Merge branch 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvar...
[linux-2.6-microblaze.git] / mm / hwpoison-inject.c
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 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, 0);
34         /*
35          * This implies unable to support non-LRU pages.
36          */
37         if (!PageLRU(hpage) && !PageHuge(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
49 inject:
50         pr_info("Injecting memory failure at pfn %#lx\n", pfn);
51         return memory_failure(pfn, 0);
52 }
53
54 static int hwpoison_unpoison(void *data, u64 val)
55 {
56         if (!capable(CAP_SYS_ADMIN))
57                 return -EPERM;
58
59         return unpoison_memory(val);
60 }
61
62 DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
63 DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
64
65 static void pfn_inject_exit(void)
66 {
67         debugfs_remove_recursive(hwpoison_dir);
68 }
69
70 static int pfn_inject_init(void)
71 {
72         hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
73
74         /*
75          * Note that the below poison/unpoison interfaces do not involve
76          * hardware status change, hence do not require hardware support.
77          * They are mainly for testing hwpoison in software level.
78          */
79         debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
80                             &hwpoison_fops);
81
82         debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
83                             &unpoison_fops);
84
85         debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
86                            &hwpoison_filter_enable);
87
88         debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
89                            &hwpoison_filter_dev_major);
90
91         debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
92                            &hwpoison_filter_dev_minor);
93
94         debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
95                            &hwpoison_filter_flags_mask);
96
97         debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
98                            &hwpoison_filter_flags_value);
99
100 #ifdef CONFIG_MEMCG
101         debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
102                            &hwpoison_filter_memcg);
103 #endif
104
105         return 0;
106 }
107
108 module_init(pfn_inject_init);
109 module_exit(pfn_inject_exit);
110 MODULE_LICENSE("GPL");