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 #include <trace/events/migrate.h> 20 21 /* 22 * Define EM() and EMe() so that MIGRATE_REASON from trace/events/migrate.h can 23 * be used to populate migrate_reason_names[]. 24 */ 25 #undef EM 26 #undef EMe 27 #define EM(a, b) b, 28 #define EMe(a, b) b 29 30 const char *migrate_reason_names[MR_TYPES] = { 31 MIGRATE_REASON 32 }; 33 34 const struct trace_print_flags pageflag_names[] = { 35 __def_pageflag_names, 36 {0, NULL} 37 }; 38 39 const struct trace_print_flags pagetype_names[] = { 40 __def_pagetype_names, 41 {0, NULL} 42 }; 43 44 const struct trace_print_flags gfpflag_names[] = { 45 __def_gfpflag_names, 46 {0, NULL} 47 }; 48 49 const struct trace_print_flags vmaflag_names[] = { 50 __def_vmaflag_names, 51 {0, NULL} 52 }; 53 54 static void __dump_folio(struct folio *folio, struct page *page, 55 unsigned long pfn, unsigned long idx) 56 { 57 struct address_space *mapping = folio_mapping(folio); 58 int mapcount = atomic_read(&page->_mapcount); 59 char *type = ""; 60 61 mapcount = page_type_has_type(mapcount) ? 0 : mapcount + 1; 62 pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", 63 folio_ref_count(folio), mapcount, mapping, 64 folio->index + idx, pfn); 65 if (folio_test_large(folio)) { 66 pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", 67 folio_order(folio), 68 folio_mapcount(folio), 69 folio_entire_mapcount(folio), 70 folio_nr_pages_mapped(folio), 71 atomic_read(&folio->_pincount)); 72 } 73 74 #ifdef CONFIG_MEMCG 75 if (folio->memcg_data) 76 pr_warn("memcg:%lx\n", folio->memcg_data); 77 #endif 78 if (folio_test_ksm(folio)) 79 type = "ksm "; 80 else if (folio_test_anon(folio)) 81 type = "anon "; 82 else if (mapping) 83 dump_mapping(mapping); 84 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 85 86 /* 87 * Accessing the pageblock without the zone lock. It could change to 88 * "isolate" again in the meantime, but since we are just dumping the 89 * state for debugging, it should be fine to accept a bit of 90 * inaccuracy here due to racing. 91 */ 92 pr_warn("%sflags: %pGp%s\n", type, &folio->flags, 93 is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); 94 if (page_has_type(&folio->page)) 95 pr_warn("page_type: %pGt\n", &folio->page.page_type); 96 97 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 98 sizeof(unsigned long), page, 99 sizeof(struct page), false); 100 if (folio_test_large(folio)) 101 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, 102 sizeof(unsigned long), folio, 103 2 * sizeof(struct page), false); 104 } 105 106 static void __dump_page(const struct page *page) 107 { 108 struct folio *foliop, folio; 109 struct page precise; 110 unsigned long pfn = page_to_pfn(page); 111 unsigned long idx, nr_pages = 1; 112 int loops = 5; 113 114 again: 115 memcpy(&precise, page, sizeof(*page)); 116 foliop = page_folio(&precise); 117 if (foliop == (struct folio *)&precise) { 118 idx = 0; 119 if (!folio_test_large(foliop)) 120 goto dump; 121 foliop = (struct folio *)page; 122 } else { 123 idx = folio_page_idx(foliop, page); 124 } 125 126 if (idx < MAX_FOLIO_NR_PAGES) { 127 memcpy(&folio, foliop, 2 * sizeof(struct page)); 128 nr_pages = folio_nr_pages(&folio); 129 foliop = &folio; 130 } 131 132 if (idx > nr_pages) { 133 if (loops-- > 0) 134 goto again; 135 pr_warn("page does not match folio\n"); 136 precise.compound_head &= ~1UL; 137 foliop = (struct folio *)&precise; 138 idx = 0; 139 } 140 141 dump: 142 __dump_folio(foliop, &precise, pfn, idx); 143 } 144 145 void dump_page(const struct page *page, const char *reason) 146 { 147 if (PagePoisoned(page)) 148 pr_warn("page:%p is uninitialized and poisoned", page); 149 else 150 __dump_page(page); 151 if (reason) 152 pr_warn("page dumped