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_page(struct page *page) |
55 | { |
56 | struct folio *folio = page_folio(page); |
57 | struct page *head = &folio->page; |
58 | struct address_space *mapping; |
59 | bool compound = PageCompound(page); |
60 | /* |
61 | * Accessing the pageblock without the zone lock. It could change to |
62 | * "isolate" again in the meantime, but since we are just dumping the |
63 | * state for debugging, it should be fine to accept a bit of |
64 | * inaccuracy here due to racing. |
65 | */ |
66 | bool page_cma = is_migrate_cma_page(page); |
67 | int mapcount; |
68 | char *type = "" ; |
69 | |
70 | if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { |
71 | /* |
72 | * Corrupt page, so we cannot call page_mapping. Instead, do a |
73 | * safe subset of the steps that page_mapping() does. Caution: |
74 | * this will be misleading for tail pages, PageSwapCache pages, |
75 | * and potentially other situations. (See the page_mapping() |
76 | * implementation for what's missing here.) |
77 | */ |
78 | unsigned long tmp = (unsigned long)page->mapping; |
79 | |
80 | if (tmp & PAGE_MAPPING_ANON) |
81 | mapping = NULL; |
82 | else |
83 | mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS); |
84 | head = page; |
85 | folio = (struct folio *)page; |
86 | compound = false; |
87 | } else { |
88 | mapping = page_mapping(page); |
89 | } |
90 | |
91 | /* |
92 | * Avoid VM_BUG_ON() in page_mapcount(). |
93 | * page->_mapcount space in struct page is used by sl[aou]b pages to |
94 | * encode own info. |
95 | */ |
96 | mapcount = PageSlab(page: head) ? 0 : page_mapcount(page); |
97 | |
98 | pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n" , |
99 | page, page_ref_count(head), mapcount, mapping, |
100 | page_to_pgoff(page), page_to_pfn(page)); |
101 | if (compound) { |
102 | pr_warn("head:%p order:%u entire_mapcount:%d nr_pages_mapped:%d pincount:%d\n" , |
103 | head, compound_order(head), |
104 | folio_entire_mapcount(folio), |
105 | folio_nr_pages_mapped(folio), |
106 | atomic_read(&folio->_pincount)); |
107 | } |
108 | |
109 | #ifdef CONFIG_MEMCG |
110 | if (head->memcg_data) |
111 | pr_warn("memcg:%lx\n" , head->memcg_data); |
112 | #endif |
113 | if (PageKsm(page)) |
114 | type = "ksm " ; |
115 | else if (PageAnon(page)) |
116 | type = "anon " ; |
117 | else if (mapping) |
118 | dump_mapping(mapping); |
119 | BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); |
120 | |
121 | pr_warn("%sflags: %pGp%s\n" , type, &head->flags, |
122 | page_cma ? " CMA" : "" ); |
123 | pr_warn("page_type: %pGt\n" , &head->page_type); |
124 | |
125 | print_hex_dump(KERN_WARNING, prefix_str: "raw: " , prefix_type: DUMP_PREFIX_NONE, rowsize: 32, |
126 | groupsize: sizeof(unsigned long), buf: page, |
127 | len: sizeof(struct page), ascii: false); |
128 | if (head != page) |
129 | print_hex_dump(KERN_WARNING, prefix_str: "head: " , prefix_type: DUMP_PREFIX_NONE, rowsize: 32, |
130 | groupsize: sizeof(unsigned long), buf: head, |
131 | len: sizeof(struct page), ascii: false); |
132 | } |
133 | |
134 | void dump_page(struct page *page, const char *reason) |
135 | { |
136 | if (PagePoisoned(page)) |
137 | pr_warn("page:%p is uninitialized and poisoned" , page); |
138 | else |
139 | __dump_page(page); |
140 | if (reason) |
141 | pr_warn("page dumped because: %s\n" , reason); |
142 | dump_page_owner(page); |
143 | } |
144 | EXPORT_SYMBOL(dump_page); |
145 | |
146 | #ifdef CONFIG_DEBUG_VM |
147 | |
148 | void dump_vma(const struct vm_area_struct *vma) |
149 | { |
150 | pr_emerg("vma %px start %px end %px mm %px\n" |
151 | "prot %lx anon_vma %px vm_ops %px\n" |
152 | "pgoff %lx file %px private_data %px\n" |
153 | "flags: %#lx(%pGv)\n" , |
154 | vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm, |
155 | (unsigned long)pgprot_val(vma->vm_page_prot), |
156 | vma->anon_vma, vma->vm_ops, vma->vm_pgoff, |
