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