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 = 0; 59 char *type = ""; 60 61 /* 62 * page->_mapcount space in struct page is used by slab pages to 63 * encode own info, and we must avoid calling page_folio() again. 64 */ 65 if (!folio_test_slab(folio)) { 66 mapcount = atomic_read(&page->_mapcount) + 1; 67 if (folio_test_large(folio)) 68 mapcount += folio_entire_mapcount(folio); 69 } 70 71 pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", 72 folio_ref_count(folio), mapcount, mapping, 73 folio->index + idx, pfn); 74 if (folio_test_large(folio)) { 75 pr_warn("head: order:%u entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n", 76 folio_order(folio), 77 folio_entire_mapcount(folio), 78 folio_nr_pages_mapped(folio), 79 atomic_read(&folio->_pincount)); 80 } 81 82 #ifdef CONFIG_MEMCG 83 if (folio->memcg_data) 84 pr_warn("memcg:%lx\n", folio->memcg_data); 85 #endif 86 if (folio_test_ksm(folio)) 87 type = "ksm "; 88 else if (folio_test_anon(folio)) 89 type = "anon "; 90 else if (mapping) 91 dump_mapping(mapping); 92 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); 93 94 /* 95 * Accessing the pageblock without the zone lock. It could change to 96 * "isolate" again in the meantime, but since we are just dumping the 97 * state for debugging, it should be fine to accept a bit of 98 * inaccuracy here due to racing. 99 */ 100 pr_warn("%sflags: %pGp%s\n", type, &folio->flags, 101 is_migrate_cma_folio(folio, pfn) ? " CMA" : ""); 102 pr_warn("page_type: %pGt\n", &folio->page.page_type); 103 104 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, 105 sizeof(unsigned long), page, 106 sizeof(struct page), false); 107 if (folio_test_large(folio)) 108 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, 109 sizeof(unsigned long), folio, 110 2 * sizeof(struct page), false); 111 } 112 113 static void __dump_page(const struct page *page) 114 { 115 struct folio *foliop, folio; 116 struct page precise; 117 unsigned long pfn = page_to_pfn(page); 118 unsigned long idx, nr_pages = 1; 119 int loops = 5; 120 121 again: 122 memcpy(&precise, page, sizeof(*page)); 123 foliop = page_folio(&precise); 124 if (foliop == (struct folio *)&precise) { 125 idx = 0; 126 if (!folio_test_large(foliop)) 127 goto dump; 128 foliop = (struct folio *)page; 129 } else { 130 idx = folio_page_idx(foliop, page); 131 } 132 133 if (idx < MAX_FOLIO_NR_PAGES) { 134 memcpy(&folio, foliop, 2 * sizeof(struct page)); 135 nr_pages = folio_nr_pages(&folio); 136 foliop = &folio; 137 } 138 139 if (idx > nr_pages) { 140 if (loops-- > 0) 141 goto again; 142 pr_warn("page does not match folio\n"); 143 precise.compound_head &= ~1UL; 144 foliop = (struct folio *)&precise; 145 idx = 0; 146 } 147 148 dump: 149 __dump_folio(foliop, &precise, pfn, idx); 150 } 151 152 void dump_page(const struct page *page, const char *reason) 153 { 154 if (PagePoisoned(page)) 155 pr_warn("page:%p is uninitialized and poisoned", page); 156 else 157 __dump_page(page); 158 if (reason) 159 pr_warn("page dumped because: %s\n", reason); 160 dump_page_owner(page); 161 } 162 EXPORT_SYMBOL(dump_page); 163 164 #ifdef CONFIG_DEBUG_VM 165 166 void dump_vma(const struct vm_area_struct *vma) 167 { 168 pr_emerg("vma %px start %px end %px mm %px\n" 169 "prot %lx anon_vma %px vm_ops %px\n" 170 "pgoff %lx file %px private_data %px\n" 171 "flags: %#lx(%pGv)\n", 172 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, 173 (unsigned long)pgprot_val(vma->vm_page_prot), 