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Source at commit ec7cab4cbb721bff91ec924ec691efd8daf36579 created 12 years 8 months ago. By Maarten ter Huurne, MIPS: JZ4740: A320: Updated quickstart documentation. | |
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1 | /* Inject a hwpoison memory failure on a arbitrary pfn */ |
2 | #include <linux/module.h> |
3 | #include <linux/debugfs.h> |
4 | #include <linux/kernel.h> |
5 | #include <linux/mm.h> |
6 | #include <linux/swap.h> |
7 | #include <linux/pagemap.h> |
8 | #include <linux/hugetlb.h> |
9 | #include "internal.h" |
10 | |
11 | static struct dentry *hwpoison_dir; |
12 | |
13 | static int hwpoison_inject(void *data, u64 val) |
14 | { |
15 | unsigned long pfn = val; |
16 | struct page *p; |
17 | struct page *hpage; |
18 | int err; |
19 | |
20 | if (!capable(CAP_SYS_ADMIN)) |
21 | return -EPERM; |
22 | |
23 | if (!hwpoison_filter_enable) |
24 | goto inject; |
25 | if (!pfn_valid(pfn)) |
26 | return -ENXIO; |
27 | |
28 | p = pfn_to_page(pfn); |
29 | hpage = compound_head(p); |
30 | /* |
31 | * This implies unable to support free buddy pages. |
32 | */ |
33 | if (!get_page_unless_zero(hpage)) |
34 | return 0; |
35 | |
36 | if (!PageLRU(p) && !PageHuge(p)) |
37 | shake_page(p, 0); |
38 | /* |
39 | * This implies unable to support non-LRU pages. |
40 | */ |
41 | if (!PageLRU(p) && !PageHuge(p)) |
42 | return 0; |
43 | |
44 | /* |
45 | * do a racy check with elevated page count, to make sure PG_hwpoison |
46 | * will only be set for the targeted owner (or on a free page). |
47 | * We temporarily take page lock for try_get_mem_cgroup_from_page(). |
48 | * __memory_failure() will redo the check reliably inside page lock. |
49 | */ |
50 | lock_page(hpage); |
51 | err = hwpoison_filter(hpage); |
52 | unlock_page(hpage); |
53 | if (err) |
54 | return 0; |
55 | |
56 | inject: |
57 | printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn); |
58 | return __memory_failure(pfn, 18, MF_COUNT_INCREASED); |
59 | } |
60 | |
61 | static int hwpoison_unpoison(void *data, u64 val) |
62 | { |
63 | if (!capable(CAP_SYS_ADMIN)) |
64 | return -EPERM; |
65 | |
66 | return unpoison_memory(val); |
67 | } |
68 | |
69 | DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n"); |
70 | DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n"); |
71 | |
72 | static void pfn_inject_exit(void) |
73 | { |
74 | if (hwpoison_dir) |
75 | debugfs_remove_recursive(hwpoison_dir); |
76 | } |
77 | |
78 | static int pfn_inject_init(void) |
79 | { |
80 | struct dentry *dentry; |
81 | |
82 | hwpoison_dir = debugfs_create_dir("hwpoison", NULL); |
83 | if (hwpoison_dir == NULL) |
84 | return -ENOMEM; |
85 | |
86 | /* |
87 | * Note that the below poison/unpoison interfaces do not involve |
88 | * hardware status change, hence do not require hardware support. |
89 | * They are mainly for testing hwpoison in software level. |
90 | */ |
91 | dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir, |
92 | NULL, &hwpoison_fops); |
93 | if (!dentry) |
94 | goto fail; |
95 | |
96 | dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir, |
97 | NULL, &unpoison_fops); |
98 | if (!dentry) |
99 | goto fail; |
100 | |
101 | dentry = debugfs_create_u32("corrupt-filter-enable", 0600, |
102 | hwpoison_dir, &hwpoison_filter_enable); |
103 | if (!dentry) |
104 | goto fail; |
105 | |
106 | dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600, |
107 | hwpoison_dir, &hwpoison_filter_dev_major); |
108 | if (!dentry) |
109 | goto fail; |
110 | |
111 | dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600, |
112 | hwpoison_dir, &hwpoison_filter_dev_minor); |
113 | if (!dentry) |
114 | goto fail; |
115 | |
116 | dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600, |
117 | hwpoison_dir, &hwpoison_filter_flags_mask); |
118 | if (!dentry) |
119 | goto fail; |
120 | |
121 | dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600, |
122 | hwpoison_dir, &hwpoison_filter_flags_value); |
123 | if (!dentry) |
124 | goto fail; |
125 | |
126 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
127 | dentry = debugfs_create_u64("corrupt-filter-memcg", 0600, |
128 | hwpoison_dir, &hwpoison_filter_memcg); |
129 | if (!dentry) |
130 | goto fail; |
131 | #endif |
132 | |
133 | return 0; |
134 | fail: |
135 | pfn_inject_exit(); |
136 | return -ENOMEM; |
137 | } |
138 | |
139 | module_init(pfn_inject_init); |
140 | module_exit(pfn_inject_exit); |
141 | MODULE_LICENSE("GPL"); |
142 |
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