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 = page_mapping(page); 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 /* 62 * Avoid VM_BUG_ON() in page_mapcount(). 63 * page->_mapcount space in struct page is used by sl[aou]b pages to 64 * encode own info. 65 */ 66 mapcount = PageSlab(page) ? 0 : page_mapcount(page); 67 68 pr_warn("page:%px count:%d mapcount:%d mapping:%px index:%#lx", 69 page, page_ref_count(page), mapcount, 70 page->mapping, page_to_pgoff(page)); 71 if (PageCompound(page)) 72 pr_cont(" compound_mapcount: %d", compound_mapcount(page)); 73 pr_cont("\n"); 74 if (PageAnon(page)) 75 pr_warn("anon "); 76 else if (PageKsm(page)) 77 pr_warn("ksm "); 78 else if (mapping) { 79 pr_warn("%ps ", mapping->a_ops); 80 if (mapping->host->i_dentry.first) { 81 struct dentry *dentry; 82 dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias); 83 pr_warn("name:\"%pd\" ", dentry); 84 } 85 } 86 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 87 88 pr_warn("flags: %#lx(%pGp)\n", page->flags, &page->flags); 89 90 hex_only: 91 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 92 sizeof(unsigned long), page, 93 sizeof(struct page), false); 94 95 if (reason) 96 pr_warn("page dumped because: %s\n", reason); 97 98 #ifdef CONFIG_MEMCG 99 if (!page_poisoned && page->mem_cgroup) 100 pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup); 101 #endif 102 } 103 104 void dump_page(struct page *page, const char *reason) 105 { 106 __dump_page(page, reason); 107 dump_page_owner(page); 108 } 109 EXPORT_SYMBOL(dump_page); 110 111 #ifdef CONFIG_DEBUG_VM 112 113 void dump_vma(const struct vm_area_struct *vma) 114 { 115 pr_emerg("vma %px start %px end %px\n" 116 "next %px prev %px mm %px\n" 117 "prot %lx anon_vma %px vm_ops %px\n" 118 "pgoff %lx file %px private_data %px\n" 119 "flags: %#lx(%pGv)\n", 120 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next, 121 vma->vm_prev, vma->vm_mm, 122 (unsigned long)pgprot_val(vma->vm_page_prot), 123 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 124 vma->vm_file, vma->vm_private_data, 125 vma->vm_flags, &vma->vm_flags); 126 } 127 EXPORT_SYMBOL(dump_vma); 128 129 void dump_mm(const struct mm_struct *mm) 130 { 131 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n" 132 #ifdef CONFIG_MMU 133 "get_unmapped_area %px\n" 134 #endif 135 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n" 136 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 137 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 138 "pinned_vm %lx data_vm %lx exec_vm %lx stack_vm %lx\n" 139 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 140 "start_brk %lx brk %lx start_stack %lx\n" 141 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 142 "binfmt %px flags %lx core_state %px\n" 143 #ifdef CONFIG_AIO 144 "ioctx_table %px\n" 145 #endif 146 #ifdef CONFIG_MEMCG 147 "owner %px " 148 #endif 149 "exe_file %px\n" 150 #ifdef CONFIG_MMU_NOTIFIER 151 "mmu_notifier_mm %px\n" 152 #endif 153 #ifdef CONFIG_NUMA_BALANCING 154 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 155 #endif 156 "tlb_flush_pending %d\n" 157 "def_flags: %#lx(%pGv)\n", 158 159 mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size, 160 #ifdef CONFIG_MMU 161 mm->get_unmapped_area, 162 #endif 163 mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end, 164 mm->pgd, atomic_read(&mm->mm_users), 165 atomic_read(&mm->mm_count), 166 mm_pgtables_bytes(mm), 167 mm->map_count, 168 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 169 mm->pinned_vm, mm->data_vm, mm->exec_vm, mm->stack_vm, 170 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 171 mm->start_brk, mm->brk, mm->start_stack, 172 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 173 mm->binfmt, mm->flags, mm->core_state, 174 #ifdef CONFIG_AIO 175 mm->ioctx_table, 176 #endif 177 #ifdef CONFIG_MEMCG 178 mm->owner, 179 #endif 180 mm->exe_file, 181 #ifdef CONFIG_MMU_NOTIFIER 182 mm->mmu_notifier_mm, 183 #endif 184 #ifdef CONFIG_NUMA_BALANCING 185 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 186 #endif 187 atomic_read(&mm->tlb_flush_pending), 188 mm->def_flags, &mm->def_flags 189 ); 190 } 191 192 static bool page_init_poisoning __read_mostly = true; 193 194 static int __init setup_vm_debug(char *str) 195 { 196 bool __page_init_poisoning = true; 197 198 /* 199 * Calling vm_debug with no arguments is equivalent to requesting 200 * to enable all debugging options we can control. 201 */ 202 if (*str++ != '=' || !*str) 203 goto out; 204 205 __page_init_poisoning = false; 206 if (*str == '-') 207 goto out; 208 209 while (*str) { 210 switch (tolower(*str)) { 211 case'p': 212 __page_init_poisoning = true; 213 break; 214 default: 215 pr_err("vm_debug option '%c' unknown. skipped\n", 216 *str); 217 } 218 219 str++; 220 } 221 out: 222 if (page_init_poisoning && !__page_init_poisoning) 223 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 224 225 page_init_poisoning = __page_init_poisoning; 226 227 return 1; 228 } 229 __setup("vm_debug", setup_vm_debug); 230 231 void page_init_poison(struct page *page, size_t size) 232 { 233 if (page_init_poisoning) 234 memset(page, PAGE_POISON_PATTERN, size); 235 } 236 EXPORT_SYMBOL_GPL(page_init_poison); 237 #endif /* CONFIG_DEBUG_VM */ 238