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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
11static struct dentry *hwpoison_dir;
12
13static 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 (!pfn_valid(pfn))
24 return -ENXIO;
25
26 p = pfn_to_page(pfn);
27 hpage = compound_head(p);
28 /*
29 * This implies unable to support free buddy pages.
30 */
31 if (!get_hwpoison_page(p))
32 return 0;
33
34 if (!hwpoison_filter_enable)
35 goto inject;
36
37 if (!PageLRU(hpage) && !PageHuge(p))
38 shake_page(hpage, 0);
39 /*
40 * This implies unable to support non-LRU pages.
41 */
42 if (!PageLRU(hpage) && !PageHuge(p))
43 goto put_out;
44
45 /*
46 * do a racy check with elevated page count, to make sure PG_hwpoison
47 * will only be set for the targeted owner (or on a free page).
48 * memory_failure() will redo the check reliably inside page lock.
49 */
50 err = hwpoison_filter(hpage);
51 if (err)
52 goto put_out;
53
54inject:
55 pr_info("Injecting memory failure at pfn %#lx\n", pfn);
56 return memory_failure(pfn, 18, MF_COUNT_INCREASED);
57put_out:
58 put_hwpoison_page(p);
59 return 0;
60}
61
62static int hwpoison_unpoison(void *data, u64 val)
63{
64 if (!capable(CAP_SYS_ADMIN))
65 return -EPERM;
66
67 return unpoison_memory(val);
68}
69
70DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
71DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
72
73static void pfn_inject_exit(void)
74{
75 debugfs_remove_recursive(hwpoison_dir);
76}
77
78static 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", 0200, hwpoison_dir,
92 NULL, &hwpoison_fops);
93 if (!dentry)
94 goto fail;
95
96 dentry = debugfs_create_file("unpoison-pfn", 0200, 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_MEMCG
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;
134fail:
135 pfn_inject_exit();
136 return -ENOMEM;
137}
138
139module_init(pfn_inject_init);
140module_exit(pfn_inject_exit);
141MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/* Inject a hwpoison memory failure on a arbitrary pfn */
3#include <linux/module.h>
4#include <linux/debugfs.h>
5#include <linux/kernel.h>
6#include <linux/mm.h>
7#include <linux/swap.h>
8#include <linux/pagemap.h>
9#include <linux/hugetlb.h>
10#include "internal.h"
11
12static struct dentry *hwpoison_dir;
13
14static int hwpoison_inject(void *data, u64 val)
15{
16 unsigned long pfn = val;
17 struct page *p;
18 struct page *hpage;
19 int err;
20
21 if (!capable(CAP_SYS_ADMIN))
22 return -EPERM;
23
24 if (!pfn_valid(pfn))
25 return -ENXIO;
26
27 p = pfn_to_page(pfn);
28 hpage = compound_head(p);
29
30 if (!hwpoison_filter_enable)
31 goto inject;
32
33 shake_page(hpage);
34 /*
35 * This implies unable to support non-LRU pages except free page.
36 */
37 if (!PageLRU(hpage) && !PageHuge(p) && !is_free_buddy_page(p))
38 return 0;
39
40 /*
41 * do a racy check to make sure PG_hwpoison will only be set for
42 * the targeted owner (or on a free page).
43 * memory_failure() will redo the check reliably inside page lock.
44 */
45 err = hwpoison_filter(hpage);
46 if (err)
47 return 0;
48
49inject:
50 pr_info("Injecting memory failure at pfn %#lx\n", pfn);
51 err = memory_failure(pfn, MF_SW_SIMULATED);
52 return (err == -EOPNOTSUPP) ? 0 : err;
53}
54
55static 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
63DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
64DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
65
66static void __exit pfn_inject_exit(void)
67{
68 hwpoison_filter_enable = 0;
69 debugfs_remove_recursive(hwpoison_dir);
70}
71
72static int __init pfn_inject_init(void)
73{
74 hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
75
76 /*
77 * Note that the below poison/unpoison interfaces do not involve
78 * hardware status change, hence do not require hardware support.
79 * They are mainly for testing hwpoison in software level.
80 */
81 debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
82 &hwpoison_fops);
83
84 debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
85 &unpoison_fops);
86
87 debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
88 &hwpoison_filter_enable);
89
90 debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
91 &hwpoison_filter_dev_major);
92
93 debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
94 &hwpoison_filter_dev_minor);
95
96 debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
97 &hwpoison_filter_flags_mask);
98
99 debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
100 &hwpoison_filter_flags_value);
101
102#ifdef CONFIG_MEMCG
103 debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
104 &hwpoison_filter_memcg);
105#endif
106
107 return 0;
108}
109
110module_init(pfn_inject_init);
111module_exit(pfn_inject_exit);
112MODULE_LICENSE("GPL");