struct bpf_program *prog){ const char *ctx_name = NULL, *ctx_tag = "arg:ctx", *fn_name; struct bpf_func_info_min *func_rec; struct btf_type *fn_t, *fn_proto_t; struct btf *btf = obj->btf; const struct btf_type *t; struct btf_param *p; int ptr_id = 0, struct_id, tag_id, orig_fn_id; int i, n, arg_idx, arg_cnt, err, rec_idx; int *orig_ids;
/* no .BTF.ext, no problem */ if (!obj->btf_ext || !prog->func_info) return 0;
/* don't do any fix ups if kernel natively supports __arg_ctx */ if (kernel_supports(obj, FEAT_ARG_CTX_TAG)) return 0;
/* some BPF program types just don't have named context structs, so * this fallback mechanism doesn't work for them */ for (i = 0; i < ARRAY_SIZE(global_ctx_map); i++) { if (global_ctx_map[i].prog_type != prog->type) continue; ctx_name = global_ctx_map[i].ctx_name; break; } if (!ctx_name) return 0;
/* remember original func BTF IDs to detect if we already cloned them */ orig_ids = calloc(prog->func_info_cnt, sizeof(*orig_ids)); if (!orig_ids) return -ENOMEM; for (i = 0; i < prog->func_info_cnt; i++) { func_rec = prog->func_info + prog->func_info_rec_size * i; orig_ids[i] = func_rec->type_id; }
/* go through each DECL_TAG with "arg:ctx" and see if it points to one * of our subprogs; if yes and subprog is global and needs adjustment, * clone and adjust FUNC -> FUNC_PROTO combo */ for (i = 1, n = btf__type_cnt(btf); i < n; i++) { /* only DECL_TAG with "arg:ctx" value are interesting */ t = btf__type_by_id(btf, i); if (!btf_is_decl_tag(t)) continue; if (strcmp(btf__str_by_offset(btf, t->name_off), ctx_tag) != 0) continue;
/* only global funcs need adjustment, if at all */ orig_fn_id = t->type; fn_t = btf_type_by_id(btf, orig_fn_id); if (!btf_is_func(fn_t) || btf_func_linkage(fn_t) != BTF_FUNC_GLOBAL) continue;
/* sanity check FUNC -> FUNC_PROTO chain, just in case */ fn_proto_t = btf_type_by_id(btf, fn_t->type); if (!fn_proto_t || !btf_is_func_proto(fn_proto_t)) continue;
/* find corresponding func_info record */ func_rec = NULL; for (rec_idx = 0; rec_idx < prog->func_info_cnt; rec_idx++) { if (orig_ids[rec_idx] == t->type) { func_rec = prog->func_info + prog->func_info_rec_size * rec_idx; break; } } /* current main program doesn't call into this subprog */ if (!func_rec) continue;
/* some more sanity checking of DECL_TAG */ arg_cnt = btf_vlen(fn_proto_t); arg_idx = btf_decl_tag(t)->component_idx; if (arg_idx < 0 || arg_idx >= arg_cnt) continue;
/* check if we should fix up argument type */ p = &btf_params(fn_proto_t)[arg_idx]; fn_name = btf__str_by_offset(btf, fn_t->name_off) ?: "<anon>"; if (!need_func_arg_type_fixup(btf, prog, fn_name, arg_idx, p->type, ctx_name)) continue;
/* clone fn/fn_proto, unless we already did it for another arg */ if (func_rec->type_id == orig_fn_id) { int fn_id;
fn_id = clone_func_btf_info(btf, orig_fn_id, prog); if (fn_id < 0) { err = fn_id; goto err_out; }
/* point func_info record to a cloned FUNC type */ func_rec->type_id = fn_id; }
/* create PTR -> STRUCT type chain to mark PTR_TO_CTX argument; * we do it just once per main BPF program, as all global * funcs share the same program type, so need only PTR -> * STRUCT type chain */ if (ptr_id == 0) { struct_id = btf__add_struct(btf, ctx_name, 0); ptr_id = btf__add_ptr(btf, struct_id); if (ptr_id < 0 || struct_id < 0) { err = -EINVAL; goto err_out; } }
/* for completeness, clone DECL_TAG and point it to cloned param */ tag_id = btf__add_decl_tag(btf, ctx_tag, func_rec->type_id, arg_idx); if (tag_id < 0) { err = -EINVAL; goto err_out; }
/* all the BTF manipulations invalidated pointers, refetch them */ fn_t = btf_type_by_id(btf, func_rec->type_id); fn_proto_t = btf_type_by_id(btf, fn_t->type);
/* fix up type ID pointed to by param */ p = &btf_params(fn_proto_t)[arg_idx]; p->type = ptr_id; }
free(orig_ids); return 0;err_out: free(orig_ids); return err;}
static int bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path){ struct bpf_program *prog; size_t i, j; int err;
if (obj->btf_ext) { err = bpf_object__relocate_core(obj, targ_btf_path); if (err) { pr_warn("failed to perform CO-RE relocations: %s\n", errstr(err)); return err; } bpf_object__sort_relos(obj); }
/* place globals at the end of the arena (if supported) */ if (obj->arena_map_idx >= 0 && kernel_supports(obj, FEAT_LDIMM64_FULL_RANGE_OFF)) { struct bpf_map *arena_map = &obj->maps[obj->arena_map_idx];
obj->arena_data_off = bpf_map_mmap_sz(arena_map) - roundup(obj->arena_data_sz, sysconf(_SC_PAGE_SIZE)); }
/* Before relocating calls pre-process relocations and mark * few ld_imm64 instructions that points to subprogs. * Otherwise bpf_object__reloc_code() later would have to consider * all ld_imm64 insns as relocation candidates. That would * reduce relocation speed, since amount of find_prog_insn_relo() * would increase and most of them will fail to find a relo. */ for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; for (j = 0; j < prog->nr_reloc; j++) { struct reloc_desc *relo = &prog->reloc_desc[j]; struct bpf_insn *insn = &prog->insns[relo->insn_idx];
/* mark the insn, so it's recognized by insn_is_pseudo_func() */ if (relo->type == RELO_SUBPROG_ADDR) insn[0].src_reg = BPF_PSEUDO_FUNC; } }
/* relocate subprogram calls and append used subprograms to main * programs; each copy of subprogram code needs to be relocated * differently for each main program, because its code location might * have changed. * Append subprog relos to main programs to allow data relos to be * processed after text is completely relocated. */ for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; /* sub-program's sub-calls are relocated within the context of * its main program only */ if (prog_is_subprog(obj, prog)) continue; if (!prog->autoload) continue;
err = bpf_object__relocate_calls(obj, prog); if (err) { pr_warn("prog '%s': failed to relocate calls: %s\n", prog->name, errstr(err)); return err; }
err = bpf_prog_assign_exc_cb(obj, prog); if (err) return err; /* Now, also append exception callback if it has not been done already. */ if (prog->exception_cb_idx >= 0) { struct bpf_program *subprog = &obj->programs[prog->exception_cb_idx];
/* Calling exception callback directly is disallowed, which the * verifier will reject later. In case it was processed already, * we can skip this step, otherwise for all other valid cases we * have to append exception callback now. */ if (subprog->sub_insn_off == 0) { err = bpf_object__append_subprog_code(obj, prog, subprog); if (err) return err; err = bpf_object__reloc_code(obj, prog, subprog); if (err) return err; } } } for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; if (!prog->autoload) continue;
/* Process data relos for main programs */ err = bpf_object__relocate_data(obj, prog); if (err) { pr_warn("prog '%s': failed to relocate data references: %s\n", prog->name, errstr(err)); return err; }
/* Fix up .BTF.ext information, if necessary */ err = bpf_program_fixup_func_info(obj, prog); if (err) { pr_warn("prog '%s': failed to perform .BTF.ext fix ups: %s\n", prog->name, errstr(err)); return err; } }
return 0;}
static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data);
static int bpf_object__collect_map_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data){ const int bpf_ptr_sz = 8, host_ptr_sz = sizeof(void *); int i, j, nrels, new_sz; const struct btf_var_secinfo *vi = NULL; const struct btf_type *sec, *var, *def; struct bpf_map *map = NULL, *targ_map = NULL; struct bpf_program *targ_prog = NULL; bool is_prog_array, is_map_in_map; const struct btf_member *member; const char *name, *mname, *type; unsigned int moff; Elf64_Sym *sym; Elf64_Rel *rel; void *tmp;
if (!obj->efile.btf_maps_sec_btf_id || !obj->btf) return -EINVAL; sec = btf__type_by_id(obj->btf, obj->efile.btf_maps_sec_btf_id); if (!sec) return -EINVAL;
nrels = shdr->sh_size / shdr->sh_entsize; for (i = 0; i < nrels; i++) { rel = elf_rel_by_idx(data, i); if (!rel) { pr_warn(".maps relo #%d: failed to get ELF relo\n", i); return -LIBBPF_ERRNO__FORMAT; }
sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info)); if (!sym) { pr_warn(".maps relo #%d: symbol %zx not found\n", i, (size_t)ELF64_R_SYM(rel->r_info)); return -LIBBPF_ERRNO__FORMAT; } name = elf_sym_str(obj, sym->st_name) ?: "<?>";
pr_debug(".maps relo #%d: for %zd value %zd rel->r_offset %zu name %d ('%s')\n", i, (ssize_t)(rel->r_info >> 32), (size_t)sym->st_value, (size_t)rel->r_offset, sym->st_name, name);
for (j = 0; j < obj->nr_maps; j++) { map = &obj->maps[j]; if (map->sec_idx != obj->efile.btf_maps_shndx) continue;
vi = btf_var_secinfos(sec) + map->btf_var_idx; if (vi->offset <= rel->r_offset && rel->r_offset + bpf_ptr_sz <= vi->offset + vi->size) break; } if (j == obj->nr_maps) { pr_warn(".maps relo #%d: cannot find map '%s' at rel->r_offset %zu\n", i, name, (size_t)rel->r_offset); return -EINVAL; }
is_map_in_map = bpf_map_type__is_map_in_map(map->def.type); is_prog_array = map->def.type == BPF_MAP_TYPE_PROG_ARRAY; type = is_map_in_map ? "map" : "prog"; if (is_map_in_map) { if (sym->st_shndx != obj->efile.btf_maps_shndx) { pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n", i, name); return -LIBBPF_ERRNO__RELOC; } if (map->def.type == BPF_MAP_TYPE_HASH_OF_MAPS && map->def.key_size != sizeof(int)) { pr_warn(".maps relo #%d: hash-of-maps '%s' should have key size %zu.\n", i, map->name, sizeof(int)); return -EINVAL; } targ_map = bpf_object__find_map_by_name(obj, name); if (!targ_map) { pr_warn(".maps relo #%d: '%s' isn't a valid map reference\n", i, name); return -ESRCH; } } else if (is_prog_array) { targ_prog = bpf_object__find_program_by_name(obj, name); if (!targ_prog) { pr_warn(".maps relo #%d: '%s' isn't a valid program reference\n", i, name); return -ESRCH; } if (targ_prog->sec_idx != sym->st_shndx || targ_prog->sec_insn_off * 8 != sym->st_value || prog_is_subprog(obj, targ_prog)) { pr_warn(".maps relo #%d: '%s' isn't an entry-point program\n", i, name); return -LIBBPF_ERRNO__RELOC; } } else { return -EINVAL; }
var = btf__type_by_id(obj->btf, vi->type); def = skip_mods_and_typedefs(obj->btf, var->type, NULL); if (btf_vlen(def) == 0) return -EINVAL; member = btf_members(def) + btf_vlen(def) - 1; mname = btf__name_by_offset(obj->btf, member->name_off); if (strcmp(mname, "values")) return -EINVAL;
moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8; if (rel->r_offset - vi->offset < moff) return -EINVAL;
moff = rel->r_offset - vi->offset - moff; /* here we use BPF pointer size, which is always 64 bit, as we * are parsing ELF that was built for BPF target */ if (moff % bpf_ptr_sz) return -EINVAL; moff /= bpf_ptr_sz; if (moff >= map->init_slots_sz) { new_sz = moff + 1; tmp = libbpf_reallocarray(map->init_slots, new_sz, host_ptr_sz); if (!tmp) return -ENOMEM; map->init_slots = tmp; memset(map->init_slots + map->init_slots_sz, 0, (new_sz - map->init_slots_sz) * host_ptr_sz); map->init_slots_sz = new_sz; } map->init_slots[moff] = is_map_in_map ? (void *)targ_map : (void *)targ_prog;
pr_debug(".maps relo #%d: map '%s' slot [%d] points to %s '%s'\n", i, map->name, moff, type, name); }
return 0;}
static int bpf_object__collect_relos(struct bpf_object *obj){ int i, err;
for (i = 0; i < obj->efile.sec_cnt; i++) { struct elf_sec_desc *sec_desc = &obj->efile.secs[i]; Elf64_Shdr *shdr; Elf_Data *data; int idx;
if (sec_desc->sec_type != SEC_RELO) continue;
shdr = sec_desc->shdr; data = sec_desc->data; idx = shdr->sh_info;
if (shdr->sh_type != SHT_REL || idx < 0 || idx >= obj->efile.sec_cnt) { pr_warn("internal error at %d\n", __LINE__); return -LIBBPF_ERRNO__INTERNAL; }
if (obj->efile.secs[idx].sec_type == SEC_ST_OPS) err = bpf_object__collect_st_ops_relos(obj, shdr, data); else if (idx == obj->efile.btf_maps_shndx) err = bpf_object__collect_map_relos(obj, shdr, data); else err = bpf_object__collect_prog_relos(obj, shdr, data); if (err) return err; }
bpf_object__sort_relos(obj); return 0;}
static bool insn_is_helper_call(struct bpf_insn *insn, enum bpf_func_id *func_id){ if (BPF_CLASS(insn->code) == BPF_JMP && BPF_OP(insn->code) == BPF_CALL && BPF_SRC(insn->code) == BPF_K && insn->src_reg == 0 && insn->dst_reg == 0) { *func_id = insn->imm; return true; } return false;}
static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program *prog){ struct bpf_insn *insn = prog->insns; enum bpf_func_id func_id; int i;
if (obj->gen_loader) return 0;
for (i = 0; i < prog->insns_cnt; i++, insn++) { if (!insn_is_helper_call(insn, &func_id)) continue;
/* on kernels that don't yet support * bpf_probe_read_{kernel,user}[_str] helpers, fall back * to bpf_probe_read() which works well for old kernels */ switch (func_id) { case BPF_FUNC_probe_read_kernel: case BPF_FUNC_probe_read_user: if (!kernel_supports(obj, FEAT_PROBE_READ_KERN)) insn->imm = BPF_FUNC_probe_read; break; case BPF_FUNC_probe_read_kernel_str: case BPF_FUNC_probe_read_user_str: if (!kernel_supports(obj, FEAT_PROBE_READ_KERN)) insn->imm = BPF_FUNC_probe_read_str; break; default: break; } } return 0;}
static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name, int *btf_obj_fd, int *btf_type_id);
static inline bool is_tracing_multi(enum bpf_attach_type type){ return type == BPF_TRACE_FENTRY_MULTI || type == BPF_TRACE_FEXIT_MULTI || type == BPF_TRACE_FSESSION_MULTI;}
static const struct module_btf *find_attach_module(struct bpf_object *obj, const char *attach){ const char *sep, *mod_name = NULL; int i, mod_len, err;
/* * We expect attach string in the form of either * - function_pattern or * - <module>:function_pattern */ sep = strchr(attach, ':'); if (sep) { mod_name = attach; mod_len = sep - mod_name; } if (!mod_name) return NULL;
err = load_module_btfs(obj); if (err) return NULL;
for (i = 0; i < obj->btf_module_cnt; i++) { const struct module_btf *mod = &obj->btf_modules[i];
if (strncmp(mod->name, mod_name, mod_len) == 0 && mod->name[mod_len] == '\0') return mod; } return NULL;}
static int tracing_multi_mod_fd(struct bpf_program *prog, int *btf_obj_fd){ const char *attach_name, *sep; const struct module_btf *mod;
*btf_obj_fd = 0; attach_name = strchr(prog->sec_name, '/');
/* Program with no details in spec, using kernel btf. */ if (!attach_name) return 0;
/* Program with no module section, using kernel btf. */ sep = strchr(++attach_name, ':'); if (!sep) return 0;
/* Program with module specified, get its btf fd. */ mod = find_attach_module(prog->obj, attach_name); if (!mod) return -EINVAL;
*btf_obj_fd = mod->fd; return 0;}
/* this is called as prog->sec_def->prog_prepare_load_fn for libbpf-supported sec_defs */static int libbpf_prepare_prog_load(struct bpf_program *prog, struct bpf_prog_load_opts *opts, long cookie){ enum sec_def_flags def = cookie;
/* old kernels might not support specifying expected_attach_type */ if ((def & SEC_EXP_ATTACH_OPT) && !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE)) opts->expected_attach_type = 0;
if (def & SEC_SLEEPABLE) opts->prog_flags |= BPF_F_SLEEPABLE;
if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_FRAGS)) opts->prog_flags |= BPF_F_XDP_HAS_FRAGS;
/* special check for usdt to use uprobe_multi link */ if ((def & SEC_USDT) && kernel_supports(prog->obj, FEAT_UPROBE_MULTI_LINK)) { /* for BPF_TRACE_UPROBE_MULTI, user might want to query expected_attach_type * in prog, and expected_attach_type we set in kernel is from opts, so we * update both. */ prog->expected_attach_type = BPF_TRACE_UPROBE_MULTI; opts->expected_attach_type = BPF_TRACE_UPROBE_MULTI; }
if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) { int btf_obj_fd = 0, btf_type_id = 0, err; const char *attach_name;
attach_name = strchr(prog->sec_name, '/'); if (!attach_name) { /* if BPF program is annotated with just SEC("fentry") * (or similar) without declaratively specifying * target, then it is expected that target will be * specified with bpf_program__set_attach_target() at * runtime before BPF object load step. If not, then * there is nothing to load into the kernel as BPF * verifier won't be able to validate BPF program * correctness anyways. */ pr_warn("prog '%s': no BTF-based attach target is specified, use bpf_program__set_attach_target()\n", prog->name); return -EINVAL; } attach_name++; /* skip over / */
err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id); if (err) return err;
/* cache resolved BTF FD and BTF type ID in the prog */ prog->attach_btf_obj_fd = btf_obj_fd; prog->attach_btf_id = btf_type_id;
/* but by now libbpf common logic is not utilizing * prog->atach_btf_obj_fd/prog->attach_btf_id anymore because * this callback is called after opts were populated by * libbpf, so this callback has to update opts explicitly here */ opts->attach_btf_obj_fd = btf_obj_fd; opts->attach_btf_id = btf_type_id; }
if (is_tracing_multi(prog->expected_attach_type)) { int err, btf_obj_fd = 0;
err = tracing_multi_mod_fd(prog, &btf_obj_fd); if (err < 0) return err;
prog->attach_btf_obj_fd = btf_obj_fd; opts->attach_btf_obj_fd = btf_obj_fd; }
return 0;}
static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz);
static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, const char *license, __u32 kern_version, int *prog_fd){ LIBBPF_OPTS(bpf_prog_load_opts, load_attr); const char *prog_name = NULL; size_t log_buf_size = 0; char *log_buf = NULL, *tmp; bool own_log_buf = true; __u32 log_level = prog->log_level; int ret, err;
/* Be more helpful by rejecting programs that can't be validated early * with more meaningful and actionable error message. */ switch (prog->type) { case BPF_PROG_TYPE_UNSPEC: /* * The program type must be set. Most likely we couldn't find a proper * section definition at load time, and thus we didn't infer the type. */ pr_warn("prog '%s': missing BPF prog type, check ELF section name '%s'\n", prog->name, prog->sec_name); return -EINVAL; case BPF_PROG_TYPE_STRUCT_OPS: if (prog->attach_btf_id == 0) { pr_warn("prog '%s': SEC(\"struct_ops\") program isn't referenced anywhere, did you forget to use it?\n", prog->name); return -EINVAL; } break; default: break; }
if (!insns || !insns_cnt) return -EINVAL;
if (kernel_supports(obj, FEAT_PROG_NAME)) prog_name = prog->name; load_attr.attach_prog_fd = prog->attach_prog_fd; load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd; load_attr.attach_btf_id = prog->attach_btf_id; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; load_attr.expected_attach_type = prog->expected_attach_type;
/* specify func_info/line_info only if kernel supports them */ if (obj->btf && btf__fd(obj->btf) >= 0 && kernel_supports(obj, FEAT_BTF_FUNC)) { load_attr.prog_btf_fd = btf__fd(obj->btf); load_attr.func_info = prog->func_info; load_attr.func_info_rec_size = prog->func_info_rec_size; load_attr.func_info_cnt = prog->func_info_cnt; load_attr.line_info = prog->line_info; load_attr.line_info_rec_size = prog->line_info_rec_size; load_attr.line_info_cnt = prog->line_info_cnt; } load_attr.log_level = log_level; load_attr.prog_flags = prog->prog_flags; load_attr.fd_array = obj->fd_array;
load_attr.token_fd = obj->token_fd; if (obj->token_fd) load_attr.prog_flags |= BPF_F_TOKEN_FD;
/* adjust load_attr if sec_def provides custom preload callback */ if (prog->sec_def && prog->sec_def->prog_prepare_load_fn) { err = prog->sec_def->prog_prepare_load_fn(prog, &load_attr, prog->sec_def->cookie); if (err < 0) { pr_warn("prog '%s': failed to prepare load attributes: %s\n", prog->name, errstr(err)); return err; } insns = prog->insns; insns_cnt = prog->insns_cnt; }
if (obj->gen_loader) { bpf_gen__prog_load(obj->gen_loader, prog->type, prog->name, license, insns, insns_cnt, &load_attr, prog - obj->programs); *prog_fd = -1; return 0; }
retry_load: /* if log_level is zero, we don't request logs initially even if * custom log_buf is specified; if the program load fails, then we'll * bump log_level to 1 and use either custom log_buf or we'll allocate * our own and retry the load to get details on what failed */ if (log_level) { if (prog->log_buf) { log_buf = prog->log_buf; log_buf_size = prog->log_size; own_log_buf = false; } else if (obj->log_buf) { log_buf = obj->log_buf; log_buf_size = obj->log_size; own_log_buf = false; } else { log_buf_size = max((size_t)BPF_LOG_BUF_SIZE, log_buf_size * 2); tmp = realloc(log_buf, log_buf_size); if (!tmp) { ret = -ENOMEM; goto out; } log_buf = tmp; log_buf[0] = '\0'; own_log_buf = true; } }
load_attr.log_buf = log_buf; load_attr.log_size = log_buf_size; load_attr.log_level = log_level;
ret = bpf_prog_load(prog->type, prog_name, license, insns, insns_cnt, &load_attr); if (ret >= 0) { if (log_level && own_log_buf) { pr_debug("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n", prog->name, log_buf); }
if (obj->has_rodata && kernel_supports(obj, FEAT_PROG_BIND_MAP)) { struct bpf_map *map; int i;
for (i = 0; i < obj->nr_maps; i++) { map = &prog->obj->maps[i]; if (map->libbpf_type != LIBBPF_MAP_RODATA) continue;
if (bpf_prog_bind_map(ret, map->fd, NULL)) { pr_warn("prog '%s': failed to bind map '%s': %s\n", prog->name, map->real_name, errstr(errno)); /* Don't fail hard if can't bind rodata. */ } } }
*prog_fd = ret; ret = 0; goto out; }
if (log_level == 0) { log_level = 1; goto retry_load; } /* On ENOSPC, increase log buffer size and retry, unless custom * log_buf is specified. * Be careful to not overflow u32, though. Kernel's log buf size limit * isn't part of UAPI so it can always be bumped to full 4GB. So don't * multiply by 2 unless we are sure we'll fit within 32 bits. * Currently, we'll get -EINVAL when we reach (UINT_MAX >> 2). */ if (own_log_buf && errno == ENOSPC && log_buf_size <= UINT_MAX / 2) goto retry_load;
ret = -errno;
/* post-process verifier log to improve error descriptions */ fixup_verifier_log(prog, log_buf, log_buf_size);
pr_warn("prog '%s': BPF program load failed: %s\n", prog->name, errstr(errno)); pr_perm_msg(ret);
if (own_log_buf && log_buf && log_buf[0] != '\0') { pr_warn("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n", prog->name, log_buf); }
out: if (own_log_buf) free(log_buf); return ret;}
static char *find_prev_line(char *buf, char *cur){ char *p;
if (cur == buf) /* end of a log buf */ return NULL;
p = cur - 1; while (p - 1 >= buf && *(p - 1) != '\n') p--;
return p;}
static void patch_log(char *buf, size_t buf_sz, size_t log_sz, char *orig, size_t orig_sz, const char *patch){ /* size of the remaining log content to the right from the to-be-replaced part */ size_t rem_sz = (buf + log_sz) - (orig + orig_sz); size_t patch_sz = strlen(patch);
if (patch_sz != orig_sz) { /* If patch line(s) are longer than original piece of verifier log, * shift log contents by (patch_sz - orig_sz) bytes to the right * starting from after to-be-replaced part of the log. * * If patch line(s) are shorter than original piece of verifier log, * shift log contents by (orig_sz - patch_sz) bytes to the left * starting from after to-be-replaced part of the log * * We need to be careful about not overflowing available * buf_sz capacity. If that's the case, we'll truncate the end * of the original log, as necessary. */ if (patch_sz > orig_sz) { if (orig + patch_sz >= buf + buf_sz) { /* patch is big enough to cover remaining space completely */ patch_sz -= (orig + patch_sz) - (buf + buf_sz) + 1; rem_sz = 0; } else if (patch_sz - orig_sz > buf_sz - log_sz) { /* patch causes part of remaining log to be truncated */ rem_sz -= (patch_sz - orig_sz) - (buf_sz - log_sz); } } /* shift remaining log to the right by calculated amount */ memmove(orig + patch_sz, orig + orig_sz, rem_sz); }
memcpy(orig, patch, patch_sz);}
static void fixup_log_failed_core_relo(struct bpf_program *prog, char *buf, size_t buf_sz, size_t log_sz, char *line1, char *line2, char *line3){ /* Expected log for failed and not properly guarded CO-RE relocation: * line1 -> 123: (85) call unknown#195896080 * line2 -> invalid func unknown#195896080 * line3 -> <anything else or end of buffer> * * "123" is the index of the instruction that was poisoned. We extract * instruction index to find corresponding CO-RE relocation and * replace this part of the log with more relevant information about * failed CO-RE relocation. */ const struct bpf_core_relo *relo; struct bpf_core_spec spec; char patch[512], spec_buf[256]; int insn_idx, err, spec_len;
