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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#include "debug.h"#include "dso.h"#include "env.h"#include "parse-events.h"#include "evlist.h"#include "evsel.h"#include "thread_map.h"#include "machine.h"#include "map.h"#include "symbol.h"#include "event.h"#include "record.h"#include "util/mmap.h"#include "util/string2.h"#include "util/synthetic-events.h"#include "util/util.h"#include "thread.h"
#include "tests.h"
#include <linux/ctype.h>
#define BUFSZ 1024#define READLEN 128
struct tested_section { struct rb_node rb_node; u64 addr; char *path;};
static bool tested_code_insert_or_exists(const char *path, u64 addr, struct rb_root *tested_sections){ struct rb_node **node = &tested_sections->rb_node; struct rb_node *parent = NULL; struct tested_section *data;
while (*node) { int cmp;
parent = *node; data = rb_entry(*node, struct tested_section, rb_node); cmp = strcmp(path, data->path); if (!cmp) { if (addr < data->addr) cmp = -1; else if (addr > data->addr) cmp = 1; else return true; /* already tested */ }
if (cmp < 0) node = &(*node)->rb_left; else node = &(*node)->rb_right; }
data = zalloc(sizeof(*data)); if (!data) return true;
data->addr = addr; data->path = strdup(path); if (!data->path) { free(data); return true; } rb_link_node(&data->rb_node, parent, node); rb_insert_color(&data->rb_node, tested_sections); return false;}
static void tested_sections__free(struct rb_root *root){ while (!RB_EMPTY_ROOT(root)) { struct rb_node *node = rb_first(root); struct tested_section *ts = rb_entry(node, struct tested_section, rb_node);
rb_erase(node, root); free(ts->path); free(ts); }}
static size_t read_objdump_chunk(const char **line, unsigned char **buf, size_t *buf_len){ size_t bytes_read = 0; unsigned char *chunk_start = *buf;
/* Read bytes */ while (*buf_len > 0) { char c1, c2;
/* Get 2 hex digits */ c1 = *(*line)++; if (!isxdigit(c1)) break; c2 = *(*line)++; if (!isxdigit(c2)) break;
/* Store byte and advance buf */ **buf = (hex(c1) << 4) | hex(c2); (*buf)++; (*buf_len)--; bytes_read++;
/* End of chunk? */ if (isspace(**line)) break; }
/* * objdump will display raw insn as LE if code endian * is LE and bytes_per_chunk > 1. In that case reverse * the chunk we just read. * * see disassemble_bytes() at binutils/objdump.c for details * how objdump chooses display endian) */ if (bytes_read > 1 && !host_is_bigendian()) { unsigned char *chunk_end = chunk_start + bytes_read - 1; unsigned char tmp;
while (chunk_start < chunk_end) { tmp = *chunk_start; *chunk_start = *chunk_end; *chunk_end = tmp; chunk_start++; chunk_end--; } }
return bytes_read;}
static size_t read_objdump_line(const char *line, unsigned char *buf, size_t buf_len){ const char *p; size_t ret, bytes_read = 0;
/* Skip to a colon */ p = strchr(line, ':'); if (!p) return 0; p++;
/* Skip initial spaces */ while (*p) { if (!isspace(*p)) break; p++; }
do { ret = read_objdump_chunk(&p, &buf, &buf_len); bytes_read += ret; p++; } while (ret > 0);
/* return number of successfully read bytes */ return bytes_read;}
static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr){ char *line = NULL; size_t line_len, off_last = 0; ssize_t ret; int err = 0; u64 addr, last_addr = start_addr;
while (off_last < *len) { size_t off, read_bytes, written_bytes; unsigned char tmp[BUFSZ];
ret = getline(&line, &line_len, f); if (feof(f)) break; if (ret < 0) { pr_debug("getline failed\n"); err = -1; break; }
/* read objdump data into temporary buffer */ read_bytes = read_objdump_line(line, tmp, sizeof(tmp)); if (!read_bytes) continue;
