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 gfpflag_names[] = { 40 __def_gfpflag_names, 41 {0, NULL} 42 }; 43 44 const struct trace_print_flags vmaflag_names[] = { 45 __def_vmaflag_names, 46 {0, NULL} 47 }; 48 49 #define DEF_PAGETYPE_NAME(_name) [PGTY_##_name - 0xf0] = __stringify(_name) 50 51 static const char *page_type_names[] = { 52 DEF_PAGETYPE_NAME(slab), 53 DEF_PAGETYPE_NAME(hugetlb), 54 DEF_PAGETYPE_NAME(offline), 55 DEF_PAGETYPE_NAME(guard), 56 DEF_PAGETYPE_NAME(table), 57 DEF_PAGETYPE_NAME(buddy), 58 DEF_PAGETYPE_NAME(unaccepted), 59 }; 60 61 static const char *page_type_name(unsigned int page_type) 62 { 63 unsigned i = (page_type >> 24) - 0xf0; 64 65 if (i >= ARRAY_SIZE(page_type_names)) 66 return "unknown"; 67 return page_type_names[i]; 68 } 69 70 static void __dump_folio(struct folio *folio, struct page *page, 71 unsigned long pfn, unsigned long idx) 72 { 73 struct address_space *mapping = folio_mapping(folio); 74 int mapcount = atomic_read(&page->_mapcount); 75 char *type = ""; 76 77 mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1; 78 pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", 79 folio_ref_count(folio), mapcount, mapping, 80 folio->index + idx, pfn); 81 if (folio_test_large(folio)) { 82 pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", 83 folio_order(folio), 84 folio_mapcount(folio), 85 folio_entire_mapcount(folio), 86 folio_nr_pages_mapped(folio), 87 atomic_read(&folio->_pincount)); 88 } 89 90 #ifdef CONFIG_MEMCG 91 if (folio->memcg_data) 92 pr_warn("memcg:%lx\n", folio->memcg_data); 93 #endif 94 if (folio_test_ksm(folio)) 95 type = "ksm "; 96 else if (folio_test_anon(folio)) 97 type = "anon "; 98 else if (mapping) 99 dump_mapping(mapping); 100 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 101 102 /* 103 * Accessing the pageblock without the zone lock. It could change to 104 * "isolate" again in the meantime, but since we are just dumping the 105 * state for debugging, it should be fine to accept a bit of 106 * inaccuracy here due to racing. 107 */ 108 pr_warn("%sflags: %pGp%s\n", type, &folio->flags, 109 is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); 110 if (page_has_type(&folio->page)) 111 pr_warn("page_type: %x(%s)\n", folio->page.page_type >> 24, 112 page_type_name(folio->page.page_type)); 113 114 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 115 sizeof(unsigned long), page, 116 sizeof(struct page), false); 117 if (folio_test_large(folio)) 118 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, 119 sizeof(unsigned long), folio, 120 2 * sizeof(struct page), false); 121 } 122 123 static void __dump_page(const struct page *page) 124 { 125 struct folio *foliop, folio; 126 struct page precise; 127 unsigned long head; 128 unsigned long pfn = page_to_pfn(page); 129 unsigned long idx, nr_pages = 1; 130 int loops = 5; 131 132 again: 133 memcpy(&precise, page, sizeof(*page)); 134 head = precise.compound_head; 135 if ((head & 1) == 0) { 136 foliop = (struct folio *)&precise; 137 idx = 0; 138 if (!folio_test_large(foliop)) 139 goto dump; 140 foliop = (struct folio *)page; 141 } else { 142 foliop = (struct folio *)(head - 1); 143 idx = folio_page_idx(foliop, page); 144 } 145 146 if (idx < MAX_FOLIO_NR_PAGES) { 147 memcpy(&folio, foliop, 2 * sizeof(struct page)); 148 nr_pages = folio_nr_pages(&folio); 149 foliop = &folio; 150 } 151 152 if (idx > nr_pages) { 153 if (loops-- > 0) 154 goto again; 155 pr_warn("page does not match folio\n"); 156 precise.compound_head &= ~1UL; 157 foliop = (struct folio *)&precise; 158 idx = 0; 159 } 160 161 dump: 162 __dump_folio(foliop, &precise, pfn, idx); 163 } 164 165 void dump_page(const struct page *page, const char *reason) 166 { 167 if (PagePoisoned(page)) 168 pr_warn("page:%p is uninitialized and poisoned", page); 169 else 170 __dump_page(page); 171 if (reason) 172 pr_warn("page dumped because: %s\n", reason); 173 dump_page_owner(page); 174 } 175 EXPORT_SYMBOL(dump_page); 176 177 #ifdef CONFIG_DEBUG_VM 178 179 void dump_vma(const struct vm_area_struct *vma) 180 { 181 pr_emerg("vma %px start %px end %px mm %px\n" 182 "prot %lx anon_vma %px vm_ops %px\n" 183 "pgoff %lx file %px private_data %px\n" 184 "flags: %#lx(%pGv)\n", 185 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 186 (unsigned long)pgprot_val(vma->vm_page_prot), 187 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 188 vma->vm_file, vma->vm_private_data, 189 vma->vm_flags, &vma->vm_flags); 190 } 191 EXPORT_SYMBOL(dump_vma); 192 193 void dump_mm(const struct mm_struct *mm) 194 { 195 pr_emerg("mm %px task_size %lu\n" 196 "mmap_base %lu mmap_legacy_base %lu\n" 197 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 