1 /* Inject a hwpoison memory failure on a arbitary pfn */
2 #include <linux/module.h>
3 #include <linux/debugfs.h>
4 #include <linux/kernel.h>
6 #include <linux/swap.h>
7 #include <linux/pagemap.h>
10 static struct dentry *hwpoison_dir;
12 static int hwpoison_inject(void *data, u64 val)
14 unsigned long pfn = val;
18 if (!capable(CAP_SYS_ADMIN))
26 * This implies unable to support free buddy pages.
28 if (!get_page_unless_zero(p))
34 * This implies unable to support non-LRU pages.
40 * do a racy check with elevated page count, to make sure PG_hwpoison
41 * will only be set for the targeted owner (or on a free page).
42 * We temporarily take page lock for try_get_mem_cgroup_from_page().
43 * __memory_failure() will redo the check reliably inside page lock.
46 err = hwpoison_filter(p);
51 printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
52 return __memory_failure(pfn, 18, MF_COUNT_INCREASED);
55 static int hwpoison_unpoison(void *data, u64 val)
57 if (!capable(CAP_SYS_ADMIN))
60 return unpoison_memory(val);
63 DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
64 DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
66 static void pfn_inject_exit(void)
69 debugfs_remove_recursive(hwpoison_dir);
72 static int pfn_inject_init(void)
74 struct dentry *dentry;
76 hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
77 if (hwpoison_dir == NULL)
81 * Note that the below poison/unpoison interfaces do not involve
82 * hardware status change, hence do not require hardware support.
83 * They are mainly for testing hwpoison in software level.
85 dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
86 NULL, &hwpoison_fops);
90 dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
91 NULL, &unpoison_fops);
95 dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
96 hwpoison_dir, &hwpoison_filter_dev_major);
100 dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
101 hwpoison_dir, &hwpoison_filter_dev_minor);
105 dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
106 hwpoison_dir, &hwpoison_filter_flags_mask);
110 dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
111 hwpoison_dir, &hwpoison_filter_flags_value);
115 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
116 dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
117 hwpoison_dir, &hwpoison_filter_memcg);
128 module_init(pfn_inject_init);
129 module_exit(pfn_inject_exit);
130 MODULE_LICENSE("GPL");