if (sscanf(line, "%"PRIx64, &addr) != 1) continue; if (addr < last_addr) { pr_debug("addr going backwards, read beyond section?\n"); break; } last_addr = addr;
/* copy it from temporary buffer to 'buf' according * to address on current objdump line */ off = addr - start_addr; if (off >= *len) break; written_bytes = MIN(read_bytes, *len - off); memcpy(buf + off, tmp, written_bytes); off_last = off + written_bytes; }
/* len returns number of bytes that could not be read */ *len -= off_last;
free(line);
return err;}
/* * Only gets GNU objdump version. Returns 0 for llvm-objdump. */static int objdump_version(void){ size_t line_len; char cmd[PATH_MAX * 2]; char *line = NULL; const char *fmt; FILE *f; int ret;
int version_tmp, version_num = 0; char *version = 0, *token;
fmt = "%s --version"; ret = snprintf(cmd, sizeof(cmd), fmt, test_objdump_path); if (ret <= 0 || (size_t)ret >= sizeof(cmd)) return -1; /* Ignore objdump errors */ strcat(cmd, " 2>/dev/null"); f = popen(cmd, "r"); if (!f) { pr_debug("popen failed\n"); return -1; } /* Get first line of objdump --version output */ ret = getline(&line, &line_len, f); pclose(f); if (ret < 0) { pr_debug("getline failed\n"); return -1; }
token = strsep(&line, " "); if (token != NULL && !strcmp(token, "GNU")) { // version is last part of first line of objdump --version output. while ((token = strsep(&line, " "))) version = token;
// Convert version into a format we can compare with token = strsep(&version, "."); version_num = atoi(token); if (version_num) version_num *= 10000;
token = strsep(&version, "."); version_tmp = atoi(token); if (token) version_num += version_tmp * 100;
token = strsep(&version, "."); version_tmp = atoi(token); if (token) version_num += version_tmp; }
return version_num;}
static int read_via_objdump(const char *filename, u64 addr, void *buf, size_t len){ u64 stop_address = addr + len; struct utsname uname_buf; char cmd[PATH_MAX * 2]; const char *fmt; FILE *f; int ret;
ret = uname(&uname_buf); if (ret) { pr_debug("uname failed\n"); return -1; }
if (!strncmp(uname_buf.machine, "riscv", 5)) { int version = objdump_version();
/* Default to this workaround if version parsing fails */ if (version < 0 || version > 24100) { /* * Starting at riscv objdump version 2.41, dumping in * the middle of an instruction is not supported. riscv * instructions are aligned along 2-byte intervals and * can be either 2-bytes or 4-bytes. This makes it * possible that the stop-address lands in the middle of * a 4-byte instruction. Increase the stop_address by * two to ensure an instruction is not cut in half, but * leave the len as-is so only the expected number of * bytes are collected. */ stop_address += 2; } }
fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s"; ret = snprintf(cmd, sizeof(cmd), fmt, test_objdump_path, addr, stop_address, filename); if (ret <= 0 || (size_t)ret >= sizeof(cmd)) return -1;
pr_debug("Objdump command is: %s\n", cmd);
/* Ignore objdump errors */ strcat(cmd, " 2>/dev/null");
f = popen(cmd, "r"); if (!f) { pr_debug("popen failed\n"); return -1; }
ret = read_objdump_output(f, buf, &len, addr); if (len) { pr_debug("objdump read too few bytes: %zd\n", len); if (!ret) ret = len; }
pclose(f);
return ret;}
static void dump_buf(unsigned char *buf, size_t len){ size_t i;
for (i = 0; i < len; i++) { pr_debug("0x%02x ", buf[i]); if (i % 16 == 15) pr_debug("\n"); } pr_debug("\n");}
