linux/mm
Wanpeng Li 29b4eedee6 mm/hwpoison.c: fix held reference count after unpoisoning empty zero page
madvise hwpoison inject will poison the read-only empty zero page if there
is no write access before poison.  Empty zero page reference count will be
increased for hwpoison, subsequent poison zero page will return directly
since page has already been set PG_hwpoison, however, page reference count
is still increased by get_user_pages_fast.  The unpoison process will
unpoison the empty zero page and decrease the reference count successfully
for the fist time, however, subsequent unpoison empty zero page will
return directly since page has already been unpoisoned and without
decrease the page reference count of empty zero page.

This patch fixes it by make madvise_hwpoison() put a page and return
immediately (without calling memory_failure() or soft_offline_page()) when
the page is already hwpoisoned.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE	4096

int main(void)
{
	char *mem;
	int i;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

Add printk to dump page reference count:

[   93.075959] Injecting memory failure for page 0x19d0 at 0xb77d8000
[   93.076207] MCE 0x19d0: non LRU page recovery: Ignored
[   93.076209] pfn 0x19d0, page count = 1 after memory failure
[   93.076220] Injecting memory failure for page 0x19d0 at 0xb77d9000
[   93.076221] MCE 0x19d0: already hardware poisoned
[   93.076222] pfn 0x19d0, page count = 2 after memory failure
[   93.076224] Injecting memory failure for page 0x19d0 at 0xb77da000
[   93.076224] MCE 0x19d0: already hardware poisoned
[   93.076225] pfn 0x19d0, page count = 3 after memory failure

