mm/memory-failure: fix race with compound page split/merge
authorKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Thu, 28 Apr 2016 23:19:03 +0000 (16:19 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 29 Apr 2016 02:34:04 +0000 (19:34 -0700)
commitc2e7e00b715d3c65f301bec8559d6af4ef8098ab
treee89161188d2a485e428e9aa61690517418f75952
parentb73413647ee36406561618f68d0661d49dc47489
mm/memory-failure: fix race with compound page split/merge

get_hwpoison_page() must recheck relation between head and tail pages.

n-horiguchi said: without this recheck, the race causes kernel to pin an
irrelevant page, and finally makes kernel crash for refcount mismatch.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-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>
mm/memory-failure.c