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
|
// SPDX-License-Identifier: GPL-2.0-only
/* 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 (!pfn_valid(pfn))
return -ENXIO;
p = pfn_to_page(pfn);
hpage = compound_head(p);
/*
* This implies unable to support free buddy pages.
*/
if (!get_hwpoison_page(p))
return 0;
if (!hwpoison_filter_enable)
goto inject;
shake_page(hpage, 0);
/*
* This implies unable to support non-LRU pages.
*/
if (!PageLRU(hpage) && !PageHuge(p))
goto put_out;
/*
* 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).
* memory_failure() will redo the check reliably inside page lock.
*/
err = hwpoison_filter(hpage);
if (err)
goto put_out;
inject:
pr_info("Injecting memory failure at pfn %#lx\n", pfn);
return memory_failure(pfn, MF_COUNT_INCREASED);
put_out:
put_hwpoison_page(p);
return 0;
}
static int hwpoison_unpoison(void *data, u64 val)
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return unpoison_memory(val);
}
DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
static void pfn_inject_exit(void)
{
debugfs_remove_recursive(hwpoison_dir);
}
static int pfn_inject_init(void)
{
hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
/*
* 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.
*/
debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
&hwpoison_fops);
debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
&unpoison_fops);
debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
&hwpoison_filter_enable);
debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
&hwpoison_filter_dev_major);
debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
&hwpoison_filter_dev_minor);
debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
&hwpoison_filter_flags_mask);
debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
&hwpoison_filter_flags_value);
#ifdef CONFIG_MEMCG
debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
&hwpoison_filter_memcg);
#endif
return 0;
}
module_init(pfn_inject_init);
module_exit(pfn_inject_exit);
MODULE_LICENSE("GPL");
|
