cris: fix a build error in kernel/fork.c
[linux-2.6.git] / mm / hwpoison-inject.c
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");