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(const struct folio *folio, const 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 page_snapshot ps; 133 134 snapshot_page(&ps, page); 135 if (!snapshot_page_is_faithful(&ps)) 136 pr_warn("page does not match folio\n"); 137 138 __dump_folio(&ps.folio_snapshot, &ps.page_snapshot, ps.pfn, ps.idx); 139 } 140 141 void dump_page(const struct page *page, const char *reason) 142 { 143 if (PagePoisoned(page)) 144 pr_warn("page:%p is uninitialized and poisoned\n", page); 145 else 146 __dump_page(page); 147 if (reason) 148 pr_warn("page dumped because: %s\n", reason); 149 dump_page_owner(page); 150 } 151 EXPORT_SYMBOL(dump_page); 152 153 #ifdef CONFIG_DEBUG_VM 154 155 void dump_vma(const struct vm_area_struct *vma) 156 { 157 pr_emerg("vma %px start %px end %px mm %px\n" 158 "prot %lx anon_vma %px vm_ops %px\n" 159 "pgoff %lx file %px private_data %px\n" 160 #ifdef CONFIG_PER_VMA_LOCK 161 "refcnt %x\n" 162 #endif 163 "flags: %#lx(%pGv)\n", 164 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 165 (unsigned long)pgprot_val(vma->vm_page_prot), 166 vma->anon_vma, vma->vm_ops, vma_start_pgoff(vma), 167 vma->vm_file, vma->vm_private_data, 168 #ifdef CONFIG_PER_VMA_LOCK 169 refcount_read(&vma->vm_refcnt), 170 #endif 171 vma->vm_flags, &vma->vm_flags); 172 } 173 EXPORT_SYMBOL(dump_vma); 174 175 void dump_mm(const struct mm_struct *mm) 176 { 177 pr_emerg("mm %px task_size %lu\n" 178 "mmap_base %lu mmap_legacy_base %lu\n" 179 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 180 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 181 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 182 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 183 "start_brk %lx brk %lx start_stack %lx\n" 184 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 185 "binfmt %px flags %*pb\n" 186 #ifdef CONFIG_AIO 187 "ioctx_table %px\n" 188 #endif 189 #ifdef CONFIG_MEMCG 190 "owner %px " 191 #endif 192 "exe_file %px\n" 193 #ifdef CONFIG_MMU_NOTIFIER 194 "notifier_subscriptions %px\n" 195 #endif 196 #ifdef CONFIG_NUMA_BALANCING 197 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 198 #endif 199 "tlb_flush_pending %d\n" 200 "def_flags: %*pb(%pGv)\n", 201 202 mm, mm->task_size, 203 mm->mmap_base, mm->mmap_legacy_base, 204 mm->pgd, atomic_read(&mm->mm_users), 205 atomic_read(&mm->mm_count), 206 mm_pgtables_bytes(mm), 207 mm->map_count, 208 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 209 (u64)atomic64_read(&mm->pinned_vm), 210 mm->data_vm, mm->exec_vm, mm->stack_vm, 211 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 212 mm->start_brk, mm->brk, mm->start_stack, 213 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 214 mm->binfmt, NUM_MM_FLAG_BITS, __mm_flags_get_bitmap(mm), 215 #ifdef CONFIG_AIO 216 mm->ioctx_table, 217 #endif 218 #ifdef CONFIG_MEMCG 219 mm->owner, 220 #endif 221 mm->exe_file, 222 #ifdef CONFIG_MMU_NOTIFIER 223 mm->notifier_subscriptions, 224 #endif 225 #ifdef CONFIG_NUMA_BALANCING 226 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 227 #endif 228 atomic_read(&mm->tlb_flush_pending), 229 NUM_VMA_FLAG_BITS, mm->def_vma_flags.