1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * mm/debug.c 3 * mm/debug.c
4 * 4 *
5 * mm/ specific debug routines. 5 * mm/ specific debug routines.
6 * 6 *
7 */ 7 */
8 8
9 #include <linux/kernel.h> 9 #include <linux/kernel.h>
10 #include <linux/mm.h> 10 #include <linux/mm.h>
11 #include <linux/trace_events.h> 11 #include <linux/trace_events.h>
12 #include <linux/memcontrol.h> 12 #include <linux/memcontrol.h>
13 #include <trace/events/mmflags.h> 13 #include <trace/events/mmflags.h>
14 #include <linux/migrate.h> 14 #include <linux/migrate.h>
15 #include <linux/page_owner.h> 15 #include <linux/page_owner.h>
16 #include <linux/ctype.h> 16 #include <linux/ctype.h>
17 17
18 #include "internal.h" 18 #include "internal.h"
19 #include <trace/events/migrate.h> 19 #include <trace/events/migrate.h>
20 20
21 /* 21 /*
22 * Define EM() and EMe() so that MIGRATE_REASO 22 * Define EM() and EMe() so that MIGRATE_REASON from trace/events/migrate.h can
23 * be used to populate migrate_reason_names[]. 23 * be used to populate migrate_reason_names[].
24 */ 24 */
25 #undef EM 25 #undef EM
26 #undef EMe 26 #undef EMe
27 #define EM(a, b) b, 27 #define EM(a, b) b,
28 #define EMe(a, b) b 28 #define EMe(a, b) b
29 29
30 const char *migrate_reason_names[MR_TYPES] = { 30 const char *migrate_reason_names[MR_TYPES] = {
31 MIGRATE_REASON 31 MIGRATE_REASON
32 }; 32 };
33 33
34 const struct trace_print_flags pageflag_names[ 34 const struct trace_print_flags pageflag_names[] = {
35 __def_pageflag_names, 35 __def_pageflag_names,
36 {0, NULL} 36 {0, NULL}
37 }; 37 };
38 38
39 const struct trace_print_flags gfpflag_names[] 39 const struct trace_print_flags gfpflag_names[] = {
40 __def_gfpflag_names, 40 __def_gfpflag_names,
41 {0, NULL} 41 {0, NULL}
42 }; 42 };
43 43
44 const struct trace_print_flags vmaflag_names[] 44 const struct trace_print_flags vmaflag_names[] = {
45 __def_vmaflag_names, 45 __def_vmaflag_names,
46 {0, NULL} 46 {0, NULL}
47 }; 47 };
48 48
49 #define DEF_PAGETYPE_NAME(_name) [PGTY_##_name !! 49 static void __dump_page(struct page *page)
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 <<
62 { 50 {
63 unsigned i = (page_type >> 24) - 0xf0; !! 51 struct folio *folio = page_folio(page);
>> 52 struct page *head = &folio->page;
>> 53 struct address_space *mapping;
>> 54 bool compound = PageCompound(page);
>> 55 /*
>> 56 * Accessing the pageblock without the zone lock. It could change to
>> 57 * "isolate" again in the meantime, but since we are just dumping the
>> 58 * state for debugging, it should be fine to accept a bit of
>> 59 * inaccuracy here due to racing.
>> 60 */
>> 61 bool page_cma = is_migrate_cma_page(page);
>> 62 int mapcount;
>> 63 char *type = "";
64 64
65 if (i >= ARRAY_SIZE(page_type_names)) !! 65 if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
66 return "unknown"; !! 66 /*
67 return page_type_names[i]; !! 67 * Corrupt page, so we cannot call page_mapping. Instead, do a
68 } !! 68 * safe subset of the steps that page_mapping() does. Caution:
>> 69 * this will be misleading for tail pages, PageSwapCache pages,
>> 70 * and potentially other situations. (See the page_mapping()
>> 71 * implementation for what's missing here.)
>> 72 */
>> 73 unsigned long tmp = (unsigned long)page->mapping;
>> 74
>> 75 if (tmp & PAGE_MAPPING_ANON)
>> 76 mapping = NULL;
>> 77 else
>> 78 mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
>> 79 head = page;
>> 80 folio = (struct folio *)page;
>> 81 compound = false;
>> 82 } else {
>> 83 mapping = page_mapping(page);
>> 84 }
69 85
70 static void __dump_folio(struct folio *folio, !! 86 /*
71 unsigned long pfn, unsigned lo !! 87 * Avoid VM_BUG_ON() in page_mapcount().