157 | vma->vm_file, vma->vm_private_data, |
158 | vma->vm_flags, &vma->vm_flags); |
159 | } |
160 | EXPORT_SYMBOL(dump_vma); |
161 | |
162 | void dump_mm(const struct mm_struct *mm) |
163 | { |
164 | pr_emerg("mm %px task_size %lu\n" |
165 | #ifdef CONFIG_MMU |
166 | "get_unmapped_area %px\n" |
167 | #endif |
168 | "mmap_base %lu mmap_legacy_base %lu\n" |
169 | "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" |
170 | "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" |
171 | "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n" |
172 | "start_code %lx end_code %lx start_data %lx end_data %lx\n" |
173 | "start_brk %lx brk %lx start_stack %lx\n" |
174 | "arg_start %lx arg_end %lx env_start %lx env_end %lx\n" |
175 | "binfmt %px flags %lx\n" |
176 | #ifdef CONFIG_AIO |
177 | "ioctx_table %px\n" |
178 | #endif |
179 | #ifdef CONFIG_MEMCG |
180 | "owner %px " |
181 | #endif |
182 | "exe_file %px\n" |
183 | #ifdef CONFIG_MMU_NOTIFIER |
184 | "notifier_subscriptions %px\n" |
185 | #endif |
186 | #ifdef CONFIG_NUMA_BALANCING |
187 | "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n" |
188 | #endif |
189 | "tlb_flush_pending %d\n" |
190 | "def_flags: %#lx(%pGv)\n" , |
191 | |
192 | mm, mm->task_size, |
193 | #ifdef CONFIG_MMU |
194 | mm->get_unmapped_area, |
195 | #endif |
196 | mm->mmap_base, mm->mmap_legacy_base, |
197 | mm->pgd, atomic_read(&mm->mm_users), |
198 | atomic_read(&mm->mm_count), |
199 | mm_pgtables_bytes(mm), |
200 | mm->map_count, |
201 | mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, |
202 | (u64)atomic64_read(&mm->pinned_vm), |
203 | mm->data_vm, mm->exec_vm, mm->stack_vm, |
204 | mm->start_code, mm->end_code, mm->start_data, mm->end_data, |
205 | mm->start_brk, mm->brk, mm->start_stack, |
206 | mm->arg_start, mm->arg_end, mm->env_start, mm->env_end, |
207 | mm->binfmt, mm->flags, |
208 | #ifdef CONFIG_AIO |
209 | mm->ioctx_table, |
210 | #endif |
211 | #ifdef CONFIG_MEMCG |
212 | mm->owner, |
213 | #endif |
214 | mm->exe_file, |
215 | #ifdef CONFIG_MMU_NOTIFIER |
216 | mm->notifier_subscriptions, |
217 | #endif |
218 | #ifdef CONFIG_NUMA_BALANCING |
219 | mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq, |
220 | #endif |
221 | atomic_read(&mm->tlb_flush_pending), |
222 | mm->def_flags, &mm->def_flags |
223 | ); |
224 | } |
225 | EXPORT_SYMBOL(dump_mm); |
226 | |
227 | static bool page_init_poisoning __read_mostly = true; |
228 | |
229 | static int __init setup_vm_debug(char *str) |
230 | { |
231 | bool __page_init_poisoning = true; |
232 | |
233 | /* |
234 | * Calling vm_debug with no arguments is equivalent to requesting |
235 | * to enable all debugging options we can control. |
236 | */ |
237 | if (*str++ != '=' || !*str) |
238 | goto out; |
239 | |
240 | __page_init_poisoning = false; |
241 | if (*str == '-') |
242 | goto out; |
243 | |
244 | while (*str) { |
245 | switch (tolower(*str)) { |
246 | case'p': |
247 | __page_init_poisoning = true; |
248 | break; |
249 | default: |
250 | pr_err("vm_debug option '%c' unknown. skipped\n" , |
251 | *str); |
252 | } |
253 | |
254 | str++; |
255 | } |
256 | out: |
257 | if (page_init_poisoning && !__page_init_poisoning) |
258 | pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n" ); |
259 | |
260 | page_init_poisoning = __page_init_poisoning; |
261 | |
262 | return 1; |
263 | } |
264 | __setup("vm_debug" , setup_vm_debug); |
265 | |
266 | void page_init_poison(struct page *page, size_t size) |
267 | { |
268 | if (page_init_poisoning) |
269 | memset(page, PAGE_POISON_PATTERN, size); |
270 | } |
271 | |
272 | void vma_iter_dump_tree(const struct vma_iterator *vmi) |
273 | { |
274 | #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) |
275 | mas_dump(mas: &vmi->mas); |
276 | mt_dump(mt: vmi->mas.tree, format: mt_dump_hex); |
277 | #endif /* CONFIG_DEBUG_VM_MAPLE_TREE */ |
278 | } |
279 | |
280 | #endif /* CONFIG_DEBUG_VM */ |
281 | |