__vma_flags, 230 &mm->def_vma_flags 231 ); 232 } 233 EXPORT_SYMBOL(dump_mm); 234 235 void dump_vmg(const struct vma_merge_struct *vmg, const char *reason) 236 { 237 if (reason) 238 pr_warn("vmg %px dumped because: %s\n", vmg, reason); 239 240 if (!vmg) { 241 pr_warn("vmg %px state: (NULL)\n", vmg); 242 return; 243 } 244 245 pr_warn("vmg %px state: mm %px pgoff %lx\n" 246 "vmi %px [%lx,%lx)\n" 247 "prev %px middle %px next %px target %px\n" 248 "start %lx end %lx flags %lx\n" 249 "file %px anon_vma %px policy %px\n" 250 "uffd_ctx %px\n" 251 "anon_name %px\n" 252 "state %x\n" 253 "just_expand %d\n" 254 "__adjust_middle_start %d __adjust_next_start %d\n" 255 "__remove_middle %d __remove_next %d\n", 256 vmg, vmg->mm, vmg->pgoff, 257 vmg->vmi, vmg->vmi ? vma_iter_addr(vmg->vmi) : 0, 258 vmg->vmi ? vma_iter_end(vmg->vmi) : 0, 259 vmg->prev, vmg->middle, vmg->next, vmg->target, 260 vmg->start, vmg->end, vmg->vm_flags, 261 vmg->file, vmg->anon_vma, vmg->policy, 262 #ifdef CONFIG_USERFAULTFD 263 vmg->uffd_ctx.ctx, 264 #else 265 (void *)0, 266 #endif 267 vmg->anon_name, 268 (int)vmg->state, 269 vmg->just_expand, 270 vmg->__adjust_middle_start, vmg->__adjust_next_start, 271 vmg->__remove_middle, vmg->__remove_next); 272 273 if (vmg->mm) { 274 pr_warn("vmg %px mm:\n", vmg); 275 dump_mm(vmg->mm); 276 } else { 277 pr_warn("vmg %px mm: (NULL)\n", vmg); 278 } 279 280 if (vmg->prev) { 281 pr_warn("vmg %px prev:\n", vmg); 282 dump_vma(vmg->prev); 283 } else { 284 pr_warn("vmg %px prev: (NULL)\n", vmg); 285 } 286 287 if (vmg->middle) { 288 pr_warn("vmg %px middle:\n", vmg); 289 dump_vma(vmg->middle); 290 } else { 291 pr_warn("vmg %px middle: (NULL)\n", vmg); 292 } 293 294 if (vmg->next) { 295 pr_warn("vmg %px next:\n", vmg); 296 dump_vma(vmg->next); 297 } else { 298 pr_warn("vmg %px next: (NULL)\n", vmg); 299 } 300 301 #ifdef CONFIG_DEBUG_VM_MAPLE_TREE 302 if (vmg->vmi) { 303 pr_warn("vmg %px vmi:\n", vmg); 304 vma_iter_dump_tree(vmg->vmi); 305 } else { 306 pr_warn("vmg %px vmi: (NULL)\n", vmg); 307 } 308 #endif 309 } 310 EXPORT_SYMBOL(dump_vmg); 311 312 static bool page_init_poisoning __read_mostly = true; 313 314 static int __init setup_vm_debug(char *str) 315 { 316 bool __page_init_poisoning = true; 317 318 /* 319 * Calling vm_debug with no arguments is equivalent to requesting 320 * to enable all debugging options we can control. 321 */ 322 if (*str++ != '=' || !*str) 323 goto out; 324 325 __page_init_poisoning = false; 326 if (*str == '-') 327 goto out; 328 329 while (*str) { 330 switch (tolower(*str)) { 331 case 'p': 332 __page_init_poisoning = true; 333 break; 334 default: 335 pr_err("vm_debug option '%c' unknown. skipped\n", 336 *str); 337 } 338 339 str++; 340 } 341 out: 342 if (page_init_poisoning && !__page_init_poisoning) 343 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 344 345 page_init_poisoning = __page_init_poisoning; 346 347 return 1; 348 } 349 __setup("vm_debug", setup_vm_debug); 350 351 void page_init_poison(struct page *page, size_t size) 352 { 353 if (page_init_poisoning) 354 memset(page, PAGE_POISON_PATTERN, size); 355 } 356 357 void vma_iter_dump_tree(const struct vma_iterator *vmi) 358 { 359 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 360 mas_dump(&vmi->mas); 361 mt_dump(vmi->mas.tree, mt_dump_hex); 362 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 363 } 364 365 #endif /* CONFIG_DEBUG_VM */ 366