1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * mm/debug.c 4 * 5 * mm/ specific debug routines. 6 * 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/mm.h> 11 #include <linux/trace_events.h> 12 #include <linux/memcontrol.h> 13 #include <trace/events/mmflags.h> 14 #include <linux/migrate.h> 15 #include <linux/page_owner.h> 16 #include <linux/ctype.h> 17 18 #include "internal.h" 19 20 char *migrate_reason_names[MR_TYPES] = { 21 "compaction", 22 "memory_failure", 23 "memory_hotplug", 24 "syscall_or_cpuset", 25 "mempolicy_mbind", 26 "numa_misplaced", 27 "cma", 28 }; 29 30 const struct trace_print_flags pageflag_names[] = { 31 __def_pageflag_names, 32 {0, NULL} 33 }; 34 35 const struct trace_print_flags gfpflag_names[] = { 36 __def_gfpflag_names, 37 {0, NULL} 38 }; 39 40 const struct trace_print_flags vmaflag_names[] = { 41 __def_vmaflag_names, 42 {0, NULL} 43 }; 44 45 void __dump_page(struct page *page, const char *reason) 46 { 47 bool page_poisoned = PagePoisoned(page); 48 int mapcount; 49 50 /* 51 * If struct page is poisoned don't access Page*() functions as that 52 * leads to recursive loop. Page*() check for poisoned pages, and calls 53 * dump_page() when detected. 54 */ 55 if (page_poisoned) { 56 pr_emerg("page:%px is uninitialized and poisoned", page); 57 goto hex_only; 58 } 59 60 /* 61 * Avoid VM_BUG_ON() in page_mapcount(). 62 * page->_mapcount space in struct page is used by sl[aou]b pages to 63 * encode own info. 64 */ 65 mapcount = PageSlab(page) ? 0 : page_mapcount(page); 66 67 pr_emerg("page:%px count:%d mapcount:%d mapping:%px index:%#lx", 68 page, page_ref_count(page), mapcount, 69 page->mapping, page_to_pgoff(page)); 70 if (PageCompound(page)) 71 pr_cont(" compound_mapcount: %d", compound_mapcount(page)); 72 pr_cont("\n"); 73 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 74 75 pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags); 76 77 hex_only: 78 print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32, 79 sizeof(unsigned long), page, 80 sizeof(struct page), false); 81 82 if (reason) 83 pr_alert("page dumped because: %s\n", reason); 84 85 #ifdef CONFIG_MEMCG 86 if (!page_poisoned && page->mem_cgroup) 87 pr_alert("page->mem_cgroup:%px\n", page->mem_cgroup); 88 #endif 89 } 90 91 void dump_page(struct page *page, const char *reason) 92 { 93 __dump_page(page, reason); 94 dump_page_owner(page); 95 } 96 EXPORT_SYMBOL(dump_page); 97 98 #ifdef CONFIG_DEBUG_VM 99 100 void dump_vma(const struct vm_area_struct *vma) 101 { 102 pr_emerg("vma %px start %px end %px\n" 103 "next %px prev %px mm %px\n" 104 "prot %lx anon_vma %px vm_ops %px\n" 105 "pgoff %lx file %px private_data %px\n" 106 "flags: %#lx(%pGv)\n", 107 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next, 108 vma->vm_prev, vma->vm_mm, 109 (unsigned long)pgprot_val(vma->vm_page_prot), 110 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 111 vma->vm_file, vma->vm_private_data, 112 vma->vm_flags, &vma->vm_flags); 113 } 114 EXPORT_SYMBOL(dump_vma); 115 116 void dump_mm(const struct mm_struct *mm) 117 { 118 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n" 119 #ifdef CONFIG_MMU 120 "get_unmapped_area %px\n" 121 #endif 122 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n" 123 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 124 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 125 "pinned_vm %lx data_vm %lx exec_vm %lx stack_vm %lx\n" 126 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 127 "start_brk %lx brk %lx start_stack %lx\n" 128 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 129 "binfmt %px flags %lx core_state %px\n" 130 #ifdef CONFIG_AIO 131 "ioctx_table %px\n" 132 #endif 133 #ifdef CONFIG_MEMCG 134 "owner %px " 135 #endif 136 "exe_file %px\n" 137 #ifdef CONFIG_MMU_NOTIFIER 138 "mmu_notifier_mm %px\n" 139 #endif 140 #ifdef CONFIG_NUMA_BALANCING 141 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 142 #endif 143 "tlb_flush_pending %d\n" 144 "def_flags: %#lx(%pGv)\n", 145 146 mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size, 147 #ifdef CONFIG_MMU 148 mm->get_unmapped_area, 149 #endif 150 mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end, 151 mm->pgd, atomic_read(&mm->mm_users), 152 atomic_read(&mm->mm_count), 153 mm_pgtables_bytes(mm), 154 mm->map_count, 155 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 156 mm->pinned_vm, mm->data_vm, mm->exec_vm, mm->stack_vm, 157 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 158 mm->start_brk, mm->brk, mm->start_stack, 159 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 160 mm->binfmt, mm->flags, mm->core_state, 161 #ifdef CONFIG_AIO 162 mm->ioctx_table, 163 #endif 164 #ifdef CONFIG_MEMCG 165 mm->owner, 166 #endif 167 mm->exe_file, 168 #ifdef CONFIG_MMU_NOTIFIER 169 mm->mmu_notifier_mm, 170 #endif 171 #ifdef CONFIG_NUMA_BALANCING 172 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 173 #endif 174 atomic_read(&mm->tlb_flush_pending), 175 mm->def_flags, &mm->def_flags 176 ); 177 } 178 179 static bool page_init_poisoning __read_mostly = true; 180 181 static int __init setup_vm_debug(char *str) 182 { 183 bool __page_init_poisoning = true; 184 185 /* 186 * Calling vm_debug with no arguments is equivalent to requesting 187 * to enable all debugging options we can control. 188 */ 189 if (*str++ != '=' || !*str) 190 goto out; 191 192 __page_init_poisoning = false; 193 if (*str == '-') 194 goto out; 195 196 while (*str) { 197 switch (tolower(*str)) { 198 case'p': 199 __page_init_poisoning = true; 200 break; 201 default: 202 pr_err("vm_debug option '%c' unknown. skipped\n", 203 *str); 204 } 205 206 str++; 207 } 208 out: 209 if (page_init_poisoning && !__page_init_poisoning) 210 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 211 212 page_init_poisoning = __page_init_poisoning; 213 214 return 1; 215 } 216 __setup("vm_debug", setup_vm_debug); 217 218 void page_init_poison(struct page *page, size_t size) 219 { 220 if (page_init_poisoning) 221 memset(page, PAGE_POISON_PATTERN, size); 222 } 223 EXPORT_SYMBOL_GPL(page_init_poison); 224 #endif /* CONFIG_DEBUG_VM */ 225