// 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 address_space *mapping; bool page_poisoned = PagePoisoned(page); int mapcount; /* * 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; } 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(page) ? 0 : page_mapcount(page); pr_warn("page:%px count:%d mapcount:%d mapping:%px index:%#lx", page, page_ref_count(page), mapcount, page->mapping, page_to_pgoff(page)); if (PageCompound(page)) pr_cont(" compound_mapcount: %d", compound_mapcount(page)); pr_cont("\n"); if (PageAnon(page)) pr_warn("anon "); else if (PageKsm(page)) pr_warn("ksm "); else if (mapping) { pr_warn("%ps ", mapping->a_ops); if (mapping->host->i_dentry.first) { struct dentry *dentry; dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias); pr_warn("name:\"%pd\" ", dentry); } } BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); pr_warn("flags: %#lx(%pGp)\n", page->flags, &page->flags); hex_only: print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), page, 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 "mmu_notifier_mm %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, 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->mmu_notifier_mm, #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 */