// SPDX-License-Identifier: GPL-2.0/* * mm/debug.c * * mm/ specific debug routines. * */ #include <linux/kernel.h>#include <linux/mm.h>#include <linux/trace_events.h>#include <linux/memcontrol.h>#include <trace/events/mmflags.h>#include <linux/migrate.h>#include <linux/page_owner.h>#include <linux/ctype.h> #include "internal.h" const char *migrate_reason_names[MR_TYPES] = { "compaction", "memory_failure", "memory_hotplug", "syscall_or_cpuset", "mempolicy_mbind", "numa_misplaced", "cma",}; const struct trace_print_flags pageflag_names[] = { __def_pageflag_names, {0, NULL}}; const struct trace_print_flags gfpflag_names[] = { __def_gfpflag_names, {0, NULL}}; const struct trace_print_flags vmaflag_names[] = { __def_vmaflag_names, {0, NULL}}; void __dump_page(struct page *page, const char *reason){ struct page *head = compound_head(page); struct address_space *mapping; bool page_poisoned = PagePoisoned(page); bool compound = PageCompound(page); /* * Accessing the pageblock without the zone lock. It could change to * "isolate" again in the meantime, but since we are just dumping the * state for debugging, it should be fine to accept a bit of * inaccuracy here due to racing. */ bool page_cma = is_migrate_cma_page(page); int mapcount; char *type = ""; /* * If struct page is poisoned don't access Page*() functions as that * leads to recursive loop. Page*() check for poisoned pages, and calls * dump_page() when detected. */ if (page_poisoned) { pr_warn("page:%px is uninitialized and poisoned", page); goto hex_only; } if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { /* * Corrupt page, so we cannot call page_mapping. Instead, do a * safe subset of the steps that page_mapping() does. Caution: * this will be misleading for tail pages, PageSwapCache pages, * and potentially other situations. (See the page_mapping() * implementation for what's missing here.) */ unsigned long tmp = (unsigned long)page->mapping; if (tmp & PAGE_MAPPING_ANON) mapping = NULL; else mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS); head = page; compound = false; } else { mapping = page_mapping(page); } /* * Avoid VM_BUG_ON() in page_mapcount(). * page->_mapcount space in struct page is used by sl[aou]b pages to * encode own info. */ mapcount = PageSlab(head) ? 0 : page_mapcount(page); pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", page, page_ref_count(head), mapcount, mapping, page_to_pgoff(page), page_to_pfn(page)); if (compound) { if (hpage_pincount_available(page)) { pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n", head, compound_order(head), head_mapcount(head), head_pincount(head)); } else { pr_warn("head:%p order:%u compound_mapcount:%d\n", head, compound_order(head), head_mapcount(head)); } } if (PageKsm(page)) type = "ksm "; else if (PageAnon(page)) type = "anon "; else if (mapping) { struct inode *host; const struct address_space_operations *a_ops; struct hlist_node *dentry_first; struct dentry *dentry_ptr; struct dentry dentry; /* * mapping can be invalid pointer and we don't want to crash * accessing it, so probe everything depending on it carefully */ if (get_kernel_nofault(host, &mapping->host) || get_kernel_nofault(a_ops, &mapping->a_ops)) { pr_warn("failed to read mapping contents, not a valid kernel address?\n"); goto out_mapping; } if (!host) { pr_warn("aops:%ps\n", a_ops); goto out_mapping; } if (get_kernel_nofault(dentry_first, &host->i_dentry.first)) { pr_warn("aops:%ps with invalid host inode %px\n", a_ops, host); goto out_mapping; } if (!dentry_first) { pr_warn("aops:%ps ino:%lx\n", a_ops, host->i_ino); goto out_mapping; } dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); if (get_kernel_nofault(dentry, dentry_ptr)) { pr_warn("aops:%ps with invalid dentry %px\n", a_ops, dentry_ptr); } else { /* * if dentry is corrupted, the %pd handler may still * crash, but it's unlikely that we reach here with a * corrupted struct page */ pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, host->i_ino, &dentry); } }out_mapping: BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags, page_cma ? " CMA" : ""); hex_only: print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), page, sizeof(struct page), false); if (head != page) print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), head, sizeof(struct page), false); if (reason) pr_warn("page dumped because: %s\n", reason); #ifdef CONFIG_MEMCG if (!page_poisoned && page->mem_cgroup) pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup);#endif} void dump_page(struct page *page, const char *reason){ __dump_page(page, reason); dump_page_owner(page);}EXPORT_SYMBOL(dump_page); #ifdef CONFIG_DEBUG_VM void dump_vma(const struct vm_area_struct *vma){ pr_emerg("vma %px start %px end %px\n" "next %px prev %px mm %px\n" "prot %lx anon_vma %px vm_ops %px\n" "pgoff %lx file %px private_data %px\n" "flags: %#lx(%pGv)\n", vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next, vma->vm_prev, vma->vm_mm, (unsigned long)pgprot_val(vma->vm_page_prot), vma->anon_vma, vma->vm_ops, vma->vm_pgoff, vma->vm_file, vma->vm_private_data, vma->vm_flags, &vma->vm_flags);}EXPORT_SYMBOL(dump_vma); void dump_mm(const struct mm_struct *mm){ pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"#ifdef CONFIG_MMU "get_unmapped_area %px\n"#endif "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n" "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" "start_code %lx end_code %lx start_data %lx end_data %lx\n" "start_brk %lx brk %lx start_stack %lx\n" "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" "binfmt %px flags %lx core_state %px\n"#ifdef CONFIG_AIO "ioctx_table %px\n"#endif#ifdef CONFIG_MEMCG "owner %px "#endif "exe_file %px\n"#ifdef CONFIG_MMU_NOTIFIER "notifier_subscriptions %px\n"#endif#ifdef CONFIG_NUMA_BALANCING "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"#endif "tlb_flush_pending %d\n" "def_flags: %#lx(%pGv)\n", mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,#ifdef CONFIG_MMU mm->get_unmapped_area,#endif mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end, mm->pgd, atomic_read(&mm->mm_users), atomic_read(&mm->mm_count), mm_pgtables_bytes(mm), mm->map_count, mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, (u64)atomic64_read(&mm->pinned_vm), mm->data_vm, mm->exec_vm, mm->stack_vm, mm->start_code, mm->end_code, mm->start_data, mm->end_data, mm->start_brk, mm->brk, mm->start_stack, mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, mm->binfmt, mm->flags, mm->core_state,#ifdef CONFIG_AIO mm->ioctx_table,#endif#ifdef CONFIG_MEMCG mm->owner,#endif mm->exe_file,#ifdef CONFIG_MMU_NOTIFIER mm->notifier_subscriptions,#endif#ifdef CONFIG_NUMA_BALANCING mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,#endif atomic_read(&mm->tlb_flush_pending), mm->def_flags, &mm->def_flags );} static bool page_init_poisoning __read_mostly = true; static int __init setup_vm_debug(char *str){ bool __page_init_poisoning = true; /* * Calling vm_debug with no arguments is equivalent to requesting * to enable all debugging options we can control. */ if (*str++ != '=' || !*str) goto out; __page_init_poisoning = false; if (*str == '-') goto out; while (*str) { switch (tolower(*str)) { case'p': __page_init_poisoning = true; break; default: pr_err("vm_debug option '%c' unknown. skipped\n", *str); } str++; }out: if (page_init_poisoning && !__page_init_poisoning) pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); page_init_poisoning = __page_init_poisoning; return 1;}__setup("vm_debug", setup_vm_debug); void page_init_poison(struct page *page, size_t size){ if (page_init_poisoning) memset(page, PAGE_POISON_PATTERN, size);}EXPORT_SYMBOL_GPL(page_init_poison);#endif /* CONFIG_DEBUG_VM */
// SPDX-License-Identifier: GPL-2.0
/*
* mm/debug.c
*
* mm/ specific debug routines.
