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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
7static 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
20static int __init setup_fail_page_alloc(char *str)
21{
22 return setup_fault_attr(attr: &fail_page_alloc.attr, str);
23}
24__setup("fail_page_alloc=", setup_fail_page_alloc);
25
26bool 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(attr: &fail_page_alloc.attr, size: 1 << order, flags);
45}
46ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
47
48#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
49
50static 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(name: "fail_page_alloc", NULL,
56 attr: &fail_page_alloc.attr);
57
58 debugfs_create_bool(name: "ignore-gfp-wait", mode, parent: dir,
59 value: &fail_page_alloc.ignore_gfp_reclaim);
60 debugfs_create_bool(name: "ignore-gfp-highmem", mode, parent: dir,
61 value: &fail_page_alloc.ignore_gfp_highmem);
62 debugfs_create_u32(name: "min-order", mode, parent: dir, value: &fail_page_alloc.min_order);
63
64 return 0;
65}
66
67late_initcall(fail_page_alloc_debugfs);
68
69#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
70

source code of linux/mm/fail_page_alloc.c