| // 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" |
| #include <trace/events/migrate.h> |
| |
| /* |
| * Define EM() and EMe() so that MIGRATE_REASON from trace/events/migrate.h can |
| * be used to populate migrate_reason_names[]. |
| */ |
| #undef EM |
| #undef EMe |
| #define EM(a, b) b, |
| #define EMe(a, b) b |
| |
| const char *migrate_reason_names[MR_TYPES] = { |
| MIGRATE_REASON |
| }; |
| |
| 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} |
| }; |
| |
| #define DEF_PAGETYPE_NAME(_name) [PGTY_##_name - 0xf0] = __stringify(_name) |
| |
| static const char *page_type_names[] = { |
| DEF_PAGETYPE_NAME(slab), |
| DEF_PAGETYPE_NAME(hugetlb), |
| DEF_PAGETYPE_NAME(offline), |
| DEF_PAGETYPE_NAME(guard), |
| DEF_PAGETYPE_NAME(table), |
| DEF_PAGETYPE_NAME(buddy), |
| DEF_PAGETYPE_NAME(unaccepted), |
| }; |
| |
| static const char *page_type_name(unsigned int page_type) |
| { |
| unsigned i = (page_type >> 24) - 0xf0; |
| |
| if (i >= ARRAY_SIZE(page_type_names)) |
| return "unknown"; |
| return page_type_names[i]; |
| } |
| |
| static void __dump_folio(struct folio *folio, struct page *page, |
| unsigned long pfn, unsigned long idx) |
| { |
| struct address_space *mapping = folio_mapping(folio); |
| int mapcount = atomic_read(&page->_mapcount); |
| char *type = ""; |
| |
| mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1; |
| pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", |
| folio_ref_count(folio), mapcount, mapping, |
| folio->index + idx, pfn); |
| if (folio_test_large(folio)) { |
| pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", |
| folio_order(folio), |
| folio_mapcount(folio), |
| folio_entire_mapcount(folio), |
| folio_nr_pages_mapped(folio), |
| atomic_read(&folio->_pincount)); |
| } |
| |
| #ifdef CONFIG_MEMCG |
| if (folio->memcg_data) |
| pr_warn("memcg:%lx\n", folio->memcg_data); |
| #endif |
| if (folio_test_ksm(folio)) |
| type = "ksm "; |
| else if (folio_test_anon(folio)) |
| type = "anon "; |
| else if (mapping) |
| dump_mapping(mapping); |
| BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); |
| |
| /* |
| * 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. |
| */ |
| pr_warn("%sflags: %pGp%s\n", type, &folio->flags, |
| is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); |
| if (page_has_type(&folio->page)) |
| pr_warn("page_type: %x(%s)\n", folio->page.page_type >> 24, |
| page_type_name(folio->page.page_type)); |
| |
| print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, |
| sizeof(unsigned long), page, |
| sizeof(struct page), false); |
| if (folio_test_large(folio)) |
| print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, |
| sizeof(unsigned long), folio, |
| 2 * sizeof(struct page), false); |
| } |
| |
| static void __dump_page(const struct page *page) |
| { |
| struct folio *foliop, folio; |
| struct page precise; |
| unsigned long head; |
| unsigned long pfn = page_to_pfn(page); |
| unsigned long idx, nr_pages = 1; |
| int loops = 5; |
| |
| again: |
| memcpy(&precise, page, sizeof(*page)); |
| head = precise.compound_head; |
| if ((head & 1) == 0) { |
| foliop = (struct folio *)&precise; |
| idx = 0; |
| if (!folio_test_large(foliop)) |
| goto dump; |
| foliop = (struct folio *)page; |
| } else { |
| foliop = (struct folio *)(head - 1); |
| idx = folio_page_idx(foliop, page); |
| } |
| |
| if (idx < MAX_FOLIO_NR_PAGES) { |
| memcpy(&folio, foliop, 2 * sizeof(struct page)); |
| nr_pages = folio_nr_pages(&folio); |
| foliop = &folio; |
| } |
| |
| if (idx > nr_pages) { |
| if (loops-- > 0) |
| goto again; |
| pr_warn("page does not match folio\n"); |
| precise.compound_head &= ~1UL; |
| foliop = (struct folio *)&precise; |
| idx = 0; |
| } |
| |
| dump: |
| __dump_folio(foliop, &precise, pfn, idx); |
| } |
| |
| void dump_page(const struct page *page, const char *reason) |
| { |
| if (PagePoisoned(page)) |
| pr_warn("page:%p is uninitialized and poisoned", page); |
| else |
| __dump_page(page); |
| if (reason) |
| pr_warn("page dumped because: %s\n", 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 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_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 task_size %lu\n" |
| "mmap_base %lu mmap_legacy_base %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\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->task_size, |
| mm->mmap_base, mm->mmap_legacy_base, |
| 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, |
| #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 |
| ); |
| } |
| EXPORT_SYMBOL(dump_mm); |
| |
| 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); |
| } |
| |
| void vma_iter_dump_tree(const struct vma_iterator *vmi) |
| { |
| #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) |
| mas_dump(&vmi->mas); |
| mt_dump(vmi->mas.tree, mt_dump_hex); |
| #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ |
| } |
| |
| #endif /* CONFIG_DEBUG_VM */ |