*
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/trace_events.h>
#include <linux/memcontrol.h>
#include <trace/events/mmflags.h>
#include <linux/migrate.h>
#include <linux/page_owner.h>
#include <linux/ctype.h>
#include "internal.h"
const char *migrate_reason_names[MR_TYPES] = {
"compaction",
"memory_failure",
"memory_hotplug",
"syscall_or_cpuset",
"mempolicy_mbind",
"numa_misplaced",
"cma",
};
const struct trace_print_flags pageflag_names[] = {
__def_pageflag_names,
{0, NULL}
};
const struct trace_print_flags gfpflag_names[] = {
__def_gfpflag_names,
{0, NULL}
};
const struct trace_print_flags vmaflag_names[] = {
__def_vmaflag_names,
{0, NULL}
};
void __dump_page(struct page *page, const char *reason)
{
struct page *head = compound_head(page);
struct address_space *mapping;
bool page_poisoned = PagePoisoned(page);
bool compound = PageCompound(page);
/*
* Accessing the pageblock without the zone lock. It could change to
* "isolate" again in the meantime, but since we are just dumping the
* state for debugging, it should be fine to accept a bit of
* inaccuracy here due to racing.
*/
bool page_cma = is_migrate_cma_page(page);
int mapcount;
char *type = "";
/*
* If struct page is poisoned don't access Page*() functions as that
* leads to recursive loop. Page*() check for poisoned pages, and calls
* dump_page() when detected.
*/
if (page_poisoned) {
pr_warn("page:%px is uninitialized and poisoned", page);
goto hex_only;
}
if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
/*
* Corrupt page, so we cannot call page_mapping. Instead, do a
* safe subset of the steps that page_mapping() does. Caution:
* this will be misleading for tail pages, PageSwapCache pages,
* and potentially other situations. (See the page_mapping()
* implementation for what's missing here.)
*/
unsigned long tmp = (unsigned long)page->mapping;
if (tmp & PAGE_MAPPING_ANON)
mapping = NULL;
else
mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
head = page;
compound = false;
} else {
mapping = page_mapping(page);
}
/*
* Avoid VM_BUG_ON() in page_mapcount().
* page->_mapcount space in struct page is used by sl[aou]b pages to
* encode own info.
*/
mapcount = PageSlab(head) ? 0 : page_mapcount(page);
pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
page, page_ref_count(head), mapcount, mapping,
page_to_pgoff(page), page_to_pfn(page));
if (compound) {
if (hpage_pincount_available(page)) {
pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
head, compound_order(head),
head_mapcount(head),
head_pincount(head));
} else {
pr_warn("head:%p order:%u compound_mapcount:%d\n",
head, compound_order(head),
head_mapcount(head));
}
}
if (PageKsm(page))
type = "ksm ";
else if (PageAnon(page))
type = "anon ";
else if (mapping) {
struct inode *host;
const struct address_space_operations *a_ops;
struct hlist_node *dentry_first;
struct dentry *dentry_ptr;
struct dentry dentry;
/*
* mapping can be invalid pointer and we don't want to crash
* accessing it, so probe everything depending on it carefully
*/
if (get_kernel_nofault(host, &mapping->host) ||
get_kernel_nofault(a_ops, &mapping->a_ops)) {
pr_warn("failed to read mapping contents, not a valid kernel address?\n");
goto out_mapping;
}
if (!host) {
pr_warn("aops:%ps\n", a_ops);
goto out_mapping;
}
if (get_kernel_nofault(dentry_first, &host->i_dentry.first)) {
pr_warn("aops:%ps with invalid host inode %px\n",
a_ops, host);
goto out_mapping;
}
if (!dentry_first) {
pr_warn("aops:%ps ino:%lx\n", a_ops, host->i_ino);
goto out_mapping;
}
dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
if (get_kernel_nofault(dentry, dentry_ptr)) {
pr_warn("aops:%ps with invalid dentry %px\n", a_ops,
dentry_ptr);
} else {
/*
* if dentry is corrupted, the %pd handler may still
* crash, but it's unlikely that we reach here with a
* corrupted struct page
*/
pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n",
