| // 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); |
| |
| if (!hwpoison_filter_enable) |
| goto inject; |
| |
| shake_page(hpage); |
| /* |
| * This implies unable to support non-LRU pages except free page. |
| */ |
| if (!PageLRU(hpage) && !PageHuge(p) && !is_free_buddy_page(p)) |
| return 0; |
| |
| /* |
| * do a racy check 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) |
| return 0; |
| |
| inject: |
| pr_info("Injecting memory failure at pfn %#lx\n", pfn); |
| err = memory_failure(pfn, MF_SW_SIMULATED); |
| return (err == -EOPNOTSUPP) ? 0 : err; |
| } |
| |
| 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) |
| { |
| hwpoison_filter_enable = 0; |
| 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"); |