static int read_object_code(u64 addr, size_t len, u8 cpumode, struct thread *thread, struct rb_root *tested_sections){ struct addr_location al; unsigned char buf1[BUFSZ] = {0}; unsigned char buf2[BUFSZ] = {0}; size_t ret_len; u64 objdump_addr; u64 skip_addr; const char *objdump_name; char decomp_name[KMOD_DECOMP_LEN]; bool decomp = false; int ret, err = 0; struct dso *dso;
pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
addr_location__init(&al); if (!thread__find_map(thread, cpumode, addr, &al) || !map__dso(al.map)) { if (cpumode == PERF_RECORD_MISC_HYPERVISOR) { pr_debug("Hypervisor address can not be resolved - skipping\n"); goto out; }
pr_debug("thread__find_map failed\n"); err = -1; goto out; } dso = map__dso(al.map); pr_debug("File is: %s\n", dso__long_name(dso));
if (dso__symtab_type(dso) == DSO_BINARY_TYPE__KALLSYMS && !dso__is_kcore(dso)) { pr_debug("Unexpected kernel address - skipping\n"); goto out; }
/* * Don't retest the same addresses. objdump struggles with kcore - try * each map only once even if the address is different. */ skip_addr = dso__is_kcore(dso) ? map__start(al.map) : al.addr; if (tested_code_insert_or_exists(dso__long_name(dso), skip_addr, tested_sections)) { pr_debug("Already tested %s @ %#"PRIx64" - skipping\n", dso__long_name(dso), skip_addr); goto out; }
pr_debug("On file address is: %#"PRIx64"\n", al.addr);
if (len > BUFSZ) len = BUFSZ;
/* Do not go off the map */ if (addr + len > map__end(al.map)) len = map__end(al.map) - addr;
/* * Some architectures (ex: powerpc) have stubs (trampolines) in kernel * modules to manage long jumps. Check if the ip offset falls in stubs * sections for kernel modules. And skip module address after text end */ if (dso__is_kmod(dso) && al.addr > dso__text_end(dso)) { pr_debug("skipping the module address %#"PRIx64" after text end\n", al.addr); goto out; }
/* Read the object code using perf */ ret_len = dso__data_read_offset(dso, maps__machine(thread__maps(thread)), al.addr, buf1, len); if (ret_len != len) { pr_debug("dso__data_read_offset failed\n"); err = -1; goto out; }
/* * Converting addresses for use by objdump requires more information. * map__load() does that. See map__rip_2objdump() for details. */ if (map__load(al.map)) { err = -1; goto out; }
objdump_name = dso__long_name(dso); if (dso__needs_decompress(dso)) { if (dso__decompress_kmodule_path(dso, objdump_name, decomp_name, sizeof(decomp_name)) < 0) { pr_debug("decompression failed\n"); err = -1; goto out; }
/* empty pathname means file wasn't actually compressed */ if (decomp_name[0] != '\0') { decomp = true; objdump_name = decomp_name; } }
/* Read the object code using objdump */ objdump_addr = map__rip_2objdump(al.map, al.addr); ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
if (decomp) unlink(objdump_name);
if (ret > 0) { /* * The kernel maps are inaccurate - assume objdump is right in * that case. */ if (cpumode == PERF_RECORD_MISC_KERNEL || cpumode == PERF_RECORD_MISC_GUEST_KERNEL) { len -= ret; if (len) { pr_debug("Reducing len to %zu\n", len); } else if (dso__is_kcore(dso)) { /* * objdump cannot handle very large segments * that may be found in kcore. */ pr_debug("objdump failed for kcore"); pr_debug(" - skipping\n"); } else { err = -1; } goto out; } } if (ret < 0) { pr_debug("read_via_objdump failed\n"); err = -1; goto out; }
/* The results should be identical */ if (memcmp(buf1, buf2, len)) { pr_debug("Bytes read differ from those read by objdump\n"); pr_debug("buf1 (dso):\n"); dump_buf(buf1, len); pr_debug("buf2 (objdump):\n"); dump_buf(buf2, len); err = -1; goto out; } pr_debug("Bytes read match those read by objdump\n");out: addr_location__exit(&al); return err;}
