mm/failslab.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/fault-inject.h>
   3 #include <linux/slab.h>
   4 #include <linux/mm.h>
   5 #include "slab.h"
   6
   7 static struct {
   8         struct fault_attr attr;
   9         bool ignore_gfp_reclaim;
  10         bool cache_filter;
  11 } failslab = {
  12         .attr = FAULT_ATTR_INITIALIZER,
  13         .ignore_gfp_reclaim = true,
  14         .cache_filter = false,
  15 };
  16
  17 bool should_failslab(struct kmem_cache *s, gfp_t gfpflags)
  18 {
  19         /* No fault-injection for bootstrap cache */
  20         if (unlikely(s == kmem_cache))
  21                 return false;
  22
  23         if (gfpflags & __GFP_NOFAIL)
  24                 return false;
  25
  26         if (failslab.ignore_gfp_reclaim && (gfpflags & __GFP_RECLAIM))
  27                 return false;
  28
  29         if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
  30                 return false;
  31
  32         return should_fail(&failslab.attr, s->object_size);
  33 }
  34
  35 static int __init setup_failslab(char *str)
  36 {
  37         return setup_fault_attr(&failslab.attr, str);
  38 }
  39 __setup("failslab=", setup_failslab);
  40
  41 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  42 static int __init failslab_debugfs_init(void)
  43 {
  44         struct dentry *dir;
  45         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
  46
  47         dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
  48         if (IS_ERR(dir))
  49                 return PTR_ERR(dir);
  50
  51         if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
  52                                 &failslab.ignore_gfp_reclaim))
  53                 goto fail;
  54         if (!debugfs_create_bool("cache-filter", mode, dir,
  55                                 &failslab.cache_filter))
  56                 goto fail;
  57
  58         return 0;
  59 fail:
  60         debugfs_remove_recursive(dir);
  61
  62         return -ENOMEM;
  63 }
  64
  65 late_initcall(failslab_debugfs_init);
  66
  67 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */