blob: 2b6b3200fa65fd5a4b154d4b9717e1d459905e02 [file] [log] [blame]
Andi Kleencae681f2009-09-16 11:50:17 +02001/* 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>
Wu Fengguang31d3d342009-12-16 12:19:59 +01006#include <linux/swap.h>
7#include <linux/pagemap.h>
Wu Fengguang7c116f22009-12-16 12:19:59 +01008#include "internal.h"
Andi Kleencae681f2009-09-16 11:50:17 +02009
Wu Fengguang847ce402009-12-16 12:19:58 +010010static struct dentry *hwpoison_dir;
Andi Kleencae681f2009-09-16 11:50:17 +020011
12static int hwpoison_inject(void *data, u64 val)
13{
Wu Fengguang31d3d342009-12-16 12:19:59 +010014 unsigned long pfn = val;
15 struct page *p;
16 int err;
17
Andi Kleencae681f2009-09-16 11:50:17 +020018 if (!capable(CAP_SYS_ADMIN))
19 return -EPERM;
Wu Fengguang31d3d342009-12-16 12:19:59 +010020
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);
Andi Kleencae681f2009-09-16 11:50:17 +020053}
54
Wu Fengguang847ce402009-12-16 12:19:58 +010055static 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
Andi Kleencae681f2009-09-16 11:50:17 +020063DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
Wu Fengguang847ce402009-12-16 12:19:58 +010064DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
Andi Kleencae681f2009-09-16 11:50:17 +020065
66static void pfn_inject_exit(void)
67{
68 if (hwpoison_dir)
69 debugfs_remove_recursive(hwpoison_dir);
70}
71
72static int pfn_inject_init(void)
73{
Wu Fengguang847ce402009-12-16 12:19:58 +010074 struct dentry *dentry;
75
Andi Kleencae681f2009-09-16 11:50:17 +020076 hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
77 if (hwpoison_dir == NULL)
78 return -ENOMEM;
Wu Fengguang847ce402009-12-16 12:19:58 +010079
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,
Andi Kleencae681f2009-09-16 11:50:17 +020086 NULL, &hwpoison_fops);
Wu Fengguang847ce402009-12-16 12:19:58 +010087 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
Wu Fengguang7c116f22009-12-16 12:19:59 +010095 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
Andi Kleencae681f2009-09-16 11:50:17 +0200105 return 0;
Wu Fengguang847ce402009-12-16 12:19:58 +0100106fail:
107 pfn_inject_exit();
108 return -ENOMEM;
Andi Kleencae681f2009-09-16 11:50:17 +0200109}
110
111module_init(pfn_inject_init);
112module_exit(pfn_inject_exit);
113MODULE_LICENSE("GPL");