1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/fault-inject.h>
3 #include <linux/debugfs.h>
4 #include <linux/error-injection.h>
5 #include <linux/mm.h>
6
7 static struct {
8 struct fault_attr attr;
9
10 bool ignore_gfp_highmem;
11 bool ignore_gfp_reclaim;
12 u32 min_order;
13 } fail_page_alloc = {
14 .attr = FAULT_ATTR_INITIALIZER,
15 .ignore_gfp_reclaim = true,
16 .ignore_gfp_highmem = true,
17 .min_order = 1,
18 };
19
setup_fail_page_alloc(char * str)20 static int __init setup_fail_page_alloc(char *str)
21 {
22 return setup_fault_attr(&fail_page_alloc.attr, str);
23 }
24 __setup("fail_page_alloc=", setup_fail_page_alloc);
25
should_fail_alloc_page(gfp_t gfp_mask,unsigned int order)26 bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
27 {
28 int flags = 0;
29
30 if (order < fail_page_alloc.min_order)
31 return false;
32 if (gfp_mask & __GFP_NOFAIL)
33 return false;
34 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
35 return false;
36 if (fail_page_alloc.ignore_gfp_reclaim &&
37 (gfp_mask & __GFP_DIRECT_RECLAIM))
38 return false;
39
40 /* See comment in __should_failslab() */
41 if (gfp_mask & __GFP_NOWARN)
42 flags |= FAULT_NOWARN;
43
44 return should_fail_ex(&fail_page_alloc.attr, 1 << order, flags);
45 }
46 ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
47
48 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
49
fail_page_alloc_debugfs(void)50 static int __init fail_page_alloc_debugfs(void)
51 {
52 umode_t mode = S_IFREG | 0600;
53 struct dentry *dir;
54
55 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
56 &fail_page_alloc.attr);
57
58 debugfs_create_bool("ignore-gfp-wait", mode, dir,
59 &fail_page_alloc.ignore_gfp_reclaim);
60 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
61 &fail_page_alloc.ignore_gfp_highmem);
62 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
63
64 return 0;
65 }
66
67 late_initcall(fail_page_alloc_debugfs);
68
69 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
70