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(&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(&fail_page_alloc.attr, 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("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
67late_initcall(fail_page_alloc_debugfs);
68
69#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */