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 int pincount = 0; 83 84 if (folio_has_pincount(folio)) 85 pincount = atomic_read(&folio->_pincount); 86 87 pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", 88 folio_order(folio), 89 folio_mapcount(folio), 90 folio_entire_mapcount(folio), 91 folio_nr_pages_mapped(folio), 92 pincount); 93 } 94 95 #ifdef CONFIG_MEMCG 96 if (folio->memcg_data) 97 pr_warn("memcg:%lx\n", folio->memcg_data); 98 #endif 99 if (folio_test_ksm(folio)) 100 type = "ksm "; 101 else if (folio_test_anon(folio)) 102 type = "anon "; 103 else if (mapping) 104 dump_mapping(mapping); 105 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 106 107 /* 108 * Accessing the pageblock without the zone lock. It could change to 109 * "isolate" again in the meantime, but since we are just dumping the 110 * state for debugging, it should be fine to accept a bit of 111 * inaccuracy here due to racing. 112 */ 113 pr_warn("%sflags: %pGp%s\n", type, &folio->flags, 114 is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); 115 if (page_has_type(&folio->page)) 116 pr_warn("page_type: %x(%s)\n", folio->page.page_type >> 24, 117 page_type_name(folio->page.page_type)); 118 119 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 120 sizeof(unsigned long), page, 121 sizeof(struct page), false); 122 if (folio_test_large(folio)) 123 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, 124 sizeof(unsigned long), folio, 125 2 * sizeof(struct page), false); 126 } 127 128 static void __dump_page(const struct page *page) 129 { 130 struct folio *foliop, folio; 131 struct page precise; 132 unsigned long head; 133 unsigned long pfn = page_to_pfn(page); 134 unsigned long idx, nr_pages = 1; 135 int loops = 5; 136 137 again: 138 memcpy(&precise, page, sizeof(*page)); 139 head = precise.compound_head; 140 if ((head & 1) == 0) { 141 foliop = (struct folio *)&precise; 142 idx = 0; 143 if (!folio_test_large(foliop)) 144 goto dump; 145 foliop = (struct folio *)page; 146 } else { 147 foliop = (struct folio *)(head - 1); 148 idx = folio_page_idx(foliop, page); 149 } 150 151 if (idx < MAX_FOLIO_NR_PAGES) { 152 memcpy(&folio, foliop, 2 * sizeof(struct page)); 153 nr_pages = folio_nr_pages(&folio); 154 if (nr_pages > 1) 155 memcpy(&folio.__page_2, &foliop->__page_2, 156 sizeof(struct page)); 157 foliop = &folio; 158 } 159 160 if (idx > nr_pages) { 161 if (loops-- > 0) 162 goto again; 163 pr_warn("page does not match folio\n"); 164 precise.compound_head &= ~1UL; 165 foliop = (struct folio *)&precise; 166 idx = 0; 167 } 168 169 dump: 170 __dump_folio(foliop, &precise, pfn, idx); 171 } 172 173 void dump_page(const struct page *page, const char *reason) 174 { 175 if (PagePoisoned(page)) 176 pr_warn("page:%p is uninitialized and poisoned\n", page); 177 else 178 __dump_page(page); 179 if (reason) 180 pr_warn("page dumped because: %s\n", reason); 181 dump_page_owner(page); 182 } 183 EXPORT_SYMBOL(dump_page); 184 185 #ifdef CONFIG_DEBUG_VM 186 187 void dump_vma(const struct vm_area_struct *vma) 188 { 189 pr_emerg("vma %px start %px end %px mm %px\n" 190 "prot %lx anon_vma %px vm_ops %px\n" 191 "pgoff %lx file %px private_data %px\n" 192 #ifdef CONFIG_PER_VMA_LOCK 193 "refcnt %x\n" 194 #endif 195 "flags: %#lx(%pGv)\n", 196 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 197 (unsigned long)pgprot_val(vma->vm_page_prot), 198 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 199 vma->vm_file, vma->vm_private_data, 200 #ifdef CONFIG_PER_VMA_LOCK 201 refcount_read(&vma->vm_refcnt), 202 #endif 203 vma->vm_flags, &vma->vm_flags); 204 } 205 EXPORT_SYMBOL(dump_vma); 206 207 void dump_mm(const struct mm_struct *mm) 208 { 209 pr_emerg("mm %px task_size %lu\n" 210 "mmap_base %lu mmap_legacy_base %lu\n" 211 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 212 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 213 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 214 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 215 "start_brk %lx brk %lx start_stack %lx\n" 216 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 217 "binfmt %px flags %lx\n" 218 #ifdef CONFIG_AIO 219 "ioctx_table %px\n" 220 #endif 221 #ifdef CONFIG_MEMCG 222 "owner %px " 223 #endif 224 "exe_file %px\n" 225 #ifdef CONFIG_MMU_NOTIFIER 226 "notifier_subscriptions %px\n" 227 #endif 228 #ifdef CONFIG_NUMA_BALANCING 229 