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>
20 const char *migrate_reason_names
[MR_TYPES
] = {
30 const struct trace_print_flags pageflag_names
[] = {
35 const struct trace_print_flags gfpflag_names
[] = {
40 const struct trace_print_flags vmaflag_names
[] = {
45 void __dump_page(struct page
*page
, const char *reason
)
47 struct address_space
*mapping
;
48 bool page_poisoned
= PagePoisoned(page
);
52 * If struct page is poisoned don't access Page*() functions as that
53 * leads to recursive loop. Page*() check for poisoned pages, and calls
54 * dump_page() when detected.
57 pr_warn("page:%px is uninitialized and poisoned", page
);
61 mapping
= page_mapping(page
);
64 * Avoid VM_BUG_ON() in page_mapcount().
65 * page->_mapcount space in struct page is used by sl[aou]b pages to
68 mapcount
= PageSlab(page
) ? 0 : page_mapcount(page
);
70 if (PageCompound(page
))
71 pr_warn("page:%px refcount:%d mapcount:%d mapping:%px "
72 "index:%#lx compound_mapcount: %d\n",
73 page
, page_ref_count(page
), mapcount
,
74 page
->mapping
, page_to_pgoff(page
),
75 compound_mapcount(page
));
77 pr_warn("page:%px refcount:%d mapcount:%d mapping:%px index:%#lx\n",
78 page
, page_ref_count(page
), mapcount
,
79 page
->mapping
, page_to_pgoff(page
));
81 pr_warn("ksm flags: %#lx(%pGp)\n", page
->flags
, &page
->flags
);
82 else if (PageAnon(page
))
83 pr_warn("anon flags: %#lx(%pGp)\n", page
->flags
, &page
->flags
);
85 if (mapping
->host
&& mapping
->host
->i_dentry
.first
) {
86 struct dentry
*dentry
;
87 dentry
= container_of(mapping
->host
->i_dentry
.first
, struct dentry
, d_u
.d_alias
);
88 pr_warn("%ps name:\"%pd\"\n", mapping
->a_ops
, dentry
);
90 pr_warn("%ps\n", mapping
->a_ops
);
91 pr_warn("flags: %#lx(%pGp)\n", page
->flags
, &page
->flags
);
93 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
+ 1);
96 print_hex_dump(KERN_WARNING
, "raw: ", DUMP_PREFIX_NONE
, 32,
97 sizeof(unsigned long), page
,
98 sizeof(struct page
), false);
101 pr_warn("page dumped because: %s\n", reason
);
104 if (!page_poisoned
&& page
->mem_cgroup
)
105 pr_warn("page->mem_cgroup:%px\n", page
->mem_cgroup
);
109 void dump_page(struct page
*page
, const char *reason
)
111 __dump_page(page
, reason
);
112 dump_page_owner(page
);
114 EXPORT_SYMBOL(dump_page
);
116 #ifdef CONFIG_DEBUG_VM
118 void dump_vma(const struct vm_area_struct
*vma
)
120 pr_emerg("vma %px start %px end %px\n"
121 "next %px prev %px mm %px\n"
122 "prot %lx anon_vma %px vm_ops %px\n"
123 "pgoff %lx file %px private_data %px\n"
124 "flags: %#lx(%pGv)\n",
125 vma
, (void *)vma
->vm_start
, (void *)vma
->vm_end
, vma
->vm_next
,
126 vma
->vm_prev
, vma
->vm_mm
,
127 (unsigned long)pgprot_val(vma
->vm_page_prot
),
128 vma
->anon_vma
, vma
->vm_ops
, vma
->vm_pgoff
,
129 vma
->vm_file
, vma
->vm_private_data
,
130 vma
->vm_flags
, &vma
->vm_flags
);
132 EXPORT_SYMBOL(dump_vma
);
134 void dump_mm(const struct mm_struct
*mm
)
136 pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
138 "get_unmapped_area %px\n"
140 "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
141 "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
142 "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
143 "pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
144 "start_code %lx end_code %lx start_data %lx end_data %lx\n"
145 "start_brk %lx brk %lx start_stack %lx\n"
146 "arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
147 "binfmt %px flags %lx core_state %px\n"
155 #ifdef CONFIG_MMU_NOTIFIER
156 "mmu_notifier_mm %px\n"
158 #ifdef CONFIG_NUMA_BALANCING
159 "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
161 "tlb_flush_pending %d\n"
162 "def_flags: %#lx(%pGv)\n",
164 mm
, mm
->mmap
, (long long) mm
->vmacache_seqnum
, mm
->task_size
,
166 mm
->get_unmapped_area
,
168 mm
->mmap_base
, mm
->mmap_legacy_base
, mm
->highest_vm_end
,
169 mm
->pgd
, atomic_read(&mm
->mm_users
),
170 atomic_read(&mm
->mm_count
),
171 mm_pgtables_bytes(mm
),
173 mm
->hiwater_rss
, mm
->hiwater_vm
, mm
->total_vm
, mm
->locked_vm
,
174 (u64
)atomic64_read(&mm
->pinned_vm
),
175 mm
->data_vm
, mm
->exec_vm
, mm
->stack_vm
,
176 mm
->start_code
, mm
->end_code
, mm
->start_data
, mm
->end_data
,
177 mm
->start_brk
, mm
->brk
, mm
->start_stack
,
178 mm
->arg_start
, mm
->arg_end
, mm
->env_start
, mm
->env_end
,
179 mm
->binfmt
, mm
->flags
, mm
->core_state
,
187 #ifdef CONFIG_MMU_NOTIFIER
190 #ifdef CONFIG_NUMA_BALANCING
191 mm
->numa_next_scan
, mm
->numa_scan_offset
, mm
->numa_scan_seq
,
193 atomic_read(&mm
->tlb_flush_pending
),
194 mm
->def_flags
, &mm
->def_flags
198 static bool page_init_poisoning __read_mostly
= true;
200 static int __init
setup_vm_debug(char *str
)
202 bool __page_init_poisoning
= true;
205 * Calling vm_debug with no arguments is equivalent to requesting
206 * to enable all debugging options we can control.
208 if (*str
++ != '=' || !*str
)
211 __page_init_poisoning
= false;
216 switch (tolower(*str
)) {
218 __page_init_poisoning
= true;
221 pr_err("vm_debug option '%c' unknown. skipped\n",
228 if (page_init_poisoning
&& !__page_init_poisoning
)
229 pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
231 page_init_poisoning
= __page_init_poisoning
;
235 __setup("vm_debug", setup_vm_debug
);
237 void page_init_poison(struct page
*page
, size_t size
)
239 if (page_init_poisoning
)
240 memset(page
, PAGE_POISON_PATTERN
, size
);
242 EXPORT_SYMBOL_GPL(page_init_poison
);
243 #endif /* CONFIG_DEBUG_VM */