1// SPDX-License-Identifier: GPL-2.0
2#include <linux/fault-inject.h>
3#include <linux/mm.h>
4
5static 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
18static 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
24bool __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
47static 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
64late_initcall(fail_page_alloc_debugfs);
65
66#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
67