1 // SPDX-License-Identifier: GPL-2.0
5 * mm/ specific debug routines.
9 #include <linux/kernel.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>
19 #include <trace/events/migrate.h>
22 * Define EM() and EMe() so that MIGRATE_REASON from trace/events/migrate.h can
23 * be used to populate migrate_reason_names[].
30 const char *migrate_reason_names
[MR_TYPES
] = {
34 const struct trace_print_flags pageflag_names
[] = {
39 const struct trace_print_flags gfpflag_names
[] = {
44 const struct trace_print_flags vmaflag_names
[] = {
49 static void __dump_page(struct page
*page
)
51 struct folio
*folio
= page_folio(page
);
52 struct page
*head
= &folio
->page
;
53 struct address_space
*mapping
;
54 bool compound
= PageCompound(page
);
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.
61 bool page_cma
= is_migrate_cma_page(page
);
65 if (page
< head
|| (page
>= head
+ MAX_ORDER_NR_PAGES
)) {
67 * Corrupt page, so we cannot call page_mapping. Instead, do a
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.)
73 unsigned long tmp
= (unsigned long)page
->mapping
;
75 if (tmp
& PAGE_MAPPING_ANON
)
78 mapping
= (void *)(tmp
& ~PAGE_MAPPING_FLAGS
);
80 folio
= (struct folio
*)page
;
83 mapping
= page_mapping(page
);
87 * Avoid VM_BUG_ON() in page_mapcount().
88 * page->_mapcount space in struct page is used by sl[aou]b pages to
91 mapcount
= PageSlab(head
) ? 0 : page_mapcount(page
);
93 pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
94 page
, page_ref_count(head
), mapcount
, mapping
,
95 page_to_pgoff(page
), page_to_pfn(page
));
97 pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
98 head
, compound_order(head
),
99 folio_entire_mapcount(folio
),
100 head_compound_pincount(head
));
104 if (head
->memcg_data
)
105 pr_warn("memcg:%lx\n", head
->memcg_data
);
109 else if (PageAnon(page
))
112 dump_mapping(mapping
);
113 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
+ 1);
115 pr_warn("%sflags: %pGp%s\n", type
, &head
->flags
,
116 page_cma
? " CMA" : "");
117 print_hex_dump(KERN_WARNING
, "raw: ", DUMP_PREFIX_NONE
, 32,
118 sizeof(unsigned long), page
,
119 sizeof(struct page
), false);
121 print_hex_dump(KERN_WARNING
, "head: ", DUMP_PREFIX_NONE
, 32,
122 sizeof(unsigned long), head
,
123 sizeof(struct page
), false);
126 void dump_page(struct page
*page
, const char *reason
)
128 if (PagePoisoned(page
))
129 pr_warn("page:%p is uninitialized and poisoned", page
);
133 pr_warn("page dumped because: %s\n", reason
);
134 dump_page_owner(page
);
136 EXPORT_SYMBOL(dump_page
);
138 #ifdef CONFIG_DEBUG_VM
140 void dump_vma(const struct vm_area_struct
*vma
)
142 pr_emerg("vma %px start %px end %px\n"
143 "next %px prev %px mm %px\n"
144 "prot %lx anon_vma %px vm_ops %px\n"
145 "pgoff %lx file %px private_data %px\n"
146 "flags: %#lx(%pGv)\n",
147 vma
, (void *)vma
->vm_start
, (void *)vma
->vm_end
, vma
->vm_next
,
148 vma
->vm_prev
, vma
->vm_mm
,
149 (unsigned long)pgprot_val(vma
->vm_page_prot
),
150 vma
->anon_vma
, vma
->vm_ops
, vma
->vm_pgoff
,
151 vma
->vm_file
, vma
->vm_private_data
,
152 vma
->vm_flags
, &vma
->vm_flags
);
154 EXPORT_SYMBOL(dump_vma
);
156 void dump_mm(const struct mm_struct
*mm
)
158 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
160 "get_unmapped_area %px\n"
162 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
163 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
164 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
165 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
166 "start_code %lx end_code %lx start_data %lx end_data %lx\n"
167 "start_brk %lx brk %lx start_stack %lx\n"
168 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
169 "binfmt %px flags %lx\n"
177 #ifdef CONFIG_MMU_NOTIFIER
178 "notifier_subscriptions %px\n"
180 #ifdef CONFIG_NUMA_BALANCING
181 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
183 "tlb_flush_pending %d\n"
184 "def_flags: %#lx(%pGv)\n",
186 mm
, mm
->mmap
, (long long) mm
->vmacache_seqnum
, mm
->task_size
,
188 mm
->get_unmapped_area
,
190 mm
->mmap_base
, mm
->mmap_legacy_base
, mm
->highest_vm_end
,
191 mm
->pgd
, atomic_read(&mm
->mm_users
),
192 atomic_read(&mm
->mm_count
),
193 mm_pgtables_bytes(mm
),
195 mm
->hiwater_rss
, mm
->hiwater_vm
, mm
->total_vm
, mm
->locked_vm
,
196 (u64
)atomic64_read(&mm
->pinned_vm
),
197 mm
->data_vm
, mm
->exec_vm
, mm
->stack_vm
,
198 mm
->start_code
, mm
->end_code
, mm
->start_data
, mm
->end_data
,
199 mm
->start_brk
, mm
->brk
, mm
->start_stack
,
200 mm
->arg_start
, mm
->arg_end
, mm
->env_start
, mm
->env_end
,
201 mm
->binfmt
, mm
->flags
,
209 #ifdef CONFIG_MMU_NOTIFIER
210 mm
->notifier_subscriptions
,
212 #ifdef CONFIG_NUMA_BALANCING
213 mm
->numa_next_scan
, mm
->numa_scan_offset
, mm
->numa_scan_seq
,
215 atomic_read(&mm
->tlb_flush_pending
),
216 mm
->def_flags
, &mm
->def_flags
220 static bool page_init_poisoning __read_mostly
= true;
222 static int __init
setup_vm_debug(char *str
)
224 bool __page_init_poisoning
= true;
227 * Calling vm_debug with no arguments is equivalent to requesting
228 * to enable all debugging options we can control.
230 if (*str
++ != '=' || !*str
)
233 __page_init_poisoning
= false;
238 switch (tolower(*str
)) {
240 __page_init_poisoning
= true;
243 pr_err("vm_debug option '%c' unknown. skipped\n",
250 if (page_init_poisoning
&& !__page_init_poisoning
)
251 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
253 page_init_poisoning
= __page_init_poisoning
;
257 __setup("vm_debug", setup_vm_debug
);
259 void page_init_poison(struct page
*page
, size_t size
)
261 if (page_init_poisoning
)
262 memset(page
, PAGE_POISON_PATTERN
, size
);
264 #endif /* CONFIG_DEBUG_VM */