static int process_sample_event(struct machine *machine, struct evlist *evlist, union perf_event *event, struct rb_root *tested_sections){ struct perf_sample sample; struct thread *thread; int ret;
perf_sample__init(&sample, /*all=*/false); ret = evlist__parse_sample(evlist, event, &sample); if (ret) { pr_debug("evlist__parse_sample failed\n"); ret = -1; goto out; }
thread = machine__findnew_thread(machine, sample.pid, sample.tid); if (!thread) { pr_debug("machine__findnew_thread failed\n"); ret = -1; goto out; }
ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, tested_sections); thread__put(thread);out: perf_sample__exit(&sample); return ret;}
static int process_event(struct machine *machine, struct evlist *evlist, union perf_event *event, struct rb_root *tested_sections){ if (event->header.type == PERF_RECORD_SAMPLE) return process_sample_event(machine, evlist, event, tested_sections);
if (event->header.type == PERF_RECORD_THROTTLE || event->header.type == PERF_RECORD_UNTHROTTLE) return 0;
if (event->header.type < PERF_RECORD_MAX) { int ret;
ret = machine__process_event(machine, event, NULL); if (ret < 0) pr_debug("machine__process_event failed, event type %u\n", event->header.type); return ret; }
return 0;}
static int process_events(struct machine *machine, struct evlist *evlist, struct rb_root *tested_sections){ union perf_event *event; struct mmap *md; int i, ret;
for (i = 0; i < evlist__core(evlist)->nr_mmaps; i++) { md = &evlist__mmap(evlist)[i]; if (perf_mmap__read_init(&md->core) < 0) continue;
while ((event = perf_mmap__read_event(&md->core)) != NULL) { ret = process_event(machine, evlist, event, tested_sections); perf_mmap__consume(&md->core); if (ret < 0) return ret; } perf_mmap__read_done(&md->core); } return 0;}
static int comp(const void *a, const void *b){ return *(int *)a - *(int *)b;}
static void do_sort_something(void){ int buf[40960], i;
for (i = 0; i < (int)ARRAY_SIZE(buf); i++) buf[i] = ARRAY_SIZE(buf) - i - 1;
qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
for (i = 0; i < (int)ARRAY_SIZE(buf); i++) { if (buf[i] != i) { pr_debug("qsort failed\n"); break; } }}
static void sort_something(void){ int i;
for (i = 0; i < 10; i++) do_sort_something();}
static void syscall_something(void){ int pipefd[2]; int i;
for (i = 0; i < 1000; i++) { if (pipe(pipefd) < 0) { pr_debug("pipe failed\n"); break; } close(pipefd[1]); close(pipefd[0]); }}
static void fs_something(void){ const char *test_file_name = "temp-perf-code-reading-test-file--"; FILE *f; int i;
for (i = 0; i < 1000; i++) { f = fopen(test_file_name, "w+"); if (f) { fclose(f); unlink(test_file_name); } }}
static void do_something(void){ fs_something();
sort_something();
syscall_something();}
enum { TEST_CODE_READING_OK, TEST_CODE_READING_NO_VMLINUX, TEST_CODE_READING_NO_KCORE, TEST_CODE_READING_NO_ACCESS, TEST_CODE_READING_NO_KERNEL_OBJ,};
static int do_test_code_reading(bool try_kcore){ struct machine *machine; struct thread *thread; struct record_opts opts = { .mmap_pages = UINT_MAX, .user_freq = UINT_MAX, .user_interval = ULLONG_MAX, .freq = 500, .target = { .uses_mmap = true, }, }; struct rb_root tested_sections = RB_ROOT; struct perf_thread_map *threads = NULL; struct perf_cpu_map *cpus = NULL; struct evlist *evlist = NULL; struct evsel *evsel = NULL; int err = -1, ret; pid_t pid; struct map *map; bool have_vmlinux, have_kcore; struct dso *dso; const char *events[] = { "cpu-cycles", "cpu-cycles:u", "cpu-clock", "cpu-clock:u", NULL }; int evidx = 0; struct perf_env host_env;