198 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 199 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 200 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 201 "start_brk %lx brk %lx start_stack %lx\n" 202 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 203 "binfmt %px flags %lx\n" 204 #ifdef CONFIG_AIO 205 "ioctx_table %px\n" 206 #endif 207 #ifdef CONFIG_MEMCG 208 "owner %px " 209 #endif 210 "exe_file %px\n" 211 #ifdef CONFIG_MMU_NOTIFIER 212 "notifier_subscriptions %px\n" 213 #endif 214 #ifdef CONFIG_NUMA_BALANCING 215 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 216 #endif 217 "tlb_flush_pending %d\n" 218 "def_flags: %#lx(%pGv)\n", 219 220 mm, mm->task_size, 221 mm->mmap_base, mm->mmap_legacy_base, 222 mm->pgd, atomic_read(&mm->mm_users), 223 atomic_read(&mm->mm_count), 224 mm_pgtables_bytes(mm), 225 mm->map_count, 226 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 227 (u64)atomic64_read(&mm->pinned_vm), 228 mm->data_vm, mm->exec_vm, mm->stack_vm, 229 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 230 mm->start_brk, mm->brk, mm->start_stack, 231 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 232 mm->binfmt, mm->flags, 233 #ifdef CONFIG_AIO 234 mm->ioctx_table, 235 #endif 236 #ifdef CONFIG_MEMCG 237 mm->owner, 238 #endif 239 mm->exe_file, 240 #ifdef CONFIG_MMU_NOTIFIER 241 mm->notifier_subscriptions, 242 #endif 243 #ifdef CONFIG_NUMA_BALANCING 244 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 245 #endif 246 atomic_read(&mm->tlb_flush_pending), 247 mm->def_flags, &mm->def_flags 248 ); 249 } 250 EXPORT_SYMBOL(dump_mm); 251 252 void dump_vmg(const struct vma_merge_struct *vmg, const char *reason) 253 { 254 if (reason) 255 pr_warn("vmg %px dumped because: %s\n", vmg, reason); 256 257 if (!vmg) { 258 pr_warn("vmg %px state: (NULL)\n", vmg); 259 return; 260 } 261 262 pr_warn("vmg %px state: mm %px pgoff %lx\n" 263 "vmi %px [%lx,%lx)\n" 264 "prev %px next %px vma %px\n" 265 "start %lx end %lx flags %lx\n" 266 "file %px anon_vma %px policy %px\n" 267 "uffd_ctx %px\n" 268 "anon_name %px\n" 269 "merge_flags %x state %x\n", 270 vmg, vmg->mm, vmg->pgoff, 271 vmg->vmi, vmg->vmi ? vma_iter_addr(vmg->vmi) : 0, 272 vmg->vmi ? vma_iter_end(vmg->vmi) : 0, 273 vmg->prev, vmg->next, vmg->vma, 274 vmg->start, vmg->end, vmg->flags, 275 vmg->file, vmg->anon_vma, vmg->policy, 276 #ifdef CONFIG_USERFAULTFD 277 vmg->uffd_ctx.ctx, 278 #else 279 (void *)0, 280 #endif 281 vmg->anon_name, 282 (int)vmg->merge_flags, (int)vmg->state); 283 284 if (vmg->mm) { 285 pr_warn("vmg %px mm:\n", vmg); 286 dump_mm(vmg->mm); 287 } else { 288 pr_warn("vmg %px mm: (NULL)\n", vmg); 289 } 290 291 if (vmg->vma) { 292 pr_warn("vmg %px vma:\n", vmg); 293 dump_vma(vmg->vma); 294 } else { 295 pr_warn("vmg %px vma: (NULL)\n", vmg); 296 } 297 298 if (vmg->prev) { 299 pr_warn("vmg %px prev:\n", vmg); 300 dump_vma(vmg->prev); 301 } else { 302 pr_warn("vmg %px prev: (NULL)\n", vmg); 303 } 304 305 if (vmg->next) { 306 pr_warn("vmg %px next:\n", vmg); 307 dump_vma(vmg->next); 308 } else { 309 pr_warn("vmg %px next: (NULL)\n", vmg); 310 } 311 312 #ifdef CONFIG_DEBUG_VM_MAPLE_TREE 313 if (vmg->vmi) { 314 pr_warn("vmg %px vmi:\n", vmg); 315 vma_iter_dump_tree(vmg->vmi); 316 } else { 317 pr_warn("vmg %px vmi: (NULL)\n", vmg); 318 } 319 #endif 320 } 321 EXPORT_SYMBOL(dump_vmg); 322 323 static bool page_init_poisoning __read_mostly = true; 324 325 static int __init setup_vm_debug(char *str) 326 { 327 bool __page_init_poisoning = true; 328 329 /* 330 * Calling vm_debug with no arguments is equivalent to requesting 331 * to enable all debugging options we can control. 332 */ 333 if (*str++ != '=' || !*str) 334 goto out; 335 336 __page_init_poisoning = false; 337 if (*str == '-') 338 goto out; 339 340 while (*str) { 341 switch (tolower(*str)) { 342 case'p': 343 __page_init_poisoning = true; 344 break; 345 default: 346 pr_err("vm_debug option '%c' unknown. skipped\n", 347 *str); 348 } 349 350 str++; 351 } 352 out: 353 if (page_init_poisoning && !__page_init_poisoning) 354 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 355 356 page_init_poisoning = __page_init_poisoning; 357 358 return 1; 359 } 360 __setup("vm_debug", setup_vm_debug); 361 362 void page_init_poison(struct page *page, size_t size) 363 { 364 if (page_init_poisoning) 365 memset(page, PAGE_POISON_PATTERN, size); 366 } 367 368 void vma_iter_dump_tree(const struct vma_iterator *vmi) 369 { 370 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 371 mas_dump(&vmi->mas); 372 mt_dump(vmi->mas.tree, mt_dump_hex); 373 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 374 } 375 376 #endif /* CONFIG_DEBUG_VM */ 377