xref: /linux/mm/failslab.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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 */
68