xref: /openbmc/linux/mm/failslab.c (revision 293d5b43)
1 #include <linux/fault-inject.h>
2 #include <linux/slab.h>
3 #include <linux/mm.h>
4 #include "slab.h"
5 
6 static struct {
7 	struct fault_attr attr;
8 	bool ignore_gfp_reclaim;
9 	bool cache_filter;
10 } failslab = {
11 	.attr = FAULT_ATTR_INITIALIZER,
12 	.ignore_gfp_reclaim = true,
13 	.cache_filter = false,
14 };
15 
16 bool should_failslab(struct kmem_cache *s, gfp_t gfpflags)
17 {
18 	/* No fault-injection for bootstrap cache */
19 	if (unlikely(s == kmem_cache))
20 		return false;
21 
22 	if (gfpflags & __GFP_NOFAIL)
23 		return false;
24 
25 	if (failslab.ignore_gfp_reclaim && (gfpflags & __GFP_RECLAIM))
26 		return false;
27 
28 	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
29 		return false;
30 
31 	return should_fail(&failslab.attr, s->object_size);
32 }
33 
34 static int __init setup_failslab(char *str)
35 {
36 	return setup_fault_attr(&failslab.attr, str);
37 }
38 __setup("failslab=", setup_failslab);
39 
40 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
41 static int __init failslab_debugfs_init(void)
42 {
43 	struct dentry *dir;
44 	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
45 
46 	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
47 	if (IS_ERR(dir))
48 		return PTR_ERR(dir);
49 
50 	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
51 				&failslab.ignore_gfp_reclaim))
52 		goto fail;
53 	if (!debugfs_create_bool("cache-filter", mode, dir,
54 				&failslab.cache_filter))
55 		goto fail;
56 
57 	return 0;
58 fail:
59 	debugfs_remove_recursive(dir);
60 
61 	return -ENOMEM;
62 }
63 
64 late_initcall(failslab_debugfs_init);
65 
66 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
67