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