if (sscanf(line1, "%d: (%*d) call unknown#195896080\n", &insn_idx) != 1) return;
relo = find_relo_core(prog, insn_idx); if (!relo) return;
err = bpf_core_parse_spec(prog->name, prog->obj->btf, relo, &spec); if (err) return;
spec_len = bpf_core_format_spec(spec_buf, sizeof(spec_buf), &spec); snprintf(patch, sizeof(patch), "%d: <invalid CO-RE relocation>\n" "failed to resolve CO-RE relocation %s%s\n", insn_idx, spec_buf, spec_len >= sizeof(spec_buf) ? "..." : "");
patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch);}
static void fixup_log_missing_map_load(struct bpf_program *prog, char *buf, size_t buf_sz, size_t log_sz, char *line1, char *line2, char *line3){ /* Expected log for failed and not properly guarded map reference: * line1 -> 123: (85) call unknown#2001000345 * line2 -> invalid func unknown#2001000345 * line3 -> <anything else or end of buffer> * * "123" is the index of the instruction that was poisoned. * "345" in "2001000345" is a map index in obj->maps to fetch map name. */ struct bpf_object *obj = prog->obj; const struct bpf_map *map; int insn_idx, map_idx; char patch[128];
if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &map_idx) != 2) return;
map_idx -= POISON_LDIMM64_MAP_BASE; if (map_idx < 0 || map_idx >= obj->nr_maps) return; map = &obj->maps[map_idx];
snprintf(patch, sizeof(patch), "%d: <invalid BPF map reference>\n" "BPF map '%s' is referenced but wasn't created\n", insn_idx, map->name);
patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch);}
static void fixup_log_missing_kfunc_call(struct bpf_program *prog, char *buf, size_t buf_sz, size_t log_sz, char *line1, char *line2, char *line3){ /* Expected log for failed and not properly guarded kfunc call: * line1 -> 123: (85) call unknown#2002000345 * line2 -> invalid func unknown#2002000345 * line3 -> <anything else or end of buffer> * * "123" is the index of the instruction that was poisoned. * "345" in "2002000345" is an extern index in obj->externs to fetch kfunc name. */ struct bpf_object *obj = prog->obj; const struct extern_desc *ext; int insn_idx, ext_idx; char patch[128];
if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &ext_idx) != 2) return;
ext_idx -= POISON_CALL_KFUNC_BASE; if (ext_idx < 0 || ext_idx >= obj->nr_extern) return; ext = &obj->externs[ext_idx];
snprintf(patch, sizeof(patch), "%d: <invalid kfunc call>\n" "kfunc '%s' is referenced but wasn't resolved\n", insn_idx, ext->name);
patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch);}
static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz){ /* look for familiar error patterns in last N lines of the log */ const size_t max_last_line_cnt = 10; char *prev_line, *cur_line, *next_line; size_t log_sz; int i;
if (!buf) return;
log_sz = strlen(buf) + 1; next_line = buf + log_sz - 1;
for (i = 0; i < max_last_line_cnt; i++, next_line = cur_line) { cur_line = find_prev_line(buf, next_line); if (!cur_line) return;
if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) { prev_line = find_prev_line(buf, cur_line); if (!prev_line) continue;
/* failed CO-RE relocation case */ fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz, prev_line, cur_line, next_line); return; } else if (str_has_pfx(cur_line, "invalid func unknown#"POISON_LDIMM64_MAP_PFX)) { prev_line = find_prev_line(buf, cur_line); if (!prev_line) continue;
/* reference to uncreated BPF map */ fixup_log_missing_map_load(prog, buf, buf_sz, log_sz, prev_line, cur_line, next_line); return; } else if (str_has_pfx(cur_line, "invalid func unknown#"POISON_CALL_KFUNC_PFX)) { prev_line = find_prev_line(buf, cur_line); if (!prev_line) continue;
/* reference to unresolved kfunc */ fixup_log_missing_kfunc_call(prog, buf, buf_sz, log_sz, prev_line, cur_line, next_line); return; } }}
static int bpf_program_record_relos(struct bpf_program *prog){ struct bpf_object *obj = prog->obj; int i;
for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct extern_desc *ext = &obj->externs[relo->ext_idx]; int kind;
switch (relo->type) { case RELO_EXTERN_LD64: if (ext->type != EXT_KSYM) continue; kind = btf_is_var(btf__type_by_id(obj->btf, ext->btf_id)) ? BTF_KIND_VAR : BTF_KIND_FUNC; bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak, !ext->ksym.type_id, true, kind, relo->insn_idx); break; case RELO_EXTERN_CALL: bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak, false, false, BTF_KIND_FUNC, relo->insn_idx); break; case RELO_CORE: { struct bpf_core_relo cr = { .insn_off = relo->insn_idx * 8, .type_id = relo->core_relo->type_id, .access_str_off = relo->core_relo->access_str_off, .kind = relo->core_relo->kind, };
bpf_gen__record_relo_core(obj->gen_loader, &cr); break; } default: continue; } } return 0;}
static intbpf_object__load_progs(struct bpf_object *obj, int log_level){ struct bpf_program *prog; size_t i; int err;
for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; if (!prog->autoload) { pr_debug("prog '%s': skipped loading\n", prog->name); continue; } prog->log_level |= log_level;
if (obj->gen_loader) bpf_program_record_relos(prog);
err = bpf_object_load_prog(obj, prog, prog->insns, prog->insns_cnt, obj->license, obj->kern_version, &prog->fd); if (err) { pr_warn("prog '%s': failed to load: %s\n", prog->name, errstr(err)); return err; } }
bpf_object__free_relocs(obj); return 0;}
static int bpf_object_prepare_progs(struct bpf_object *obj){ struct bpf_program *prog; size_t i; int err;
for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; err = bpf_object__sanitize_prog(obj, prog); if (err) return err; } return 0;}
static const struct bpf_sec_def *find_sec_def(const char *sec_name);
static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object_open_opts *opts){ struct bpf_program *prog; int err;
bpf_object__for_each_program(prog, obj) { prog->sec_def = find_sec_def(prog->sec_name); if (!prog->sec_def) { /* couldn't guess, but user might manually specify */ pr_debug("prog '%s': unrecognized ELF section name '%s'\n", prog->name, prog->sec_name); continue; }
prog->type = prog->sec_def->prog_type; prog->expected_attach_type = prog->sec_def->expected_attach_type;
/* sec_def can have custom callback which should be called * after bpf_program is initialized to adjust its properties */ if (prog->sec_def->prog_setup_fn) { err = prog->sec_def->prog_setup_fn(prog, prog->sec_def->cookie); if (err < 0) { pr_warn("prog '%s': failed to initialize: %s\n", prog->name, errstr(err)); return err; } } }
return 0;}
static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf, size_t obj_buf_sz, const char *obj_name, const struct bpf_object_open_opts *opts){ const char *kconfig, *btf_tmp_path, *token_path; struct bpf_object *obj; int err; char *log_buf; size_t log_size; __u32 log_level;
if (obj_buf && !obj_name) return ERR_PTR(-EINVAL);
if (elf_version(EV_CURRENT) == EV_NONE) { pr_warn("failed to init libelf for %s\n", path ? : "(mem buf)"); return ERR_PTR(-LIBBPF_ERRNO__LIBELF); }
if (!OPTS_VALID(opts, bpf_object_open_opts)) return ERR_PTR(-EINVAL);
obj_name = OPTS_GET(opts, object_name, NULL) ?: obj_name; if (obj_buf) { path = obj_name; pr_debug("loading object '%s' from buffer\n", obj_name); } else { pr_debug("loading object from %s\n", path); }
log_buf = OPTS_GET(opts, kernel_log_buf, NULL); log_size = OPTS_GET(opts, kernel_log_size, 0); log_level = OPTS_GET(opts, kernel_log_level, 0); if (log_size > UINT_MAX) return ERR_PTR(-EINVAL); if (log_size && !log_buf) return ERR_PTR(-EINVAL);
token_path = OPTS_GET(opts, bpf_token_path, NULL); /* if user didn't specify bpf_token_path explicitly, check if * LIBBPF_BPF_TOKEN_PATH envvar was set and treat it as bpf_token_path * option */ if (!token_path) token_path = getenv("LIBBPF_BPF_TOKEN_PATH"); if (token_path && strlen(token_path) >= PATH_MAX) return ERR_PTR(-ENAMETOOLONG);
obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name); if (IS_ERR(obj)) return obj;
obj->log_buf = log_buf; obj->log_size = log_size; obj->log_level = log_level;
if (token_path) { obj->token_path = strdup(token_path); if (!obj->token_path) { err = -ENOMEM; goto out; } }
btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL); if (btf_tmp_path) { if (strlen(btf_tmp_path) >= PATH_MAX) { err = -ENAMETOOLONG; goto out; } obj->btf_custom_path = strdup(btf_tmp_path); if (!obj->btf_custom_path) { err = -ENOMEM; goto out; } }
kconfig = OPTS_GET(opts, kconfig, NULL); if (kconfig) { obj->kconfig = strdup(kconfig); if (!obj->kconfig) { err = -ENOMEM; goto out; } }
err = bpf_object__elf_init(obj); err = err ? : bpf_object__elf_collect(obj); err = err ? : bpf_object__collect_externs(obj); err = err ? : bpf_object_fixup_btf(obj); err = err ? : bpf_object__init_maps(obj, opts); err = err ? : bpf_object_init_progs(obj, opts); err = err ? : bpf_object__collect_relos(obj); if (err) goto out;
bpf_object__elf_finish(obj);
return obj;out: bpf_object__close(obj); return ERR_PTR(err);}
struct bpf_object *bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts){ if (!path) return libbpf_err_ptr(-EINVAL);
return libbpf_ptr(bpf_object_open(path, NULL, 0, NULL, opts));}
struct bpf_object *bpf_object__open(const char *path){ return bpf_object__open_file(path, NULL);}
struct bpf_object *bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, const struct bpf_object_open_opts *opts){ char tmp_name[64];
if (!obj_buf || obj_buf_sz == 0) return libbpf_err_ptr(-EINVAL);
/* create a (quite useless) default "name" for this memory buffer object */ snprintf(tmp_name, sizeof(tmp_name), "%lx-%zx", (unsigned long)obj_buf, obj_buf_sz);
return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, tmp_name, opts));}
static int bpf_object_unload(struct bpf_object *obj){ size_t i;
if (!obj) return libbpf_err(-EINVAL);
for (i = 0; i < obj->nr_maps; i++) { zclose(obj->maps[i].fd); if (obj->maps[i].st_ops) zfree(&obj->maps[i].st_ops->kern_vdata); }
for (i = 0; i < obj->nr_programs; i++) bpf_program__unload(&obj->programs[i]);
return 0;}
static int bpf_object__sanitize_maps(struct bpf_object *obj){ struct bpf_map *m;
bpf_object__for_each_map(m, obj) { if (!bpf_map__is_internal(m)) continue; if (!kernel_supports(obj, FEAT_ARRAY_MMAP)) m->def.map_flags &= ~BPF_F_MMAPABLE; }
return 0;}
typedef int (*kallsyms_cb_t)(unsigned long long sym_addr, char sym_type, const char *sym_name, void *ctx);
static int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *ctx){ char sym_type, sym_name[500]; unsigned long long sym_addr; int ret, err = 0; FILE *f;
f = fopen("/proc/kallsyms", "re"); if (!f) { err = -errno; pr_warn("failed to open /proc/kallsyms: %s\n", errstr(err)); return err; }
while (true) { ret = fscanf(f, "%llx %c %499s%*[^\n]\n", &sym_addr, &sym_type, sym_name); if (ret == EOF && feof(f)) break; if (ret != 3) { pr_warn("failed to read kallsyms entry: %d\n", ret); err = -EINVAL; break; }
err = cb(sym_addr, sym_type, sym_name, ctx); if (err) break; }
fclose(f); return err;}
static int kallsyms_cb(unsigned long long sym_addr, char sym_type, const char *sym_name, void *ctx){ struct bpf_object *obj = ctx; const struct btf_type *t; struct extern_desc *ext; const char *res;
res = strstr(sym_name, ".llvm."); if (sym_type == 'd' && res) ext = find_extern_by_name_with_len(obj, sym_name, res - sym_name); else ext = find_extern_by_name(obj, sym_name); if (!ext || ext->type != EXT_KSYM) return 0;
t = btf__type_by_id(obj->btf, ext->btf_id); if (!btf_is_var(t)) return 0;
if (ext->is_set && ext->ksym.addr != sym_addr) { pr_warn("extern (ksym) '%s': resolution is ambiguous: 0x%llx or 0x%llx\n", sym_name, ext->ksym.addr, sym_addr); return -EINVAL; } if (!ext->is_set) { ext->is_set = true; ext->ksym.addr = sym_addr; pr_debug("extern (ksym) '%s': set to 0x%llx\n", sym_name, sym_addr); } return 0;}
static int bpf_object__read_kallsyms_file(struct bpf_object *obj){ return libbpf_kallsyms_parse(kallsyms_cb, obj);}
static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, __u16 kind, struct btf **res_btf, struct module_btf **res_mod_btf){ struct module_btf *mod_btf; struct btf *btf; int i, id, err;
btf = obj->btf_vmlinux; mod_btf = NULL; id = btf__find_by_name_kind(btf, ksym_name, kind);
if (id == -ENOENT) { err = load_module_btfs(obj); if (err) return err;
for (i = 0; i < obj->btf_module_cnt; i++) { /* we assume module_btf's BTF FD is always >0 */ mod_btf = &obj->btf_modules[i]; btf = mod_btf->btf; id = btf__find_by_name_kind_own(btf, ksym_name, kind); if (id != -ENOENT) break; } } if (id <= 0) return -ESRCH;
*res_btf = btf; *res_mod_btf = mod_btf; return id;}
static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj, struct extern_desc *ext){ const struct btf_type *targ_var, *targ_type; __u32 targ_type_id, local_type_id; struct module_btf *mod_btf = NULL; const char *targ_var_name; struct btf *btf = NULL; int id, err;
id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &mod_btf); if (id < 0) { if (id == -ESRCH && ext->is_weak) return 0; pr_warn("extern (var ksym) '%s': not found in kernel BTF\n", ext->name); return id; }
/* find local type_id */ local_type_id = ext->ksym.type_id;
/* find target type_id */ targ_var = btf__type_by_id(btf, id); targ_var_name = btf__name_by_offset(btf, targ_var->name_off); targ_type = skip_mods_and_typedefs(btf, targ_var->type, &targ_type_id);
err = bpf_core_types_are_compat(obj->btf, local_type_id, btf, targ_type_id); if (err <= 0) { const struct btf_type *local_type; const char *targ_name, *local_name;
local_type = btf__type_by_id(obj->btf, local_type_id); local_name = btf__name_by_offset(obj->btf, local_type->name_off); targ_name = btf__name_by_offset(btf, targ_type->name_off);
pr_warn("extern (var ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n", ext->name, local_type_id, btf_kind_str(local_type), local_name, targ_type_id, btf_kind_str(targ_type), targ_name); return -EINVAL; }
ext->is_set = true; ext->ksym.kernel_btf_obj_fd = mod_btf ? mod_btf->fd : 0; ext->ksym.kernel_btf_id = id; pr_debug("extern (var ksym) '%s': resolved to [%d] %s %s\n", ext->name, id, btf_kind_str(targ_var), targ_var_name);
return 0;}
static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj, struct extern_desc *ext){ int local_func_proto_id, kfunc_proto_id, kfunc_id; struct module_btf *mod_btf = NULL; const struct btf_type *kern_func; struct btf *kern_btf = NULL; int ret;
local_func_proto_id = ext->ksym.type_id;
kfunc_id = find_ksym_btf_id(obj, ext->essent_name ?: ext->name, BTF_KIND_FUNC, &kern_btf, &mod_btf); if (kfunc_id < 0) { if (kfunc_id == -ESRCH && ext->is_weak) return 0; pr_warn("extern (func ksym) '%s': not found in kernel or module BTFs\n", ext->name); return kfunc_id; }
kern_func = btf__type_by_id(kern_btf, kfunc_id); kfunc_proto_id = kern_func->type;
ret = bpf_core_types_are_compat(obj->btf, local_func_proto_id, kern_btf, kfunc_proto_id); if (ret <= 0) { if (ext->is_weak) return 0;
pr_warn("extern (func ksym) '%s': func_proto [%d] incompatible with %s [%d]\n", ext->name, local_func_proto_id, mod_btf ? mod_btf->name : "vmlinux", kfunc_proto_id); return -EINVAL; }
/* set index for module BTF fd in fd_array, if unset */ if (mod_btf && !mod_btf->fd_array_idx) { /* insn->off is s16 */ if (obj->fd_array_cnt == INT16_MAX) { pr_warn("extern (func ksym) '%s': module BTF fd index %d too big to fit in bpf_insn offset\n", ext->name, mod_btf->fd_array_idx); return -E2BIG; } /* Cannot use index 0 for module BTF fd */ if (!obj->fd_array_cnt) obj->fd_array_cnt = 1;
ret = libbpf_ensure_mem((void **)&obj->fd_array, &obj->fd_array_cap, sizeof(int), obj->fd_array_cnt + 1); if (ret) return ret; mod_btf->fd_array_idx = obj->fd_array_cnt; /* we assume module BTF FD is always >0 */ obj->fd_array[obj->fd_array_cnt++] = mod_btf->fd; }
ext->is_set = true; ext->ksym.kernel_btf_id = kfunc_id; ext->ksym.btf_fd_idx = mod_btf ? mod_btf->fd_array_idx : 0; /* Also set kernel_btf_obj_fd to make sure that bpf_object__relocate_data() * populates FD into ld_imm64 insn when it's used to point to kfunc. * {kernel_btf_id, btf_fd_idx} -> fixup bpf_call. * {kernel_btf_id, kernel_btf_obj_fd} -> fixup ld_imm64. */ ext->ksym.kernel_btf_obj_fd = mod_btf ? mod_btf->fd : 0; pr_debug("extern (func ksym) '%s': resolved to %s [%d]\n", ext->name, mod_btf ? mod_btf->name : "vmlinux", kfunc_id);
return 0;}
static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj){ const struct btf_type *t; struct extern_desc *ext; int i, err;
for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; if (ext->type != EXT_KSYM || !ext->ksym.type_id) continue;
if (obj->gen_loader) { ext->is_set = true; ext->ksym.kernel_btf_obj_fd = 0; ext->ksym.kernel_btf_id = 0; continue; } t = btf__type_by_id(obj->btf, ext->btf_id); if (btf_is_var(t)) err = bpf_object__resolve_ksym_var_btf_id(obj, ext); else err = bpf_object__resolve_ksym_func_btf_id(obj, ext); if (err) return err; } return 0;}
static int bpf_object__resolve_externs(struct bpf_object *obj, const char *extra_kconfig){ bool need_config = false, need_kallsyms = false; bool need_vmlinux_btf = false; struct extern_desc *ext; void *kcfg_data = NULL; int err, i;
if (obj->nr_extern == 0) return 0;
if (obj->kconfig_map_idx >= 0) kcfg_data = obj->maps[obj->kconfig_map_idx].mmaped;
for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i];
if (ext->type == EXT_KSYM) { if (ext->ksym.type_id) need_vmlinux_btf = true; else need_kallsyms = true; continue; } else if (ext->type == EXT_KCFG) { void *ext_ptr = kcfg_data + ext->kcfg.data_off; __u64 value = 0;
/* Kconfig externs need actual /proc/config.gz */ if (str_has_pfx(ext->name, "CONFIG_")) { need_config = true; continue; }
/* Virtual kcfg externs are customly handled by libbpf */ if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { value = get_kernel_version(); if (!value) { pr_warn("extern (kcfg) '%s': failed to get kernel version\n", ext->name); return -EINVAL; } } else if (strcmp(ext->name, "LINUX_HAS_BPF_COOKIE") == 0) { value = kernel_supports(obj, FEAT_BPF_COOKIE); } else if (strcmp(ext->name, "LINUX_HAS_SYSCALL_WRAPPER") == 0) { value = kernel_supports(obj, FEAT_SYSCALL_WRAPPER); } else if (!str_has_pfx(ext->name, "LINUX_") || !ext->is_weak) { /* Currently libbpf supports only CONFIG_ and LINUX_ prefixed * __kconfig externs, where LINUX_ ones are virtual and filled out * customly by libbpf (their values don't come from Kconfig). * If LINUX_xxx variable is not recognized by libbpf, but is marked * __weak, it defaults to zero value, just like for CONFIG_xxx * externs. */ pr_warn("extern (kcfg) '%s': unrecognized virtual extern\n", ext->name); return -EINVAL; }
err = set_kcfg_value_num(ext, ext_ptr, value); if (err) return err; pr_debug("extern (kcfg) '%s': set to 0x%llx\n", ext->name, (long long)value); } else { pr_warn("extern '%s': unrecognized extern kind\n", ext->name); return -EINVAL; } } if (need_config && extra_kconfig) { err = bpf_object__read_kconfig_mem(obj, extra_kconfig, kcfg_data); if (err) return -EINVAL; need_config = false; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; if (ext->type == EXT_KCFG && !ext->is_set) { need_config = true; break; } } } if (need_config) { err = bpf_object__read_kconfig_file(obj, kcfg_data); if (err) return -EINVAL; } if (need_kallsyms) { err = bpf_object__read_kallsyms_file(obj); if (err) return -EINVAL; } if (need_vmlinux_btf) { err = bpf_object__resolve_ksyms_btf_id(obj); if (err) return -EINVAL; } for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i];
if (!ext->is_set && !ext->is_weak) { pr_warn("extern '%s' (strong): not resolved\n", ext->name); return -ESRCH; } else if (!ext->is_set) { pr_debug("extern '%s' (weak): not resolved, defaulting to zero\n", ext->name); } }
return 0;}
static void bpf_map_prepare_vdata(const struct bpf_map *map){ const struct btf_type *type; struct bpf_struct_ops *st_ops; __u32 i;
st_ops = map->st_ops; type = btf__type_by_id(map->obj->btf, st_ops->type_id); for (i = 0; i < btf_vlen(type); i++) { struct bpf_program *prog = st_ops->progs[i]; void *kern_data; int prog_fd;
if (!prog) continue;
prog_fd = bpf_program__fd(prog); kern_data = st_ops->kern_vdata + st_ops->kern_func_off[i]; *(unsigned long *)kern_data = prog_fd; }}
static int bpf_object_prepare_struct_ops(struct bpf_object *obj){ struct bpf_map *map; int i;
for (i = 0; i < obj->nr_maps; i++) { map = &obj->maps[i];
if (!bpf_map__is_struct_ops(map)) continue;
if (!map->autocreate) continue;
bpf_map_prepare_vdata(map); }
return 0;}
static void bpf_object_unpin(struct bpf_object *obj){ int i;
/* unpin any maps that were auto-pinned during load */ for (i = 0; i < obj->nr_maps; i++) if (obj->maps[i].pinned && !obj->maps[i].reused) bpf_map__unpin(&obj->maps[i], NULL);}
static void bpf_object_cleanup_btf(struct bpf_object *obj){ int i;
/* clean up module BTFs */ for (i = 0; i < obj->btf_module_cnt; i++) { close(obj->btf_modules[i].fd); btf__free(obj->btf_modules[i].btf); free(obj->btf_modules[i].name); } obj->btf_module_cnt = 0; obj->btf_module_cap = 0; obj->btf_modules_loaded = false; zfree(&obj->btf_modules);
/* clean up vmlinux BTF */ btf__free(obj->btf_vmlinux); obj->btf_vmlinux = NULL;}
static void bpf_object_post_load_cleanup(struct bpf_object *obj){ /* clean up fd_array */ zfree(&obj->fd_array);
/* clean up BTF */ bpf_object_cleanup_btf(obj);}
static int bpf_object_prepare(struct bpf_object *obj, const char *target_btf_path){ int err;
if (obj->state >= OBJ_PREPARED) { pr_warn("object '%s': prepare loading can't be attempted twice\n", obj->name); return -EINVAL; }
err = bpf_object_prepare_token(obj); err = err ? : bpf_object__probe_loading(obj); err = err ? : bpf_object__load_vmlinux_btf(obj, false); err = err ? : bpf_object__resolve_externs(obj, obj->kconfig); err = err ? : bpf_object__sanitize_maps(obj); err = err ? : bpf_object__init_kern_struct_ops_maps(obj); err = err ? : bpf_object_adjust_struct_ops_autoload(obj); err = err ? : bpf_object__relocate(obj, obj->btf_custom_path ? : target_btf_path); err = err ? : bpf_object__sanitize_and_load_btf(obj); err = err ? : bpf_object__create_maps(obj); err = err ? : bpf_object_prepare_progs(obj);
if (err) { bpf_object_unpin(obj); bpf_object_unload(obj); obj->state = OBJ_LOADED; return err; }
obj->state = OBJ_PREPARED; return 0;}
static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const char *target_btf_path){ int err;
if (!obj) return libbpf_err(-EINVAL);
if (obj->state >= OBJ_LOADED) { pr_warn("object '%s': load can't be attempted twice\n", obj->name); return libbpf_err(-EINVAL); }
/* Disallow kernel loading programs of non-native endianness but * permit cross-endian creation of "light skeleton". */ if (obj->gen_loader) { bpf_gen__init(obj->gen_loader, extra_log_level, obj->nr_programs, obj->nr_maps); } else if (!is_native_endianness(obj)) { pr_warn("object '%s': loading non-native endianness is unsupported\n", obj->name); return libbpf_err(-LIBBPF_ERRNO__ENDIAN); }
if (obj->state < OBJ_PREPARED) { err = bpf_object_prepare(obj, target_btf_path); if (err) return libbpf_err(err); } err = bpf_object__load_progs(obj, extra_log_level); err = err ? : bpf_object_init_prog_arrays(obj); err = err ? : bpf_object_prepare_struct_ops(obj);
if (obj->gen_loader) { /* reset FDs */ if (obj->btf) btf__set_fd(obj->btf, -1); if (!err) err = bpf_gen__finish(obj->gen_loader, obj->nr_programs, obj->nr_maps); }
bpf_object_post_load_cleanup(obj); obj->state = OBJ_LOADED; /* doesn't matter if successfully or not */
if (err) { bpf_object_unpin(obj); bpf_object_unload(obj); pr_warn("failed to load object '%s'\n", obj->path); return libbpf_err(err); }
return 0;}
int bpf_object__prepare(struct bpf_object *obj){ return libbpf_err(bpf_object_prepare(obj, NULL));}
int bpf_object__load(struct bpf_object *obj){ return bpf_object_load(obj, 0, NULL);}
