hc
2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c
kernel/mm/debug.c
....@@ -13,10 +13,12 @@
1313 #include <trace/events/mmflags.h>
1414 #include <linux/migrate.h>
1515 #include <linux/page_owner.h>
16
+#include <linux/page_pinner.h>
17
+#include <linux/ctype.h>
1618
1719 #include "internal.h"
1820
19
-char *migrate_reason_names[MR_TYPES] = {
21
+const char *migrate_reason_names[MR_TYPES] = {
2022 "compaction",
2123 "memory_failure",
2224 "memory_hotplug",
....@@ -43,8 +45,19 @@
4345
4446 void __dump_page(struct page *page, const char *reason)
4547 {
48
+ struct page *head = compound_head(page);
49
+ struct address_space *mapping;
4650 bool page_poisoned = PagePoisoned(page);
51
+ bool compound = PageCompound(page);
52
+ /*
53
+ * Accessing the pageblock without the zone lock. It could change to
54
+ * "isolate" again in the meantime, but since we are just dumping the
55
+ * state for debugging, it should be fine to accept a bit of
56
+ * inaccuracy here due to racing.
57
+ */
58
+ bool page_cma = is_migrate_cma_page(page);
4759 int mapcount;
60
+ char *type = "";
4861
4962 /*
5063 * If struct page is poisoned don't access Page*() functions as that
....@@ -52,8 +65,28 @@
5265 * dump_page() when detected.
5366 */
5467 if (page_poisoned) {
55
- pr_emerg("page:%px is uninitialized and poisoned", page);
68
+ pr_warn("page:%px is uninitialized and poisoned", page);
5669 goto hex_only;
70
+ }
71
+
72
+ if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
73
+ /*
74
+ * Corrupt page, so we cannot call page_mapping. Instead, do a
75
+ * safe subset of the steps that page_mapping() does. Caution:
76
+ * this will be misleading for tail pages, PageSwapCache pages,
77
+ * and potentially other situations. (See the page_mapping()
78
+ * implementation for what's missing here.)
79
+ */
80
+ unsigned long tmp = (unsigned long)page->mapping;
81
+
82
+ if (tmp & PAGE_MAPPING_ANON)
83
+ mapping = NULL;
84
+ else
85
+ mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
86
+ head = page;
87
+ compound = false;
88
+ } else {
89
+ mapping = page_mapping(page);
5790 }
5891
5992 /*
....@@ -61,29 +94,97 @@
6194 * page->_mapcount space in struct page is used by sl[aou]b pages to
6295 * encode own info.
6396 */
64
- mapcount = PageSlab(page) ? 0 : page_mapcount(page);
97
+ mapcount = PageSlab(head) ? 0 : page_mapcount(page);
6598
66
- pr_emerg("page:%px count:%d mapcount:%d mapping:%px index:%#lx",
67
- page, page_ref_count(page), mapcount,
68
- page->mapping, page_to_pgoff(page));
69
- if (PageCompound(page))
70
- pr_cont(" compound_mapcount: %d", compound_mapcount(page));
71
- pr_cont("\n");
99
+ pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
100
+ page, page_ref_count(head), mapcount, mapping,
101
+ page_to_pgoff(page), page_to_pfn(page));
102
+ if (compound) {
103
+ if (hpage_pincount_available(page)) {
104
+ pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
105
+ head, compound_order(head),
106
+ head_compound_mapcount(head),
107
+ head_compound_pincount(head));
108
+ } else {
109
+ pr_warn("head:%p order:%u compound_mapcount:%d\n",
110
+ head, compound_order(head),
111
+ head_compound_mapcount(head));
112
+ }
113
+ }
114
+ if (PageKsm(page))
115
+ type = "ksm ";
116
+ else if (PageAnon(page))
117
+ type = "anon ";
118
+ else if (mapping) {
119
+ struct inode *host;
120
+ const struct address_space_operations *a_ops;
121
+ struct hlist_node *dentry_first;
122
+ struct dentry *dentry_ptr;
123
+ struct dentry dentry;
124
+ unsigned long ino;
125
+
126
+ /*
127
+ * mapping can be invalid pointer and we don't want to crash
128
+ * accessing it, so probe everything depending on it carefully
129
+ */
130
+ if (get_kernel_nofault(host, &mapping->host) ||
131
+ get_kernel_nofault(a_ops, &mapping->a_ops)) {
132
+ pr_warn("failed to read mapping contents, not a valid kernel address?\n");
133
+ goto out_mapping;
134
+ }
135
+
136
+ if (!host) {
137
+ pr_warn("aops:%ps\n", a_ops);
138
+ goto out_mapping;
139
+ }
140
+
141
+ if (get_kernel_nofault(dentry_first, &host->i_dentry.first) ||
142
+ get_kernel_nofault(ino, &host->i_ino)) {
143
+ pr_warn("aops:%ps with invalid host inode %px\n",
144
+ a_ops, host);
145
+ goto out_mapping;
146
+ }
147
+
148
+ if (!dentry_first) {
149
+ pr_warn("aops:%ps ino:%lx\n", a_ops, ino);
150
+ goto out_mapping;
151
+ }
152
+
153
+ dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
154
+ if (get_kernel_nofault(dentry, dentry_ptr)) {
155
+ pr_warn("aops:%ps ino:%lx with invalid dentry %px\n",
156
+ a_ops, ino, dentry_ptr);
157
+ } else {
158
+ /*
159
+ * if dentry is corrupted, the %pd handler may still
160
+ * crash, but it's unlikely that we reach here with a
161
+ * corrupted struct page
162
+ */
163
+ pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n",
164
+ a_ops, ino, &dentry);
165
+ }
166
+ }
167
+out_mapping:
72168 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
73169
74
- pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);
170
+ pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
171
+ page_cma ? " CMA" : "");
75172
76173 hex_only:
77
- print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32,
174
+ print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
78175 sizeof(unsigned long), page,
176
+ sizeof(struct page), false);
177
+ if (head != page)
178
+ print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
179
+ sizeof(unsigned long), head,
79180 sizeof(struct page), false);
80181
81182 if (reason)
82
- pr_alert("page dumped because: %s\n", reason);
183
+ pr_warn("page dumped because: %s\n", reason);
83184
84185 #ifdef CONFIG_MEMCG
85186 if (!page_poisoned && page->mem_cgroup)
86
- pr_alert("page->mem_cgroup:%px\n", page->mem_cgroup);
187
+ pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup);
87188 #endif
88189 }
89190
....@@ -91,6 +192,7 @@
91192 {
92193 __dump_page(page, reason);
93194 dump_page_owner(page);
195
+ dump_page_pinner(page);
94196 }
95197 EXPORT_SYMBOL(dump_page);
96198
....@@ -121,7 +223,7 @@
121223 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
122224 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
123225 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
124
- "pinned_vm %lx data_vm %lx exec_vm %lx stack_vm %lx\n"
226
+ "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
125227 "start_code %lx end_code %lx start_data %lx end_data %lx\n"
126228 "start_brk %lx brk %lx start_stack %lx\n"
127229 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
....@@ -134,7 +236,7 @@
134236 #endif
135237 "exe_file %px\n"
136238 #ifdef CONFIG_MMU_NOTIFIER
137
- "mmu_notifier_mm %px\n"
239
+ "notifier_subscriptions %px\n"
138240 #endif
139241 #ifdef CONFIG_NUMA_BALANCING
140242 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
....@@ -152,7 +254,8 @@
152254 mm_pgtables_bytes(mm),
153255 mm->map_count,
154256 mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
155
- mm->pinned_vm, mm->data_vm, mm->exec_vm, mm->stack_vm,
257
+ (u64)atomic64_read(&mm->pinned_vm),
258
+ mm->data_vm, mm->exec_vm, mm->stack_vm,
156259 mm->start_code, mm->end_code, mm->start_data, mm->end_data,
157260 mm->start_brk, mm->brk, mm->start_stack,
158261 mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
....@@ -165,7 +268,7 @@
165268 #endif
166269 mm->exe_file,
167270 #ifdef CONFIG_MMU_NOTIFIER
168
- mm->mmu_notifier_mm,
271
+ mm->notifier_subscriptions,
169272 #endif
170273 #ifdef CONFIG_NUMA_BALANCING
171274 mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
....@@ -175,4 +278,49 @@
175278 );
176279 }
177280
281
+static bool page_init_poisoning __read_mostly = true;
282
+
283
+static int __init setup_vm_debug(char *str)
284
+{
285
+ bool __page_init_poisoning = true;
286
+
287
+ /*
288
+ * Calling vm_debug with no arguments is equivalent to requesting
289
+ * to enable all debugging options we can control.
290
+ */
291
+ if (*str++ != '=' || !*str)
292
+ goto out;
293
+
294
+ __page_init_poisoning = false;
295
+ if (*str == '-')
296
+ goto out;
297
+
298
+ while (*str) {
299
+ switch (tolower(*str)) {
300
+ case'p':
301
+ __page_init_poisoning = true;
302
+ break;
303
+ default:
304
+ pr_err("vm_debug option '%c' unknown. skipped\n",
305
+ *str);
306
+ }
307
+
308
+ str++;
309
+ }
310
+out:
311
+ if (page_init_poisoning && !__page_init_poisoning)
312
+ pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
313
+
314
+ page_init_poisoning = __page_init_poisoning;
315
+
316
+ return 1;
317
+}
318
+__setup("vm_debug", setup_vm_debug);
319
+
320
+void page_init_poison(struct page *page, size_t size)
321
+{
322
+ if (page_init_poisoning)
323
+ memset(page, PAGE_POISON_PATTERN, size);
324
+}
325
+EXPORT_SYMBOL_GPL(page_init_poison);
178326 #endif /* CONFIG_DEBUG_VM */