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	This mostly reverts commit af3b854492 ("mm/page_alloc.c: allow error
injection").  The commit made should_fail_alloc_page() a noinline function
that's always called from the page allocation hotpath, even if it's empty
because CONFIG_FAIL_PAGE_ALLOC is not enabled, and there is no option to
disable it and prevent the associated function call overhead.
As with the preceding patch "mm, slab: put should_failslab back behind
CONFIG_SHOULD_FAILSLAB" and for the same reasons, put the
should_fail_alloc_page() back behind the config option.  When enabled, the
ALLOW_ERROR_INJECTION and BTF_ID records are preserved so it's not a
complete revert.
Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-2-9e2651945d68@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
	
			
		
			
				
	
	
		
			68 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include <linux/fault-inject.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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