LXR linux/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
  12static struct dentry *hwpoison_dir;
  13
  14static 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);
  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
  49inject:
  50        pr_info("Injecting memory failure at pfn %#lx\n", pfn);
  51        return memory_failure(pfn, 0);
  52}
  53
  54static 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
  62DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
  63DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
  64
  65static void pfn_inject_exit(void)
  66{
  67        debugfs_remove_recursive(hwpoison_dir);
  68}
  69
  70static 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
 108module_init(pfn_inject_init);
 109module_exit(pfn_inject_exit);
 110MODULE_LICENSE("GPL");
 111