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Lucas De Marchi25985ed2011-03-30 22:57:33 -03001/* Inject a hwpoison memory failure on a arbitrary pfn */
Andi Kleencae681f2009-09-16 11:50:17 +02002#include <linux/module.h>
3#include <linux/debugfs.h>
4#include <linux/kernel.h>
5#include <linux/mm.h>
Wu Fengguang31d3d342009-12-16 12:19:59 +01006#include <linux/swap.h>
7#include <linux/pagemap.h>
Naoya Horiguchi43131e12010-05-28 09:29:22 +09008#include <linux/hugetlb.h>
Wu Fengguang7c116f22009-12-16 12:19:59 +01009#include "internal.h"
Andi Kleencae681f2009-09-16 11:50:17 +020010
Wu Fengguang847ce402009-12-16 12:19:58 +010011static struct dentry *hwpoison_dir;
Andi Kleencae681f2009-09-16 11:50:17 +020012
13static int hwpoison_inject(void *data, u64 val)
14{
Wu Fengguang31d3d342009-12-16 12:19:59 +010015 unsigned long pfn = val;
16 struct page *p;
Naoya Horiguchi43131e12010-05-28 09:29:22 +090017 struct page *hpage;
Wu Fengguang31d3d342009-12-16 12:19:59 +010018 int err;
19
Andi Kleencae681f2009-09-16 11:50:17 +020020 if (!capable(CAP_SYS_ADMIN))
21 return -EPERM;
Wu Fengguang31d3d342009-12-16 12:19:59 +010022
Andi Kleen0d57eb82009-12-16 12:20:01 +010023 if (!hwpoison_filter_enable)
24 goto inject;
Wu Fengguang31d3d342009-12-16 12:19:59 +010025 if (!pfn_valid(pfn))
26 return -ENXIO;
27
28 p = pfn_to_page(pfn);
Naoya Horiguchi43131e12010-05-28 09:29:22 +090029 hpage = compound_head(p);
Wu Fengguang31d3d342009-12-16 12:19:59 +010030 /*
31 * This implies unable to support free buddy pages.
32 */
Naoya Horiguchi43131e12010-05-28 09:29:22 +090033 if (!get_page_unless_zero(hpage))
Wu Fengguang31d3d342009-12-16 12:19:59 +010034 return 0;
35
Naoya Horiguchi43131e12010-05-28 09:29:22 +090036 if (!PageLRU(p) && !PageHuge(p))
Andi Kleenfacb6012009-12-16 12:20:00 +010037 shake_page(p, 0);
Wu Fengguang31d3d342009-12-16 12:19:59 +010038 /*
39 * This implies unable to support non-LRU pages.
40 */
Naoya Horiguchi43131e12010-05-28 09:29:22 +090041 if (!PageLRU(p) && !PageHuge(p))
Wu Fengguang31d3d342009-12-16 12:19:59 +010042 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 */
Naoya Horiguchi43131e12010-05-28 09:29:22 +090050 lock_page(hpage);
51 err = hwpoison_filter(hpage);
52 unlock_page(hpage);
Wu Fengguang31d3d342009-12-16 12:19:59 +010053 if (err)
54 return 0;
55
Andi Kleen0d57eb82009-12-16 12:20:01 +010056inject:
Wu Fengguang31d3d342009-12-16 12:19:59 +010057 printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
58 return __memory_failure(pfn, 18, MF_COUNT_INCREASED);
Andi Kleencae681f2009-09-16 11:50:17 +020059}
60
Wu Fengguang847ce402009-12-16 12:19:58 +010061static 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
Andi Kleencae681f2009-09-16 11:50:17 +020069DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
Wu Fengguang847ce402009-12-16 12:19:58 +010070DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
Andi Kleencae681f2009-09-16 11:50:17 +020071
72static void pfn_inject_exit(void)
73{
74 if (hwpoison_dir)
75 debugfs_remove_recursive(hwpoison_dir);
76}
77
78static int pfn_inject_init(void)
79{
Wu Fengguang847ce402009-12-16 12:19:58 +010080 struct dentry *dentry;
81
Andi Kleencae681f2009-09-16 11:50:17 +020082 hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
83 if (hwpoison_dir == NULL)
84 return -ENOMEM;
Wu Fengguang847ce402009-12-16 12:19:58 +010085
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,
Andi Kleencae681f2009-09-16 11:50:17 +020092 NULL, &hwpoison_fops);
Wu Fengguang847ce402009-12-16 12:19:58 +010093 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
Haicheng Li1bfe5fe2009-12-16 12:19:59 +0100101 dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
102 hwpoison_dir, &hwpoison_filter_enable);
103 if (!dentry)
104 goto fail;
105
Wu Fengguang7c116f22009-12-16 12:19:59 +0100106 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
Wu Fengguang478c5ff2009-12-16 12:19:59 +0100116 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
Andi Kleen4fd466e2009-12-16 12:19:59 +0100126#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
Andi Kleencae681f2009-09-16 11:50:17 +0200133 return 0;
Wu Fengguang847ce402009-12-16 12:19:58 +0100134fail:
135 pfn_inject_exit();
136 return -ENOMEM;
Andi Kleencae681f2009-09-16 11:50:17 +0200137}
138
139module_init(pfn_inject_init);
140module_exit(pfn_inject_exit);
141MODULE_LICENSE("GPL");