a_ops, host->i_ino, &dentry);
}
}
out_mapping:
BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
page_cma ? " CMA" : "");
hex_only:
print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
sizeof(unsigned long), page,
sizeof(struct page), false);
if (head != page)
print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
sizeof(unsigned long), head,
sizeof(struct page), false);
if (reason)
pr_warn("page dumped because: %s\n", reason);
#ifdef CONFIG_MEMCG
if (!page_poisoned && page->mem_cgroup)
pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup);
#endif
}
void dump_page(struct page *page, const char *reason)
{
__dump_page(page, reason);
dump_page_owner(page);
}
EXPORT_SYMBOL(dump_page);
#ifdef CONFIG_DEBUG_VM
void dump_vma(const struct vm_area_struct *vma)
{
pr_emerg("vma %px start %px end %px\n"
"next %px prev %px mm %px\n"
"prot %lx anon_vma %px vm_ops %px\n"
"pgoff %lx file %px private_data %px\n"
"flags: %#lx(%pGv)\n",
vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next,
vma->vm_prev, vma->vm_mm,
(unsigned long)pgprot_val(vma->vm_page_prot),
vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
vma->vm_file, vma->vm_private_data,
vma->vm_flags, &vma->vm_flags);
}
EXPORT_SYMBOL(dump_vma);
void dump_mm(const struct mm_struct *mm)
{
pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
#ifdef CONFIG_MMU
"get_unmapped_area %px\n"
#endif
"mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
"pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
"pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
"start_code %lx end_code %lx start_data %lx end_data %lx\n"
"start_brk %lx brk %lx start_stack %lx\n"
"arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
"binfmt %px flags %lx core_state %px\n"
#ifdef CONFIG_AIO
"ioctx_table %px\n"
#endif
#ifdef CONFIG_MEMCG
"owner %px "
#endif
"exe_file %px\n"
#ifdef CONFIG_MMU_NOTIFIER
"notifier_subscriptions %px\n"
#endif
#ifdef CONFIG_NUMA_BALANCING
"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
#endif
"tlb_flush_pending %d\n"
"def_flags: %#lx(%pGv)\n",
mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,
#ifdef CONFIG_MMU
mm->get_unmapped_area,
#endif
mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
mm->pgd, atomic_read(&mm->mm_users),
atomic_read(&mm->mm_count),
mm_pgtables_bytes(mm),
mm->map_count,
mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
(u64)atomic64_read(&mm->pinned_vm),
mm->data_vm, mm->exec_vm, mm->stack_vm,
mm->start_code, mm->end_code, mm->start_data, mm->end_data,
mm->start_brk, mm->brk, mm->start_stack,
mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
mm->binfmt, mm->flags, mm->core_state,
#ifdef CONFIG_AIO
mm->ioctx_table,
#endif
#ifdef CONFIG_MEMCG
mm->owner,
#endif
mm->exe_file,
#ifdef CONFIG_MMU_NOTIFIER
mm->notifier_subscriptions,
#endif
#ifdef CONFIG_NUMA_BALANCING
mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
#endif
atomic_read(&mm->tlb_flush_pending),
mm->def_flags, &mm->def_flags
);
}
static bool page_init_poisoning __read_mostly = true;
static int __init setup_vm_debug(char *str)
{
bool __page_init_poisoning = true;
/*
* Calling vm_debug with no arguments is equivalent to requesting
* to enable all debugging options we can control.
*/
if (*str++ != '=' || !*str)
goto out;
__page_init_poisoning = false;
if (*str == '-')
goto out;
while (*str) {
switch (tolower(*str)) {
case'p':
__page_init_poisoning = true;
break;
default:
pr_err("vm_debug option '%c' unknown. skipped\n",
*str);
}
str++;
}
out:
if (page_init_poisoning && !__page_init_poisoning)
pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
page_init_poisoning = __page_init_poisoning;
return 1;
}
__setup("vm_debug", setup_vm_debug);
void page_init_poison(struct page *page, size_t size)
{
if (page_init_poisoning)
memset(page, PAGE_POISON_PATTERN, size);
}
EXPORT_SYMBOL_GPL(page_init_poison);
#endif /* CONFIG_DEBUG_VM */