xref: /linux/mm/failslab.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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 &&
27 			(gfpflags & __GFP_DIRECT_RECLAIM))
28 		return false;
29 
30 	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
31 		return false;
32 
33 	if (gfpflags & __GFP_NOWARN)
34 		failslab.attr.no_warn = true;
35 
36 	return should_fail(&failslab.attr, s->object_size);
37 }
38 
39 static int __init setup_failslab(char *str)
40 {
41 	return setup_fault_attr(&failslab.attr, str);
42 }
43 __setup("failslab=", setup_failslab);
44 
45 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
46 static int __init failslab_debugfs_init(void)
47 {
48 	struct dentry *dir;
49 	umode_t mode = S_IFREG | 0600;
50 
51 	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
52 	if (IS_ERR(dir))
53 		return PTR_ERR(dir);
54 
55 	debugfs_create_bool("ignore-gfp-wait", mode, dir,
56 			    &failslab.ignore_gfp_reclaim);
57 	debugfs_create_bool("cache-filter", mode, dir,
58 			    &failslab.cache_filter);
59 
60 	return 0;
61 }
62 
63 late_initcall(failslab_debugfs_init);
64 
65 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
66