* + mm-memory-failure-fix-race-with-compound-page-split-merge.patch added to -mm tree
@ 2016-04-21 23:45 akpm
0 siblings, 0 replies; only message in thread
From: akpm @ 2016-04-21 23:45 UTC (permalink / raw)
To: khlebnikov, n-horiguchi, mm-commits
The patch titled
Subject: mm/memory-failure: fix race with compound page split/merge
has been added to the -mm tree. Its filename is
mm-memory-failure-fix-race-with-compound-page-split-merge.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memory-failure-fix-race-with-compound-page-split-merge.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory-failure-fix-race-with-compound-page-split-merge.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Subject: 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>
---
mm/memory-failure.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff -puN mm/memory-failure.c~mm-memory-failure-fix-race-with-compound-page-split-merge mm/memory-failure.c
--- a/mm/memory-failure.c~mm-memory-failure-fix-race-with-compound-page-split-merge
+++ a/mm/memory-failure.c
@@ -888,7 +888,15 @@ int get_hwpoison_page(struct page *page)
}
}
- return get_page_unless_zero(head);
+ if (get_page_unless_zero(head)) {
+ if (head == compound_head(page))
+ return 1;
+
+ pr_info("MCE: %#lx cannot catch tail\n", page_to_pfn(page));
+ put_page(head);
+ }
+
+ return 0;
}
EXPORT_SYMBOL_GPL(get_hwpoison_page);
_
Patches currently in -mm which might be from khlebnikov@yandex-team.ru are
mm-memory-failure-fix-race-with-compound-page-split-merge.patch
mm-rmap-replace-bug_onanon_vma-degree-with-vm_warn_on.patch
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2016-04-21 23:45 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-21 23:45 + mm-memory-failure-fix-race-with-compound-page-split-merge.patch added to -mm tree akpm
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.