72 { !! 88 * page->_mapcount space in struct page is used by sl[aou]b pages to
73 struct address_space *mapping = folio_ !! 89 * encode own info.
74 int mapcount = atomic_read(&page->_map !! 90 */
75 char *type = ""; !! 91 mapcount = PageSlab(head) ? 0 : page_mapcount(page);
76 92
77 mapcount = page_mapcount_is_type(mapco !! 93 pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
78 pr_warn("page: refcount:%d mapcount:%d !! 94 page, page_ref_count(head), mapcount, mapping,
79 folio_ref_count(folio) !! 95 page_to_pgoff(page), page_to_pfn(page));
80 folio->index + idx, pf !! 96 if (compound) {
81 if (folio_test_large(folio)) { !! 97 pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
82 pr_warn("head: order:%u mapcou !! 98 head, compound_order(head),
83 folio_order(fo <<
84 folio_mapcount <<
85 folio_entire_m 99 folio_entire_mapcount(folio),
86 folio_nr_pages !! 100 head_compound_pincount(head));
87 atomic_read(&f <<
88 } 101 }
89 102
90 #ifdef CONFIG_MEMCG 103 #ifdef CONFIG_MEMCG
91 if (folio->memcg_data) !! 104 if (head->memcg_data)
92 pr_warn("memcg:%lx\n", folio-> !! 105 pr_warn("memcg:%lx\n", head->memcg_data);
93 #endif 106 #endif
94 if (folio_test_ksm(folio)) !! 107 if (PageKsm(page))
95 type = "ksm "; 108 type = "ksm ";
96 else if (folio_test_anon(folio)) !! 109 else if (PageAnon(page))
97 type = "anon "; 110 type = "anon ";
98 else if (mapping) 111 else if (mapping)
99 dump_mapping(mapping); 112 dump_mapping(mapping);
100 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names 113 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
101 114
102 /* !! 115 pr_warn("%sflags: %pGp%s\n", type, &head->flags,
103 * Accessing the pageblock without the !! 116 page_cma ? " CMA" : "");
104 * "isolate" again in the meantime, bu <<
105 * state for debugging, it should be f <<
106 * inaccuracy here due to racing. <<
107 */ <<
108 pr_warn("%sflags: %pGp%s\n", type, &fo <<
109 is_migrate_cma_folio(folio, pf <<
110 if (page_has_type(&folio->page)) <<
111 pr_warn("page_type: %x(%s)\n", <<
112 page_type_name <<
113 <<
114 print_hex_dump(KERN_WARNING, "raw: ", 117 print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
115 sizeof(unsigned long), 118 sizeof(unsigned long), page,
116 sizeof(struct page), f 119 sizeof(struct page), false);
117 if (folio_test_large(folio)) !! 120 if (head != page)
118 print_hex_dump(KERN_WARNING, " 121 print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
119 sizeof(unsigned long), !! 122 sizeof(unsigned long), head,
120 2 * sizeof(struct page !! 123 sizeof(struct page), false);
121 } <<
122 <<
123 static void __dump_page(const struct page *pag <<
124 { <<
125 struct folio *foliop, folio; <<
126 struct page precise; <<
127 unsigned long pfn = page_to_pfn(page); <<
128 unsigned long idx, nr_pages = 1; <<
129 int loops = 5; <<
130 <<
131 again: <<
132 memcpy(&precise, page, sizeof(*page)); <<
133 foliop = page_folio(&precise); <<
134 if (foliop == (struct folio *)&precise <<
135 idx = 0; <<
136 if (!folio_test_large(foliop)) <<
137 goto dump; <<
138 foliop = (struct folio *)page; <<
139 } else { <<
140 idx = folio_page_idx(foliop, p <<
141 } <<
142 <<
143 if (idx < MAX_FOLIO_NR_PAGES) { <<
144 memcpy(&folio, foliop, 2 * siz <<
145 nr_pages = folio_nr_pages(&fol <<
146 foliop = &folio; <<
147 } <<
148 <<
149 if (idx > nr_pages) { <<
150 if (loops-- > 0) <<
151 goto again; <<
152 pr_warn("page does not match f <<
153 precise.compound_head &= ~1UL; <<
154 foliop = (struct folio *)&prec <<
155 idx = 0; <<
156 } <<
157 <<
158 dump: <<
159 __dump_folio(foliop, &precise, pfn, id <<
160 } 124 }
161 125
162 void dump_page(const struct page *page, const !! 126 void dump_page(struct page *page, const char *reason)