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:58:11 -07:00
..
backing-dev.c mm/backing-dev.c: check user buffer length before copying data to the related user buffer 2013-09-11 15:58:03 -07:00
balloon_compaction.c
bootmem.c mm: kill free_all_bootmem_node() 2013-07-03 16:07:39 -07:00
bounce.c Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block 2013-05-08 10:13:35 -07:00
cleancache.c mm: cleancache: clean up cleancache_enabled 2013-04-30 17:04:01 -07:00
compaction.c mm: compaction: do not compact pgdat for order-0 2013-09-11 15:57:55 -07:00
debug-pagealloc.c
dmapool.c
fadvise.c teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long 2013-03-03 22:46:22 -05:00
failslab.c
filemap.c direct-io: Handle O_(D)SYNC AIO 2013-09-04 09:23:46 -04:00
filemap_xip.c lift sb_start_write() out of ->write() 2013-04-09 14:12:56 -04:00
fremap.c mm: save soft-dirty bits on file pages 2013-08-13 17:57:48 -07:00
frontswap.c frontswap: fix incorrect zeroing and allocation size for frontswap_map 2013-06-12 16:29:46 -07:00
highmem.c Some nice cleanups, and even a patch my wife did as a "live" demo for 2012-12-20 08:37:05 -08:00
huge_memory.c mm/huge_memory.c: fix potential NULL pointer dereference 2013-09-11 15:57:19 -07:00
hugetlb.c mm: prepare to remove /proc/sys/vm/hugepages_treat_as_movable 2013-09-11 15:57:49 -07:00
hugetlb_cgroup.c cgroup: pass around cgroup_subsys_state instead of cgroup in file methods 2013-08-08 20:11:24 -04:00
hwpoison-inject.c
init-mm.c
internal.h mm: vmscan: fix do_try_to_free_pages() livelock 2013-09-11 15:58:01 -07:00
interval_tree.c
Kconfig Merge remote-tracking branch 'origin/next' into kvm-ppc-next 2013-08-29 00:41:59 +02:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: replace strict_strtoul() with kstrtoul() 2013-09-11 15:57:11 -07:00
ksm.c mm: replace strict_strtoul() with kstrtoul() 2013-09-11 15:57:11 -07:00
maccess.c
madvise.c mm/hwpoison.c: fix held reference count after unpoisoning empty zero page 2013-09-11 15:58:11 -07:00
Makefile zswap: add to mm/ 2013-07-10 18:11:34 -07:00
memblock.c memblock, numa: binary search node id 2013-09-11 15:57:51 -07:00
memcontrol.c kmemcg: don't allocate extra memory for root memcg_cache_params 2013-09-11 15:57:53 -07:00
memory-failure.c mm/hwpoison: drop forward reference declarations __soft_offline_page() 2013-09-11 15:58:11 -07:00
memory.c mm: migrate: add hugepage migration code to move_pages() 2013-09-11 15:57:48 -07:00
memory_hotplug.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
mempolicy.c mbind: add BUG_ON(!vma) in new_vma_page() 2013-09-11 15:57:50 -07:00
mempool.c
migrate.c mm: vmscan: fix do_try_to_free_pages() livelock 2013-09-11 15:58:01 -07:00
mincore.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
mlock.c mm: munlock: manual pte walk in fast path instead of follow_page_mask() 2013-09-11 15:58:01 -07:00
mm_init.c mm: tune vm_committed_as percpu_counter batching size 2013-07-03 16:07:32 -07:00
mmap.c mm: track vma changes with VM_SOFTDIRTY bit 2013-09-11 15:57:56 -07:00
mmu_context.c mm: remove old aio use_mm() comment 2013-05-07 18:38:27 -07:00
mmu_notifier.c treewide: relase -> release 2013-06-28 14:34:33 +02:00
mmzone.c mm: rename page struct field helpers 2013-02-23 17:50:18 -08:00
mprotect.c mm/mprotect.c: coding-style cleanups 2012-12-18 15:02:15 -08:00
mremap.c mm/mremap.c: call pud_free() after fail calling pmd_alloc() 2013-09-11 15:58:03 -07:00
msync.c
nobootmem.c mm: concentrate modification of totalram_pages into the mm core 2013-07-03 16:07:33 -07:00
nommu.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
oom_kill.c mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR(). 2013-07-15 11:25:05 +09:30
page-writeback.c mm/page-writeback.c: add strictlimit feature 2013-09-11 15:58:04 -07:00
page_alloc.c mm: correct the comment about the value for buddy _mapcount 2013-09-11 15:58:06 -07:00
page_cgroup.c
page_io.c mm: remove compressed copy from zram in-memory 2013-07-03 16:07:26 -07:00
page_isolation.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
pagewalk.c mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areas 2013-05-24 16:22:53 -07:00
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c mm: move pgtable related functions to right place 2013-09-11 15:57:30 -07:00
process_vm_access.c Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
quicklist.c
readahead.c readahead: make context readahead more conservative 2013-09-11 15:57:39 -07:00
rmap.c s390/mm: implement software referenced bits 2013-08-29 13:20:11 +02:00
shmem.c shm_mnt is as longterm as it gets, TYVM... 2013-09-03 22:50:27 -04:00
slab.c kernel: delete __cpuinit usage from all core kernel files 2013-07-14 19:36:59 -04:00
slab.h memcg: check that kmem_cache has memcg_params before accessing it 2013-08-28 19:26:38 -07:00
slab_common.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-07-14 15:14:29 -07:00
slob.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-07-14 15:14:29 -07:00
slub.c mm: replace strict_strtoul() with kstrtoul() 2013-09-11 15:57:11 -07:00
sparse-vmemmap.c sparse-vmemmap: specify vmemmap population range in bytes 2013-04-29 15:54:35 -07:00
sparse.c mm/sparse: introduce alloc_usemap_and_memmap 2013-09-11 15:58:01 -07:00
swap.c mm: fix aio performance regression for database caused by THP 2013-09-11 15:57:55 -07:00
swap_state.c swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion 2013-06-12 16:29:45 -07:00
swapfile.c swap: make cluster allocation per-cpu 2013-09-11 15:57:17 -07:00
truncate.c mm: teach truncate_inode_pages_range() to handle non page aligned ranges 2013-05-27 23:32:35 -04:00
util.c swap: clean-up #ifdef in page_mapping() 2013-09-11 15:57:31 -07:00
vmalloc.c mm/vmalloc: use wrapper function get_vm_area_size to caculate size of vm area 2013-09-11 15:58:02 -07:00
vmpressure.c Merge branch 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2013-09-03 18:25:03 -07:00
vmscan.c mm: vmscan: fix do_try_to_free_pages() livelock 2013-09-11 15:58:01 -07:00
vmstat.c mm: vmscan: fix do_try_to_free_pages() livelock 2013-09-11 15:58:01 -07:00
zbud.c mm/zbud: fix some trivial typos in comments 2013-09-11 15:57:35 -07:00
zswap.c mm/zswap.c: get swapper address_space by using macro 2013-09-11 15:57:08 -07:00