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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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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288// SPDX-License-Identifier: GPL-2.0#include <linux/memblock.h>#include <linux/compiler.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/ksm.h>#include <linux/mm.h>#include <linux/mmzone.h>#include <linux/huge_mm.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/hugetlb.h>#include <linux/memremap.h>#include <linux/memcontrol.h>#include <linux/mmu_notifier.h>#include <linux/page_idle.h>#include <linux/kernel-page-flags.h>#include <linux/uaccess.h>#include "internal.h"
#define KPMSIZE sizeof(u64)#define KPMMASK (KPMSIZE - 1)
enum kpage_operation { KPAGE_FLAGS, KPAGE_COUNT, KPAGE_CGROUP,};
static inline unsigned long get_max_dump_pfn(void){#ifdef CONFIG_SPARSEMEM /* * If max_pfn does not fall on a section boundary, pfn_to_online_page() * can succeed on PFNs beyond max_pfn within the same section. Allow * inspection of these memmaps. */ return round_up(max_pfn, PAGES_PER_SECTION);#else return max_pfn;#endif}
static u64 get_kpage_count(const struct page *page){ struct page_snapshot ps; u64 ret;
snapshot_page(&ps, page);
if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) ret = folio_precise_page_mapcount(&ps.folio_snapshot, &ps.page_snapshot); else ret = folio_average_page_mapcount(&ps.folio_snapshot);
return ret;}
static ssize_t kpage_read(struct file *file, char __user *buf, size_t count, loff_t *ppos, enum kpage_operation op){ const unsigned long max_dump_pfn = get_max_dump_pfn(); u64 __user *out = (u64 __user *)buf; struct page *page; unsigned long src = *ppos; unsigned long pfn; ssize_t ret = 0; u64 info;
pfn = src / KPMSIZE; if (src & KPMMASK || count & KPMMASK) return -EINVAL; if (src >= max_dump_pfn * KPMSIZE) return 0; count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
while (count > 0) { /* * TODO: ZONE_DEVICE support requires to identify * memmaps that were actually initialized. */ page = pfn_to_online_page(pfn);
if (page) { switch (op) { case KPAGE_FLAGS: info = stable_page_flags(page); break; case KPAGE_COUNT: info = get_kpage_count(page); break; case KPAGE_CGROUP: info = page_cgroup_ino(page); break; default: info = 0; break; } } else info = 0;
if (put_user(info, out)) { ret = -EFAULT; break; }
pfn++; out++; count -= KPMSIZE;
cond_resched(); }
*ppos += (char __user *)out - buf; if (!ret) ret = (char __user *)out - buf; return ret;}
/* /proc/kpagecount - an array exposing page mapcounts * * Each entry is a u64 representing the corresponding * physical page mapcount. */static ssize_t kpagecount_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){ return kpage_read(file, buf, count, ppos, KPAGE_COUNT);}
static const struct proc_ops kpagecount_proc_ops = { .proc_flags = PROC_ENTRY_PERMANENT, .proc_lseek = mem_lseek, .proc_read = kpagecount_read,};
static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit){ return ((kflags >> kbit) & 1) << ubit;}
u64 stable_page_flags(const struct page *page){ const struct folio *folio; struct page_snapshot ps; unsigned long k; u64 u = 0;
/* * pseudo flag: KPF_NOPAGE * it differentiates a memory hole from a page with no flags */ if (!page) return BIT_ULL(KPF_NOPAGE);
snapshot_page(&ps, page); folio = &ps.folio_snapshot; k = folio->flags.f;
/* * pseudo flags for the well known (anonymous) memory mapped pages */ if (folio_mapped(folio)) u |= BIT_ULL(KPF_MMAP); if (folio_test_anon(folio)) { u |= BIT_ULL(KPF_ANON); if (folio_test_ksm(folio)) u |= BIT_ULL(KPF_KSM); }
/* * compound pages: export both head/tail info * they together define a compound page's start/end pos and order */ if (ps.idx == 0) u |= kpf_copy_bit(k, KPF_COMPOUND_HEAD, PG_head); else u |= BIT_ULL(KPF_COMPOUND_TAIL); if (folio_test_hugetlb(folio)) u |= BIT_ULL(KPF_HUGE); else if (folio_test_large(folio) && folio_test_large_rmappable(folio)) { /* Note: we indicate any THPs here, not just PMD-sized ones */ u |= BIT_ULL(KPF_THP); } else if (is_huge_zero_pfn(ps.pfn)) { u |= BIT_ULL(KPF_ZERO_PAGE); u |= BIT_ULL(KPF_THP); } else if (is_zero_pfn(ps.pfn)) { u |= BIT_ULL(KPF_ZERO_PAGE); }
if (ps.flags & PAGE_SNAPSHOT_PG_BUDDY) u |= BIT_ULL(KPF_BUDDY);
if (ps.flags & PAGE_SNAPSHOT_PG_IDLE) u |= BIT_ULL(KPF_IDLE);
if (folio_test_offline(folio)) u |= BIT_ULL(KPF_OFFLINE); if (folio_test_pgtable(folio)) u |= BIT_ULL(KPF_PGTABLE); if (folio_test_slab(folio)) u |= BIT_ULL(KPF_SLAB);
u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked); u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty); u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate); u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
u |= kpf_copy_bit(k, KPF_LRU, PG_lru); u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced); u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active); u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
if (folio_test_swapcache(folio)) u |= BIT_ULL(KPF_SWAPCACHE);
u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked); u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable); u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
#ifdef CONFIG_MEMORY_FAILURE if (u & BIT_ULL(KPF_HUGE)) u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison); else u |= kpf_copy_bit(ps.page_snapshot.flags.f, KPF_HWPOISON, PG_hwpoison);#endif
u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved); u |= kpf_copy_bit(k, KPF_OWNER_2, PG_owner_2); u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2); u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1); u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);#ifdef CONFIG_ARCH_USES_PG_ARCH_2 u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);#endif#ifdef CONFIG_ARCH_USES_PG_ARCH_3 u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);#endif
return u;}EXPORT_SYMBOL_GPL(stable_page_flags);
/* /proc/kpageflags - an array exposing page flags * * Each entry is a u64 representing the corresponding * physical page flags. */static ssize_t kpageflags_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){ return kpage_read(file, buf, count, ppos, KPAGE_FLAGS);}
static const struct proc_ops kpageflags_proc_ops = { .proc_flags = PROC_ENTRY_PERMANENT, .proc_lseek = mem_lseek, .proc_read = kpageflags_read,};
#ifdef CONFIG_MEMCGstatic ssize_t kpagecgroup_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){ return kpage_read(file, buf, count, ppos, KPAGE_CGROUP);}static const struct proc_ops kpagecgroup_proc_ops = { .proc_flags = PROC_ENTRY_PERMANENT, .proc_lseek = mem_lseek, .proc_read = kpagecgroup_read,};#endif /* CONFIG_MEMCG */
static int __init proc_page_init(void){ proc_create("kpagecount", S_IRUSR, NULL, &kpagecount_proc_ops); proc_create("kpageflags", S_IRUSR, NULL, &kpageflags_proc_ops);#ifdef CONFIG_MEMCG proc_create("kpagecgroup", S_IRUSR, NULL, &kpagecgroup_proc_ops);#endif return 0;}fs_initcall(proc_page_init);