163 { 127 {
164 if (PagePoisoned(page)) 128 if (PagePoisoned(page))
165 pr_warn("page:%p is uninitiali 129 pr_warn("page:%p is uninitialized and poisoned", page);
166 else 130 else
167 __dump_page(page); 131 __dump_page(page);
168 if (reason) 132 if (reason)
169 pr_warn("page dumped because: 133 pr_warn("page dumped because: %s\n", reason);
170 dump_page_owner(page); 134 dump_page_owner(page);
171 } 135 }
172 EXPORT_SYMBOL(dump_page); 136 EXPORT_SYMBOL(dump_page);
173 137
174 #ifdef CONFIG_DEBUG_VM 138 #ifdef CONFIG_DEBUG_VM
175 139
176 void dump_vma(const struct vm_area_struct *vma 140 void dump_vma(const struct vm_area_struct *vma)
177 { 141 {
178 pr_emerg("vma %px start %px end %px mm !! 142 pr_emerg("vma %px start %px end %px\n"
>> 143 "next %px prev %px mm %px\n"
179 "prot %lx anon_vma %px vm_ops 144 "prot %lx anon_vma %px vm_ops %px\n"
180 "pgoff %lx file %px private_da 145 "pgoff %lx file %px private_data %px\n"
181 "flags: %#lx(%pGv)\n", 146 "flags: %#lx(%pGv)\n",
182 vma, (void *)vma->vm_start, (v !! 147 vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next,
>> 148 vma->vm_prev, vma->vm_mm,
183 (unsigned long)pgprot_val(vma- 149 (unsigned long)pgprot_val(vma->vm_page_prot),
184 vma->anon_vma, vma->vm_ops, vm 150 vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
185 vma->vm_file, vma->vm_private_ 151 vma->vm_file, vma->vm_private_data,
186 vma->vm_flags, &vma->vm_flags) 152 vma->vm_flags, &vma->vm_flags);
187 } 153 }
188 EXPORT_SYMBOL(dump_vma); 154 EXPORT_SYMBOL(dump_vma);
189 155
190 void dump_mm(const struct mm_struct *mm) 156 void dump_mm(const struct mm_struct *mm)
191 { 157 {
192 pr_emerg("mm %px task_size %lu\n" !! 158 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
193 "mmap_base %lu mmap_legacy_bas !! 159 #ifdef CONFIG_MMU
>> 160 "get_unmapped_area %px\n"
>> 161 #endif
>> 162 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
194 "pgd %px mm_users %d mm_count 163 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
195 "hiwater_rss %lx hiwater_vm %l 164 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
196 "pinned_vm %llx data_vm %lx ex 165 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
197 "start_code %lx end_code %lx s 166 "start_code %lx end_code %lx start_data %lx end_data %lx\n"
198 "start_brk %lx brk %lx start_s 167 "start_brk %lx brk %lx start_stack %lx\n"
199 "arg_start %lx arg_end %lx env 168 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
200 "binfmt %px flags %lx\n" 169 "binfmt %px flags %lx\n"
201 #ifdef CONFIG_AIO 170 #ifdef CONFIG_AIO
202 "ioctx_table %px\n" 171 "ioctx_table %px\n"
203 #endif 172 #endif
204 #ifdef CONFIG_MEMCG 173 #ifdef CONFIG_MEMCG
205 "owner %px " 174 "owner %px "
206 #endif 175 #endif
207 "exe_file %px\n" 176 "exe_file %px\n"
208 #ifdef CONFIG_MMU_NOTIFIER 177 #ifdef CONFIG_MMU_NOTIFIER
209 "notifier_subscriptions %px\n" 178 "notifier_subscriptions %px\n"
210 #endif 179 #endif
211 #ifdef CONFIG_NUMA_BALANCING 180 #ifdef CONFIG_NUMA_BALANCING
212 "numa_next_scan %lu numa_scan_ 181 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
213 #endif 182 #endif
214 "tlb_flush_pending %d\n" 183 "tlb_flush_pending %d\n"
215 "def_flags: %#lx(%pGv)\n", 184 "def_flags: %#lx(%pGv)\n",
216 185
217 mm, mm->task_size, !! 186 mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,
218 mm->mmap_base, mm->mmap_legacy !! 187 #ifdef CONFIG_MMU
>> 188 mm->get_unmapped_area,
>> 189 #endif
>> 190 mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
219 mm->pgd, atomic_read(&mm->mm_u 191 mm->pgd, atomic_read(&mm->mm_users),
220 atomic_read(&mm->mm_count), 192 atomic_read(&mm->mm_count),
221 mm_pgtables_bytes(mm), 193 mm_pgtables_bytes(mm),