because: %s\n", reason); 153 dump_page_owner(page); 154 } 155 EXPORT_SYMBOL(dump_page); 156 157 #ifdef CONFIG_DEBUG_VM 158 159 void dump_vma(const struct vm_area_struct *vma) 160 { 161 pr_emerg("vma %px start %px end %px mm %px\n" 162 "prot %lx anon_vma %px vm_ops %px\n" 163 "pgoff %lx file %px private_data %px\n" 164 "flags: %#lx(%pGv)\n", 165 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 166 (unsigned long)pgprot_val(vma->vm_page_prot), 167 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 168 vma->vm_file, vma->vm_private_data, 169 vma->vm_flags, &vma->vm_flags); 170 } 171 EXPORT_SYMBOL(dump_vma); 172 173 void dump_mm(const struct mm_struct *mm) 174 { 175 pr_emerg("mm %px task_size %lu\n" 176 "mmap_base %lu mmap_legacy_base %lu\n" 177 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 178 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 179 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 180 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 181 "start_brk %lx brk %lx start_stack %lx\n" 182 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 183 "binfmt %px flags %lx\n" 184 #ifdef CONFIG_AIO 185 "ioctx_table %px\n" 186 #endif 187 #ifdef CONFIG_MEMCG 188 "owner %px " 189 #endif 190 "exe_file %px\n" 191 #ifdef CONFIG_MMU_NOTIFIER 192 "notifier_subscriptions %px\n" 193 #endif 194 #ifdef CONFIG_NUMA_BALANCING 195 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 196 #endif 197 "tlb_flush_pending %d\n" 198 "def_flags: %#lx(%pGv)\n", 199 200 mm, mm->task_size, 201 mm->mmap_base, mm->mmap_legacy_base, 202 mm->pgd, atomic_read(&mm->mm_users), 203 atomic_read(&mm->mm_count), 204 mm_pgtables_bytes(mm), 205 mm->map_count, 206 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 207 (u64)atomic64_read(&mm->pinned_vm), 208 mm->data_vm, mm->exec_vm, mm->stack_vm, 209 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 210 mm->start_brk, mm->brk, mm->start_stack, 211 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 212 mm->binfmt, mm->flags, 213 #ifdef CONFIG_AIO 214 mm->ioctx_table, 215 #endif 216 #ifdef CONFIG_MEMCG 217 mm->owner, 218 #endif 219 mm->exe_file, 220 #ifdef CONFIG_MMU_NOTIFIER 221 mm->notifier_subscriptions, 222 #endif 223 #ifdef CONFIG_NUMA_BALANCING 224 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 225 #endif 226 atomic_read(&mm->tlb_flush_pending), 227 mm->def_flags, &mm->def_flags 228 ); 229 } 230 EXPORT_SYMBOL(dump_mm); 231 232 static bool page_init_poisoning __read_mostly = true; 233 234 static int __init setup_vm_debug(char *str) 235 { 236 bool __page_init_poisoning = true; 237 238 /* 239 * Calling vm_debug with no arguments is equivalent to requesting 240 * to enable all debugging options we can control. 241 */ 242 if (*str++ != '=' || !*str) 243 goto out; 244 245 __page_init_poisoning = false; 246 if (*str == '-') 247 goto out; 248 249 while (*str) { 250 switch (tolower(*str)) { 251 case'p': 252 __page_init_poisoning = true; 253 break; 254 default: 255 pr_err("vm_debug option '%c' unknown. skipped\n", 256 *str); 257 } 258 259 str++; 260 } 261 out: 262 if (page_init_poisoning && !__page_init_poisoning) 263 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 264 265 page_init_poisoning = __page_init_poisoning; 266 267 return 1; 268 } 269 __setup("vm_debug", setup_vm_debug); 270 271 void page_init_poison(struct page *page, size_t size) 272 { 273 if (page_init_poisoning) 274 memset(page, PAGE_POISON_PATTERN, size); 275 } 276 277 void vma_iter_dump_tree(const struct vma_iterator *vmi) 278 { 279 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 280 mas_dump(&vmi->mas); 281 mt_dump(vmi->mas.tree, mt_dump_hex); 282 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 283 } 284 285 #endif /* CONFIG_DEBUG_VM */ 286