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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-05-05 16:23:35 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-17 09:51:32 -0700
commit0073e613da6fb1f39ab75f0373a63ee30d51d635 (patch)
tree830b2c595ab016cfab110456200e648d2e6b290e
parentc043edcc42acda62fc86eb8a2d03122000421d74 (diff)
downloadlinux-linaro-stable-0073e613da6fb1f39ab75f0373a63ee30d51d635.tar.gz
mm/memory-failure: call shake_page() when error hits thp tail page
commit 09789e5de18e4e442870b2d700831f5cb802eb05 upstream. Currently memory_failure() calls shake_page() to sweep pages out from pcplists only when the victim page is 4kB LRU page or thp head page. But we should do this for a thp tail page too. Consider that a memory error hits a thp tail page whose head page is on a pcplist when memory_failure() runs. Then, the current kernel skips shake_pages() part, so hwpoison_user_mappings() returns without calling split_huge_page() nor try_to_unmap() because PageLRU of the thp head is still cleared due to the skip of shake_page(). As a result, me_huge_page() runs for the thp, which is broken behavior. One effect is a leak of the thp. And another is to fail to isolate the memory error, so later access to the error address causes another MCE, which kills the processes which used the thp. This patch fixes this problem by calling shake_page() for thp tail case. Fixes: 385de35722c9 ("thp: allow a hwpoisoned head page to be put back to LRU") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jin Dongming <jin.dongming@np.css.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/memory-failure.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 603f1fa1b7a3..ca96f411b034 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1117,10 +1117,10 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
* The check (unnecessarily) ignores LRU pages being isolated and
* walked by the page reclaim code, however that's not a big loss.
*/
- if (!PageHuge(p) && !PageTransTail(p)) {
- if (!PageLRU(p))
- shake_page(p, 0);
- if (!PageLRU(p)) {
+ if (!PageHuge(p)) {
+ if (!PageLRU(hpage))
+ shake_page(hpage, 0);
+ if (!PageLRU(hpage)) {
/*
* shake_page could have turned it free.
*/