static int make_parent_dir(const char *path){ char *dname, *dir; int err = 0;
dname = strdup(path); if (dname == NULL) return -ENOMEM;
dir = dirname(dname); if (mkdir(dir, 0700) && errno != EEXIST) err = -errno;
free(dname); if (err) { pr_warn("failed to mkdir %s: %s\n", path, errstr(err)); } return err;}
static int check_path(const char *path){ struct statfs st_fs; char *dname, *dir; int err = 0;
if (path == NULL) return -EINVAL;
dname = strdup(path); if (dname == NULL) return -ENOMEM;
dir = dirname(dname); if (statfs(dir, &st_fs)) { pr_warn("failed to statfs %s: %s\n", dir, errstr(errno)); err = -errno; } free(dname);
if (!err && st_fs.f_type != BPF_FS_MAGIC) { pr_warn("specified path %s is not on BPF FS\n", path); err = -EINVAL; }
return err;}
int bpf_program__pin(struct bpf_program *prog, const char *path){ int err;
if (prog->fd < 0) { pr_warn("prog '%s': can't pin program that wasn't loaded\n", prog->name); return libbpf_err(-EINVAL); }
err = make_parent_dir(path); if (err) return libbpf_err(err);
err = check_path(path); if (err) return libbpf_err(err);
if (bpf_obj_pin(prog->fd, path)) { err = -errno; pr_warn("prog '%s': failed to pin at '%s': %s\n", prog->name, path, errstr(err)); return libbpf_err(err); }
pr_debug("prog '%s': pinned at '%s'\n", prog->name, path); return 0;}
int bpf_program__unpin(struct bpf_program *prog, const char *path){ int err;
if (prog->fd < 0) { pr_warn("prog '%s': can't unpin program that wasn't loaded\n", prog->name); return libbpf_err(-EINVAL); }
err = check_path(path); if (err) return libbpf_err(err);
err = unlink(path); if (err) return libbpf_err(-errno);
pr_debug("prog '%s': unpinned from '%s'\n", prog->name, path); return 0;}
int bpf_map__pin(struct bpf_map *map, const char *path){ int err;
if (map == NULL) { pr_warn("invalid map pointer\n"); return libbpf_err(-EINVAL); }
if (map->fd < 0) { pr_warn("map '%s': can't pin BPF map without FD (was it created?)\n", map->name); return libbpf_err(-EINVAL); }
if (map->pin_path) { if (path && strcmp(path, map->pin_path)) { pr_warn("map '%s' already has pin path '%s' different from '%s'\n", bpf_map__name(map), map->pin_path, path); return libbpf_err(-EINVAL); } else if (map->pinned) { pr_debug("map '%s' already pinned at '%s'; not re-pinning\n", bpf_map__name(map), map->pin_path); return 0; } } else { if (!path) { pr_warn("missing a path to pin map '%s' at\n", bpf_map__name(map)); return libbpf_err(-EINVAL); } else if (map->pinned) { pr_warn("map '%s' already pinned\n", bpf_map__name(map)); return libbpf_err(-EEXIST); }
map->pin_path = strdup(path); if (!map->pin_path) { err = -errno; goto out_err; } }
err = make_parent_dir(map->pin_path); if (err) return libbpf_err(err);
err = check_path(map->pin_path); if (err) return libbpf_err(err);
if (bpf_obj_pin(map->fd, map->pin_path)) { err = -errno; goto out_err; }
map->pinned = true; pr_debug("pinned map '%s'\n", map->pin_path);
return 0;
out_err: pr_warn("failed to pin map: %s\n", errstr(err)); return libbpf_err(err);}
int bpf_map__unpin(struct bpf_map *map, const char *path){ int err;
if (map == NULL) { pr_warn("invalid map pointer\n"); return libbpf_err(-EINVAL); }
if (map->pin_path) { if (path && strcmp(path, map->pin_path)) { pr_warn("map '%s' already has pin path '%s' different from '%s'\n", bpf_map__name(map), map->pin_path, path); return libbpf_err(-EINVAL); } path = map->pin_path; } else if (!path) { pr_warn("no path to unpin map '%s' from\n", bpf_map__name(map)); return libbpf_err(-EINVAL); }
err = check_path(path); if (err) return libbpf_err(err);
err = unlink(path); if (err != 0) return libbpf_err(-errno);
map->pinned = false; pr_debug("unpinned map '%s' from '%s'\n", bpf_map__name(map), path);
return 0;}
int bpf_map__set_pin_path(struct bpf_map *map, const char *path){ char *new = NULL;
if (path) { new = strdup(path); if (!new) return libbpf_err(-errno); }
free(map->pin_path); map->pin_path = new; return 0;}
__alias(bpf_map__pin_path)const char *bpf_map__get_pin_path(const struct bpf_map *map);
const char *bpf_map__pin_path(const struct bpf_map *map){ return map->pin_path;}
bool bpf_map__is_pinned(const struct bpf_map *map){ return map->pinned;}
static void sanitize_pin_path(char *s){ /* bpffs disallows periods in path names */ while (*s) { if (*s == '.') *s = '_'; s++; }}
int bpf_object__pin_maps(struct bpf_object *obj, const char *path){ struct bpf_map *map; int err;
if (!obj) return libbpf_err(-ENOENT);
if (obj->state < OBJ_PREPARED) { pr_warn("object not yet loaded; load it first\n"); return libbpf_err(-ENOENT); }
bpf_object__for_each_map(map, obj) { char *pin_path = NULL; char buf[PATH_MAX];
if (!map->autocreate) continue;
if (path) { err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); if (err) goto err_unpin_maps; sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { continue; }
err = bpf_map__pin(map, pin_path); if (err) goto err_unpin_maps; }
return 0;
err_unpin_maps: while ((map = bpf_object__prev_map(obj, map))) { if (!map->pin_path) continue;
bpf_map__unpin(map, NULL); }
return libbpf_err(err);}
int bpf_object__unpin_maps(struct bpf_object *obj, const char *path){ struct bpf_map *map; int err;
if (!obj) return libbpf_err(-ENOENT);
bpf_object__for_each_map(map, obj) { char *pin_path = NULL; char buf[PATH_MAX];
if (path) { err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); if (err) return libbpf_err(err); sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { continue; }
err = bpf_map__unpin(map, pin_path); if (err) return libbpf_err(err); }
return 0;}
int bpf_object__pin_programs(struct bpf_object *obj, const char *path){ struct bpf_program *prog; char buf[PATH_MAX]; int err;
if (!obj) return libbpf_err(-ENOENT);
if (obj->state < OBJ_LOADED) { pr_warn("object not yet loaded; load it first\n"); return libbpf_err(-ENOENT); }
bpf_object__for_each_program(prog, obj) { err = pathname_concat(buf, sizeof(buf), path, prog->name); if (err) goto err_unpin_programs;
err = bpf_program__pin(prog, buf); if (err) goto err_unpin_programs; }
return 0;
err_unpin_programs: while ((prog = bpf_object__prev_program(obj, prog))) { if (pathname_concat(buf, sizeof(buf), path, prog->name)) continue;
bpf_program__unpin(prog, buf); }
return libbpf_err(err);}
int bpf_object__unpin_programs(struct bpf_object *obj, const char *path){ struct bpf_program *prog; int err;
if (!obj) return libbpf_err(-ENOENT);
bpf_object__for_each_program(prog, obj) { char buf[PATH_MAX];
err = pathname_concat(buf, sizeof(buf), path, prog->name); if (err) return libbpf_err(err);
err = bpf_program__unpin(prog, buf); if (err) return libbpf_err(err); }
return 0;}
int bpf_object__pin(struct bpf_object *obj, const char *path){ int err;
err = bpf_object__pin_maps(obj, path); if (err) return libbpf_err(err);
err = bpf_object__pin_programs(obj, path); if (err) { bpf_object__unpin_maps(obj, path); return libbpf_err(err); }
return 0;}
int bpf_object__unpin(struct bpf_object *obj, const char *path){ int err;
err = bpf_object__unpin_programs(obj, path); if (err) return libbpf_err(err);
err = bpf_object__unpin_maps(obj, path); if (err) return libbpf_err(err);
return 0;}
static void bpf_map__destroy(struct bpf_map *map){ if (map->inner_map) { bpf_map__destroy(map->inner_map); zfree(&map->inner_map); }
zfree(&map->init_slots); map->init_slots_sz = 0;
if (map->mmaped && map->mmaped != map->obj->arena_data) munmap(map->mmaped, bpf_map_mmap_sz(map)); map->mmaped = NULL;
if (map->st_ops) { zfree(&map->st_ops->data); zfree(&map->st_ops->progs); zfree(&map->st_ops->kern_func_off); zfree(&map->st_ops); }
zfree(&map->name); zfree(&map->real_name); zfree(&map->pin_path);
if (map->fd >= 0) zclose(map->fd);}
void bpf_object__close(struct bpf_object *obj){ size_t i;
if (IS_ERR_OR_NULL(obj)) return;
/* * if user called bpf_object__prepare() without ever getting to * bpf_object__load(), we need to clean up stuff that is normally * cleaned up at the end of loading step */ bpf_object_post_load_cleanup(obj);
usdt_manager_free(obj->usdt_man); obj->usdt_man = NULL;
bpf_gen__free(obj->gen_loader); bpf_object__elf_finish(obj); bpf_object_unload(obj); btf__free(obj->btf); btf__free(obj->btf_vmlinux); btf_ext__free(obj->btf_ext);
for (i = 0; i < obj->nr_maps; i++) bpf_map__destroy(&obj->maps[i]);
zfree(&obj->btf_custom_path); zfree(&obj->kconfig);
for (i = 0; i < obj->nr_extern; i++) { zfree(&obj->externs[i].name); zfree(&obj->externs[i].essent_name); }
zfree(&obj->externs); obj->nr_extern = 0;
zfree(&obj->maps); obj->nr_maps = 0;
if (obj->programs && obj->nr_programs) { for (i = 0; i < obj->nr_programs; i++) bpf_program__exit(&obj->programs[i]); } zfree(&obj->programs);
zfree(&obj->feat_cache); zfree(&obj->token_path); if (obj->token_fd > 0) close(obj->token_fd);
zfree(&obj->arena_data);
zfree(&obj->jumptables_data); obj->jumptables_data_sz = 0;
for (i = 0; i < obj->jumptable_map_cnt; i++) close(obj->jumptable_maps[i].fd); zfree(&obj->jumptable_maps);
free(obj);}
const char *bpf_object__name(const struct bpf_object *obj){ return obj ? obj->name : libbpf_err_ptr(-EINVAL);}
unsigned int bpf_object__kversion(const struct bpf_object *obj){ return obj ? obj->kern_version : 0;}
int bpf_object__token_fd(const struct bpf_object *obj){ return obj->token_fd ?: -1;}
struct btf *bpf_object__btf(const struct bpf_object *obj){ return obj ? obj->btf : NULL;}
int bpf_object__btf_fd(const struct bpf_object *obj){ return obj->btf ? btf__fd(obj->btf) : -1;}
int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version){ if (obj->state >= OBJ_LOADED) return libbpf_err(-EINVAL);
obj->kern_version = kern_version;
return 0;}
int bpf_object__gen_loader(struct bpf_object *obj, struct gen_loader_opts *opts){ struct bpf_gen *gen;
if (!opts) return libbpf_err(-EFAULT); if (!OPTS_VALID(opts, gen_loader_opts)) return libbpf_err(-EINVAL); gen = calloc(1, sizeof(*gen)); if (!gen) return libbpf_err(-ENOMEM); gen->opts = opts; gen->swapped_endian = !is_native_endianness(obj); obj->gen_loader = gen; return 0;}
static struct bpf_program *__bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj, bool forward){ size_t nr_programs = obj->nr_programs; ssize_t idx;
if (!nr_programs) return NULL;
if (!p) /* Iter from the beginning */ return forward ? &obj->programs[0] : &obj->programs[nr_programs - 1];
if (p->obj != obj) { pr_warn("error: program handler doesn't match object\n"); return errno = EINVAL, NULL; }
idx = (p - obj->programs) + (forward ? 1 : -1); if (idx >= obj->nr_programs || idx < 0) return NULL; return &obj->programs[idx];}
struct bpf_program *bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev){ struct bpf_program *prog = prev;
do { prog = __bpf_program__iter(prog, obj, true); } while (prog && prog_is_subprog(obj, prog));
return prog;}
struct bpf_program *bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *next){ struct bpf_program *prog = next;
do { prog = __bpf_program__iter(prog, obj, false); } while (prog && prog_is_subprog(obj, prog));
return prog;}
void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex){ prog->prog_ifindex = ifindex;}
const char *bpf_program__name(const struct bpf_program *prog){ return prog->name;}
const char *bpf_program__section_name(const struct bpf_program *prog){ return prog->sec_name;}
bool bpf_program__autoload(const struct bpf_program *prog){ return prog->autoload;}
int bpf_program__set_autoload(struct bpf_program *prog, bool autoload){ if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EINVAL);
prog->autoload = autoload; return 0;}
bool bpf_program__autoattach(const struct bpf_program *prog){ return prog->autoattach;}
void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach){ prog->autoattach = autoattach;}
const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog){ return prog->insns;}
size_t bpf_program__insn_cnt(const struct bpf_program *prog){ return prog->insns_cnt;}
int bpf_program__set_insns(struct bpf_program *prog, struct bpf_insn *new_insns, size_t new_insn_cnt){ struct bpf_insn *insns;
if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
insns = libbpf_reallocarray(prog->insns, new_insn_cnt, sizeof(*insns)); /* NULL is a valid return from reallocarray if the new count is zero */ if (!insns && new_insn_cnt) { pr_warn("prog '%s': failed to realloc prog code\n", prog->name); return libbpf_err(-ENOMEM); } memcpy(insns, new_insns, new_insn_cnt * sizeof(*insns));
prog->insns = insns; prog->insns_cnt = new_insn_cnt; return 0;}
int bpf_program__fd(const struct bpf_program *prog){ if (!prog) return libbpf_err(-EINVAL);
if (prog->fd < 0) return libbpf_err(-ENOENT);
return prog->fd;}
__alias(bpf_program__type)enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
enum bpf_prog_type bpf_program__type(const struct bpf_program *prog){ return prog->type;}
static size_t custom_sec_def_cnt;static struct bpf_sec_def *custom_sec_defs;static struct bpf_sec_def custom_fallback_def;static bool has_custom_fallback_def;static int last_custom_sec_def_handler_id;
int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type){ if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
/* if type is not changed, do nothing */ if (prog->type == type) return 0;
prog->type = type;
/* If a program type was changed, we need to reset associated SEC() * handler, as it will be invalid now. The only exception is a generic * fallback handler, which by definition is program type-agnostic and * is a catch-all custom handler, optionally set by the application, * so should be able to handle any type of BPF program. */ if (prog->sec_def != &custom_fallback_def) prog->sec_def = NULL; return 0;}
__alias(bpf_program__expected_attach_type)enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog){ return prog->expected_attach_type;}
int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type){ if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
prog->expected_attach_type = type; return 0;}
__u32 bpf_program__flags(const struct bpf_program *prog){ return prog->prog_flags;}
int bpf_program__set_flags(struct bpf_program *prog, __u32 flags){ if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
prog->prog_flags = flags; return 0;}
__u32 bpf_program__log_level(const struct bpf_program *prog){ return prog->log_level;}
int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level){ if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
prog->log_level = log_level; return 0;}
const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size){ *log_size = prog->log_size; return prog->log_buf;}
int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size){ if (log_size && !log_buf) return libbpf_err(-EINVAL); if (prog->log_size > UINT_MAX) return libbpf_err(-EINVAL); if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EBUSY);
prog->log_buf = log_buf; prog->log_size = log_size; return 0;}
struct bpf_func_info *bpf_program__func_info(const struct bpf_program *prog){ if (prog->func_info_rec_size != sizeof(struct bpf_func_info)) return libbpf_err_ptr(-EOPNOTSUPP); return prog->func_info;}
__u32 bpf_program__func_info_cnt(const struct bpf_program *prog){ return prog->func_info_cnt;}
struct bpf_line_info *bpf_program__line_info(const struct bpf_program *prog){ if (prog->line_info_rec_size != sizeof(struct bpf_line_info)) return libbpf_err_ptr(-EOPNOTSUPP); return prog->line_info;}
__u32 bpf_program__line_info_cnt(const struct bpf_program *prog){ return prog->line_info_cnt;}
int bpf_program__clone(struct bpf_program *prog, const struct bpf_prog_load_opts *opts){ LIBBPF_OPTS(bpf_prog_load_opts, attr); struct bpf_object *obj; const void *info; __u32 info_cnt, info_rec_size; int err, fd, prog_btf_fd;
if (!prog) return libbpf_err(-EINVAL);
if (!OPTS_VALID(opts, bpf_prog_load_opts)) return libbpf_err(-EINVAL);
obj = prog->obj; if (obj->state < OBJ_PREPARED) return libbpf_err(-EINVAL);
/* * Caller-provided opts take priority; fall back to * prog/object defaults when the caller leaves them zero. */ attr.attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0) ?: prog->attach_prog_fd; attr.prog_flags = OPTS_GET(opts, prog_flags, 0) ?: prog->prog_flags; attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0) ?: prog->prog_ifindex; attr.kern_version = OPTS_GET(opts, kern_version, 0) ?: obj->kern_version; attr.fd_array = OPTS_GET(opts, fd_array, NULL) ?: obj->fd_array; attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0) ?: obj->fd_array_cnt; attr.token_fd = OPTS_GET(opts, token_fd, 0) ?: obj->token_fd; if (attr.token_fd) attr.prog_flags |= BPF_F_TOKEN_FD;
prog_btf_fd = OPTS_GET(opts, prog_btf_fd, 0); if (!prog_btf_fd && obj->btf) prog_btf_fd = btf__fd(obj->btf);
/* BTF func/line info: only pass if kernel supports it */ if (kernel_supports(obj, FEAT_BTF_FUNC) && prog_btf_fd > 0) { attr.prog_btf_fd = prog_btf_fd;
/* func_info/line_info triples: all-or-nothing from caller */ info = OPTS_GET(opts, func_info, NULL); info_cnt = OPTS_GET(opts, func_info_cnt, 0); info_rec_size = OPTS_GET(opts, func_info_rec_size, 0); if (!!info != !!info_cnt || !!info != !!info_rec_size) { pr_warn("prog '%s': func_info, func_info_cnt, and func_info_rec_size must all be specified or all omitted\n", prog->name); return libbpf_err(-EINVAL); } attr.func_info = info ?: prog->func_info; attr.func_info_cnt = info ? info_cnt : prog->func_info_cnt; attr.func_info_rec_size = info ? info_rec_size : prog->func_info_rec_size;
info = OPTS_GET(opts, line_info, NULL); info_cnt = OPTS_GET(opts, line_info_cnt, 0); info_rec_size = OPTS_GET(opts, line_info_rec_size, 0); if (!!info != !!info_cnt || !!info != !!info_rec_size) { pr_warn("prog '%s': line_info, line_info_cnt, and line_info_rec_size must all be specified or all omitted\n", prog->name); return libbpf_err(-EINVAL); } attr.line_info = info ?: prog->line_info; attr.line_info_cnt = info ? info_cnt : prog->line_info_cnt; attr.line_info_rec_size = info ? info_rec_size : prog->line_info_rec_size; }
/* Logging is caller-controlled; no fallback to prog/obj log settings */ attr.log_buf = OPTS_GET(opts, log_buf, NULL); attr.log_size = OPTS_GET(opts, log_size, 0); attr.log_level = OPTS_GET(opts, log_level, 0);
/* * Fields below may be mutated by prog_prepare_load_fn: * Seed them from prog/obj defaults here; * Later override with caller-provided opts. */ attr.expected_attach_type = prog->expected_attach_type; attr.attach_btf_id = prog->attach_btf_id; attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
if (prog->sec_def && prog->sec_def->prog_prepare_load_fn) { err = prog->sec_def->prog_prepare_load_fn(prog, &attr, prog->sec_def->cookie); if (err) return libbpf_err(err); }
/* Re-apply caller overrides for output fields */ if (OPTS_GET(opts, expected_attach_type, 0)) attr.expected_attach_type = OPTS_GET(opts, expected_attach_type, 0); if (OPTS_GET(opts, attach_btf_id, 0)) attr.attach_btf_id = OPTS_GET(opts, attach_btf_id, 0); if (OPTS_GET(opts, attach_btf_obj_fd, 0)) attr.attach_btf_obj_fd = OPTS_GET(opts, attach_btf_obj_fd, 0);
/* * Unlike bpf_object_load_prog(), we intentionally do not call bpf_prog_bind_map() * for RODATA maps here to avoid mutating the object's state. Callers can bind the * required maps themselves using bpf_prog_bind_map(). */ fd = bpf_prog_load(prog->type, prog->name, obj->license, prog->insns, prog->insns_cnt, &attr);
return libbpf_err(fd);}
#define SEC_DEF(sec_pfx, ptype, atype, flags, ...) { \ .sec = (char *)sec_pfx, \ .prog_type = BPF_PROG_TYPE_##ptype, \ .expected_attach_type = atype, \ .cookie = (long)(flags), \ .prog_prepare_load_fn = libbpf_prepare_prog_load, \ __VA_ARGS__ \}
static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_kprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link);static int attach_tracing_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link);
static const struct bpf_sec_def section_defs[] = { SEC_DEF("socket", SOCKET_FILTER, 0, SEC_NONE), SEC_DEF("sk_reuseport/migrate", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE), SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE), SEC_DEF("kprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), SEC_DEF("uprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), SEC_DEF("uprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kretprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), SEC_DEF("uretprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), SEC_DEF("uretprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kprobe.session+", KPROBE, BPF_TRACE_KPROBE_SESSION, SEC_NONE, attach_kprobe_session), SEC_DEF("uprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi), SEC_DEF("uretprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi), SEC_DEF("uprobe.session+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_NONE, attach_uprobe_multi), SEC_DEF("uprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi), SEC_DEF("uretprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi), SEC_DEF("uprobe.session.s+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_SLEEPABLE, attach_uprobe_multi), SEC_DEF("ksyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), SEC_DEF("kretsyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), SEC_DEF("usdt+", KPROBE, 0, SEC_USDT, attach_usdt), SEC_DEF("usdt.s+", KPROBE, 0, SEC_USDT | SEC_SLEEPABLE, attach_usdt), SEC_DEF("tc/ingress", SCHED_CLS, BPF_TCX_INGRESS, SEC_NONE), /* alias for tcx */ SEC_DEF("tc/egress", SCHED_CLS, BPF_TCX_EGRESS, SEC_NONE), /* alias for tcx */ SEC_DEF("tcx/ingress", SCHED_CLS, BPF_TCX_INGRESS, SEC_NONE), SEC_DEF("tcx/egress", SCHED_CLS, BPF_TCX_EGRESS, SEC_NONE), SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */ SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */ SEC_DEF("action", SCHED_ACT, 0, SEC_NONE), /* deprecated / legacy, use tcx */ SEC_DEF("netkit/primary", SCHED_CLS, BPF_NETKIT_PRIMARY, SEC_NONE), SEC_DEF("netkit/peer", SCHED_CLS, BPF_NETKIT_PEER, SEC_NONE), SEC_DEF("tracepoint+", TRACEPOINT, 0, SEC_NONE, attach_tp), SEC_DEF("tp+", TRACEPOINT, 0, SEC_NONE, attach_tp), SEC_DEF("tracepoint.s+", TRACEPOINT, 0, SEC_SLEEPABLE, attach_tp), SEC_DEF("tp.s+", TRACEPOINT, 0, SEC_SLEEPABLE, attach_tp), SEC_DEF("raw_tracepoint+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), SEC_DEF("raw_tp+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), SEC_DEF("raw_tracepoint.s+", RAW_TRACEPOINT, 0, SEC_SLEEPABLE, attach_raw_tp), SEC_DEF("raw_tp.s+", RAW_TRACEPOINT, 0, SEC_SLEEPABLE, attach_raw_tp), SEC_DEF("raw_tracepoint.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), SEC_DEF("raw_tp.