222 mm->map_count, 194 mm->map_count,
223 mm->hiwater_rss, mm->hiwater_v 195 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
224 (u64)atomic64_read(&mm->pinned 196 (u64)atomic64_read(&mm->pinned_vm),
225 mm->data_vm, mm->exec_vm, mm-> 197 mm->data_vm, mm->exec_vm, mm->stack_vm,
226 mm->start_code, mm->end_code, 198 mm->start_code, mm->end_code, mm->start_data, mm->end_data,
227 mm->start_brk, mm->brk, mm->st 199 mm->start_brk, mm->brk, mm->start_stack,
228 mm->arg_start, mm->arg_end, mm 200 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
229 mm->binfmt, mm->flags, 201 mm->binfmt, mm->flags,
230 #ifdef CONFIG_AIO 202 #ifdef CONFIG_AIO
231 mm->ioctx_table, 203 mm->ioctx_table,
232 #endif 204 #endif
233 #ifdef CONFIG_MEMCG 205 #ifdef CONFIG_MEMCG
234 mm->owner, 206 mm->owner,
235 #endif 207 #endif
236 mm->exe_file, 208 mm->exe_file,
237 #ifdef CONFIG_MMU_NOTIFIER 209 #ifdef CONFIG_MMU_NOTIFIER
238 mm->notifier_subscriptions, 210 mm->notifier_subscriptions,
239 #endif 211 #endif
240 #ifdef CONFIG_NUMA_BALANCING 212 #ifdef CONFIG_NUMA_BALANCING
241 mm->numa_next_scan, mm->numa_s 213 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
242 #endif 214 #endif
243 atomic_read(&mm->tlb_flush_pen 215 atomic_read(&mm->tlb_flush_pending),
244 mm->def_flags, &mm->def_flags 216 mm->def_flags, &mm->def_flags
245 ); 217 );
246 } 218 }
247 EXPORT_SYMBOL(dump_mm); <<
248 219
249 static bool page_init_poisoning __read_mostly 220 static bool page_init_poisoning __read_mostly = true;
250 221
251 static int __init setup_vm_debug(char *str) 222 static int __init setup_vm_debug(char *str)
252 { 223 {
253 bool __page_init_poisoning = true; 224 bool __page_init_poisoning = true;
254 225
255 /* 226 /*
256 * Calling vm_debug with no arguments 227 * Calling vm_debug with no arguments is equivalent to requesting
257 * to enable all debugging options we 228 * to enable all debugging options we can control.
258 */ 229 */
259 if (*str++ != '=' || !*str) 230 if (*str++ != '=' || !*str)
260 goto out; 231 goto out;
261 232
262 __page_init_poisoning = false; 233 __page_init_poisoning = false;
263 if (*str == '-') 234 if (*str == '-')
264 goto out; 235 goto out;
265 236
266 while (*str) { 237 while (*str) {
267 switch (tolower(*str)) { 238 switch (tolower(*str)) {
268 case'p': 239 case'p':
269 __page_init_poisoning 240 __page_init_poisoning = true;
270 break; 241 break;
271 default: 242 default:
272 pr_err("vm_debug optio 243 pr_err("vm_debug option '%c' unknown. skipped\n",
273 *str); 244 *str);
274 } 245 }
275 246
276 str++; 247 str++;
277 } 248 }
278 out: 249 out:
279 if (page_init_poisoning && !__page_ini 250 if (page_init_poisoning && !__page_init_poisoning)
280 pr_warn("Page struct poisoning 251 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
281 252
282 page_init_poisoning = __page_init_pois 253 page_init_poisoning = __page_init_poisoning;
283 254
284 return 1; 255 return 1;
285 } 256 }
286 __setup("vm_debug", setup_vm_debug); 257 __setup("vm_debug", setup_vm_debug);
287 258
288 void page_init_poison(struct page *page, size_ 259 void page_init_poison(struct page *page, size_t size)
289 { 260 {
290 if (page_init_poisoning) 261 if (page_init_poisoning)
291 memset(page, PAGE_POISON_PATTE 262 memset(page, PAGE_POISON_PATTERN, size);
292 } 263 }
293 <<
294 void vma_iter_dump_tree(const struct vma_itera <<
295 { <<
296 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) <<
297 mas_dump(&vmi->mas); <<
298 mt_dump(vmi->mas.tree, mt_dump_hex); <<
299 #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ <<
300 } <<
301 <<
302 #endif /* CONFIG_DEBUG_VM */ 264 #endif /* CONFIG_DEBUG_VM */
303 265
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