Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/mm/hwpoison-inject.c
26131 views
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


12
static struct dentry *hwpoison_dir;

13


14
static int hwpoison_inject(void *data, u64 val)

15
{

16
	unsigned long pfn = val;

17
	struct page *p;

18
	struct folio *folio;

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
	folio = page_folio(p);

29


30
	if (!hwpoison_filter_enable)

31
		goto inject;

32


33
	shake_folio(folio);

34
	/*

35
	 * This implies unable to support non-LRU pages except free page.

36
	 */

37
	if (!folio_test_lru(folio) && !folio_test_hugetlb(folio) &&

38
	    !is_free_buddy_page(p))

39
		return 0;

40


41
	/*

42
	 * do a racy check to make sure PG_hwpoison will only be set for

43
	 * the targeted owner (or on a free page).

44
	 * memory_failure() will redo the check reliably inside page lock.

45
	 */

46
	err = hwpoison_filter(&folio->page);

47
	if (err)

48
		return 0;

49


50
inject:

51
	pr_info("Injecting memory failure at pfn %#lx\n", pfn);

52
	err = memory_failure(pfn, MF_SW_SIMULATED);

53
	return (err == -EOPNOTSUPP) ? 0 : err;

54
}

55


56
static int hwpoison_unpoison(void *data, u64 val)

57
{

58
	if (!capable(CAP_SYS_ADMIN))

59
		return -EPERM;

60


61
	return unpoison_memory(val);

62
}

63


64
DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");

65
DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");

66


67
static void __exit pfn_inject_exit(void)

68
{

69
	hwpoison_filter_enable = 0;

70
	debugfs_remove_recursive(hwpoison_dir);

71
}

72


73
static int __init pfn_inject_init(void)

74
{

75
	hwpoison_dir = debugfs_create_dir("hwpoison", NULL);

76


77
	/*

78
	 * Note that the below poison/unpoison interfaces do not involve

79
	 * hardware status change, hence do not require hardware support.

80
	 * They are mainly for testing hwpoison in software level.

81
	 */

82
	debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,

83
			    &hwpoison_fops);

84


85
	debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,

86
			    &unpoison_fops);

87


88
	debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,

89
			   &hwpoison_filter_enable);

90


91
	debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,

92
			   &hwpoison_filter_dev_major);

93


94
	debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,

95
			   &hwpoison_filter_dev_minor);

96


97
	debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,

98
			   &hwpoison_filter_flags_mask);

99


100
	debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,

101
			   &hwpoison_filter_flags_value);

102


103
#ifdef CONFIG_MEMCG

104
	debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,

105
			   &hwpoison_filter_memcg);

106
#endif

107


108
	return 0;

109
}

110


111
module_init(pfn_inject_init);

112
module_exit(pfn_inject_exit);

113
MODULE_DESCRIPTION("HWPoison pages injector");

114
MODULE_LICENSE("GPL");

115


116