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), SEC_DEF("tp_btf+", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace), SEC_DEF("tp_btf.s+", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), SEC_DEF("fentry+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace), SEC_DEF("fmod_ret+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace), SEC_DEF("fexit+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace), SEC_DEF("fentry.s+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), SEC_DEF("fmod_ret.s+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), SEC_DEF("fexit.s+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), SEC_DEF("fsession+", TRACING, BPF_TRACE_FSESSION, SEC_ATTACH_BTF, attach_trace), SEC_DEF("fsession.s+", TRACING, BPF_TRACE_FSESSION, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), SEC_DEF("fsession.multi+", TRACING, BPF_TRACE_FSESSION_MULTI, 0, attach_tracing_multi), SEC_DEF("fsession.multi.s+", TRACING, BPF_TRACE_FSESSION_MULTI, SEC_SLEEPABLE, attach_tracing_multi), SEC_DEF("fentry.multi+", TRACING, BPF_TRACE_FENTRY_MULTI, 0, attach_tracing_multi), SEC_DEF("fexit.multi+", TRACING, BPF_TRACE_FEXIT_MULTI, 0, attach_tracing_multi), SEC_DEF("fentry.multi.s+", TRACING, BPF_TRACE_FENTRY_MULTI, SEC_SLEEPABLE, attach_tracing_multi), SEC_DEF("fexit.multi.s+", TRACING, BPF_TRACE_FEXIT_MULTI, SEC_SLEEPABLE, attach_tracing_multi), SEC_DEF("freplace+", EXT, 0, SEC_ATTACH_BTF, attach_trace), SEC_DEF("lsm+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm), SEC_DEF("lsm.s+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm), SEC_DEF("lsm_cgroup+", LSM, BPF_LSM_CGROUP, SEC_ATTACH_BTF), SEC_DEF("iter+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter), SEC_DEF("iter.s+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_iter), SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE), SEC_DEF("xdp.frags/devmap", XDP, BPF_XDP_DEVMAP, SEC_XDP_FRAGS), SEC_DEF("xdp/devmap", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE), SEC_DEF("xdp.frags/cpumap", XDP, BPF_XDP_CPUMAP, SEC_XDP_FRAGS), SEC_DEF("xdp/cpumap", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE), SEC_DEF("xdp.frags", XDP, BPF_XDP, SEC_XDP_FRAGS), SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT), SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE), SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE), SEC_DEF("lwt_out", LWT_OUT, 0, SEC_NONE), SEC_DEF("lwt_xmit", LWT_XMIT, 0, SEC_NONE), SEC_DEF("lwt_seg6local", LWT_SEG6LOCAL, 0, SEC_NONE), SEC_DEF("sockops", SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT), SEC_DEF("sk_skb/stream_parser", SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT), SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT), SEC_DEF("sk_skb/verdict", SK_SKB, BPF_SK_SKB_VERDICT, SEC_ATTACHABLE_OPT), SEC_DEF("sk_skb", SK_SKB, 0, SEC_NONE), SEC_DEF("sk_msg", SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT), SEC_DEF("lirc_mode2", LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT), SEC_DEF("flow_dissector", FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT), SEC_DEF("cgroup_skb/ingress", CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT), SEC_DEF("cgroup_skb/egress", CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT), SEC_DEF("cgroup/skb", CGROUP_SKB, 0, SEC_NONE), SEC_DEF("cgroup/sock_create", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE), SEC_DEF("cgroup/sock_release", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE), SEC_DEF("cgroup/sock", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT), SEC_DEF("cgroup/post_bind4", CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE), SEC_DEF("cgroup/post_bind6", CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE), SEC_DEF("cgroup/bind4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE), SEC_DEF("cgroup/bind6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE), SEC_DEF("cgroup/connect4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE), SEC_DEF("cgroup/connect6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE), SEC_DEF("cgroup/connect_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_CONNECT, SEC_ATTACHABLE), SEC_DEF("cgroup/sendmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/sendmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/sendmsg_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_SENDMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/recvmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/recvmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/recvmsg_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_RECVMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/getpeername4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getpeername6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getpeername_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_GETPEERNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockname4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockname6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockname_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_GETSOCKNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/sysctl", CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockopt", CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE), SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE), SEC_DEF("cgroup/dev", CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT), SEC_DEF("struct_ops+", STRUCT_OPS, 0, SEC_NONE), SEC_DEF("struct_ops.s+", STRUCT_OPS, 0, SEC_SLEEPABLE), SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE), SEC_DEF("netfilter", NETFILTER, BPF_NETFILTER, SEC_NONE),};
int libbpf_register_prog_handler(const char *sec, enum bpf_prog_type prog_type, enum bpf_attach_type exp_attach_type, const struct libbpf_prog_handler_opts *opts){ struct bpf_sec_def *sec_def;
if (!OPTS_VALID(opts, libbpf_prog_handler_opts)) return libbpf_err(-EINVAL);
if (last_custom_sec_def_handler_id == INT_MAX) /* prevent overflow */ return libbpf_err(-E2BIG);
if (sec) { sec_def = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt + 1, sizeof(*sec_def)); if (!sec_def) return libbpf_err(-ENOMEM);
custom_sec_defs = sec_def; sec_def = &custom_sec_defs[custom_sec_def_cnt]; } else { if (has_custom_fallback_def) return libbpf_err(-EBUSY);
sec_def = &custom_fallback_def; }
sec_def->sec = sec ? strdup(sec) : NULL; if (sec && !sec_def->sec) return libbpf_err(-ENOMEM);
sec_def->prog_type = prog_type; sec_def->expected_attach_type = exp_attach_type; sec_def->cookie = OPTS_GET(opts, cookie, 0);
sec_def->prog_setup_fn = OPTS_GET(opts, prog_setup_fn, NULL); sec_def->prog_prepare_load_fn = OPTS_GET(opts, prog_prepare_load_fn, NULL); sec_def->prog_attach_fn = OPTS_GET(opts, prog_attach_fn, NULL);
sec_def->handler_id = ++last_custom_sec_def_handler_id;
if (sec) custom_sec_def_cnt++; else has_custom_fallback_def = true;
return sec_def->handler_id;}
int libbpf_unregister_prog_handler(int handler_id){ struct bpf_sec_def *sec_defs; int i;
if (handler_id <= 0) return libbpf_err(-EINVAL);
if (has_custom_fallback_def && custom_fallback_def.handler_id == handler_id) { memset(&custom_fallback_def, 0, sizeof(custom_fallback_def)); has_custom_fallback_def = false; return 0; }
for (i = 0; i < custom_sec_def_cnt; i++) { if (custom_sec_defs[i].handler_id == handler_id) break; }
if (i == custom_sec_def_cnt) return libbpf_err(-ENOENT);
free(custom_sec_defs[i].sec); for (i = i + 1; i < custom_sec_def_cnt; i++) custom_sec_defs[i - 1] = custom_sec_defs[i]; custom_sec_def_cnt--;
/* try to shrink the array, but it's ok if we couldn't */ sec_defs = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt, sizeof(*sec_defs)); /* if new count is zero, reallocarray can return a valid NULL result; * in this case the previous pointer will be freed, so we *have to* * reassign old pointer to the new value (even if it's NULL) */ if (sec_defs || custom_sec_def_cnt == 0) custom_sec_defs = sec_defs;
return 0;}
static bool sec_def_matches(const struct bpf_sec_def *sec_def, const char *sec_name){ size_t len = strlen(sec_def->sec);
/* "type/" always has to have proper SEC("type/extras") form */ if (sec_def->sec[len - 1] == '/') { if (str_has_pfx(sec_name, sec_def->sec)) return true; return false; }
/* "type+" means it can be either exact SEC("type") or * well-formed SEC("type/extras") with proper '/' separator */ if (sec_def->sec[len - 1] == '+') { len--; /* not even a prefix */ if (strncmp(sec_name, sec_def->sec, len) != 0) return false; /* exact match or has '/' separator */ if (sec_name[len] == '\0' || sec_name[len] == '/') return true; return false; }
return strcmp(sec_name, sec_def->sec) == 0;}
static const struct bpf_sec_def *find_sec_def(const char *sec_name){ const struct bpf_sec_def *sec_def; int i, n;
n = custom_sec_def_cnt; for (i = 0; i < n; i++) { sec_def = &custom_sec_defs[i]; if (sec_def_matches(sec_def, sec_name)) return sec_def; }
n = ARRAY_SIZE(section_defs); for (i = 0; i < n; i++) { sec_def = §ion_defs[i]; if (sec_def_matches(sec_def, sec_name)) return sec_def; }
if (has_custom_fallback_def) return &custom_fallback_def;
return NULL;}
#define MAX_TYPE_NAME_SIZE 32
static char *libbpf_get_type_names(bool attach_type){ int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE; char *buf;
buf = malloc(len); if (!buf) return NULL;
buf[0] = '\0'; /* Forge string buf with all available names */ for (i = 0; i < ARRAY_SIZE(section_defs); i++) { const struct bpf_sec_def *sec_def = §ion_defs[i];
if (attach_type) { if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load) continue;
if (!(sec_def->cookie & SEC_ATTACHABLE)) continue; }
if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) { free(buf); return NULL; } strcat(buf, " "); strcat(buf, section_defs[i].sec); }
return buf;}
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, enum bpf_attach_type *expected_attach_type){ const struct bpf_sec_def *sec_def; char *type_names;
if (!name) return libbpf_err(-EINVAL);
sec_def = find_sec_def(name); if (sec_def) { *prog_type = sec_def->prog_type; *expected_attach_type = sec_def->expected_attach_type; return 0; }
pr_debug("failed to guess program type from ELF section '%s'\n", name); type_names = libbpf_get_type_names(false); if (type_names != NULL) { pr_debug("supported section(type) names are:%s\n", type_names); free(type_names); }
return libbpf_err(-ESRCH);}
const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t){ if (t < 0 || t >= ARRAY_SIZE(attach_type_name)) return NULL;
return attach_type_name[t];}
const char *libbpf_bpf_link_type_str(enum bpf_link_type t){ if (t < 0 || t >= ARRAY_SIZE(link_type_name)) return NULL;
return link_type_name[t];}
const char *libbpf_bpf_map_type_str(enum bpf_map_type t){ if (t < 0 || t >= ARRAY_SIZE(map_type_name)) return NULL;
return map_type_name[t];}
const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t){ if (t < 0 || t >= ARRAY_SIZE(prog_type_name)) return NULL;
return prog_type_name[t];}
static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj, int sec_idx, size_t offset){ struct bpf_map *map; size_t i;
for (i = 0; i < obj->nr_maps; i++) { map = &obj->maps[i]; if (!bpf_map__is_struct_ops(map)) continue; if (map->sec_idx == sec_idx && map->sec_offset <= offset && offset - map->sec_offset < map->def.value_size) return map; }
return NULL;}
/* Collect the reloc from ELF, populate the st_ops->progs[], and update * st_ops->data for shadow type. */static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data){ const struct btf_type *type; const struct btf_member *member; struct bpf_struct_ops *st_ops; struct bpf_program *prog; unsigned int shdr_idx; const struct btf *btf; struct bpf_map *map; unsigned int moff, insn_idx; const char *name; __u32 member_idx; Elf64_Sym *sym; Elf64_Rel *rel; int i, nrels;
btf = obj->btf; nrels = shdr->sh_size / shdr->sh_entsize; for (i = 0; i < nrels; i++) { rel = elf_rel_by_idx(data, i); if (!rel) { pr_warn("struct_ops reloc: failed to get %d reloc\n", i); return -LIBBPF_ERRNO__FORMAT; }
sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info)); if (!sym) { pr_warn("struct_ops reloc: symbol %zx not found\n", (size_t)ELF64_R_SYM(rel->r_info)); return -LIBBPF_ERRNO__FORMAT; }
name = elf_sym_str(obj, sym->st_name) ?: "<?>"; map = find_struct_ops_map_by_offset(obj, shdr->sh_info, rel->r_offset); if (!map) { pr_warn("struct_ops reloc: cannot find map at rel->r_offset %zu\n", (size_t)rel->r_offset); return -EINVAL; }
moff = rel->r_offset - map->sec_offset; shdr_idx = sym->st_shndx; st_ops = map->st_ops; pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel->r_offset %zu map->sec_offset %zu name %d (\'%s\')\n", map->name, (long long)(rel->r_info >> 32), (long long)sym->st_value, shdr_idx, (size_t)rel->r_offset, map->sec_offset, sym->st_name, name);
if (shdr_idx >= SHN_LORESERVE) { pr_warn("struct_ops reloc %s: rel->r_offset %zu shdr_idx %u unsupported non-static function\n", map->name, (size_t)rel->r_offset, shdr_idx); return -LIBBPF_ERRNO__RELOC; } if (sym->st_value % BPF_INSN_SZ) { pr_warn("struct_ops reloc %s: invalid target program offset %llu\n", map->name, (unsigned long long)sym->st_value); return -LIBBPF_ERRNO__FORMAT; } insn_idx = sym->st_value / BPF_INSN_SZ;
type = btf__type_by_id(btf, st_ops->type_id); member = find_member_by_offset(type, moff * 8); if (!member) { pr_warn("struct_ops reloc %s: cannot find member at moff %u\n", map->name, moff); return -EINVAL; } member_idx = member - btf_members(type); name = btf__name_by_offset(btf, member->name_off);
if (!resolve_func_ptr(btf, member->type, NULL)) { pr_warn("struct_ops reloc %s: cannot relocate non func ptr %s\n", map->name, name); return -EINVAL; }
prog = find_prog_by_sec_insn(obj, shdr_idx, insn_idx); if (!prog) { pr_warn("struct_ops reloc %s: cannot find prog at shdr_idx %u to relocate func ptr %s\n", map->name, shdr_idx, name); return -EINVAL; }
/* prevent the use of BPF prog with invalid type */ if (prog->type != BPF_PROG_TYPE_STRUCT_OPS) { pr_warn("struct_ops reloc %s: prog %s is not struct_ops BPF program\n", map->name, prog->name); return -EINVAL; }
st_ops->progs[member_idx] = prog;
/* st_ops->data will be exposed to users, being returned by * bpf_map__initial_value() as a pointer to the shadow * type. All function pointers in the original struct type * should be converted to a pointer to struct bpf_program * in the shadow type. */ *((struct bpf_program **)(st_ops->data + moff)) = prog; }
return 0;}
#define BTF_TRACE_PREFIX "btf_trace_"#define BTF_LSM_PREFIX "bpf_lsm_"#define BTF_ITER_PREFIX "bpf_iter_"#define BTF_MAX_NAME_SIZE 128
void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, const char **prefix, int *kind){ switch (attach_type) { case BPF_TRACE_RAW_TP: *prefix = BTF_TRACE_PREFIX; *kind = BTF_KIND_TYPEDEF; break; case BPF_LSM_MAC: case BPF_LSM_CGROUP: *prefix = BTF_LSM_PREFIX; *kind = BTF_KIND_FUNC; break; case BPF_TRACE_ITER: *prefix = BTF_ITER_PREFIX; *kind = BTF_KIND_FUNC; break; default: *prefix = ""; *kind = BTF_KIND_FUNC; }}
static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix, const char *name, __u32 kind){ char btf_type_name[BTF_MAX_NAME_SIZE]; int ret;
ret = snprintf(btf_type_name, sizeof(btf_type_name), "%s%s", prefix, name); /* snprintf returns the number of characters written excluding the * terminating null. So, if >= BTF_MAX_NAME_SIZE are written, it * indicates truncation. */ if (ret < 0 || ret >= sizeof(btf_type_name)) return -ENAMETOOLONG; return btf__find_by_name_kind(btf, btf_type_name, kind);}
static inline int find_attach_btf_id(struct btf *btf, const char *name, enum bpf_attach_type attach_type){ const char *prefix; int kind;
btf_get_kernel_prefix_kind(attach_type, &prefix, &kind); return find_btf_by_prefix_kind(btf, prefix, name, kind);}
int libbpf_find_vmlinux_btf_id(const char *name, enum bpf_attach_type attach_type){ struct btf *btf; int err;
btf = btf__load_vmlinux_btf(); err = libbpf_get_error(btf); if (err) { pr_warn("vmlinux BTF is not found\n"); return libbpf_err(err); }
err = find_attach_btf_id(btf, name, attach_type); if (err <= 0) pr_warn("%s is not found in vmlinux BTF\n", name);
btf__free(btf); return libbpf_err(err);}
static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd, int token_fd){ struct bpf_prog_info info; __u32 info_len = sizeof(info); struct btf *btf; int err;
memset(&info, 0, info_len); err = bpf_prog_get_info_by_fd(attach_prog_fd, &info, &info_len); if (err) { pr_warn("failed bpf_prog_get_info_by_fd for FD %d: %s\n", attach_prog_fd, errstr(err)); return err; }
err = -EINVAL; if (!info.btf_id) { pr_warn("The target program doesn't have BTF\n"); goto out; } btf = btf_load_from_kernel(info.btf_id, NULL, token_fd); err = libbpf_get_error(btf); if (err) { pr_warn("Failed to get BTF %d of the program: %s\n", info.btf_id, errstr(err)); goto out; } err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); btf__free(btf); if (err <= 0) { pr_warn("%s is not found in prog's BTF\n", name); goto out; }out: return err;}
static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name, enum bpf_attach_type attach_type, int *btf_obj_fd, int *btf_type_id){ int ret, i, mod_len = 0; const char *fn_name, *mod_name = NULL;
fn_name = strchr(attach_name, ':'); if (fn_name) { mod_name = attach_name; mod_len = fn_name - mod_name; fn_name++; }
if (!mod_name || strncmp(mod_name, "vmlinux", mod_len) == 0) { ret = find_attach_btf_id(obj->btf_vmlinux, mod_name ? fn_name : attach_name, attach_type); if (ret > 0) { *btf_obj_fd = 0; /* vmlinux BTF */ *btf_type_id = ret; return 0; } if (ret != -ENOENT) return ret; }
ret = load_module_btfs(obj); if (ret) return ret;
for (i = 0; i < obj->btf_module_cnt; i++) { const struct module_btf *mod = &obj->btf_modules[i];
if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0) continue;
ret = find_attach_btf_id(mod->btf, mod_name ? fn_name : attach_name, attach_type); if (ret > 0) { *btf_obj_fd = mod->fd; *btf_type_id = ret; return 0; } if (ret == -ENOENT) continue;
return ret; }
return -ESRCH;}
static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name, int *btf_obj_fd, int *btf_type_id){ enum bpf_attach_type attach_type = prog->expected_attach_type; __u32 attach_prog_fd = prog->attach_prog_fd; int err = 0;
/* BPF program's BTF ID */ if (prog->type == BPF_PROG_TYPE_EXT || attach_prog_fd) { if (!attach_prog_fd) { pr_warn("prog '%s': attach program FD is not set\n", prog->name); return -EINVAL; } err = libbpf_find_prog_btf_id(attach_name, attach_prog_fd, prog->obj->token_fd); if (err < 0) { pr_warn("prog '%s': failed to find BPF program (FD %d) BTF ID for '%s': %s\n", prog->name, attach_prog_fd, attach_name, errstr(err)); return err; } *btf_obj_fd = 0; *btf_type_id = err; return 0; }
/* kernel/module BTF ID */ if (prog->obj->gen_loader) { bpf_gen__record_attach_target(prog->obj->gen_loader, attach_name, attach_type); *btf_obj_fd = 0; *btf_type_id = 1; } else { err = find_kernel_btf_id(prog->obj, attach_name, attach_type, btf_obj_fd, btf_type_id); } if (err) { pr_warn("prog '%s': failed to find kernel BTF type ID of '%s': %s\n", prog->name, attach_name, errstr(err)); return err; } return 0;}
int libbpf_attach_type_by_name(const char *name, enum bpf_attach_type *attach_type){ char *type_names; const struct bpf_sec_def *sec_def;
if (!name) return libbpf_err(-EINVAL);
sec_def = find_sec_def(name); if (!sec_def) { pr_debug("failed to guess attach type based on ELF section name '%s'\n", name); type_names = libbpf_get_type_names(true); if (type_names != NULL) { pr_debug("attachable section(type) names are:%s\n", type_names); free(type_names); }
return libbpf_err(-EINVAL); }
if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load) return libbpf_err(-EINVAL); if (!(sec_def->cookie & SEC_ATTACHABLE)) return libbpf_err(-EINVAL);
*attach_type = sec_def->expected_attach_type; return 0;}
int bpf_map__fd(const struct bpf_map *map){ if (!map) return libbpf_err(-EINVAL); if (!map_is_created(map)) return -1; return map->fd;}
static bool map_uses_real_name(const struct bpf_map *map){ /* Since libbpf started to support custom .data.* and .rodata.* maps, * their user-visible name differs from kernel-visible name. Users see * such map's corresponding ELF section name as a map name. * This check distinguishes .data/.rodata from .data.* and .rodata.* * maps to know which name has to be returned to the user. */ if (map->libbpf_type == LIBBPF_MAP_DATA && strcmp(map->real_name, DATA_SEC) != 0) return true; if (map->libbpf_type == LIBBPF_MAP_RODATA && strcmp(map->real_name, RODATA_SEC) != 0) return true; return false;}
const char *bpf_map__name(const struct bpf_map *map){ if (!map) return NULL;
if (map_uses_real_name(map)) return map->real_name;
return map->name;}
enum bpf_map_type bpf_map__type(const struct bpf_map *map){ return map->def.type;}
int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->def.type = type; return 0;}
__u32 bpf_map__map_flags(const struct bpf_map *map){ return map->def.map_flags;}
int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->def.map_flags = flags; return 0;}
__u64 bpf_map__map_extra(const struct bpf_map *map){ return map->map_extra;}
int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->map_extra = map_extra; return 0;}
__u32 bpf_map__numa_node(const struct bpf_map *map){ return map->numa_node;}
int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->numa_node = numa_node; return 0;}
__u32 bpf_map__key_size(const struct bpf_map *map){ return map->def.key_size;}
int bpf_map__set_key_size(struct bpf_map *map, __u32 size){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->def.key_size = size; return 0;}
__u32 bpf_map__value_size(const struct bpf_map *map){ return map->def.value_size;}
static int map_btf_datasec_resize(struct bpf_map *map, __u32 size){ struct btf *btf; struct btf_type *datasec_type, *var_type; struct btf_var_secinfo *var; const struct btf_type *array_type; const struct btf_array *array; int vlen, element_sz, new_array_id; __u32 nr_elements;
/* check btf existence */ btf = bpf_object__btf(map->obj); if (!btf) return -ENOENT;
/* verify map is datasec */ datasec_type = btf_type_by_id(btf, bpf_map__btf_value_type_id(map)); if (!btf_is_datasec(datasec_type)) { pr_warn("map '%s': cannot be resized, map value type is not a datasec\n", bpf_map__name(map)); return -EINVAL; }
/* verify datasec has at least one var */ vlen = btf_vlen(datasec_type); if (vlen == 0) { pr_warn("map '%s': cannot be resized, map value datasec is empty\n", bpf_map__name(map)); return -EINVAL; }
/* verify last var in the datasec is an array */ var = &btf_var_secinfos(datasec_type)[vlen - 1]; var_type = btf_type_by_id(btf, var->type); array_type = skip_mods_and_typedefs(btf, var_type->type, NULL); if (!btf_is_array(array_type)) { pr_warn("map '%s': cannot be resized, last var must be an array\n", bpf_map__name(map)); return -EINVAL; }
/* verify request size aligns with array */ array = btf_array(array_type); element_sz = btf__resolve_size(btf, array->type); if (element_sz <= 0 || (size - var->offset) % element_sz != 0) { pr_warn("map '%s': cannot be resized, element size (%d) doesn't align with new total size (%u)\n", bpf_map__name(map), element_sz, size); return -EINVAL; }
/* create a new array based on the existing array, but with new length */ nr_elements = (size - var->offset) / element_sz; new_array_id = btf__add_array(btf, array->index_type, array->type, nr_elements); if (new_array_id < 0) return new_array_id;
/* adding a new btf type invalidates existing pointers to btf objects, * so refresh pointers before proceeding */ datasec_type = btf_type_by_id(btf, map->btf_value_type_id); var = &btf_var_secinfos(datasec_type)[vlen - 1]; var_type = btf_type_by_id(btf, var->type);
/* finally update btf info */ datasec_type->size = size; var->size = size - var->offset; var_type->type = new_array_id;
return 0;}
int bpf_map__set_value_size(struct bpf_map *map, __u32 size){ if (map_is_created(map)) return libbpf_err(-EBUSY);
if (map->mmaped) { size_t mmap_old_sz, mmap_new_sz; int err;
if (map->def.type != BPF_MAP_TYPE_ARRAY) return libbpf_err(-EOPNOTSUPP);
mmap_old_sz = bpf_map_mmap_sz(map); mmap_new_sz = array_map_mmap_sz(size, map->def.max_entries); err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz); if (err) { pr_warn("map '%s': failed to resize memory-mapped region: %s\n", bpf_map__name(map), errstr(err)); return libbpf_err(err); } err = map_btf_datasec_resize(map, size); if (err && err != -ENOENT) { pr_warn("map '%s': failed to adjust resized BTF, clearing BTF key/value info: %s\n", bpf_map__name(map), errstr(err)); map->btf_value_type_id = 0; map->btf_key_type_id = 0; } }
map->def.value_size = size; return 0;}
__u32 bpf_map__btf_key_type_id(const struct bpf_map *map){ return map ? map->btf_key_type_id : 0;}
__u32 bpf_map__btf_value_type_id(const struct bpf_map *map){ return map ? map->btf_value_type_id : 0;}
int bpf_map__set_initial_value(struct bpf_map *map, const void *data, size_t size){ size_t actual_sz;
if (map_is_created(map)) return libbpf_err(-EBUSY);
if (!map->mmaped || map->libbpf_type == LIBBPF_MAP_KCONFIG) return libbpf_err(-EINVAL);
if (map->def.type == BPF_MAP_TYPE_ARENA) actual_sz = map->obj->arena_data_sz; else actual_sz = map->def.value_size; if (size != actual_sz) return libbpf_err(-EINVAL);
memcpy(map->mmaped, data, size); return 0;}
