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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/mm/fail_page_alloc.c
26131 views
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// SPDX-License-Identifier: GPL-2.0

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#include <linux/fault-inject.h>

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#include <linux/debugfs.h>

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#include <linux/error-injection.h>

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#include <linux/mm.h>

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static struct {

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	struct fault_attr attr;

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	bool ignore_gfp_highmem;

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	bool ignore_gfp_reclaim;

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	u32 min_order;

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} fail_page_alloc = {

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	.attr = FAULT_ATTR_INITIALIZER,

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	.ignore_gfp_reclaim = true,

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	.ignore_gfp_highmem = true,

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	.min_order = 1,

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};

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static int __init setup_fail_page_alloc(char *str)

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{

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	return setup_fault_attr(&fail_page_alloc.attr, str);

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}

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__setup("fail_page_alloc=", setup_fail_page_alloc);

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bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)

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{

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	int flags = 0;

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	if (order < fail_page_alloc.min_order)

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		return false;

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	if (gfp_mask & __GFP_NOFAIL)

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		return false;

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	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))

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		return false;

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	if (fail_page_alloc.ignore_gfp_reclaim &&

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			(gfp_mask & __GFP_DIRECT_RECLAIM))

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		return false;

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	/* See comment in __should_failslab() */

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	if (gfp_mask & __GFP_NOWARN)

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		flags |= FAULT_NOWARN;

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	return should_fail_ex(&fail_page_alloc.attr, 1 << order, flags);

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}

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ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);

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#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

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static int __init fail_page_alloc_debugfs(void)

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{

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	umode_t mode = S_IFREG | 0600;

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	struct dentry *dir;

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	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,

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					&fail_page_alloc.attr);

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	debugfs_create_bool("ignore-gfp-wait", mode, dir,

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			    &fail_page_alloc.ignore_gfp_reclaim);

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	debugfs_create_bool("ignore-gfp-highmem", mode, dir,

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			    &fail_page_alloc.ignore_gfp_highmem);

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	debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);

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	return 0;

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}

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late_initcall(fail_page_alloc_debugfs);

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#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

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