mm/hwpoison-inject.c

   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>
   5 #include <linux/mm.h>
   6
   7 static struct dentry *hwpoison_dir;
   8
   9 static int hwpoison_inject(void *data, u64 val)
  10 {
  11         if (!capable(CAP_SYS_ADMIN))
  12                 return -EPERM;
  13         printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
  14         return __memory_failure(val, 18, 0);
  15 }
  16
  17 static int hwpoison_unpoison(void *data, u64 val)
  18 {
  19         if (!capable(CAP_SYS_ADMIN))
  20                 return -EPERM;
  21
  22         return unpoison_memory(val);
  23 }
  24
  25 DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
  26 DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
  27
  28 static void pfn_inject_exit(void)
  29 {
  30         if (hwpoison_dir)
  31                 debugfs_remove_recursive(hwpoison_dir);
  32 }
  33
  34 static int pfn_inject_init(void)
  35 {
  36         struct dentry *dentry;
  37
  38         hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
  39         if (hwpoison_dir == NULL)
  40                 return -ENOMEM;
  41
  42         /*
  43          * Note that the below poison/unpoison interfaces do not involve
  44          * hardware status change, hence do not require hardware support.
  45          * They are mainly for testing hwpoison in software level.
  46          */
  47         dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
  48                                           NULL, &hwpoison_fops);
  49         if (!dentry)
  50                 goto fail;
  51
  52         dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
  53                                      NULL, &unpoison_fops);
  54         if (!dentry)
  55                 goto fail;
  56
  57         return 0;
  58 fail:
  59         pfn_inject_exit();
  60         return -ENOMEM;
  61 }
  62
  63 module_init(pfn_inject_init);
  64 module_exit(pfn_inject_exit);
  65 MODULE_LICENSE("GPL");