void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize){ if (bpf_map__is_struct_ops(map)) { if (psize) *psize = map->def.value_size; return map->st_ops->data; }
if (!map->mmaped) return NULL;
if (map->def.type == BPF_MAP_TYPE_ARENA) *psize = map->obj->arena_data_sz; else *psize = map->def.value_size;
return map->mmaped;}
bool bpf_map__is_internal(const struct bpf_map *map){ return map->libbpf_type != LIBBPF_MAP_UNSPEC;}
__u32 bpf_map__ifindex(const struct bpf_map *map){ return map->map_ifindex;}
int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex){ if (map_is_created(map)) return libbpf_err(-EBUSY); map->map_ifindex = ifindex; return 0;}
int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd){ if (!bpf_map_type__is_map_in_map(map->def.type)) { pr_warn("error: unsupported map type\n"); return libbpf_err(-EINVAL); } if (map->inner_map_fd != -1) { pr_warn("error: inner_map_fd already specified\n"); return libbpf_err(-EINVAL); } if (map->inner_map) { bpf_map__destroy(map->inner_map); zfree(&map->inner_map); } map->inner_map_fd = fd; return 0;}
int bpf_map__set_exclusive_program(struct bpf_map *map, struct bpf_program *prog){ if (map_is_created(map)) { pr_warn("exclusive programs must be set before map creation\n"); return libbpf_err(-EINVAL); }
if (map->obj != prog->obj) { pr_warn("excl_prog and map must be from the same bpf object\n"); return libbpf_err(-EINVAL); }
map->excl_prog = prog; return 0;}
struct bpf_program *bpf_map__exclusive_program(struct bpf_map *map){ return map->excl_prog;}
static struct bpf_map *__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i){ ssize_t idx; struct bpf_map *s, *e;
if (!obj || !obj->maps) return errno = EINVAL, NULL;
s = obj->maps; e = obj->maps + obj->nr_maps;
if ((m < s) || (m >= e)) { pr_warn("error in %s: map handler doesn't belong to object\n", __func__); return errno = EINVAL, NULL; }
idx = (m - obj->maps) + i; if (idx >= obj->nr_maps || idx < 0) return NULL; return &obj->maps[idx];}
struct bpf_map *bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev){ if (prev == NULL && obj != NULL) return obj->maps;
return __bpf_map__iter(prev, obj, 1);}
struct bpf_map *bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next){ if (next == NULL && obj != NULL) { if (!obj->nr_maps) return NULL; return obj->maps + obj->nr_maps - 1; }
return __bpf_map__iter(next, obj, -1);}
struct bpf_map *bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name){ struct bpf_map *pos;
bpf_object__for_each_map(pos, obj) { /* if it's a special internal map name (which always starts * with dot) then check if that special name matches the * real map name (ELF section name) */ if (name[0] == '.') { if (pos->real_name && strcmp(pos->real_name, name) == 0) return pos; continue; } /* otherwise map name has to be an exact match */ if (map_uses_real_name(pos)) { if (strcmp(pos->real_name, name) == 0) return pos; continue; } if (strcmp(pos->name, name) == 0) return pos; } return errno = ENOENT, NULL;}
intbpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name){ return bpf_map__fd(bpf_object__find_map_by_name(obj, name));}
static int validate_map_op(const struct bpf_map *map, size_t key_sz, size_t value_sz, bool check_value_sz, __u64 flags){ if (!map_is_created(map)) /* map is not yet created */ return -ENOENT;
if (map->def.key_size != key_sz) { pr_warn("map '%s': unexpected key size %zu provided, expected %u\n", map->name, key_sz, map->def.key_size); return -EINVAL; }
if (map->fd < 0) { pr_warn("map '%s': can't use BPF map without FD (was it created?)\n", map->name); return -EINVAL; }
if (!check_value_sz) return 0;
switch (map->def.type) { case BPF_MAP_TYPE_PERCPU_ARRAY: case BPF_MAP_TYPE_PERCPU_HASH: case BPF_MAP_TYPE_LRU_PERCPU_HASH: case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: { int num_cpu = libbpf_num_possible_cpus(); size_t elem_sz = roundup(map->def.value_size, 8);
if (flags & (BPF_F_CPU | BPF_F_ALL_CPUS)) { if ((flags & BPF_F_CPU) && (flags & BPF_F_ALL_CPUS)) { pr_warn("map '%s': BPF_F_CPU and BPF_F_ALL_CPUS are mutually exclusive\n", map->name); return -EINVAL; } if (map->def.value_size != value_sz) { pr_warn("map '%s': unexpected value size %zu provided for either BPF_F_CPU or BPF_F_ALL_CPUS, expected %u\n", map->name, value_sz, map->def.value_size); return -EINVAL; } break; }
if (value_sz != num_cpu * elem_sz) { pr_warn("map '%s': unexpected value size %zu provided for per-CPU map, expected %d * %zu = %zd\n", map->name, value_sz, num_cpu, elem_sz, num_cpu * elem_sz); return -EINVAL; } break; } default: if (map->def.value_size != value_sz) { pr_warn("map '%s': unexpected value size %zu provided, expected %u\n", map->name, value_sz, map->def.value_size); return -EINVAL; } break; } return 0;}
int bpf_map__lookup_elem(const struct bpf_map *map, const void *key, size_t key_sz, void *value, size_t value_sz, __u64 flags){ int err;
err = validate_map_op(map, key_sz, value_sz, true, flags); if (err) return libbpf_err(err);
return bpf_map_lookup_elem_flags(map->fd, key, value, flags);}
int bpf_map__update_elem(const struct bpf_map *map, const void *key, size_t key_sz, const void *value, size_t value_sz, __u64 flags){ int err;
err = validate_map_op(map, key_sz, value_sz, true, flags); if (err) return libbpf_err(err);
return bpf_map_update_elem(map->fd, key, value, flags);}
int bpf_map__delete_elem(const struct bpf_map *map, const void *key, size_t key_sz, __u64 flags){ int err;
err = validate_map_op(map, key_sz, 0, false /* check_value_sz */, flags); if (err) return libbpf_err(err);
return bpf_map_delete_elem_flags(map->fd, key, flags);}
int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, const void *key, size_t key_sz, void *value, size_t value_sz, __u64 flags){ int err;
err = validate_map_op(map, key_sz, value_sz, true, flags); if (err) return libbpf_err(err);
return bpf_map_lookup_and_delete_elem_flags(map->fd, key, value, flags);}
int bpf_map__get_next_key(const struct bpf_map *map, const void *cur_key, void *next_key, size_t key_sz){ int err;
err = validate_map_op(map, key_sz, 0, false /* check_value_sz */, 0); if (err) return libbpf_err(err);
return bpf_map_get_next_key(map->fd, cur_key, next_key);}
long libbpf_get_error(const void *ptr){ if (!IS_ERR_OR_NULL(ptr)) return 0;
if (IS_ERR(ptr)) errno = -PTR_ERR(ptr);
/* If ptr == NULL, then errno should be already set by the failing * API, because libbpf never returns NULL on success and it now always * sets errno on error. So no extra errno handling for ptr == NULL * case. */ return -errno;}
/* Replace link's underlying BPF program with the new one */int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog){ int ret; int prog_fd = bpf_program__fd(prog);
if (prog_fd < 0) { pr_warn("prog '%s': can't use BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err(-EINVAL); }
ret = bpf_link_update(bpf_link__fd(link), prog_fd, NULL); return libbpf_err_errno(ret);}
/* Release "ownership" of underlying BPF resource (typically, BPF program * attached to some BPF hook, e.g., tracepoint, kprobe, etc). Disconnected * link, when destructed through bpf_link__destroy() call won't attempt to * detach/unregisted that BPF resource. This is useful in situations where, * say, attached BPF program has to outlive userspace program that attached it * in the system. Depending on type of BPF program, though, there might be * additional steps (like pinning BPF program in BPF FS) necessary to ensure * exit of userspace program doesn't trigger automatic detachment and clean up * inside the kernel. */void bpf_link__disconnect(struct bpf_link *link){ link->disconnected = true;}
int bpf_link__destroy(struct bpf_link *link){ int err = 0;
if (IS_ERR_OR_NULL(link)) return 0;
if (!link->disconnected && link->detach) err = link->detach(link); if (link->pin_path) free(link->pin_path); if (link->dealloc) link->dealloc(link); else free(link);
return libbpf_err(err);}
int bpf_link__fd(const struct bpf_link *link){ return link->fd;}
const char *bpf_link__pin_path(const struct bpf_link *link){ return link->pin_path;}
static int bpf_link__detach_fd(struct bpf_link *link){ return libbpf_err_errno(close(link->fd));}
struct bpf_link *bpf_link__open(const char *path){ struct bpf_link *link; int fd;
fd = bpf_obj_get(path); if (fd < 0) { fd = -errno; pr_warn("failed to open link at %s: %d\n", path, fd); return libbpf_err_ptr(fd); }
link = calloc(1, sizeof(*link)); if (!link) { close(fd); return libbpf_err_ptr(-ENOMEM); } link->detach = &bpf_link__detach_fd; link->fd = fd;
link->pin_path = strdup(path); if (!link->pin_path) { bpf_link__destroy(link); return libbpf_err_ptr(-ENOMEM); }
return link;}
int bpf_link__detach(struct bpf_link *link){ return bpf_link_detach(link->fd) ? -errno : 0;}
int bpf_link__pin(struct bpf_link *link, const char *path){ int err;
if (link->pin_path) return libbpf_err(-EBUSY); err = make_parent_dir(path); if (err) return libbpf_err(err); err = check_path(path); if (err) return libbpf_err(err);
link->pin_path = strdup(path); if (!link->pin_path) return libbpf_err(-ENOMEM);
if (bpf_obj_pin(link->fd, link->pin_path)) { err = -errno; zfree(&link->pin_path); return libbpf_err(err); }
pr_debug("link fd=%d: pinned at %s\n", link->fd, link->pin_path); return 0;}
int bpf_link__unpin(struct bpf_link *link){ int err;
if (!link->pin_path) return libbpf_err(-EINVAL);
err = unlink(link->pin_path); if (err != 0) return -errno;
pr_debug("link fd=%d: unpinned from %s\n", link->fd, link->pin_path); zfree(&link->pin_path); return 0;}
struct bpf_link_perf { struct bpf_link link; int perf_event_fd; /* legacy kprobe support: keep track of probe identifier and type */ char *legacy_probe_name; bool legacy_is_kprobe; bool legacy_is_retprobe;};
static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe);static int remove_uprobe_event_legacy(const char *probe_name, bool retprobe);
static int bpf_link_perf_detach(struct bpf_link *link){ struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); int err = 0;
if (ioctl(perf_link->perf_event_fd, PERF_EVENT_IOC_DISABLE, 0) < 0) err = -errno;
if (perf_link->perf_event_fd != link->fd) close(perf_link->perf_event_fd); close(link->fd);
/* legacy uprobe/kprobe needs to be removed after perf event fd closure */ if (perf_link->legacy_probe_name) { if (perf_link->legacy_is_kprobe) { err = remove_kprobe_event_legacy(perf_link->legacy_probe_name, perf_link->legacy_is_retprobe); } else { err = remove_uprobe_event_legacy(perf_link->legacy_probe_name, perf_link->legacy_is_retprobe); } }
return err;}
static void bpf_link_perf_dealloc(struct bpf_link *link){ struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
free(perf_link->legacy_probe_name); free(perf_link);}
struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, const struct bpf_perf_event_opts *opts){ struct bpf_link_perf *link; int prog_fd, link_fd = -1, err; bool force_ioctl_attach;
if (!OPTS_VALID(opts, bpf_perf_event_opts)) return libbpf_err_ptr(-EINVAL);
if (pfd < 0) { pr_warn("prog '%s': invalid perf event FD %d\n", prog->name, pfd); return libbpf_err_ptr(-EINVAL); } prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); link->link.detach = &bpf_link_perf_detach; link->link.dealloc = &bpf_link_perf_dealloc; link->perf_event_fd = pfd;
force_ioctl_attach = OPTS_GET(opts, force_ioctl_attach, false); if (kernel_supports(prog->obj, FEAT_PERF_LINK) && !force_ioctl_attach) { DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts, .perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0));
link_fd = bpf_link_create(prog_fd, pfd, BPF_PERF_EVENT, &link_opts); if (link_fd < 0) { err = -errno; pr_warn("prog '%s': failed to create BPF link for perf_event FD %d: %s\n", prog->name, pfd, errstr(err)); goto err_out; } link->link.fd = link_fd; } else { if (OPTS_GET(opts, bpf_cookie, 0)) { pr_warn("prog '%s': user context value is not supported\n", prog->name); err = -EOPNOTSUPP; goto err_out; }
if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { err = -errno; pr_warn("prog '%s': failed to attach to perf_event FD %d: %s\n", prog->name, pfd, errstr(err)); if (err == -EPROTO) pr_warn("prog '%s': try add PERF_SAMPLE_CALLCHAIN to or remove exclude_callchain_[kernel|user] from pfd %d\n", prog->name, pfd); goto err_out; } link->link.fd = pfd; }
if (!OPTS_GET(opts, dont_enable, false)) { if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { err = -errno; pr_warn("prog '%s': failed to enable perf_event FD %d: %s\n", prog->name, pfd, errstr(err)); goto err_out; } }
return &link->link;err_out: if (link_fd >= 0) close(link_fd); free(link); return libbpf_err_ptr(err);}
struct bpf_link *bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd){ return bpf_program__attach_perf_event_opts(prog, pfd, NULL);}
/* * this function is expected to parse integer in the range of [0, 2^31-1] from * given file using scanf format string fmt. If actual parsed value is * negative, the result might be indistinguishable from error */static int parse_uint_from_file(const char *file, const char *fmt){ int err, ret; FILE *f;
f = fopen(file, "re"); if (!f) { err = -errno; pr_debug("failed to open '%s': %s\n", file, errstr(err)); return err; } err = fscanf(f, fmt, &ret); if (err != 1) { err = err == EOF ? -EIO : -errno; pr_debug("failed to parse '%s': %s\n", file, errstr(err)); fclose(f); return err; } fclose(f); return ret;}
static int determine_kprobe_perf_type(void){ const char *file = "/sys/bus/event_source/devices/kprobe/type";
return parse_uint_from_file(file, "%d\n");}
static int determine_uprobe_perf_type(void){ const char *file = "/sys/bus/event_source/devices/uprobe/type";
return parse_uint_from_file(file, "%d\n");}
static int determine_kprobe_retprobe_bit(void){ const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe";
return parse_uint_from_file(file, "config:%d\n");}
static int determine_uprobe_retprobe_bit(void){ const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
return parse_uint_from_file(file, "config:%d\n");}
#define PERF_UPROBE_REF_CTR_OFFSET_BITS 32#define PERF_UPROBE_REF_CTR_OFFSET_SHIFT 32
static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, uint64_t offset, int pid, size_t ref_ctr_off){ const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_event_attr attr; int type, pfd;
if ((__u64)ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS)) return -EINVAL;
memset(&attr, 0, attr_sz);
type = uprobe ? determine_uprobe_perf_type() : determine_kprobe_perf_type(); if (type < 0) { pr_warn("failed to determine %s perf type: %s\n", uprobe ? "uprobe" : "kprobe", errstr(type)); return type; } if (retprobe) { int bit = uprobe ? determine_uprobe_retprobe_bit() : determine_kprobe_retprobe_bit();
if (bit < 0) { pr_warn("failed to determine %s retprobe bit: %s\n", uprobe ? "uprobe" : "kprobe", errstr(bit)); return bit; } attr.config |= 1 << bit; } attr.size = attr_sz; attr.type = type; attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT; attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */ attr.config2 = offset; /* kprobe_addr or probe_offset */
/* pid filter is meaningful only for uprobes */ pfd = syscall(__NR_perf_event_open, &attr, pid < 0 ? -1 : pid /* pid */, pid == -1 ? 0 : -1 /* cpu */, -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); return pfd >= 0 ? pfd : -errno;}
static int append_to_file(const char *file, const char *fmt, ...){ int fd, n, err = 0; va_list ap; char buf[1024];
va_start(ap, fmt); n = vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap);
if (n < 0 || n >= sizeof(buf)) return -EINVAL;
fd = open(file, O_WRONLY | O_APPEND | O_CLOEXEC, 0); if (fd < 0) return -errno;
if (write(fd, buf, n) < 0) err = -errno;
close(fd); return err;}
#define DEBUGFS "/sys/kernel/debug/tracing"#define TRACEFS "/sys/kernel/tracing"
static bool use_debugfs(void){ static int has_debugfs = -1;
if (has_debugfs < 0) has_debugfs = faccessat(AT_FDCWD, DEBUGFS, F_OK, AT_EACCESS) == 0;
return has_debugfs == 1;}
static const char *tracefs_path(void){ return use_debugfs() ? DEBUGFS : TRACEFS;}
static const char *tracefs_kprobe_events(void){ return use_debugfs() ? DEBUGFS"/kprobe_events" : TRACEFS"/kprobe_events";}
static const char *tracefs_uprobe_events(void){ return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events";}
static const char *tracefs_available_filter_functions(void){ return use_debugfs() ? DEBUGFS"/available_filter_functions" : TRACEFS"/available_filter_functions";}
static const char *tracefs_available_filter_functions_addrs(void){ return use_debugfs() ? DEBUGFS"/available_filter_functions_addrs" : TRACEFS"/available_filter_functions_addrs";}
static void gen_probe_legacy_event_name(char *buf, size_t buf_sz, const char *name, size_t offset){ static int index = 0; int i;
snprintf(buf, buf_sz, "libbpf_%u_%d_%s_0x%zx", getpid(), __sync_fetch_and_add(&index, 1), name, offset);
/* sanitize name in the probe name */ for (i = 0; buf[i]; i++) { if (!isalnum(buf[i])) buf[i] = '_'; }}
static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset){ return append_to_file(tracefs_kprobe_events(), "%c:%s/%s %s+0x%zx", retprobe ? 'r' : 'p', retprobe ? "kretprobes" : "kprobes", probe_name, kfunc_name, offset);}
static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe){ return append_to_file(tracefs_kprobe_events(), "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name);}
static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe){ char file[256];
snprintf(file, sizeof(file), "%s/events/%s/%s/id", tracefs_path(), retprobe ? "kretprobes" : "kprobes", probe_name);
return parse_uint_from_file(file, "%d\n");}
static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset, int pid){ const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_event_attr attr; int type, pfd, err;
err = add_kprobe_event_legacy(probe_name, retprobe, kfunc_name, offset); if (err < 0) { pr_warn("failed to add legacy kprobe event for '%s+0x%zx': %s\n", kfunc_name, offset, errstr(err)); return err; } type = determine_kprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { err = type; pr_warn("failed to determine legacy kprobe event id for '%s+0x%zx': %s\n", kfunc_name, offset, errstr(err)); goto err_clean_legacy; }
memset(&attr, 0, attr_sz); attr.size = attr_sz; attr.config = type; attr.type = PERF_TYPE_TRACEPOINT;
pfd = syscall(__NR_perf_event_open, &attr, pid < 0 ? -1 : pid, /* pid */ pid == -1 ? 0 : -1, /* cpu */ -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); if (pfd < 0) { err = -errno; pr_warn("legacy kprobe perf_event_open() failed: %s\n", errstr(err)); goto err_clean_legacy; } return pfd;
err_clean_legacy: /* Clear the newly added legacy kprobe_event */ remove_kprobe_event_legacy(probe_name, retprobe); return err;}
static const char *arch_specific_syscall_pfx(void){#if defined(__x86_64__) return "x64";#elif defined(__i386__) return "ia32";#elif defined(__s390x__) return "s390x";#elif defined(__arm__) return "arm";#elif defined(__aarch64__) return "arm64";#elif defined(__mips__) return "mips";#elif defined(__riscv) return "riscv";#elif defined(__powerpc__) return "powerpc";#elif defined(__powerpc64__) return "powerpc64";#else return NULL;#endif}
int probe_kern_syscall_wrapper(int token_fd){ char syscall_name[64]; const char *ksys_pfx;
ksys_pfx = arch_specific_syscall_pfx(); if (!ksys_pfx) return 0;
snprintf(syscall_name, sizeof(syscall_name), "__%s_sys_bpf", ksys_pfx);
if (determine_kprobe_perf_type() >= 0) { int pfd;
pfd = perf_event_open_probe(false, false, syscall_name, 0, getpid(), 0); if (pfd >= 0) close(pfd);
return pfd >= 0 ? 1 : 0; } else { /* legacy mode */ char probe_name[MAX_EVENT_NAME_LEN];
gen_probe_legacy_event_name(probe_name, sizeof(probe_name), syscall_name, 0); if (add_kprobe_event_legacy(probe_name, false, syscall_name, 0) < 0) return 0;
(void)remove_kprobe_event_legacy(probe_name, false); return 1; }}
struct bpf_link *bpf_program__attach_kprobe_opts(const struct bpf_program *prog, const char *func_name, const struct bpf_kprobe_opts *opts){ DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); enum probe_attach_mode attach_mode; char *legacy_probe = NULL; struct bpf_link *link; size_t offset; bool retprobe, legacy; int pfd, err;
if (!OPTS_VALID(opts, bpf_kprobe_opts)) return libbpf_err_ptr(-EINVAL);
attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); offset = OPTS_GET(opts, offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
legacy = determine_kprobe_perf_type() < 0; switch (attach_mode) { case PROBE_ATTACH_MODE_LEGACY: legacy = true; pe_opts.force_ioctl_attach = true; break; case PROBE_ATTACH_MODE_PERF: if (legacy) return libbpf_err_ptr(-ENOTSUP); pe_opts.force_ioctl_attach = true; break; case PROBE_ATTACH_MODE_LINK: if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK)) return libbpf_err_ptr(-ENOTSUP); break; case PROBE_ATTACH_MODE_DEFAULT: break; default: return libbpf_err_ptr(-EINVAL); } if (!func_name && legacy) return libbpf_err_ptr(-EOPNOTSUPP);
if (!legacy) { pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, offset, -1 /* pid */, 0 /* ref_ctr_off */); } else { char probe_name[MAX_EVENT_NAME_LEN];
gen_probe_legacy_event_name(probe_name, sizeof(probe_name), func_name, offset);
legacy_probe = strdup(probe_name); if (!legacy_probe) return libbpf_err_ptr(-ENOMEM);
pfd = perf_event_kprobe_open_legacy(legacy_probe, retprobe, func_name, offset, -1 /* pid */); } if (pfd < 0) { err = pfd; pr_warn("prog '%s': failed to create %s '%s%s0x%zx' perf event: %s\n", prog->name, retprobe ? "kretprobe" : "kprobe", func_name ?: "", func_name ? "+" : "", offset, errstr(err)); goto err_out; } link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); pr_warn("prog '%s': failed to attach to %s '%s%s0x%zx': %s\n", prog->name, retprobe ? "kretprobe" : "kprobe", func_name ?: "", func_name ? "+" : "", offset, errstr(err)); goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
perf_link->legacy_probe_name = legacy_probe; perf_link->legacy_is_kprobe = true; perf_link->legacy_is_retprobe = retprobe; }
return link;
err_clean_legacy: if (legacy) remove_kprobe_event_legacy(legacy_probe, retprobe);err_out: free(legacy_probe); return libbpf_err_ptr(err);}
struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, const char *func_name){ DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts, .retprobe = retprobe, );
return bpf_program__attach_kprobe_opts(prog, func_name, &opts);}
struct bpf_link *bpf_program__attach_ksyscall(const struct bpf_program *prog, const char *syscall_name, const struct bpf_ksyscall_opts *opts){ LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts); char func_name[128];
if (!OPTS_VALID(opts, bpf_ksyscall_opts)) return libbpf_err_ptr(-EINVAL);
if (kernel_supports(prog->obj, FEAT_SYSCALL_WRAPPER)) { /* arch_specific_syscall_pfx() should never return NULL here * because it is guarded by kernel_supports(). However, since * compiler does not know that we have an explicit conditional * as well. */ snprintf(func_name, sizeof(func_name), "__%s_sys_%s", arch_specific_syscall_pfx() ? : "", syscall_name); } else { snprintf(func_name, sizeof(func_name), "__se_sys_%s", syscall_name); }
kprobe_opts.retprobe = OPTS_GET(opts, retprobe, false); kprobe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
return bpf_program__attach_kprobe_opts(prog, func_name, &kprobe_opts);}
/* Adapted from perf/util/string.c */bool glob_match(const char *str, const char *pat){ while (*str && *pat && *pat != '*') { if (*pat == '?') { /* Matches any single character */ str++; pat++; continue; } if (*str != *pat) return false; str++; pat++; } /* Check wild card */ if (*pat == '*') { while (*pat == '*') pat++; if (!*pat) /* Tail wild card matches all */ return true; while (*str) if (glob_match(str++, pat)) return true; } return !*str && !*pat;}
struct kprobe_multi_resolve { const char *pattern; unsigned long *addrs; size_t cap; size_t cnt;};
struct avail_kallsyms_data { char **syms; size_t cnt; struct kprobe_multi_resolve *res;};
static int avail_func_cmp(const void *a, const void *b){ return strcmp(*(const char **)a, *(const char **)b);}
