Commit 478c5ffc authored by Wu Fengguang's avatar Wu Fengguang Committed by Andi Kleen
Browse files

HWPOISON: add page flags filter 



When specified, only poison pages if ((page_flags & mask) == value).

-       corrupt-filter-flags-mask
-       corrupt-filter-flags-value

This allows stress testing of many kinds of pages.

Strictly speaking, the buddy pages requires taking zone lock, to avoid
setting PG_hwpoison on a "was buddy but now allocated to someone" page.
However we can just do nothing because we set PG_locked in the beginning,
this prevents the page allocator from allocating it to someone. (It will
BUG() on the unexpected PG_locked, which is fine for hwpoison testing.)

[AK: Add select PROC_PAGE_MONITOR to satisfy dependency]

CC: Nick Piggin <npiggin@suse.de>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent 1a9b5b7f

Documentation/vm/hwpoison.txt

+10 −0
Original line number Diff line number Diff line
@@ -123,6 +123,16 @@ Only handle memory failures to pages associated with the file system defined 
by block device major/minor.  -1U is the wildcard value.

This should be only used for testing with artificial injection.





corrupt-filter-flags-mask

corrupt-filter-flags-value



When specified, only poison pages if ((page_flags & mask) == value).

This allows stress testing of many kinds of pages. The page_flags

are the same as in /proc/kpageflags. The flag bits are defined in

include/linux/kernel-page-flags.h and documented in

Documentation/vm/pagemap.txt



Architecture specific MCE injector



x86 has mce-inject, mce-test

mm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -253,6 +253,7 @@ config MEMORY_FAILURE 
config HWPOISON_INJECT

	tristate "Poison pages injector"

	depends on MEMORY_FAILURE && DEBUG_KERNEL

	select PROC_PAGE_MONITOR



config NOMMU_INITIAL_TRIM_EXCESS

	int "Turn on mmap() excess space trimming before booting"

mm/hwpoison-inject.c

+10 −0
Original line number Diff line number Diff line
@@ -102,6 +102,16 @@ static int pfn_inject_init(void) 
	if (!dentry)

		goto fail;



	dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,

				    hwpoison_dir, &hwpoison_filter_flags_mask);

	if (!dentry)

		goto fail;



	dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,

				    hwpoison_dir, &hwpoison_filter_flags_value);

	if (!dentry)

		goto fail;



	return 0;

fail:

	pfn_inject_exit();

mm/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -255,3 +255,5 @@ extern int hwpoison_filter(struct page *p); 


extern u32 hwpoison_filter_dev_major;

extern u32 hwpoison_filter_dev_minor;

extern u64 hwpoison_filter_flags_mask;

extern u64 hwpoison_filter_flags_value;

mm/memory-failure.c

+20 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/page-flags.h>

#include <linux/kernel-page-flags.h>

#include <linux/sched.h>

#include <linux/ksm.h>

#include <linux/rmap.h>
@@ -50,8 +51,12 @@ atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0); 


u32 hwpoison_filter_dev_major = ~0U;

u32 hwpoison_filter_dev_minor = ~0U;

u64 hwpoison_filter_flags_mask;

u64 hwpoison_filter_flags_value;

EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major);

EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);

EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);

EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);



static int hwpoison_filter_dev(struct page *p)

{
@@ -83,11 +88,26 @@ static int hwpoison_filter_dev(struct page *p) 
	return 0;

}



static int hwpoison_filter_flags(struct page *p)

{

	if (!hwpoison_filter_flags_mask)

		return 0;



	if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==

				    hwpoison_filter_flags_value)

		return 0;

	else

		return -EINVAL;

}



int hwpoison_filter(struct page *p)

{

	if (hwpoison_filter_dev(p))

		return -EINVAL;



	if (hwpoison_filter_flags(p))

		return -EINVAL;



	return 0;

}

EXPORT_SYMBOL_GPL(hwpoison_filter);

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