174 vma->anon_vma, vma->vm_ops, vma->vm_pgoff, 175 vma->vm_file, vma->vm_private_data, 176 vma->vm_flags, &vma->vm_flags); 177 } 178 EXPORT_SYMBOL(dump_vma); 179 180 void dump_mm(const struct mm_struct *mm) 181 { 182 pr_emerg("mm %px task_size %lu\n" 183 #ifdef CONFIG_MMU 184 "get_unmapped_area %px\n" 185 #endif 186 "mmap_base %lu mmap_legacy_base %lu\n" 187 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" 188 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" 189 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" 190 "start_code %lx end_code %lx start_data %lx end_data %lx\n" 191 "start_brk %lx brk %lx start_stack %lx\n" 192 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" 193 "binfmt %px flags %lx\n" 194 #ifdef CONFIG_AIO 195 "ioctx_table %px\n" 196 #endif 197 #ifdef CONFIG_MEMCG 198 "owner %px " 199 #endif 200 "exe_file %px\n" 201 #ifdef CONFIG_MMU_NOTIFIER 202 "notifier_subscriptions %px\n" 203 #endif 204 #ifdef CONFIG_NUMA_BALANCING 205 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" 206 #endif 207 "tlb_flush_pending %d\n" 208 "def_flags: %#lx(%pGv)\n", 209 210 mm, mm->task_size, 211 #ifdef CONFIG_MMU 212 mm->get_unmapped_area, 213 #endif 214 mm->mmap_base, mm->mmap_legacy_base, 215 mm->pgd, atomic_read(&mm->mm_users), 216 atomic_read(&mm->mm_count), 217 mm_pgtables_bytes(mm), 218 mm->map_count, 219 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, 220 (u64)atomic64_read(&mm->pinned_vm), 221 mm->data_vm, mm->exec_vm, mm->stack_vm, 222 mm->start_code, mm->end_code, mm->start_data, mm->end_data, 223 mm->start_brk, mm->brk, mm->start_stack, 224 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, 225 mm->binfmt, mm->flags, 226 #ifdef CONFIG_AIO 227 mm->ioctx_table, 228 #endif 229 #ifdef CONFIG_MEMCG 230 mm->owner, 231 #endif 232 mm->exe_file, 233 #ifdef CONFIG_MMU_NOTIFIER 234 mm->notifier_subscriptions, 235 #endif 236 #ifdef CONFIG_NUMA_BALANCING 237 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, 238 #endif 239 atomic_read(&mm->tlb_flush_pending), 240 mm->def_flags, &mm->def_flags 241 ); 242 } 243 EXPORT_SYMBOL(dump_mm); 244 245 static bool page_init_poisoning __read_mostly = true; 246 247 static int __init setup_vm_debug(char *str) 248 { 249 bool __page_init_poisoning = true; 250 251 /* 252 * Calling vm_debug with no arguments is equivalent to requesting 253 * to enable all debugging options we can control. 254 */ 255 if (*str++ != '=' || !*str) 256 goto out; 257 258 __page_init_poisoning = false; 259 if (*str == '-') 260 goto out; 261 262 while (*str) { 263 switch (tolower(*str)) { 264 case'p': 265 __page_init_poisoning = true; 266 break; 267 default: 268 pr_err("vm_debug option '%c' unknown. skipped\n", 269 *str); 270 } 271 272 str++; 273 } 274 out: 275 if (page_init_poisoning && !__page_init_poisoning) 276 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); 277 278 page_init_poisoning = __page_init_poisoning; 279 280 return 1; 281 } 282 __setup("vm_debug", setup_vm_debug); 283 284 void page_init_poison(struct page *page, size_t size) 285 { 286 if (page_init_poisoning) 287 memset(page, PAGE_POISON_PATTERN, size); 288 } 289 290 void vma_iter_dump_tree(const struct vma_iterator *vmi) 291 { 292 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 293 mas_dump(&vmi->mas); 294 mt_dump(vmi->mas.tree, mt_dump_hex); 295 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ 296 } 297 298 #endif /* CONFIG_DEBUG_VM */ 299