static int avail_kallsyms_cb(unsigned long long sym_addr, char sym_type, const char *sym_name, void *ctx){ struct avail_kallsyms_data *data = ctx; struct kprobe_multi_resolve *res = data->res; int err;
if (!glob_match(sym_name, res->pattern)) return 0;
if (!bsearch(&sym_name, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp)) { /* Some versions of kernel strip out .llvm.<hash> suffix from * function names reported in available_filter_functions, but * don't do so for kallsyms. While this is clearly a kernel * bug (fixed by [0]) we try to accommodate that in libbpf to * make multi-kprobe usability a bit better: if no match is * found, we will strip .llvm. suffix and try one more time. * * [0] fb6a421fb615 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG") */ char sym_trim[256], *psym_trim = sym_trim; const char *sym_sfx;
if (!(sym_sfx = strstr(sym_name, ".llvm."))) return 0;
/* psym_trim vs sym_trim dance is done to avoid pointer vs array * coercion differences and get proper `const char **` pointer * which avail_func_cmp() expects */ snprintf(sym_trim, sizeof(sym_trim), "%.*s", (int)(sym_sfx - sym_name), sym_name); if (!bsearch(&psym_trim, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp)) return 0; }
err = libbpf_ensure_mem((void **)&res->addrs, &res->cap, sizeof(*res->addrs), res->cnt + 1); if (err) return err;
res->addrs[res->cnt++] = (unsigned long)sym_addr; return 0;}
static int libbpf_available_kallsyms_parse(struct kprobe_multi_resolve *res){ const char *available_functions_file = tracefs_available_filter_functions(); struct avail_kallsyms_data data; char sym_name[500]; FILE *f; int err = 0, ret, i; char **syms = NULL; size_t cap = 0, cnt = 0;
f = fopen(available_functions_file, "re"); if (!f) { err = -errno; pr_warn("failed to open %s: %s\n", available_functions_file, errstr(err)); return err; }
while (true) { char *name;
ret = fscanf(f, "%499s%*[^\n]\n", sym_name); if (ret == EOF && feof(f)) break;
if (ret != 1) { pr_warn("failed to parse available_filter_functions entry: %d\n", ret); err = -EINVAL; goto cleanup; }
if (!glob_match(sym_name, res->pattern)) continue;
err = libbpf_ensure_mem((void **)&syms, &cap, sizeof(*syms), cnt + 1); if (err) goto cleanup;
name = strdup(sym_name); if (!name) { err = -errno; goto cleanup; }
syms[cnt++] = name; }
/* no entries found, bail out */ if (cnt == 0) { err = -ENOENT; goto cleanup; }
/* sort available functions */ qsort(syms, cnt, sizeof(*syms), avail_func_cmp);
data.syms = syms; data.res = res; data.cnt = cnt; libbpf_kallsyms_parse(avail_kallsyms_cb, &data);
if (res->cnt == 0) err = -ENOENT;
cleanup: for (i = 0; i < cnt; i++) free((char *)syms[i]); free(syms);
fclose(f); return err;}
static bool has_available_filter_functions_addrs(void){ return access(tracefs_available_filter_functions_addrs(), R_OK) != -1;}
static int libbpf_available_kprobes_parse(struct kprobe_multi_resolve *res){ const char *available_path = tracefs_available_filter_functions_addrs(); char sym_name[500]; FILE *f; int ret, err = 0; unsigned long long sym_addr;
f = fopen(available_path, "re"); if (!f) { err = -errno; pr_warn("failed to open %s: %s\n", available_path, errstr(err)); return err; }
while (true) { ret = fscanf(f, "%llx %499s%*[^\n]\n", &sym_addr, sym_name); if (ret == EOF && feof(f)) break;
if (ret != 2) { pr_warn("failed to parse available_filter_functions_addrs entry: %d\n", ret); err = -EINVAL; goto cleanup; }
if (!glob_match(sym_name, res->pattern)) continue;
err = libbpf_ensure_mem((void **)&res->addrs, &res->cap, sizeof(*res->addrs), res->cnt + 1); if (err) goto cleanup;
res->addrs[res->cnt++] = (unsigned long)sym_addr; }
if (res->cnt == 0) err = -ENOENT;
cleanup: fclose(f); return err;}
struct bpf_link *bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const char *pattern, const struct bpf_kprobe_multi_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, lopts); struct kprobe_multi_resolve res = { .pattern = pattern, }; enum bpf_attach_type attach_type; struct bpf_link *link = NULL; const unsigned long *addrs; int err, link_fd, prog_fd; bool retprobe, session, unique_match; const __u64 *cookies; const char **syms; size_t cnt;
if (!OPTS_VALID(opts, bpf_kprobe_multi_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
syms = OPTS_GET(opts, syms, false); addrs = OPTS_GET(opts, addrs, false); cnt = OPTS_GET(opts, cnt, false); cookies = OPTS_GET(opts, cookies, false); unique_match = OPTS_GET(opts, unique_match, false);
if (!pattern && !addrs && !syms) return libbpf_err_ptr(-EINVAL); if (pattern && (addrs || syms || cookies || cnt)) return libbpf_err_ptr(-EINVAL); if (!pattern && !cnt) return libbpf_err_ptr(-EINVAL); if (!pattern && unique_match) return libbpf_err_ptr(-EINVAL); if (addrs && syms) return libbpf_err_ptr(-EINVAL);
/* * Exact function name (no wildcards) without unique_match: * bypass kallsyms parsing and pass the symbol directly to the * kernel via syms[] array. When unique_match is set, fall * through to the slow path which detects duplicate symbols. */ if (pattern && !strpbrk(pattern, "*?") && !unique_match) { syms = &pattern; cnt = 1; } else if (pattern) { if (has_available_filter_functions_addrs()) err = libbpf_available_kprobes_parse(&res); else err = libbpf_available_kallsyms_parse(&res); if (err) goto error;
if (unique_match && res.cnt != 1) { pr_warn("prog '%s': failed to find a unique match for '%s' (%zu matches)\n", prog->name, pattern, res.cnt); err = -EINVAL; goto error; }
addrs = res.addrs; cnt = res.cnt; }
retprobe = OPTS_GET(opts, retprobe, false); session = OPTS_GET(opts, session, false);
if (retprobe && session) return libbpf_err_ptr(-EINVAL);
attach_type = session ? BPF_TRACE_KPROBE_SESSION : BPF_TRACE_KPROBE_MULTI;
lopts.kprobe_multi.syms = syms; lopts.kprobe_multi.addrs = addrs; lopts.kprobe_multi.cookies = cookies; lopts.kprobe_multi.cnt = cnt; lopts.kprobe_multi.flags = retprobe ? BPF_F_KPROBE_MULTI_RETURN : 0;
link = calloc(1, sizeof(*link)); if (!link) { err = -ENOMEM; goto error; } link->detach = &bpf_link__detach_fd;
link_fd = bpf_link_create(prog_fd, 0, attach_type, &lopts); if (link_fd < 0) { err = -errno; /* * Normalize error code: when exact name bypasses kallsyms * parsing, kernel returns ESRCH from ftrace_lookup_symbols(). * Convert to ENOENT for API consistency with the pattern * matching path which returns ENOENT from userspace. */ if (err == -ESRCH) err = -ENOENT; pr_warn("prog '%s': failed to attach: %s\n", prog->name, errstr(err)); goto error; } link->fd = link_fd; free(res.addrs); return link;
error: free(link); free(res.addrs); return libbpf_err_ptr(err);}
static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link){ DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); long offset = 0; const char *func_name; char *func; int n;
*link = NULL;
/* no auto-attach for SEC("kprobe") and SEC("kretprobe") */ if (strcmp(prog->sec_name, "kprobe") == 0 || strcmp(prog->sec_name, "kretprobe") == 0) return 0;
opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe/"); if (opts.retprobe) func_name = prog->sec_name + sizeof("kretprobe/") - 1; else func_name = prog->sec_name + sizeof("kprobe/") - 1;
n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset); if (n < 1) { pr_warn("kprobe name is invalid: %s\n", func_name); return -EINVAL; }
if (offset < 0) { free(func); pr_warn("kprobe offset must be a non-negative integer: %li\n", offset); return -EINVAL; }
if (opts.retprobe && offset != 0) { free(func); pr_warn("kretprobes do not support offset specification\n"); return -EINVAL; }
opts.offset = offset; *link = bpf_program__attach_kprobe_opts(prog, func, &opts); free(func); return libbpf_get_error(*link);}
static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link){ LIBBPF_OPTS(bpf_ksyscall_opts, opts); const char *syscall_name;
*link = NULL;
/* no auto-attach for SEC("ksyscall") and SEC("kretsyscall") */ if (strcmp(prog->sec_name, "ksyscall") == 0 || strcmp(prog->sec_name, "kretsyscall") == 0) return 0;
opts.retprobe = str_has_pfx(prog->sec_name, "kretsyscall/"); if (opts.retprobe) syscall_name = prog->sec_name + sizeof("kretsyscall/") - 1; else syscall_name = prog->sec_name + sizeof("ksyscall/") - 1;
*link = bpf_program__attach_ksyscall(prog, syscall_name, &opts); return *link ? 0 : -errno;}
static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link){ LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); const char *spec; char *pattern; int n;
*link = NULL;
/* no auto-attach for SEC("kprobe.multi") and SEC("kretprobe.multi") */ if (strcmp(prog->sec_name, "kprobe.multi") == 0 || strcmp(prog->sec_name, "kretprobe.multi") == 0) return 0;
opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe.multi/"); if (opts.retprobe) spec = prog->sec_name + sizeof("kretprobe.multi/") - 1; else spec = prog->sec_name + sizeof("kprobe.multi/") - 1;
n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern); if (n < 1) { pr_warn("kprobe multi pattern is invalid: %s\n", spec); return -EINVAL; }
*link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts); free(pattern); return libbpf_get_error(*link);}
static int attach_kprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link){ LIBBPF_OPTS(bpf_kprobe_multi_opts, opts, .session = true); const char *spec; char *pattern; int n;
*link = NULL;
/* no auto-attach for SEC("kprobe.session") */ if (strcmp(prog->sec_name, "kprobe.session") == 0) return 0;
spec = prog->sec_name + sizeof("kprobe.session/") - 1; n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern); if (n < 1) { pr_warn("kprobe session pattern is invalid: %s\n", spec); return -EINVAL; }
*link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts); free(pattern); return *link ? 0 : -errno;}
static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link){ char *probe_type = NULL, *binary_path = NULL, *func_name = NULL; LIBBPF_OPTS(bpf_uprobe_multi_opts, opts); int n, ret = -EINVAL;
*link = NULL;
n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[^\n]", &probe_type, &binary_path, &func_name); switch (n) { case 1: /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */ ret = 0; break; case 3: opts.session = str_has_pfx(probe_type, "uprobe.session"); opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
*link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts); ret = libbpf_get_error(*link); break; default: pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, prog->sec_name); break; } free(probe_type); free(binary_path); free(func_name); return ret;}
#define MAX_BPF_FUNC_ARGS 12
static bool btf_type_is_modifier(const struct btf_type *t){ switch (BTF_INFO_KIND(t->info)) { case BTF_KIND_TYPEDEF: case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: case BTF_KIND_TYPE_TAG: return true; default: return false; }}
#define MAX_RESOLVE_DEPTH 32
static int btf_get_type_size(const struct btf *btf, __u32 type_id, const struct btf_type **ret_type){ const struct btf_type *t; int i;
*ret_type = btf__type_by_id(btf, 0); if (!type_id) return 0; t = btf__type_by_id(btf, type_id); for (i = 0; i < MAX_RESOLVE_DEPTH && t && btf_type_is_modifier(t); i++) t = btf__type_by_id(btf, t->type); if (!t || i == MAX_RESOLVE_DEPTH) return -EINVAL; *ret_type = t; if (btf_is_ptr(t)) return btf__pointer_size(btf); if (btf_is_int(t) || btf_is_any_enum(t) || btf_is_struct(t) || btf_is_union(t)) return t->size; return -EINVAL;}
bool btf_type_is_traceable_func(const struct btf *btf, const struct btf_type *t){ const struct btf_param *args; const struct btf_type *proto; __u32 i, nargs; int ret;
if (!btf_is_func(t)) return false; proto = btf__type_by_id(btf, t->type); if (!proto || !btf_is_func_proto(proto)) return false;
args = (const struct btf_param *)(proto + 1); nargs = btf_vlen(proto); if (nargs > MAX_BPF_FUNC_ARGS) return false;
/* No support for struct return type. */ ret = btf_get_type_size(btf, proto->type, &t); if (ret < 0 || btf_is_struct(t) || btf_is_union(t)) return false;
for (i = 0; i < nargs; i++) { /* No support for variable args. */ if (i == nargs - 1 && args[i].type == 0) return false; ret = btf_get_type_size(btf, args[i].type, &t); /* No support of struct argument size greater than 16 bytes. */ if (ret < 0 || ret > 16) return false; /* No support for void argument. */ if (ret == 0) return false; }
return true;}
static intcollect_btf_func_ids_by_glob(const struct btf *btf, const char *pattern, __u32 **ids){ __u32 type_id, nr_types = btf__type_cnt(btf); size_t cap = 0, cnt = 0;
if (!pattern) return -EINVAL;
for (type_id = 1; type_id < nr_types; type_id++) { const struct btf_type *t = btf__type_by_id(btf, type_id); const char *name; int err;
if (btf_kind(t) != BTF_KIND_FUNC) continue; name = btf__name_by_offset(btf, t->name_off); if (!name) continue;
if (!glob_match(name, pattern)) continue; if (!btf_type_is_traceable_func(btf, t)) continue;
err = libbpf_ensure_mem((void **) ids, &cap, sizeof(**ids), cnt + 1); if (err) { free(*ids); return -ENOMEM; } (*ids)[cnt++] = type_id; }
return cnt;}
static int collect_func_ids_by_glob(const struct bpf_program *prog, const char *pattern, __u32 **ids){ struct bpf_object *obj = prog->obj; const struct module_btf *mod; struct btf *btf = NULL; const char *sep; int err;
err = bpf_object__load_vmlinux_btf(obj, true); if (err) return err;
/* In case we have module specified, we will find its btf and use that. */ sep = strchr(pattern, ':'); if (sep) { mod = find_attach_module(obj, pattern); if (!mod) { err = -EINVAL; goto cleanup; } btf = mod->btf; pattern = sep + 1; } else { /* Program is loaded for kernel module. */ if (prog->attach_btf_obj_fd) { err = -EINVAL; goto cleanup; } btf = obj->btf_vmlinux; }
err = collect_btf_func_ids_by_glob(btf, pattern, ids);
cleanup: bpf_object_cleanup_btf(obj); return err;}
struct bpf_link *bpf_program__attach_tracing_multi(const struct bpf_program *prog, const char *pattern, const struct bpf_tracing_multi_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, lopts); int prog_fd, link_fd, err, cnt; __u32 *free_ids = NULL; struct bpf_link *link; const __u64 *cookies; const __u32 *ids;
if (!OPTS_VALID(opts, bpf_tracing_multi_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
cnt = OPTS_GET(opts, cnt, 0); ids = OPTS_GET(opts, ids, NULL); cookies = OPTS_GET(opts, cookies, NULL);
if (!!ids != !!cnt) return libbpf_err_ptr(-EINVAL); if (pattern && (ids || cookies)) return libbpf_err_ptr(-EINVAL); if (!pattern && !ids) return libbpf_err_ptr(-EINVAL);
if (pattern) { cnt = collect_func_ids_by_glob(prog, pattern, &free_ids); if (cnt < 0) return libbpf_err_ptr(cnt); if (cnt == 0) return libbpf_err_ptr(-EINVAL); ids = (const __u32 *) free_ids; }
lopts.tracing_multi.ids = ids; lopts.tracing_multi.cookies = cookies; lopts.tracing_multi.cnt = cnt;
link = calloc(1, sizeof(*link)); if (!link) { err = -ENOMEM; goto error; } link->detach = &bpf_link__detach_fd;
link_fd = bpf_link_create(prog_fd, 0, prog->expected_attach_type, &lopts); if (link_fd < 0) { err = -errno; pr_warn("prog '%s': failed to attach: %s\n", prog->name, errstr(err)); goto error; } link->fd = link_fd; free(free_ids); return link;
error: free(link); free(free_ids); return libbpf_err_ptr(err);}
static int attach_tracing_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link){ static const char *const prefixes[] = { "fentry.multi", "fexit.multi", "fsession.multi", "fentry.multi.s", "fexit.multi.s", "fsession.multi.s", }; const char *spec = NULL; char *pattern; size_t i; int n;
*link = NULL;
for (i = 0; i < ARRAY_SIZE(prefixes); i++) { size_t pfx_len;
if (!str_has_pfx(prog->sec_name, prefixes[i])) continue;
pfx_len = strlen(prefixes[i]); /* no auto-attach case of, e.g., SEC("fentry.multi") */ if (prog->sec_name[pfx_len] == '\0') return 0;
if (prog->sec_name[pfx_len] != '/') continue;
spec = prog->sec_name + pfx_len + 1; break; }
if (!spec) { pr_warn("prog '%s': invalid section name '%s'\n", prog->name, prog->sec_name); return -EINVAL; }
n = sscanf(spec, "%m[a-zA-Z0-9_.*?:]", &pattern); if (n < 1) { pr_warn("tracing multi pattern is invalid: %s\n", spec); return -EINVAL; }
*link = bpf_program__attach_tracing_multi(prog, pattern, NULL); free(pattern); return libbpf_get_error(*link);}
static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset){ return append_to_file(tracefs_uprobe_events(), "%c:%s/%s %s:0x%zx", retprobe ? 'r' : 'p', retprobe ? "uretprobes" : "uprobes", probe_name, binary_path, offset);}
static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe){ return append_to_file(tracefs_uprobe_events(), "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name);}
static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe){ char file[512];
snprintf(file, sizeof(file), "%s/events/%s/%s/id", tracefs_path(), retprobe ? "uretprobes" : "uprobes", probe_name);
return parse_uint_from_file(file, "%d\n");}
static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset, int pid){ const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_event_attr attr; int type, pfd, err;
err = add_uprobe_event_legacy(probe_name, retprobe, binary_path, offset); if (err < 0) { pr_warn("failed to add legacy uprobe event for %s:0x%zx: %s\n", binary_path, (size_t)offset, errstr(err)); return err; } type = determine_uprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { err = type; pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %s\n", binary_path, offset, errstr(err)); goto err_clean_legacy; }
memset(&attr, 0, attr_sz); attr.size = attr_sz; attr.config = type; attr.type = PERF_TYPE_TRACEPOINT;
pfd = syscall(__NR_perf_event_open, &attr, pid < 0 ? -1 : pid, /* pid */ pid == -1 ? 0 : -1, /* cpu */ -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); if (pfd < 0) { err = -errno; pr_warn("legacy uprobe perf_event_open() failed: %s\n", errstr(err)); goto err_clean_legacy; } return pfd;
err_clean_legacy: /* Clear the newly added legacy uprobe_event */ remove_uprobe_event_legacy(probe_name, retprobe); return err;}
/* Find offset of function name in archive specified by path. Currently * supported are .zip files that do not compress their contents, as used on * Android in the form of APKs, for example. "file_name" is the name of the ELF * file inside the archive. "func_name" matches symbol name or name@@LIB for * library functions. * * An overview of the APK format specifically provided here: * https://en.wikipedia.org/w/index.php?title=Apk_(file_format)&oldid=1139099120#Package_contents */static long elf_find_func_offset_from_archive(const char *archive_path, const char *file_name, const char *func_name){ struct zip_archive *archive; struct zip_entry entry; long ret; Elf *elf;
archive = zip_archive_open(archive_path); if (IS_ERR(archive)) { ret = PTR_ERR(archive); pr_warn("zip: failed to open %s: %ld\n", archive_path, ret); return ret; }
ret = zip_archive_find_entry(archive, file_name, &entry); if (ret) { pr_warn("zip: could not find archive member %s in %s: %ld\n", file_name, archive_path, ret); goto out; } pr_debug("zip: found entry for %s in %s at 0x%lx\n", file_name, archive_path, (unsigned long)entry.data_offset);
if (entry.compression) { pr_warn("zip: entry %s of %s is compressed and cannot be handled\n", file_name, archive_path); ret = -LIBBPF_ERRNO__FORMAT; goto out; }
elf = elf_memory((void *)entry.data, entry.data_length); if (!elf) { pr_warn("elf: could not read elf file %s from %s: %s\n", file_name, archive_path, elf_errmsg(-1)); ret = -LIBBPF_ERRNO__LIBELF; goto out; }
ret = elf_find_func_offset(elf, file_name, func_name); if (ret > 0) { pr_debug("elf: symbol address match for %s of %s in %s: 0x%x + 0x%lx = 0x%lx\n", func_name, file_name, archive_path, entry.data_offset, ret, ret + entry.data_offset); ret += entry.data_offset; } elf_end(elf);
out: zip_archive_close(archive); return ret;}
static const char *arch_specific_lib_paths(void){ /* * Based on https://packages.debian.org/sid/libc6. * * Assume that the traced program is built for the same architecture * as libbpf, which should cover the vast majority of cases. */#if defined(__x86_64__) return "/lib/x86_64-linux-gnu";#elif defined(__i386__) return "/lib/i386-linux-gnu";#elif defined(__s390x__) return "/lib/s390x-linux-gnu";#elif defined(__arm__) && defined(__SOFTFP__) return "/lib/arm-linux-gnueabi";#elif defined(__arm__) && !defined(__SOFTFP__) return "/lib/arm-linux-gnueabihf";#elif defined(__aarch64__) return "/lib/aarch64-linux-gnu";#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 64 return "/lib/mips64el-linux-gnuabi64";#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 32 return "/lib/mipsel-linux-gnu";#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ return "/lib/powerpc64le-linux-gnu";#elif defined(__sparc__) && defined(__arch64__) return "/lib/sparc64-linux-gnu";#elif defined(__riscv) && __riscv_xlen == 64 return "/lib/riscv64-linux-gnu";#else return NULL;#endif}
/* Get full path to program/shared library. */static int resolve_full_path(const char *file, char *result, size_t result_sz){ const char *search_paths[3] = {}; int i, perm;
if (str_has_sfx(file, ".so") || strstr(file, ".so.")) { search_paths[0] = getenv("LD_LIBRARY_PATH"); search_paths[1] = "/usr/lib64:/usr/lib"; search_paths[2] = arch_specific_lib_paths(); perm = R_OK; } else { search_paths[0] = getenv("PATH"); search_paths[1] = "/usr/bin:/usr/sbin"; perm = R_OK | X_OK; }
for (i = 0; i < ARRAY_SIZE(search_paths); i++) { const char *s;
if (!search_paths[i]) continue; for (s = search_paths[i]; s != NULL; s = strchr(s, ':')) { const char *next_path; int seg_len;
if (s[0] == ':') s++; next_path = strchr(s, ':'); seg_len = next_path ? next_path - s : strlen(s); if (!seg_len) continue; snprintf(result, result_sz, "%.*s/%s", seg_len, s, file); /* ensure it has required permissions */ if (faccessat(AT_FDCWD, result, perm, AT_EACCESS) < 0) continue; pr_debug("resolved '%s' to '%s'\n", file, result); return 0; } } return -ENOENT;}
struct bpf_link *bpf_program__attach_uprobe_multi(const struct bpf_program *prog, pid_t pid, const char *path, const char *func_pattern, const struct bpf_uprobe_multi_opts *opts){ const unsigned long *ref_ctr_offsets = NULL, *offsets = NULL; LIBBPF_OPTS(bpf_link_create_opts, lopts); unsigned long *resolved_offsets = NULL; enum bpf_attach_type attach_type; int err = 0, link_fd, prog_fd; struct bpf_link *link = NULL; char full_path[PATH_MAX]; bool retprobe, session; const __u64 *cookies; const char **syms; size_t cnt;
if (!OPTS_VALID(opts, bpf_uprobe_multi_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
syms = OPTS_GET(opts, syms, NULL); offsets = OPTS_GET(opts, offsets, NULL); ref_ctr_offsets = OPTS_GET(opts, ref_ctr_offsets, NULL); cookies = OPTS_GET(opts, cookies, NULL); cnt = OPTS_GET(opts, cnt, 0); retprobe = OPTS_GET(opts, retprobe, false); session = OPTS_GET(opts, session, false);
/* * User can specify 2 mutually exclusive set of inputs: * * 1) use only path/func_pattern/pid arguments * * 2) use path/pid with allowed combinations of: * syms/offsets/ref_ctr_offsets/cookies/cnt * * - syms and offsets are mutually exclusive * - ref_ctr_offsets and cookies are optional * * Any other usage results in error. */
if (!path) return libbpf_err_ptr(-EINVAL); if (!func_pattern && cnt == 0) return libbpf_err_ptr(-EINVAL);
if (func_pattern) { if (syms || offsets || ref_ctr_offsets || cookies || cnt) return libbpf_err_ptr(-EINVAL); } else { if (!!syms == !!offsets) return libbpf_err_ptr(-EINVAL); }
if (retprobe && session) return libbpf_err_ptr(-EINVAL);
if (func_pattern) { if (!strchr(path, '/')) { err = resolve_full_path(path, full_path, sizeof(full_path)); if (err) { pr_warn("prog '%s': failed to resolve full path for '%s': %s\n", prog->name, path, errstr(err)); return libbpf_err_ptr(err); } path = full_path; }
err = elf_resolve_pattern_offsets(path, func_pattern, &resolved_offsets, &cnt); if (err < 0) return libbpf_err_ptr(err); offsets = resolved_offsets; } else if (syms) { err = elf_resolve_syms_offsets(path, cnt, syms, &resolved_offsets, STT_FUNC); if (err < 0) return libbpf_err_ptr(err); offsets = resolved_offsets; }
