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>
7 #include <linux/swap.h>
8 #include <linux/pagemap.h>
9 #include <linux/hugetlb.h>
12 static struct dentry *hwpoison_dir;
14 static int hwpoison_inject(void *data, u64 val)
16 unsigned long pfn = val;
21 if (!capable(CAP_SYS_ADMIN))
28 folio = page_folio(p);
30 if (!hwpoison_filter_enable)
35 * This implies unable to support non-LRU pages except free page.
37 if (!folio_test_lru(folio) && !folio_test_hugetlb(folio) &&
38 !is_free_buddy_page(p))
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.
46 err = hwpoison_filter(&folio->page);
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;
56 static int hwpoison_unpoison(void *data, u64 val)
58 if (!capable(CAP_SYS_ADMIN))
61 return unpoison_memory(val);
64 DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
65 DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
67 static void __exit pfn_inject_exit(void)
69 hwpoison_filter_enable = 0;
70 debugfs_remove_recursive(hwpoison_dir);
73 static int __init pfn_inject_init(void)
75 hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
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.
82 debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
85 debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
88 debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
89 &hwpoison_filter_enable);
91 debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
92 &hwpoison_filter_dev_major);
94 debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
95 &hwpoison_filter_dev_minor);
97 debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
98 &hwpoison_filter_flags_mask);
100 debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
101 &hwpoison_filter_flags_value);
104 debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
105 &hwpoison_filter_memcg);
111 module_init(pfn_inject_init);
112 module_exit(pfn_inject_exit);
113 MODULE_DESCRIPTION("HWPoison pages injector");
114 MODULE_LICENSE("GPL");