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 const 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 struct address_space *mapping; 48 bool page_poisoned = PagePoisoned(page); 49 int mapcount; 50 char *type = ""; 51 52 /* 53 * If struct page is poisoned don't access Page*() functions as that 54 * leads to recursive loop. Page*() check for poisoned pages, and calls 55 * dump_page() when detected. 56 */ 57 if (page_poisoned) { 58 pr_warn("page:%px is uninitialized and poisoned", page); 59 goto hex_only; 60 } 61 62 mapping = page_mapping(page); 63 64 /* 65 * Avoid VM_BUG_ON() in page_mapcount(). 66 * page->_mapcount space in struct page is used by sl[aou]b pages to 67 * encode own info. 68 */ 69 mapcount = PageSlab(page) ? 0 : page_mapcount(page); 70 71 if (PageCompound(page)) 72 pr_warn("page:%px refcount:%d mapcount:%d mapping:%px " 73 "index:%#lx compound_mapcount: %d\n", 74 page, page_ref_count(page), mapcount, 75 page->mapping, page_to_pgoff(page), 76 compound_mapcount(page)); 77 else 78 pr_warn("page:%px refcount:%d mapcount:%d mapping:%px index:%#lx\n", 79 page, page_ref_count(page), mapcount, 80 page->mapping, page_to_pgoff(page)); 81 if (PageKsm(page)) 82 type = "ksm "; 83 else if (PageAnon(page)) 84 type = "anon "; 85 else if (mapping) { 86 if (mapping->host && mapping->host->i_dentry.first) { 87 struct dentry *dentry; 88 dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias); 89 pr_warn("%ps name:\"%pd\"\n", mapping->a_ops, dentry); 90 } else 91 pr_warn("%ps\n", mapping->a_ops); 92 } 93 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 94 95 pr_warn("%sflags: %#lx(%pGp)\n", type, page->flags, &page->flags); 96 97 hex_only: 98 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 99 sizeof(unsigned long), page, 100 sizeof(struct page), false); 101 102 if (reason) 103 pr_warn("page dumped because: %s\n", reason); 104 105 #ifdef CONFIG_MEMCG 106 if (!page_poisoned && page->mem_cgroup) 107 pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup); 108 #endif 109 } 110 111 void dump_page(struct page *page, const char *reason) 112 { 113 __dump_page(page, reason); 114 dump_page_owner(page); 115 } 116 EXPORT_SYMBOL(dump_page); 117 118 #ifdef CONFIG_DEBUG_VM 119 120 void dump_vma(const struct vm_area_struct *vma) 121 { 122 pr_emerg("vma %px start %px end %px\n" 123 "next %px prev %px mm %px\n" 124 "prot %lx anon_vma %px vm_ops %px\n" 125 "pgoff %lx file %px private_data %px\n" 126 "flags: %#lx(%pGv)\n", 127 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next, 128 vma->vm_prev, vma->vm_mm, 129 (unsigned long)pgprot_val(vma->vm_page_prot), 130 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 131 vma->vm_file, vma->vm_private_data, 132 vma->vm_flags, &vma->vm_flags); 133 } 134 EXPORT_SYMBOL(dump_vma); 135 136 void dump_mm(const struct mm_struct *mm) 137 { 138 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n" 139 #ifdef CONFIG_MMU 140 "get_unmapped_area %px\n" 141 #endif 142 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n" 143 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 144 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 145 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 146 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 147 "start_brk %lx brk %lx start_stack %lx\n" 148 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 149 "binfmt %px flags %lx core_state %px\n" 150 #ifdef CONFIG_AIO 151 "ioctx_table %px\n" 152 #endif 153 #ifdef CONFIG_MEMCG 154 "owner %px " 155 #endif 156 "exe_file %px\n" 157 #ifdef CONFIG_MMU_NOTIFIER 158 "notifier_subscriptions %px\n" 159 #endif 160 #ifdef CONFIG_NUMA_BALANCING 161 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 162 #endif 163 "tlb_flush_pending %d\n" 164 "def_flags: %#lx(%pGv)\n", 165 166 mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size, 167 #ifdef CONFIG_MMU 168 mm->get_unmapped_area, 169 #endif 170 mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end, 171 mm->pgd, atomic_read(&mm->mm_users), 172 atomic_read(&mm->mm_count), 173 mm_pgtables_bytes(mm), 174 mm->map_count, 175 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 176 (u64)atomic64_read(&mm->pinned_vm), 177 mm->data_vm, mm->exec_vm, mm->stack_vm, 178 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 179 mm->start_brk, mm->brk, mm->start_stack, 180 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 181 mm->binfmt, mm->flags, mm->core_state, 182 #ifdef CONFIG_AIO 183 mm->ioctx_table, 184 #endif 185 #ifdef CONFIG_MEMCG 186 mm->owner, 187 #endif 188 mm->exe_file, 189 #ifdef CONFIG_MMU_NOTIFIER 190 mm->notifier_subscriptions, 191 #endif 192 #ifdef CONFIG_NUMA_BALANCING 193 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 194 #endif 195 atomic_read(&mm->tlb_flush_pending), 196 mm->def_flags, &mm->def_flags 197 ); 198 } 199 200 static bool page_init_poisoning __read_mostly = true; 201 202 static int __init setup_vm_debug(char *str) 203 { 204 bool __page_init_poisoning = true; 205 206 /* 207 * Calling vm_debug with no arguments is equivalent to requesting 208 * to enable all debugging options we can control. 209 */ 210 if (*str++ != '=' || !*str) 211 goto out; 212 213 __page_init_poisoning = false; 214 if (*str == '-') 215 goto out; 216 217 while (*str) { 218 switch (tolower(*str)) { 219 case'p': 220 __page_init_poisoning = true; 221 break; 222 default: 223 pr_err("vm_debug option '%c' unknown. skipped\n", 224 *str); 225 } 226 227 str++; 228 } 229 out: 230 if (page_init_poisoning && !__page_init_poisoning) 231 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 232 233 page_init_poisoning = __page_init_poisoning; 234 235 return 1; 236 } 237 __setup("vm_debug", setup_vm_debug); 238 239 void page_init_poison(struct page *page, size_t size) 240 { 241 if (page_init_poisoning) 242 memset(page, PAGE_POISON_PATTERN, size); 243 } 244 EXPORT_SYMBOL_GPL(page_init_poison); 245 #endif /* CONFIG_DEBUG_VM */ 246