attach_type = session ? BPF_TRACE_UPROBE_SESSION : BPF_TRACE_UPROBE_MULTI;
lopts.uprobe_multi.path = path; lopts.uprobe_multi.offsets = offsets; lopts.uprobe_multi.ref_ctr_offsets = ref_ctr_offsets; lopts.uprobe_multi.cookies = cookies; lopts.uprobe_multi.cnt = cnt; lopts.uprobe_multi.flags = retprobe ? BPF_F_UPROBE_MULTI_RETURN : 0;
if (pid == 0) pid = getpid(); if (pid > 0) lopts.uprobe_multi.pid = pid;
link = calloc(1, sizeof(*link)); if (!link) { err = -ENOMEM; goto error; } link->detach = &bpf_link__detach_fd;
link_fd = bpf_link_create(prog_fd, 0, attach_type, &lopts); if (link_fd < 0) { err = -errno; pr_warn("prog '%s': failed to attach multi-uprobe: %s\n", prog->name, errstr(err)); goto error; } link->fd = link_fd; free(resolved_offsets); return link;
error: free(resolved_offsets); free(link); return libbpf_err_ptr(err);}
LIBBPF_API struct bpf_link *bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, const char *binary_path, size_t func_offset, const struct bpf_uprobe_opts *opts){ const char *archive_path = NULL, *archive_sep = NULL; char *legacy_probe = NULL; DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); enum probe_attach_mode attach_mode; char full_path[PATH_MAX]; struct bpf_link *link; size_t ref_ctr_off; int pfd, err; bool retprobe, legacy; const char *func_name;
if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL);
attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
if (!binary_path) return libbpf_err_ptr(-EINVAL);
/* Check if "binary_path" refers to an archive. */ archive_sep = strstr(binary_path, "!/"); if (archive_sep) { full_path[0] = '\0'; libbpf_strlcpy(full_path, binary_path, min(sizeof(full_path), (size_t)(archive_sep - binary_path + 1))); archive_path = full_path; binary_path = archive_sep + 2; } else if (!strchr(binary_path, '/')) { err = resolve_full_path(binary_path, full_path, sizeof(full_path)); if (err) { pr_warn("prog '%s': failed to resolve full path for '%s': %s\n", prog->name, binary_path, errstr(err)); return libbpf_err_ptr(err); } binary_path = full_path; } func_name = OPTS_GET(opts, func_name, NULL); if (func_name) { long sym_off;
if (archive_path) { sym_off = elf_find_func_offset_from_archive(archive_path, binary_path, func_name); binary_path = archive_path; } else { sym_off = elf_find_func_offset_from_file(binary_path, func_name); } if (sym_off < 0) return libbpf_err_ptr(sym_off); func_offset += sym_off; }
legacy = determine_uprobe_perf_type() < 0; switch (attach_mode) { case PROBE_ATTACH_MODE_LEGACY: legacy = true; pe_opts.force_ioctl_attach = true; break; case PROBE_ATTACH_MODE_PERF: if (legacy) return libbpf_err_ptr(-ENOTSUP); pe_opts.force_ioctl_attach = true; break; case PROBE_ATTACH_MODE_LINK: if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK)) return libbpf_err_ptr(-ENOTSUP); break; case PROBE_ATTACH_MODE_DEFAULT: break; default: return libbpf_err_ptr(-EINVAL); }
if (!legacy) { pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid, ref_ctr_off); } else { char probe_name[MAX_EVENT_NAME_LEN];
if (ref_ctr_off) return libbpf_err_ptr(-EINVAL);
gen_probe_legacy_event_name(probe_name, sizeof(probe_name), strrchr(binary_path, '/') ? : binary_path, func_offset);
legacy_probe = strdup(probe_name); if (!legacy_probe) return libbpf_err_ptr(-ENOMEM);
pfd = perf_event_uprobe_open_legacy(legacy_probe, retprobe, binary_path, func_offset, pid); } if (pfd < 0) { err = pfd; pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n", prog->name, retprobe ? "uretprobe" : "uprobe", binary_path, func_offset, errstr(err)); goto err_out; }
link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); pr_warn("prog '%s': failed to attach to %s '%s:0x%zx': %s\n", prog->name, retprobe ? "uretprobe" : "uprobe", binary_path, func_offset, errstr(err)); goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
perf_link->legacy_probe_name = legacy_probe; perf_link->legacy_is_kprobe = false; perf_link->legacy_is_retprobe = retprobe; } return link;
err_clean_legacy: if (legacy) remove_uprobe_event_legacy(legacy_probe, retprobe);err_out: free(legacy_probe); return libbpf_err_ptr(err);}
/* Format of u[ret]probe section definition supporting auto-attach: * u[ret]probe/binary:function[+offset] * * binary can be an absolute/relative path or a filename; the latter is resolved to a * full binary path via bpf_program__attach_uprobe_opts. * * Specifying uprobe+ ensures we carry out strict matching; either "uprobe" must be * specified (and auto-attach is not possible) or the above format is specified for * auto-attach. */static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link){ DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); char *probe_type = NULL, *binary_path = NULL, *func_name = NULL, *func_off; int n, c, ret = -EINVAL; long offset = 0;
*link = NULL;
n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[^\n]", &probe_type, &binary_path, &func_name); switch (n) { case 1: /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */ ret = 0; break; case 2: pr_warn("prog '%s': section '%s' missing ':function[+offset]' specification\n", prog->name, prog->sec_name); break; case 3: /* check if user specifies `+offset`, if yes, this should be * the last part of the string, make sure sscanf read to EOL */ func_off = strrchr(func_name, '+'); if (func_off) { n = sscanf(func_off, "+%li%n", &offset, &c); if (n == 1 && *(func_off + c) == '\0') func_off[0] = '\0'; else offset = 0; } opts.retprobe = strcmp(probe_type, "uretprobe") == 0 || strcmp(probe_type, "uretprobe.s") == 0; if (opts.retprobe && offset != 0) { pr_warn("prog '%s': uretprobes do not support offset specification\n", prog->name); break; } opts.func_name = func_name; *link = bpf_program__attach_uprobe_opts(prog, -1, binary_path, offset, &opts); ret = libbpf_get_error(*link); break; default: pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, prog->sec_name); break; } free(probe_type); free(binary_path); free(func_name);
return ret;}
struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, pid_t pid, const char *binary_path, size_t func_offset){ DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts, .retprobe = retprobe);
return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts);}
struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog, pid_t pid, const char *binary_path, const char *usdt_provider, const char *usdt_name, const struct bpf_usdt_opts *opts){ char resolved_path[512]; struct bpf_object *obj = prog->obj; struct bpf_link *link; __u64 usdt_cookie; int err;
if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL);
if (bpf_program__fd(prog) < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
if (!binary_path) return libbpf_err_ptr(-EINVAL);
if (!strchr(binary_path, '/')) { err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path)); if (err) { pr_warn("prog '%s': failed to resolve full path for '%s': %s\n", prog->name, binary_path, errstr(err)); return libbpf_err_ptr(err); } binary_path = resolved_path; }
/* USDT manager is instantiated lazily on first USDT attach. It will * be destroyed together with BPF object in bpf_object__close(). */ if (IS_ERR(obj->usdt_man)) return libbpf_ptr(obj->usdt_man); if (!obj->usdt_man) { obj->usdt_man = usdt_manager_new(obj); if (IS_ERR(obj->usdt_man)) return libbpf_ptr(obj->usdt_man); }
usdt_cookie = OPTS_GET(opts, usdt_cookie, 0); link = usdt_manager_attach_usdt(obj->usdt_man, prog, pid, binary_path, usdt_provider, usdt_name, usdt_cookie); err = libbpf_get_error(link); if (err) return libbpf_err_ptr(err); return link;}
static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link){ char *path = NULL, *provider = NULL, *name = NULL; const char *sec_name; int n, err;
sec_name = bpf_program__section_name(prog); if (strcmp(sec_name, "usdt") == 0) { /* no auto-attach for just SEC("usdt") */ *link = NULL; return 0; }
n = sscanf(sec_name, "usdt/%m[^:]:%m[^:]:%m[^:]", &path, &provider, &name); if (n != 3) { pr_warn("invalid section '%s', expected SEC(\"usdt/<path>:<provider>:<name>\")\n", sec_name); err = -EINVAL; } else { *link = bpf_program__attach_usdt(prog, -1 /* any process */, path, provider, name, NULL); err = libbpf_get_error(*link); } free(path); free(provider); free(name); return err;}
static int determine_tracepoint_id(const char *tp_category, const char *tp_name){ char file[PATH_MAX]; int ret;
ret = snprintf(file, sizeof(file), "%s/events/%s/%s/id", tracefs_path(), tp_category, tp_name); if (ret < 0) return -errno; if (ret >= sizeof(file)) { pr_debug("tracepoint %s/%s path is too long\n", tp_category, tp_name); return -E2BIG; } return parse_uint_from_file(file, "%d\n");}
static int perf_event_open_tracepoint(const char *tp_category, const char *tp_name){ const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_event_attr attr; int tp_id, pfd, err;
tp_id = determine_tracepoint_id(tp_category, tp_name); if (tp_id < 0) { pr_warn("failed to determine tracepoint '%s/%s' perf event ID: %s\n", tp_category, tp_name, errstr(tp_id)); return tp_id; }
memset(&attr, 0, attr_sz); attr.type = PERF_TYPE_TRACEPOINT; attr.size = attr_sz; attr.config = tp_id;
pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */, -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); if (pfd < 0) { err = -errno; pr_warn("tracepoint '%s/%s' perf_event_open() failed: %s\n", tp_category, tp_name, errstr(err)); return err; } return pfd;}
struct bpf_link *bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, const char *tp_category, const char *tp_name, const struct bpf_tracepoint_opts *opts){ DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); struct bpf_link *link; int pfd, err;
if (!OPTS_VALID(opts, bpf_tracepoint_opts)) return libbpf_err_ptr(-EINVAL);
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
pfd = perf_event_open_tracepoint(tp_category, tp_name); if (pfd < 0) { pr_warn("prog '%s': failed to create tracepoint '%s/%s' perf event: %s\n", prog->name, tp_category, tp_name, errstr(pfd)); return libbpf_err_ptr(pfd); } link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); pr_warn("prog '%s': failed to attach to tracepoint '%s/%s': %s\n", prog->name, tp_category, tp_name, errstr(err)); return libbpf_err_ptr(err); } return link;}
struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog, const char *tp_category, const char *tp_name){ return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);}
/* * Match section name against a prefix array. Returns pointer past * "prefix/" on match, empty string for bare sections (exact prefix * match), or NULL if no prefix matches. */static const char *sec_name_match_prefix(const char *sec_name, const char *const *prefixes, size_t n){ size_t i;
for (i = 0; i < n; i++) { size_t pfx_len;
if (!str_has_pfx(sec_name, prefixes[i])) continue;
pfx_len = strlen(prefixes[i]); if (sec_name[pfx_len] == '\0') return sec_name + pfx_len;
if (sec_name[pfx_len] != '/' || sec_name[pfx_len + 1] == '\0') continue;
return sec_name + pfx_len + 1; } return NULL;}
static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link){ static const char *const prefixes[] = { "tp.s", "tp", "tracepoint.s", "tracepoint", }; char *sec_name, *tp_cat, *tp_name; const char *match;
*link = NULL;
match = sec_name_match_prefix(prog->sec_name, prefixes, ARRAY_SIZE(prefixes)); if (!match) { pr_warn("prog '%s': invalid section name '%s'\n", prog->name, prog->sec_name); return -EINVAL; } if (!match[0]) /* bare section name no autoattach */ return 0;
sec_name = strdup(prog->sec_name); if (!sec_name) return -ENOMEM;
tp_cat = sec_name + (match - prog->sec_name); tp_name = strchr(tp_cat, '/'); if (!tp_name) { free(sec_name); return -EINVAL; } *tp_name = '\0'; tp_name++;
*link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name); free(sec_name); return libbpf_get_error(*link);}
struct bpf_link *bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog, const char *tp_name, struct bpf_raw_tracepoint_opts *opts){ LIBBPF_OPTS(bpf_raw_tp_opts, raw_opts); struct bpf_link *link; int prog_fd, pfd;
if (!OPTS_VALID(opts, bpf_raw_tracepoint_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd;
raw_opts.tp_name = tp_name; raw_opts.cookie = OPTS_GET(opts, cookie, 0); pfd = bpf_raw_tracepoint_open_opts(prog_fd, &raw_opts); if (pfd < 0) { pfd = -errno; free(link); pr_warn("prog '%s': failed to attach to raw tracepoint '%s': %s\n", prog->name, tp_name, errstr(pfd)); return libbpf_err_ptr(pfd); } link->fd = pfd; return link;}
struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, const char *tp_name){ return bpf_program__attach_raw_tracepoint_opts(prog, tp_name, NULL);}
static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link){ static const char *const prefixes[] = { "raw_tp", "raw_tracepoint", "raw_tp.w", "raw_tracepoint.w", "raw_tp.s", "raw_tracepoint.s", }; const char *match;
*link = NULL;
match = sec_name_match_prefix(prog->sec_name, prefixes, ARRAY_SIZE(prefixes)); if (!match) { pr_warn("prog '%s': invalid section name '%s'\n", prog->name, prog->sec_name); return -EINVAL; } if (!match[0]) return 0;
*link = bpf_program__attach_raw_tracepoint(prog, match); return libbpf_get_error(*link);}
/* Common logic for all BPF program types that attach to a btf_id */static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog, const struct bpf_trace_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, link_opts); struct bpf_link *link; int prog_fd, pfd;
if (!OPTS_VALID(opts, bpf_trace_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd;
/* libbpf is smart enough to redirect to BPF_RAW_TRACEPOINT_OPEN on old kernels */ link_opts.tracing.cookie = OPTS_GET(opts, cookie, 0); pfd = bpf_link_create(prog_fd, 0, bpf_program__expected_attach_type(prog), &link_opts); if (pfd < 0) { pfd = -errno; free(link); pr_warn("prog '%s': failed to attach: %s\n", prog->name, errstr(pfd)); return libbpf_err_ptr(pfd); } link->fd = pfd; return link;}
struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog){ return bpf_program__attach_btf_id(prog, NULL);}
struct bpf_link *bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts){ return bpf_program__attach_btf_id(prog, opts);}
struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog){ return bpf_program__attach_btf_id(prog, NULL);}
static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link){ *link = bpf_program__attach_trace(prog); return libbpf_get_error(*link);}
static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link){ *link = bpf_program__attach_lsm(prog); return libbpf_get_error(*link);}
static struct bpf_link *bpf_program_attach_fd(const struct bpf_program *prog, int target_fd, const char *target_name, const struct bpf_link_create_opts *opts){ enum bpf_attach_type attach_type; struct bpf_link *link; int prog_fd, link_fd;
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd;
attach_type = bpf_program__expected_attach_type(prog); link_fd = bpf_link_create(prog_fd, target_fd, attach_type, opts); if (link_fd < 0) { link_fd = -errno; free(link); pr_warn("prog '%s': failed to attach to %s: %s\n", prog->name, target_name, errstr(link_fd)); return libbpf_err_ptr(link_fd); } link->fd = link_fd; return link;}
struct bpf_link *bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd){ return bpf_program_attach_fd(prog, cgroup_fd, "cgroup", NULL);}
struct bpf_link *bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd){ return bpf_program_attach_fd(prog, netns_fd, "netns", NULL);}
struct bpf_link *bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd){ return bpf_program_attach_fd(prog, map_fd, "sockmap", NULL);}
struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex){ /* target_fd/target_ifindex use the same field in LINK_CREATE */ return bpf_program_attach_fd(prog, ifindex, "xdp", NULL);}
struct bpf_link *bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, const struct bpf_cgroup_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, link_create_opts); __u32 relative_id; int relative_fd;
if (!OPTS_VALID(opts, bpf_cgroup_opts)) return libbpf_err_ptr(-EINVAL);
relative_id = OPTS_GET(opts, relative_id, 0); relative_fd = OPTS_GET(opts, relative_fd, 0);
if (relative_fd && relative_id) { pr_warn("prog '%s': relative_fd and relative_id cannot be set at the same time\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link_create_opts.cgroup.expected_revision = OPTS_GET(opts, expected_revision, 0); link_create_opts.cgroup.relative_fd = relative_fd; link_create_opts.cgroup.relative_id = relative_id; link_create_opts.flags = OPTS_GET(opts, flags, 0);
return bpf_program_attach_fd(prog, cgroup_fd, "cgroup", &link_create_opts);}
struct bpf_link *bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, const struct bpf_tcx_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, link_create_opts); __u32 relative_id; int relative_fd;
if (!OPTS_VALID(opts, bpf_tcx_opts)) return libbpf_err_ptr(-EINVAL);
relative_id = OPTS_GET(opts, relative_id, 0); relative_fd = OPTS_GET(opts, relative_fd, 0);
/* validate we don't have unexpected combinations of non-zero fields */ if (!ifindex) { pr_warn("prog '%s': target netdevice ifindex cannot be zero\n", prog->name); return libbpf_err_ptr(-EINVAL); } if (relative_fd && relative_id) { pr_warn("prog '%s': relative_fd and relative_id cannot be set at the same time\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link_create_opts.tcx.expected_revision = OPTS_GET(opts, expected_revision, 0); link_create_opts.tcx.relative_fd = relative_fd; link_create_opts.tcx.relative_id = relative_id; link_create_opts.flags = OPTS_GET(opts, flags, 0);
/* target_fd/target_ifindex use the same field in LINK_CREATE */ return bpf_program_attach_fd(prog, ifindex, "tcx", &link_create_opts);}
struct bpf_link *bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex, const struct bpf_netkit_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, link_create_opts); __u32 relative_id; int relative_fd;
if (!OPTS_VALID(opts, bpf_netkit_opts)) return libbpf_err_ptr(-EINVAL);
relative_id = OPTS_GET(opts, relative_id, 0); relative_fd = OPTS_GET(opts, relative_fd, 0);
/* validate we don't have unexpected combinations of non-zero fields */ if (!ifindex) { pr_warn("prog '%s': target netdevice ifindex cannot be zero\n", prog->name); return libbpf_err_ptr(-EINVAL); } if (relative_fd && relative_id) { pr_warn("prog '%s': relative_fd and relative_id cannot be set at the same time\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link_create_opts.netkit.expected_revision = OPTS_GET(opts, expected_revision, 0); link_create_opts.netkit.relative_fd = relative_fd; link_create_opts.netkit.relative_id = relative_id; link_create_opts.flags = OPTS_GET(opts, flags, 0);
return bpf_program_attach_fd(prog, ifindex, "netkit", &link_create_opts);}
struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog, int target_fd, const char *attach_func_name){ int btf_id;
if (!!target_fd != !!attach_func_name) { pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n", prog->name); return libbpf_err_ptr(-EINVAL); }
if (prog->type != BPF_PROG_TYPE_EXT) { pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace\n", prog->name); return libbpf_err_ptr(-EINVAL); }
if (target_fd) { LIBBPF_OPTS(bpf_link_create_opts, target_opts);
btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd, prog->obj->token_fd); if (btf_id < 0) return libbpf_err_ptr(btf_id);
target_opts.target_btf_id = btf_id;
return bpf_program_attach_fd(prog, target_fd, "freplace", &target_opts); } else { /* no target, so use raw_tracepoint_open for compatibility * with old kernels */ return bpf_program__attach_trace(prog); }}
struct bpf_link *bpf_program__attach_iter(const struct bpf_program *prog, const struct bpf_iter_attach_opts *opts){ DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts); struct bpf_link *link; int prog_fd, link_fd; __u32 target_fd = 0;
if (!OPTS_VALID(opts, bpf_iter_attach_opts)) return libbpf_err_ptr(-EINVAL);
link_create_opts.iter_info = OPTS_GET(opts, link_info, (void *)0); link_create_opts.iter_info_len = OPTS_GET(opts, link_info_len, 0);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd;
link_fd = bpf_link_create(prog_fd, target_fd, BPF_TRACE_ITER, &link_create_opts); if (link_fd < 0) { link_fd = -errno; free(link); pr_warn("prog '%s': failed to attach to iterator: %s\n", prog->name, errstr(link_fd)); return libbpf_err_ptr(link_fd); } link->fd = link_fd; return link;}
static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link){ *link = bpf_program__attach_iter(prog, NULL); return libbpf_get_error(*link);}
struct bpf_link *bpf_program__attach_netfilter(const struct bpf_program *prog, const struct bpf_netfilter_opts *opts){ LIBBPF_OPTS(bpf_link_create_opts, lopts); struct bpf_link *link; int prog_fd, link_fd;
if (!OPTS_VALID(opts, bpf_netfilter_opts)) return libbpf_err_ptr(-EINVAL);
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM);
link->detach = &bpf_link__detach_fd;
lopts.netfilter.pf = OPTS_GET(opts, pf, 0); lopts.netfilter.hooknum = OPTS_GET(opts, hooknum, 0); lopts.netfilter.priority = OPTS_GET(opts, priority, 0); lopts.netfilter.flags = OPTS_GET(opts, flags, 0);
link_fd = bpf_link_create(prog_fd, 0, BPF_NETFILTER, &lopts); if (link_fd < 0) { link_fd = -errno; free(link); pr_warn("prog '%s': failed to attach to netfilter: %s\n", prog->name, errstr(link_fd)); return libbpf_err_ptr(link_fd); } link->fd = link_fd;
return link;}
struct bpf_link *bpf_program__attach(const struct bpf_program *prog){ struct bpf_link *link = NULL; int err;
if (!prog->sec_def || !prog->sec_def->prog_attach_fn) return libbpf_err_ptr(-EOPNOTSUPP);
if (bpf_program__fd(prog) < 0) { pr_warn("prog '%s': can't attach BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err_ptr(-EINVAL); }
err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, &link); if (err) return libbpf_err_ptr(err);
/* When calling bpf_program__attach() explicitly, auto-attach support * is expected to work, so NULL returned link is considered an error. * This is different for skeleton's attach, see comment in * bpf_object__attach_skeleton(). */ if (!link) return libbpf_err_ptr(-EOPNOTSUPP);
return link;}
struct bpf_link_struct_ops { struct bpf_link link; int map_fd;};
static int bpf_link__detach_struct_ops(struct bpf_link *link){ struct bpf_link_struct_ops *st_link; __u32 zero = 0;
st_link = container_of(link, struct bpf_link_struct_ops, link);
if (st_link->map_fd < 0) /* w/o a real link */ return bpf_map_delete_elem(link->fd, &zero);
return close(link->fd);}
struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map){ struct bpf_link_struct_ops *link; __u32 zero = 0; int err, fd;
if (!bpf_map__is_struct_ops(map)) { pr_warn("map '%s': can't attach non-struct_ops map\n", map->name); return libbpf_err_ptr(-EINVAL); }
if (map->fd < 0) { pr_warn("map '%s': can't attach BPF map without FD (was it created?)\n", map->name); return libbpf_err_ptr(-EINVAL); }
link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-EINVAL);
/* kern_vdata should be prepared during the loading phase. */ err = bpf_map_update_elem(map->fd, &zero, map->st_ops->kern_vdata, 0); /* It can be EBUSY if the map has been used to create or * update a link before. We don't allow updating the value of * a struct_ops once it is set. That ensures that the value * never changed. So, it is safe to skip EBUSY. */ if (err && (!(map->def.map_flags & BPF_F_LINK) || err != -EBUSY)) { free(link); return libbpf_err_ptr(err); }
link->link.detach = bpf_link__detach_struct_ops;
if (!(map->def.map_flags & BPF_F_LINK)) { /* w/o a real link */ link->link.fd = map->fd; link->map_fd = -1; return &link->link; }
fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, NULL); if (fd < 0) { free(link); return libbpf_err_ptr(fd); }
link->link.fd = fd; link->map_fd = map->fd;
return &link->link;}
/* * Swap the back struct_ops of a link with a new struct_ops map. */int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map){ struct bpf_link_struct_ops *st_ops_link; __u32 zero = 0; int err;
if (!bpf_map__is_struct_ops(map)) return libbpf_err(-EINVAL);
if (map->fd < 0) { pr_warn("map '%s': can't use BPF map without FD (was it created?)\n", map->name); return libbpf_err(-EINVAL); }
st_ops_link = container_of(link, struct bpf_link_struct_ops, link); /* Ensure the type of a link is correct */ if (st_ops_link->map_fd < 0) return libbpf_err(-EINVAL);
err = bpf_map_update_elem(map->fd, &zero, map->st_ops->kern_vdata, 0); /* It can be EBUSY if the map has been used to create or * update a link before. We don't allow updating the value of * a struct_ops once it is set. That ensures that the value * never changed. So, it is safe to skip EBUSY. */ if (err && err != -EBUSY) return err;
err = bpf_link_update(link->fd, map->fd, NULL); if (err < 0) return err;
st_ops_link->map_fd = map->fd;
return 0;}
typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(struct perf_event_header *hdr, void *private_data);
static enum bpf_perf_event_retperf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, bpf_perf_event_print_t fn, void *private_data){ struct perf_event_mmap_page *header = mmap_mem; __u64 data_head = ring_buffer_read_head(header); __u64 data_tail = header->data_tail; void *base = ((__u8 *)header) + page_size; int ret = LIBBPF_PERF_EVENT_CONT; struct perf_event_header *ehdr; size_t ehdr_size;
while (data_head != data_tail) { ehdr = base + (data_tail & (mmap_size - 1)); ehdr_size = ehdr->size;
if (((void *)ehdr) + ehdr_size > base + mmap_size) { void *copy_start = ehdr; size_t len_first = base + mmap_size - copy_start; size_t len_secnd = ehdr_size - len_first;
if (*copy_size < ehdr_size) { free(*copy_mem); *copy_mem = malloc(ehdr_size); if (!*copy_mem) { *copy_size = 0; ret = LIBBPF_PERF_EVENT_ERROR; break; } *copy_size = ehdr_size; }
memcpy(*copy_mem, copy_start, len_first); memcpy(*copy_mem + len_first, base, len_secnd); ehdr = *copy_mem; }
ret = fn(ehdr, private_data); data_tail += ehdr_size; if (ret != LIBBPF_PERF_EVENT_CONT) break; }
ring_buffer_write_tail(header, data_tail); return libbpf_err(ret);}
struct perf_buffer;
struct perf_buffer_params { struct perf_event_attr *attr; /* if event_cb is specified, it takes precendence */ perf_buffer_event_fn event_cb; /* sample_cb and lost_cb are higher-level common-case callbacks */ perf_buffer_sample_fn sample_cb; perf_buffer_lost_fn lost_cb; void *ctx; int cpu_cnt; int *cpus; int *map_keys;};
struct perf_cpu_buf { struct perf_buffer *pb; void *base; /* mmap()'ed memory */ void *buf; /* for reconstructing segmented data */ size_t buf_size; int fd; int cpu; int map_key;};
struct perf_buffer { perf_buffer_event_fn event_cb; perf_buffer_sample_fn sample_cb; perf_buffer_lost_fn lost_cb; void *ctx; /* passed into callbacks */
size_t page_size; size_t mmap_size; struct perf_cpu_buf **cpu_bufs; struct epoll_event *events; int cpu_cnt; /* number of allocated CPU buffers */ int epoll_fd; /* perf event FD */ int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */};
static void perf_buffer__free_cpu_buf(struct perf_buffer *pb, struct perf_cpu_buf *cpu_buf){ if (!cpu_buf) return; if (cpu_buf->base && munmap(cpu_buf->base, pb->mmap_size + pb->page_size)) pr_warn("failed to munmap cpu_buf #%d\n", cpu_buf->cpu); if (cpu_buf->fd >= 0) { ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0); close(cpu_buf->fd); } free(cpu_buf->buf); free(cpu_buf);}
void perf_buffer__free(struct perf_buffer *pb){ int i;
if (IS_ERR_OR_NULL(pb)) return; if (pb->cpu_bufs) { for (i = 0; i < pb->cpu_cnt; i++) { struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
if (!cpu_buf) continue;
bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key); perf_buffer__free_cpu_buf(pb, cpu_buf); } free(pb->cpu_bufs); } if (pb->epoll_fd >= 0) close(pb->epoll_fd); free(pb->events); free(pb);}
static struct perf_cpu_buf *perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr, int cpu, int map_key){ struct perf_cpu_buf *cpu_buf; int err;
cpu_buf = calloc(1, sizeof(*cpu_buf)); if (!cpu_buf) return ERR_PTR(-ENOMEM);
cpu_buf->pb = pb; cpu_buf->cpu = cpu; cpu_buf->map_key = map_key;
cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu, -1, PERF_FLAG_FD_CLOEXEC); if (cpu_buf->fd < 0) { err = -errno; pr_warn("failed to open perf buffer event on cpu #%d: %s\n", cpu, errstr(err)); goto error; }
cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size, PROT_READ | PROT_WRITE, MAP_SHARED, cpu_buf->fd, 0); if (cpu_buf->base == MAP_FAILED) { cpu_buf->base = NULL; err = -errno; pr_warn("failed to mmap perf buffer on cpu #%d: %s\n", cpu, errstr(err)); goto error; }
if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) { err = -errno; pr_warn("failed to enable perf buffer event on cpu #%d: %s\n", cpu, errstr(err)); goto error; }
return cpu_buf;
error: perf_buffer__free_cpu_buf(pb, cpu_buf); return (struct perf_cpu_buf *)ERR_PTR(err);}
static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, struct perf_buffer_params *p);
struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, const struct perf_buffer_opts *opts){ const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_buffer_params p = {}; struct perf_event_attr attr; __u32 sample_period;
if (!OPTS_VALID(opts, perf_buffer_opts)) return libbpf_err_ptr(-EINVAL);
sample_period = OPTS_GET(opts, sample_period, 1); if (!sample_period) sample_period = 1;
memset(&attr, 0, attr_sz); attr.size = attr_sz; attr.config = PERF_COUNT_SW_BPF_OUTPUT; attr.type = PERF_TYPE_SOFTWARE; attr.sample_type = PERF_SAMPLE_RAW; attr.wakeup_events = sample_period;
p.attr = &attr; p.sample_cb = sample_cb; p.lost_cb = lost_cb; p.ctx = ctx;
return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p));}
struct perf_buffer *perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, perf_buffer_event_fn event_cb, void *ctx, const struct perf_buffer_raw_opts *opts){ struct perf_buffer_params p = {};
if (!attr) return libbpf_err_ptr(-EINVAL);
if (!OPTS_VALID(opts, perf_buffer_raw_opts)) return libbpf_err_ptr(-EINVAL);
p.attr = attr; p.event_cb = event_cb; p.ctx = ctx; p.cpu_cnt = OPTS_GET(opts, cpu_cnt, 0); p.cpus = OPTS_GET(opts, cpus, NULL); p.map_keys = OPTS_GET(opts, map_keys, NULL);
return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p));}
static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, struct perf_buffer_params *p){ const char *online_cpus_file = "/sys/devices/system/cpu/online"; struct bpf_map_info map; struct perf_buffer *pb; bool *online = NULL; __u32 map_info_len; int err, i, j, n;
if (page_cnt == 0 || (page_cnt & (page_cnt - 1))) { pr_warn("page count should be power of two, but is %zu\n", page_cnt); return ERR_PTR(-EINVAL); }
/* best-effort sanity checks */ memset(&map, 0, sizeof(map)); map_info_len = sizeof(map); err = bpf_map_get_info_by_fd(map_fd, &map, &map_info_len); if (err) { err = -errno; /* if BPF_OBJ_GET_INFO_BY_FD is supported, will return * -EBADFD, -EFAULT, or -E2BIG on real error */ if (err != -EINVAL) { pr_warn("failed to get map info for map FD %d: %s\n", map_fd, errstr(err)); return ERR_PTR(err); } pr_debug("failed to get map info for FD %d; API not supported? Ignoring...\n", map_fd); } else { if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) { pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n", map.name); return ERR_PTR(-EINVAL); } }
pb = calloc(1, sizeof(*pb)); if (!pb) return ERR_PTR(-ENOMEM);
pb->event_cb = p->event_cb; pb->sample_cb = p->sample_cb; pb->lost_cb = p->lost_cb; pb->ctx = p->ctx;
pb->page_size = getpagesize(); pb->mmap_size = pb->page_size * page_cnt; pb->map_fd = map_fd;
pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC); if (pb->epoll_fd < 0) { err = -errno; pr_warn("failed to create epoll instance: %s\n", errstr(err)); goto error; }
if (p->cpu_cnt > 0) { pb->cpu_cnt = p->cpu_cnt; } else { pb->cpu_cnt = libbpf_num_possible_cpus(); if (pb->cpu_cnt < 0) { err = pb->cpu_cnt; goto error; } if (map.max_entries && map.max_entries < pb->cpu_cnt) pb->cpu_cnt = map.max_entries; }
pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events)); if (!pb->events) { err = -ENOMEM; pr_warn("failed to allocate events: out of memory\n"); goto error; } pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs)); if (!pb->cpu_bufs) { err = -ENOMEM; pr_warn("failed to allocate buffers: out of memory\n"); goto error; }
err = parse_cpu_mask_file(online_cpus_file, &online, &n); if (err) { pr_warn("failed to get online CPU mask: %s\n", errstr(err)); goto error; }
for (i = 0, j = 0; i < pb->cpu_cnt; i++) { struct perf_cpu_buf *cpu_buf; int cpu, map_key;
cpu = p->cpu_cnt > 0 ? p->cpus[i] : i; map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i;
/* in case user didn't explicitly requested particular CPUs to * be attached to, skip offline/not present CPUs */ if (p->cpu_cnt <= 0 && (cpu >= n || !online[cpu])) continue;
cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key); if (IS_ERR(cpu_buf)) { err = PTR_ERR(cpu_buf); goto error; }
pb->cpu_bufs[j] = cpu_buf;
err = bpf_map_update_elem(pb->map_fd, &map_key, &cpu_buf->fd, 0); if (err) { err = -errno; pr_warn("failed to set cpu #%d, key %d -> perf FD %d: %s\n", cpu, map_key, cpu_buf->fd, errstr(err)); goto error; }
pb->events[j].events = EPOLLIN; pb->events[j].data.ptr = cpu_buf; if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd, &pb->events[j]) < 0) { err = -errno; pr_warn("failed to epoll_ctl cpu #%d perf FD %d: %s\n", cpu, cpu_buf->fd, errstr(err)); goto error; } j++; } pb->cpu_cnt = j; free(online);
return pb;
error: free(online); if (pb) perf_buffer__free(pb); return ERR_PTR(err);}
struct perf_sample_raw { struct perf_event_header header; uint32_t size; char data[];};
struct perf_sample_lost { struct perf_event_header header; uint64_t id; uint64_t lost; uint64_t sample_id;};
static enum bpf_perf_event_retperf_buffer__process_record(struct perf_event_header *e, void *ctx){ struct perf_cpu_buf *cpu_buf = ctx; struct perf_buffer *pb = cpu_buf->pb; void *data = e;
/* user wants full control over parsing perf event */ if (pb->event_cb) return pb->event_cb(pb->ctx, cpu_buf->cpu, e);
switch (e->type) { case PERF_RECORD_SAMPLE: { struct perf_sample_raw *s = data;
if (pb->sample_cb) pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size); break; } case PERF_RECORD_LOST: { struct perf_sample_lost *s = data;
if (pb->lost_cb) pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost); break; } default: pr_warn("unknown perf sample type %d\n", e->type); return LIBBPF_PERF_EVENT_ERROR; } return LIBBPF_PERF_EVENT_CONT;}
static int perf_buffer__process_records(struct perf_buffer *pb, struct perf_cpu_buf *cpu_buf){ enum bpf_perf_event_ret ret;
ret = perf_event_read_simple(cpu_buf->base, pb->mmap_size, pb->page_size, &cpu_buf->buf, &cpu_buf->buf_size, perf_buffer__process_record, cpu_buf); if (ret != LIBBPF_PERF_EVENT_CONT) return ret; return 0;}
int perf_buffer__epoll_fd(const struct perf_buffer *pb){ return pb->epoll_fd;}
int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms){ int i, cnt, err;
cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms); if (cnt < 0) return -errno;
for (i = 0; i < cnt; i++) { struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr;
err = perf_buffer__process_records(pb, cpu_buf); if (err) { pr_warn("error while processing records: %s\n", errstr(err)); return libbpf_err(err); } } return cnt;}
/* Return number of PERF_EVENT_ARRAY map slots set up by this perf_buffer * manager. */size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb){ return pb->cpu_cnt;}
/* * Return perf_event FD of a ring buffer in *buf_idx* slot of * PERF_EVENT_ARRAY BPF map. This FD can be polled for new data using * select()/poll()/epoll() Linux syscalls. */int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx){ struct perf_cpu_buf *cpu_buf;
if (buf_idx >= pb->cpu_cnt) return libbpf_err(-EINVAL);
cpu_buf = pb->cpu_bufs[buf_idx]; if (!cpu_buf) return libbpf_err(-ENOENT);
return cpu_buf->fd;}
int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, size_t *buf_size){ struct perf_cpu_buf *cpu_buf;
if (buf_idx >= pb->cpu_cnt) return libbpf_err(-EINVAL);
cpu_buf = pb->cpu_bufs[buf_idx]; if (!cpu_buf) return libbpf_err(-ENOENT);
*buf = cpu_buf->base; *buf_size = pb->mmap_size; return 0;}
/* * Consume data from perf ring buffer corresponding to slot *buf_idx* in * PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to * consume, do nothing and return success. * Returns: * - 0 on success; * - <0 on failure. */int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx){ struct perf_cpu_buf *cpu_buf;
if (buf_idx >= pb->cpu_cnt) return libbpf_err(-EINVAL);
cpu_buf = pb->cpu_bufs[buf_idx]; if (!cpu_buf) return libbpf_err(-ENOENT);
return perf_buffer__process_records(pb, cpu_buf);}
int perf_buffer__consume(struct perf_buffer *pb){ int i, err;
for (i = 0; i < pb->cpu_cnt; i++) { struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
if (!cpu_buf) continue;
err = perf_buffer__process_records(pb, cpu_buf); if (err) { pr_warn("perf_buffer: failed to process records in buffer #%d: %s\n", i, errstr(err)); return libbpf_err(err); } } return 0;}
int bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, const char *attach_func_name){ int btf_obj_fd = 0, btf_id = 0, err;
if (!prog || attach_prog_fd < 0) return libbpf_err(-EINVAL);
if (prog->obj->state >= OBJ_LOADED) return libbpf_err(-EINVAL);
if (attach_prog_fd && !attach_func_name) { /* Store attach_prog_fd. The BTF ID will be resolved later during * the normal object/program load phase. */ prog->attach_prog_fd = attach_prog_fd; return 0; }
if (attach_prog_fd) { btf_id = libbpf_find_prog_btf_id(attach_func_name, attach_prog_fd, prog->obj->token_fd); if (btf_id < 0) return libbpf_err(btf_id); } else { if (!attach_func_name) return libbpf_err(-EINVAL);
/* load btf_vmlinux, if not yet */ err = bpf_object__load_vmlinux_btf(prog->obj, true); if (err) return libbpf_err(err); err = find_kernel_btf_id(prog->obj, attach_func_name, prog->expected_attach_type, &btf_obj_fd, &btf_id); if (err) return libbpf_err(err); }
prog->attach_btf_id = btf_id; prog->attach_btf_obj_fd = btf_obj_fd; prog->attach_prog_fd = attach_prog_fd; return 0;}
int bpf_program__assoc_struct_ops(struct bpf_program *prog, struct bpf_map *map, struct bpf_prog_assoc_struct_ops_opts *opts){ int prog_fd, map_fd;
prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't associate BPF program without FD (was it loaded?)\n", prog->name); return libbpf_err(-EINVAL); }
if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { pr_warn("prog '%s': can't associate struct_ops program\n", prog->name); return libbpf_err(-EINVAL); }
map_fd = bpf_map__fd(map); if (map_fd < 0) { pr_warn("map '%s': can't associate BPF map without FD (was it created?)\n", map->name); return libbpf_err(-EINVAL); }
if (!bpf_map__is_struct_ops(map)) { pr_warn("map '%s': can't associate non-struct_ops map\n", map->name); return libbpf_err(-EINVAL); }
return bpf_prog_assoc_struct_ops(prog_fd, map_fd, opts);}
int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz){ int err = 0, n, len, start, end = -1; bool *tmp;
*mask = NULL; *mask_sz = 0;
/* Each sub string separated by ',' has format \d+-\d+ or \d+ */ while (*s) { if (*s == ',' || *s == '\n') { s++; continue; } n = sscanf(s, "%d%n-%d%n", &start, &len, &end, &len); if (n <= 0 || n > 2) { pr_warn("Failed to get CPU range %s: %d\n", s, n); err = -EINVAL; goto cleanup; } else if (n == 1) { end = start; } if (start < 0 || start > end) { pr_warn("Invalid CPU range [%d,%d] in %s\n", start, end, s); err = -EINVAL; goto cleanup; } tmp = realloc(*mask, end + 1); if (!tmp) { err = -ENOMEM; goto cleanup; } *mask = tmp; memset(tmp + *mask_sz, 0, start - *mask_sz); memset(tmp + start, 1, end - start + 1); *mask_sz = end + 1; s += len; } if (!*mask_sz) { pr_warn("Empty CPU range\n"); return -EINVAL; } return 0;cleanup: free(*mask); *mask = NULL; return err;}
int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz){ int fd, err = 0, len; char buf[128];
fd = open(fcpu, O_RDONLY | O_CLOEXEC); if (fd < 0) { err = -errno; pr_warn("Failed to open cpu mask file %s: %s\n", fcpu, errstr(err)); return err; } len = read(fd, buf, sizeof(buf)); close(fd); if (len <= 0) { err = len ? -errno : -EINVAL; pr_warn("Failed to read cpu mask from %s: %s\n", fcpu, errstr(err)); return err; } if (len >= sizeof(buf)) { pr_warn("CPU mask is too big in file %s\n", fcpu); return -E2BIG; } buf[len] = '\0';
return parse_cpu_mask_str(buf, mask, mask_sz);}
int libbpf_num_possible_cpus(void){ static const char *fcpu = "/sys/devices/system/cpu/possible"; static int cpus; int err, n, i, tmp_cpus; bool *mask;
tmp_cpus = READ_ONCE(cpus); if (tmp_cpus > 0) return tmp_cpus;
err = parse_cpu_mask_file(fcpu, &mask, &n); if (err) return libbpf_err(err);
tmp_cpus = 0; for (i = 0; i < n; i++) { if (mask[i]) tmp_cpus++; } free(mask);
WRITE_ONCE(cpus, tmp_cpus); return tmp_cpus;}
static int populate_skeleton_maps(const struct bpf_object *obj, struct bpf_map_skeleton *maps, size_t map_cnt, size_t map_skel_sz){ int i;
for (i = 0; i < map_cnt; i++) { struct bpf_map_skeleton *map_skel = (void *)maps + i * map_skel_sz; struct bpf_map **map = map_skel->map; const char *name = map_skel->name; void **mmaped = map_skel->mmaped;
*map = bpf_object__find_map_by_name(obj, name); if (!*map) { pr_warn("failed to find skeleton map '%s'\n", name); return -ESRCH; }
/* externs shouldn't be pre-setup from user code */ if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG) *mmaped = (*map)->mmaped; } return 0;}
static int populate_skeleton_progs(const struct bpf_object *obj, struct bpf_prog_skeleton *progs, size_t prog_cnt, size_t prog_skel_sz){ int i;
for (i = 0; i < prog_cnt; i++) { struct bpf_prog_skeleton *prog_skel = (void *)progs + i * prog_skel_sz; struct bpf_program **prog = prog_skel->prog; const char *name = prog_skel->name;
*prog = bpf_object__find_program_by_name(obj, name); if (!*prog) { pr_warn("failed to find skeleton program '%s'\n", name); return -ESRCH; } } return 0;}
int bpf_object__open_skeleton(struct bpf_object_skeleton *s, const struct bpf_object_open_opts *opts){ struct bpf_object *obj; int err;
obj = bpf_object_open(NULL, s->data, s->data_sz, s->name, opts); if (IS_ERR(obj)) { err = PTR_ERR(obj); pr_warn("failed to initialize skeleton BPF object '%s': %s\n", s->name, errstr(err)); return libbpf_err(err); }
*s->obj = obj; err = populate_skeleton_maps(obj, s->maps, s->map_cnt, s->map_skel_sz); if (err) { pr_warn("failed to populate skeleton maps for '%s': %s\n", s->name, errstr(err)); return libbpf_err(err); }
err = populate_skeleton_progs(obj, s->progs, s->prog_cnt, s->prog_skel_sz); if (err) { pr_warn("failed to populate skeleton progs for '%s': %s\n", s->name, errstr(err)); return libbpf_err(err); }
return 0;}
int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s){ int err, len, var_idx, i; const char *var_name; const struct bpf_map *map; struct btf *btf; __u32 map_type_id; const struct btf_type *map_type, *var_type; const struct bpf_var_skeleton *var_skel; struct btf_var_secinfo *var;
if (!s->obj) return libbpf_err(-EINVAL);
btf = bpf_object__btf(s->obj); if (!btf) { pr_warn("subskeletons require BTF at runtime (object %s)\n", bpf_object__name(s->obj)); return libbpf_err(-errno); }
err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt, s->map_skel_sz); if (err) { pr_warn("failed to populate subskeleton maps: %s\n", errstr(err)); return libbpf_err(err); }
err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt, s->prog_skel_sz); if (err) { pr_warn("failed to populate subskeleton maps: %s\n", errstr(err)); return libbpf_err(err); }
for (var_idx = 0; var_idx < s->var_cnt; var_idx++) { var_skel = (void *)s->vars + var_idx * s->var_skel_sz; map = *var_skel->map; map_type_id = bpf_map__btf_value_type_id(map); map_type = btf__type_by_id(btf, map_type_id);
if (!btf_is_datasec(map_type)) { pr_warn("type for map '%1$s' is not a datasec: %2$s\n", bpf_map__name(map), __btf_kind_str(btf_kind(map_type))); return libbpf_err(-EINVAL); }
len = btf_vlen(map_type); var = btf_var_secinfos(map_type); for (i = 0; i < len; i++, var++) { var_type = btf__type_by_id(btf, var->type); var_name = btf__name_by_offset(btf, var_type->name_off); if (strcmp(var_name, var_skel->name) == 0) { *var_skel->addr = map->mmaped + var->offset; break; } } } return 0;}
void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s){ if (!s) return; free(s->maps); free(s->progs); free(s->vars); free(s);}
int bpf_object__load_skeleton(struct bpf_object_skeleton *s){ int i, err;
err = bpf_object__load(*s->obj); if (err) { pr_warn("failed to load BPF skeleton '%s': %s\n", s->name, errstr(err)); return libbpf_err(err); }
for (i = 0; i < s->map_cnt; i++) { struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz; struct bpf_map *map = *map_skel->map;
if (!map_skel->mmaped) continue;
if (map->def.type == BPF_MAP_TYPE_ARENA) *map_skel->mmaped = map->mmaped + map->obj->arena_data_off; else *map_skel->mmaped = map->mmaped; }
return 0;}
int bpf_object__attach_skeleton(struct bpf_object_skeleton *s){ int i, err;
for (i = 0; i < s->prog_cnt; i++) { struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz; struct bpf_program *prog = *prog_skel->prog; struct bpf_link **link = prog_skel->link;
if (!prog->autoload || !prog->autoattach) continue;
/* auto-attaching not supported for this program */ if (!prog->sec_def || !prog->sec_def->prog_attach_fn) continue;
/* if user already set the link manually, don't attempt auto-attach */ if (*link) continue;
err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, link); if (err) { pr_warn("prog '%s': failed to auto-attach: %s\n", bpf_program__name(prog), errstr(err)); return libbpf_err(err); }
/* It's possible that for some SEC() definitions auto-attach * is supported in some cases (e.g., if definition completely * specifies target information), but is not in other cases. * SEC("uprobe") is one such case. If user specified target * binary and function name, such BPF program can be * auto-attached. But if not, it shouldn't trigger skeleton's * attach to fail. It should just be skipped. * attach_fn signals such case with returning 0 (no error) and * setting link to NULL. */ }
for (i = 0; i < s->map_cnt; i++) { struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz; struct bpf_map *map = *map_skel->map; struct bpf_link **link;
if (!map->autocreate || !map->autoattach) continue;
/* only struct_ops maps can be attached */ if (!bpf_map__is_struct_ops(map)) continue;
/* skeleton is created with earlier version of bpftool, notify user */ if (s->map_skel_sz < offsetofend(struct bpf_map_skeleton, link)) { pr_warn("map '%s': BPF skeleton version is old, skipping map auto-attachment...\n", bpf_map__name(map)); continue; }
link = map_skel->link; if (!link) { pr_warn("map '%s': BPF map skeleton link is uninitialized\n", bpf_map__name(map)); continue; }
if (*link) continue;
*link = bpf_map__attach_struct_ops(map); if (!*link) { err = -errno; pr_warn("map '%s': failed to auto-attach: %s\n", bpf_map__name(map), errstr(err)); return libbpf_err(err); } }
return 0;}
void bpf_object__detach_skeleton(struct bpf_object_skeleton *s){ int i;
for (i = 0; i < s->prog_cnt; i++) { struct bpf_prog_skeleton *prog_skel = (void *)s->progs + i * s->prog_skel_sz; struct bpf_link **link = prog_skel->link;
bpf_link__destroy(*link); *link = NULL; }
if (s->map_skel_sz < sizeof(struct bpf_map_skeleton)) return;
for (i = 0; i < s->map_cnt; i++) { struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz; struct bpf_link **link = map_skel->link;
if (link) { bpf_link__destroy(*link); *link = NULL; } }}
void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s){ if (!s) return;
bpf_object__detach_skeleton(s); if (s->obj) bpf_object__close(*s->obj); free(s->maps); free(s->progs); free(s);}