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authorWanpeng Li <wanpeng.li@hotmail.com>2015-09-08 15:03:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 15:35:28 -0700
commit1e0e635be82132167a134b5a9c884e70e61f8373 (patch)
treebe7f964bee75f72d71df0bde9b6844b9fa4286d6 /mm
parent7d1900c744b2e4687b3e467edf58373c02bcf22d (diff)
mm/hwpoison: fix PageHWPoison test/set race
There is a race between madvise_hwpoison path and memory_failure: CPU0 CPU1 madvise_hwpoison get_user_pages_fast PageHWPoison check (false) memory_failure TestSetPageHWPoison soft_offline_page PageHWPoison check (true) return -EBUSY (without put_page) Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory-failure.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 8ad923a93539..863544d84a09 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1719,6 +1719,8 @@ int soft_offline_page(struct page *page, int flags)
if (PageHWPoison(page)) {
pr_info("soft offline: %#lx page already poisoned\n", pfn);
+ if (flags & MF_COUNT_INCREASED)
+ put_page(page);
return -EBUSY;
}
if (!PageHuge(page) && PageTransHuge(hpage)) {