pid = getpid();
perf_env__init(&host_env); machine = machine__new_host(&host_env);
ret = machine__create_kernel_maps(machine); if (ret < 0) { pr_debug("machine__create_kernel_maps failed\n"); goto out_err; }
/* Force the use of kallsyms instead of vmlinux to try kcore */ if (try_kcore) symbol_conf.kallsyms_name = "/proc/kallsyms";
/* Load kernel map */ map = machine__kernel_map(machine); ret = map__load(map); if (ret < 0) { pr_debug("map__load failed\n"); goto out_err; } dso = map__dso(map); have_vmlinux = dso__is_vmlinux(dso); have_kcore = dso__is_kcore(dso);
/* 2nd time through we just try kcore */ if (try_kcore && !have_kcore) return TEST_CODE_READING_NO_KCORE;
/* No point getting kernel events if there is no kernel object */ if (!have_vmlinux && !have_kcore) evidx++;
threads = thread_map__new_by_tid(pid); if (!threads) { pr_debug("thread_map__new_by_tid failed\n"); goto out_err; }
ret = perf_event__synthesize_thread_map(NULL, threads, perf_event__process, machine, true, false); if (ret < 0) { pr_debug("perf_event__synthesize_thread_map failed\n"); goto out_err; }
thread = machine__findnew_thread(machine, pid, pid); if (!thread) { pr_debug("machine__findnew_thread failed\n"); goto out_put; }
cpus = perf_cpu_map__new_online_cpus(); if (!cpus) { pr_debug("perf_cpu_map__new failed\n"); goto out_put; }
while (events[evidx]) { const char *str;
evlist = evlist__new(); if (!evlist) { pr_debug("evlist__new failed\n"); goto out_put; }
perf_evlist__set_maps(evlist__core(evlist), cpus, threads);
str = events[evidx]; pr_debug("Parsing event '%s'\n", str); ret = parse_event(evlist, str); if (ret < 0) { pr_debug("parse_events failed\n"); goto out_put; }
evlist__config(evlist, &opts, NULL);
evlist__for_each_entry(evlist, evsel) { evsel->core.attr.comm = 1; evsel->core.attr.disabled = 1; evsel->core.attr.enable_on_exec = 0; }
ret = evlist__open(evlist); if (ret < 0) { evidx++;
if (events[evidx] == NULL && verbose > 0) { char errbuf[512]; evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); }
perf_evlist__set_maps(evlist__core(evlist), NULL, NULL); evlist__put(evlist); evlist = NULL; continue; } break; }
if (events[evidx] == NULL) goto out_put;
ret = evlist__do_mmap(evlist, UINT_MAX); if (ret < 0) { pr_debug("evlist__mmap failed\n"); goto out_put; }
evlist__enable(evlist);
do_something();
evlist__disable(evlist);
ret = process_events(machine, evlist, &tested_sections); if (ret < 0) goto out_put;
if (!have_vmlinux && !have_kcore && !try_kcore) err = TEST_CODE_READING_NO_KERNEL_OBJ; else if (!have_vmlinux && !try_kcore) err = TEST_CODE_READING_NO_VMLINUX; else if (strstr(events[evidx], ":u")) err = TEST_CODE_READING_NO_ACCESS; else err = TEST_CODE_READING_OK;out_put: thread__put(thread);out_err: evlist__put(evlist); perf_cpu_map__put(cpus); perf_thread_map__put(threads); machine__delete(machine); perf_env__exit(&host_env); tested_sections__free(&tested_sections);
return err;}
static int test__code_reading(struct test_suite *test __maybe_unused, int subtest __maybe_unused){ int ret;
ret = do_test_code_reading(false); if (!ret) ret = do_test_code_reading(true);
switch (ret) { case TEST_CODE_READING_OK: return 0; case TEST_CODE_READING_NO_VMLINUX: pr_debug("no vmlinux\n"); return 0; case TEST_CODE_READING_NO_KCORE: pr_debug("no kcore\n"); return 0; case TEST_CODE_READING_NO_ACCESS: pr_debug("no access\n"); return 0; case TEST_CODE_READING_NO_KERNEL_OBJ: pr_debug("no kernel obj\n"); return 0; default: return -1; };}
DEFINE_SUITE("Object code reading", code_reading);