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) + 1; 75 char *type = ""; 76 77 if (page_mapcount_is_type(mapcount)) 78 mapcount = 0; 79 80 pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", 81 folio_ref_count(folio), mapcount, mapping, 82 folio->index + idx, pfn); 83 if (folio_test_large(folio)) { 84 int pincount = 0; 85 86 if (folio_has_pincount(folio)) 87 pincount = atomic_read(&folio->_pincount); 88 89 pr_warn("head: order:%u mapcount:%d entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", 90 folio_order(folio), 91 folio_mapcount(folio), 92 folio_entire_mapcount(folio), 93 folio_nr_pages_mapped(folio), 94 pincount); 95 } 96 97 #ifdef CONFIG_MEMCG 98 if (folio->memcg_data) 99 pr_warn("memcg:%lx\n", folio->memcg_data); 100 #endif 101 if (folio_test_ksm(folio)) 102 type = "ksm "; 103 else if (folio_test_anon(folio)) 104 type = "anon "; 105 else if (mapping) 106 dump_mapping(mapping); 107 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 108 109 /* 110 * Accessing the pageblock without the zone lock. It could change to 111 * "isolate" again in the meantime, but since we are just dumping the 112 * state for debugging, it should be fine to accept a bit of 113 * inaccuracy here due to racing. 114 */ 115 pr_warn("%sflags: %pGp%s\n", type, &folio->flags, 116 is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); 117 if (page_has_type(&folio->page)) 118 pr_warn("page_type: %x(%s)\n", folio->page.page_type >> 24, 119 page_type_name(folio->page.page_type)); 120 121 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 122 sizeof(unsigned long), page, 123 sizeof(struct page), false); 124 if (folio_test_large(folio)) 125 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, 126 sizeof(unsigned long), folio, 127 2 * sizeof(struct page), false); 128 } 129 130 static void __dump_page(const struct page *page) 131 { 132 struct folio *foliop, folio; 133 struct page precise; 134 unsigned long head; 135 unsigned long pfn = page_to_pfn(page); 136 unsigned long idx, nr_pages = 1; 137 int loops = 5; 138 139 again: 140 memcpy(&precise, page, sizeof(*page)); 141 head = precise.compound_head; 142 if ((head & 1) == 0) { 143 foliop = (struct folio *)&precise; 144 idx = 0; 145 if (!folio_test_large(foliop)) 146 goto dump; 147 foliop = (struct folio *)page; 148 } else { 149 foliop = (struct folio *)(head - 1); 150 idx = folio_page_idx(foliop, page); 151 } 152 153 if (idx < MAX_FOLIO_NR_PAGES) { 154 memcpy(&folio, foliop, 2 * sizeof(struct page)); 155 nr_pages = folio_nr_pages(&folio); 156 if (nr_pages > 1) 157 memcpy(&folio.__page_2, &foliop->__page_2, 158 sizeof(struct page)); 159 foliop = &folio; 160 } 161 162 if (idx > nr_pages) { 163 if (loops-- > 0) 164 goto again; 165 pr_warn("page does not match folio\n"); 166 precise.compound_head &= ~1UL; 167 foliop = (struct folio *)&precise; 168 idx = 0; 169 } 170 171 dump: 172 __dump_folio(foliop, &precise, pfn, idx); 173 } 174 175 void dump_page(const struct page *page, const char *reason) 176 { 177 if (PagePoisoned(page)) 178 pr_warn("page:%p is uninitialized and poisoned\n", page); 179 else 180 __dump_page(page); 181 if (reason) 182 pr_warn("page dumped because: %s\n", reason); 183 dump_page_owner(page); 184 } 185 EXPORT_SYMBOL(dump_page); 186 187 #ifdef CONFIG_DEBUG_VM 188 189 void dump_vma(const struct vm_area_struct *vma) 190 { 191 pr_emerg("vma %px start %px end %px mm %px\n" 192 "prot %lx anon_vma %px vm_ops %px\n" 193 "pgoff %lx file %px private_data %px\n" 194 #ifdef CONFIG_PER_VMA_LOCK 195 "refcnt %x\n" 196 #endif 197 "flags: %#lx(%pGv)\n", 198 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 199 (unsigned long)pgprot_val(vma->vm_page_prot), 200 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 201 vma->vm_file, vma->vm_private_data, 202 #ifdef CONFIG_PER_VMA_LOCK 203 refcount_read(&vma->vm_refcnt), 204 #endif 205 vma->vm_flags, &vma->vm_flags); 206 } 207 EXPORT_SYMBOL(dump_vma); 208 209 void dump_mm(const struct mm_struct *mm) 210 { 211 pr_emerg("mm %px task_size %lu\n" 212 "mmap_base %lu mmap_legacy_base %lu\n" 213 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 214 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 215 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 216 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 217 "start_brk %lx brk %lx start_stack %lx\n" 218 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 219 "binfmt %px flags %lx\n" 220 #ifdef CONFIG_AIO 221 "ioctx_table %px\n" 222 #endif 223 #ifdef CONFIG_MEMCG 224 "owner %px " 225 #endif 226 "exe_file %px\n" 227 #ifdef CONFIG_MMU_NOTIFIER 228 "notifier_subscriptions %px\n" 229 #endif 230 #ifdef CONFIG_NUMA_BALANCING 231 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 232 #endif 233 "tlb_flush_pending %d\n" 234 "def_flags: %#lx(%pGv)\n", 235 236 mm, mm->task_size, 237 mm->mmap_base, mm->mmap_legacy_base, 238 mm->pgd, atomic_read(&mm->mm_users), 239 atomic_read(&mm->mm_count), 240 mm_pgtables_bytes(mm), 241 mm->map_count, 242 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 243 (u64)atomic64_read(&mm->pinned_vm), 244 mm->data_vm, mm->exec_vm, mm->stack_vm, 245 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 246 mm->start_brk, mm->brk, mm->start_stack, 247 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 248 mm->binfmt, mm->flags, 249 #ifdef CONFIG_AIO 250 mm->ioctx_table, 251 #endif 252 #ifdef CONFIG_MEMCG 253 mm->owner, 254 #endif 255 mm->exe_file, 256 #ifdef CONFIG_MMU_NOTIFIER 257 mm->notifier_subscriptions, 258 #endif 259 #ifdef CONFIG_NUMA_BALANCING 260 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 261 #endif 262 atomic_read(&mm->tlb_flush_pending), 263 mm->def_flags, &mm->def_flags 264 ); 265 } 266 EXPORT_SYMBOL(dump_mm); 267 268 void dump_vmg(const struct vma_merge_struct *vmg, const char *reason) 269 { 270 if (reason) 271 pr_warn("vmg %px dumped because: %s\n", vmg, reason); 272 273 if (!vmg) { 274 pr_warn("vmg %px state: (NULL)\n", vmg); 275 return; 276 } 277 278 pr_warn("vmg %px state: mm %px pgoff %lx\n" 279 "vmi %px [%lx,%lx)\n" 280 "prev %px middle %px next %px target %px\n" 281 "start %lx end %lx flags %lx\n" 282 "file %px anon_vma %px policy %px\n" 283 "uffd_ctx %px\n" 284 "anon_name %px\n" 285 "state %x\n" 286 "just_expand %d\n" 287 "__adjust_middle_start %d __adjust_next_start %d\n" 288 "__remove_middle %d __remove_next %d\n", 289 vmg, vmg->mm, vmg->pgoff, 290 vmg->vmi, vmg->vmi ? vma_iter_addr(vmg->vmi) : 0, 291 vmg->vmi ? vma_iter_end(vmg->vmi) : 0, 292 vmg->prev, vmg->middle, vmg->next, vmg->target, 293 vmg->start, vmg->end, vmg->flags, 294 vmg->file, vmg->anon_vma, vmg->policy, 295 #ifdef CONFIG_USERFAULTFD 296 vmg->uffd_ctx.ctx, 297 #else 298 (void *)0, 299 #endif 300 vmg->anon_name, 301 (int)vmg->state, 302 vmg->just_expand, 303 vmg->__adjust_middle_start, vmg->__adjust_next_start, 304 vmg->__remove_middle, vmg->__remove_next); 305 306 if (vmg->mm) { 307 pr_warn("vmg %px mm:\n", vmg); 308 dump_mm(vmg->mm); 309 } else { 310 pr_warn("vmg %px mm: (NULL)\n", vmg); 311 } 312 313 if (vmg->prev) { 314 pr_warn("vmg %px prev:\n", vmg); 315 dump_vma(vmg->prev); 316 } else { 317 pr_warn("vmg %px prev: (NULL)\n", vmg); 318 } 319 320 if (vmg->middle) { 321 pr_warn("vmg %px middle:\n", vmg); 322 dump_vma(vmg->middle); 323 } else { 324 pr_warn("vmg %px middle: (NULL)\n", vmg); 325 } 326 327 if (vmg->next) { 328 pr_warn("vmg %px next:\n", vmg); 329 dump_vma(vmg->next); 330 } else { 331 pr_warn("vmg %px next: (NULL)\n", vmg); 332 } 333 334 #ifdef CONFIG_DEBUG_VM_MAPLE_TREE 335 if (vmg->vmi) { 336 pr_warn("vmg %px vmi:\n", vmg); 337 vma_iter_dump_tree(vmg->vmi); 338 } else { 339 pr_warn("vmg %px vmi: (NULL)\n", vmg); 340 } 341 #endif 342 } 343 EXPORT_SYMBOL(dump_vmg); 344 345 static bool page_init_poisoning __read_mostly = true; 346 347 static int __init setup_vm_debug(char *str) 348 { 349 bool __page_init_poisoning = true; 350 351 /* 352 * Calling vm_debug with no arguments is equivalent to requesting 353 * to enable all debugging options we can control. 354 */ 355 if (*str++ != '=' || !*str) 356 goto out; 357 358 __page_init_poisoning = false; 359 if (*str == '-') 360 goto out; 361 362 while (*str) { 363 switch (tolower(*str)) { 364 case'p': 365 __page_init_poisoning = true; 366 break; 367 default: 368 pr_err("vm_debug option '%c' unknown. skipped\n", 369 *str); 370 } 371 372 str++; 373 } 374 out: 375 if (page_init_poisoning && !__page_init_poisoning) 376 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 377 378 page_init_poisoning = __page_init_poisoning; 379 380 return 1; 381 } 382 __setup("vm_debug", setup_vm_debug); 383 384 void page_init_poison(struct page *page, size_t size) 385 { 386 if (page_init_poisoning) 387 memset(page, PAGE_POISON_PATTERN, size); 388 } 389 390 void vma_iter_dump_tree(const struct vma_iterator *vmi) 391 { 392 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 393 mas_dump(&vmi->mas); 394 mt_dump(vmi->mas.tree, mt_dump_hex); 395 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 396 } 397 398 #endif /* CONFIG_DEBUG_VM */ 399