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 230 #endif 231 "tlb_flush_pending %d\n" 232 "def_flags: %#lx(%pGv)\n", 233 234 mm, mm->task_size, 235 mm->mmap_base, mm->mmap_legacy_base, 236 mm->pgd, atomic_read(&mm->mm_users), 237 atomic_read(&mm->mm_count), 238 mm_pgtables_bytes(mm), 239 mm->map_count, 240 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 241 (u64)atomic64_read(&mm->pinned_vm), 242 mm->data_vm, mm->exec_vm, mm->stack_vm, 243 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 244 mm->start_brk, mm->brk, mm->start_stack, 245 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 246 mm->binfmt, mm->flags, 247 #ifdef CONFIG_AIO 248 mm->ioctx_table, 249 #endif 250 #ifdef CONFIG_MEMCG 251 mm->owner, 252 #endif 253 mm->exe_file, 254 #ifdef CONFIG_MMU_NOTIFIER 255 mm->notifier_subscriptions, 256 #endif 257 #ifdef CONFIG_NUMA_BALANCING 258 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 259 #endif 260 atomic_read(&mm->tlb_flush_pending), 261 mm->def_flags, &mm->def_flags 262 ); 263 } 264 EXPORT_SYMBOL(dump_mm); 265 266 void dump_vmg(const struct vma_merge_struct *vmg, const char *reason) 267 { 268 if (reason) 269 pr_warn("vmg %px dumped because: %s\n", vmg, reason); 270 271 if (!vmg) { 272 pr_warn("vmg %px state: (NULL)\n", vmg); 273 return; 274 } 275 276 pr_warn("vmg %px state: mm %px pgoff %lx\n" 277 "vmi %px [%lx,%lx)\n" 278 "prev %px middle %px next %px target %px\n" 279 "start %lx end %lx flags %lx\n" 280 "file %px anon_vma %px policy %px\n" 281 "uffd_ctx %px\n" 282 "anon_name %px\n" 283 "state %x\n" 284 "just_expand %d\n" 285 "__adjust_middle_start %d __adjust_next_start %d\n" 286 "__remove_middle %d __remove_next %d\n", 287 vmg, vmg->mm, vmg->pgoff, 288 vmg->vmi, vmg->vmi ? vma_iter_addr(vmg->vmi) : 0, 289 vmg->vmi ? vma_iter_end(vmg->vmi) : 0, 290 vmg->prev, vmg->middle, vmg->next, vmg->target, 291 vmg->start, vmg->end, vmg->flags, 292 vmg->file, vmg->anon_vma, vmg->policy, 293 #ifdef CONFIG_USERFAULTFD 294 vmg->uffd_ctx.ctx, 295 #else 296 (void *)0, 297 #endif 298 vmg->anon_name, 299 (int)vmg->state, 300 vmg->just_expand, 301 vmg->__adjust_middle_start, vmg->__adjust_next_start, 302 vmg->__remove_middle, vmg->__remove_next); 303 304 if (vmg->mm) { 305 pr_warn("vmg %px mm:\n", vmg); 306 dump_mm(vmg->mm); 307 } else { 308 pr_warn("vmg %px mm: (NULL)\n", vmg); 309 } 310 311 if (vmg->prev) { 312 pr_warn("vmg %px prev:\n", vmg); 313 dump_vma(vmg->prev); 314 } else { 315 pr_warn("vmg %px prev: (NULL)\n", vmg); 316 } 317 318 if (vmg->middle) { 319 pr_warn("vmg %px middle:\n", vmg); 320 dump_vma(vmg->middle); 321 } else { 322 pr_warn("vmg %px middle: (NULL)\n", vmg); 323 } 324 325 if (vmg->next) { 326 pr_warn("vmg %px next:\n", vmg); 327 dump_vma(vmg->next); 328 } else { 329 pr_warn("vmg %px next: (NULL)\n", vmg); 330 } 331 332 #ifdef CONFIG_DEBUG_VM_MAPLE_TREE 333 if (vmg->vmi) { 334 pr_warn("vmg %px vmi:\n", vmg); 335 vma_iter_dump_tree(vmg->vmi); 336 } else { 337 pr_warn("vmg %px vmi: (NULL)\n", vmg); 338 } 339 #endif 340 } 341 EXPORT_SYMBOL(dump_vmg); 342 343 static bool page_init_poisoning __read_mostly = true; 344 345 static int __init setup_vm_debug(char *str) 346 { 347 bool __page_init_poisoning = true; 348 349 /* 350 * Calling vm_debug with no arguments is equivalent to requesting 351 * to enable all debugging options we can control. 352 */ 353 if (*str++ != '=' || !*str) 354 goto out; 355 356 __page_init_poisoning = false; 357 if (*str == '-') 358 goto out; 359 360 while (*str) { 361 switch (tolower(*str)) { 362 case'p': 363 __page_init_poisoning = true; 364 break; 365 default: 366 pr_err("vm_debug option '%c' unknown. skipped\n", 367 *str); 368 } 369 370 str++; 371 } 372 out: 373 if (page_init_poisoning && !__page_init_poisoning) 374 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 375 376 page_init_poisoning = __page_init_poisoning; 377 378 return 1; 379 } 380 __setup("vm_debug", setup_vm_debug); 381 382 void page_init_poison(struct page *page, size_t size) 383 { 384 if (page_init_poisoning) 385 memset(page, PAGE_POISON_PATTERN, size); 386 } 387 388 void vma_iter_dump_tree(const struct vma_iterator *vmi) 389 { 390 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 391 mas_dump(&vmi->mas); 392 mt_dump(vmi->mas.tree, mt_dump_hex); 393 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 394 } 395 396 #endif /* CONFIG_DEBUG_VM */ 397