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