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Commit | Line | Data |
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cae681fc AK |
1 | /* Inject a hwpoison memory failure on a arbitary pfn */ |
2 | #include <linux/module.h> | |
3 | #include <linux/debugfs.h> | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/mm.h> | |
31d3d348 WF |
6 | #include <linux/swap.h> |
7 | #include <linux/pagemap.h> | |
7c116f2b | 8 | #include "internal.h" |
cae681fc | 9 | |
847ce401 | 10 | static struct dentry *hwpoison_dir; |
cae681fc AK |
11 | |
12 | static int hwpoison_inject(void *data, u64 val) | |
13 | { | |
31d3d348 WF |
14 | unsigned long pfn = val; |
15 | struct page *p; | |
16 | int err; | |
17 | ||
cae681fc AK |
18 | if (!capable(CAP_SYS_ADMIN)) |
19 | return -EPERM; | |
31d3d348 WF |
20 | |
21 | if (!pfn_valid(pfn)) | |
22 | return -ENXIO; | |
23 | ||
24 | p = pfn_to_page(pfn); | |
25 | /* | |
26 | * This implies unable to support free buddy pages. | |
27 | */ | |
28 | if (!get_page_unless_zero(p)) | |
29 | return 0; | |
30 | ||
31 | if (!PageLRU(p)) | |
32 | shake_page(p); | |
33 | /* | |
34 | * This implies unable to support non-LRU pages. | |
35 | */ | |
36 | if (!PageLRU(p)) | |
37 | return 0; | |
38 | ||
39 | /* | |
40 | * do a racy check with elevated page count, to make sure PG_hwpoison | |
41 | * will only be set for the targeted owner (or on a free page). | |
42 | * We temporarily take page lock for try_get_mem_cgroup_from_page(). | |
43 | * __memory_failure() will redo the check reliably inside page lock. | |
44 | */ | |
45 | lock_page(p); | |
46 | err = hwpoison_filter(p); | |
47 | unlock_page(p); | |
48 | if (err) | |
49 | return 0; | |
50 | ||
51 | printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn); | |
52 | return __memory_failure(pfn, 18, MF_COUNT_INCREASED); | |
cae681fc AK |
53 | } |
54 | ||
847ce401 WF |
55 | static int hwpoison_unpoison(void *data, u64 val) |
56 | { | |
57 | if (!capable(CAP_SYS_ADMIN)) | |
58 | return -EPERM; | |
59 | ||
60 | return unpoison_memory(val); | |
61 | } | |
62 | ||
cae681fc | 63 | DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n"); |
847ce401 | 64 | DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n"); |
cae681fc AK |
65 | |
66 | static void pfn_inject_exit(void) | |
67 | { | |
68 | if (hwpoison_dir) | |
69 | debugfs_remove_recursive(hwpoison_dir); | |
70 | } | |
71 | ||
72 | static int pfn_inject_init(void) | |
73 | { | |
847ce401 WF |
74 | struct dentry *dentry; |
75 | ||
cae681fc AK |
76 | hwpoison_dir = debugfs_create_dir("hwpoison", NULL); |
77 | if (hwpoison_dir == NULL) | |
78 | return -ENOMEM; | |
847ce401 WF |
79 | |
80 | /* | |
81 | * Note that the below poison/unpoison interfaces do not involve | |
82 | * hardware status change, hence do not require hardware support. | |
83 | * They are mainly for testing hwpoison in software level. | |
84 | */ | |
85 | dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir, | |
cae681fc | 86 | NULL, &hwpoison_fops); |
847ce401 WF |
87 | if (!dentry) |
88 | goto fail; | |
89 | ||
90 | dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir, | |
91 | NULL, &unpoison_fops); | |
92 | if (!dentry) | |
93 | goto fail; | |
94 | ||
7c116f2b WF |
95 | dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600, |
96 | hwpoison_dir, &hwpoison_filter_dev_major); | |
97 | if (!dentry) | |
98 | goto fail; | |
99 | ||
100 | dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600, | |
101 | hwpoison_dir, &hwpoison_filter_dev_minor); | |
102 | if (!dentry) | |
103 | goto fail; | |
104 | ||
478c5ffc WF |
105 | dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600, |
106 | hwpoison_dir, &hwpoison_filter_flags_mask); | |
107 | if (!dentry) | |
108 | goto fail; | |
109 | ||
110 | dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600, | |
111 | hwpoison_dir, &hwpoison_filter_flags_value); | |
112 | if (!dentry) | |
113 | goto fail; | |
114 | ||
4fd466eb AK |
115 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
116 | dentry = debugfs_create_u64("corrupt-filter-memcg", 0600, | |
117 | hwpoison_dir, &hwpoison_filter_memcg); | |
118 | if (!dentry) | |
119 | goto fail; | |
120 | #endif | |
121 | ||
cae681fc | 122 | return 0; |
847ce401 WF |
123 | fail: |
124 | pfn_inject_exit(); | |
125 | return -ENOMEM; | |
cae681fc AK |
126 | } |
127 | ||
128 | module_init(pfn_inject_init); | |
129 | module_exit(pfn_inject_exit); | |
130 | MODULE_LICENSE("GPL"); |