| From | Kamal Mostafa <> | Subject | [PATCH 3.8 050/166] futex: fix handling of read-only-mapped hugepages | Date | Wed, 15 Jan 2014 13:51:04 -0800 |
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3.8.13.16 -stable review patch. If anyone has any objections, please let me know.
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From: Linus Torvalds <torvalds@linux-foundation.org>
commit f12d5bfceb7e1f9051563381ec047f7f13956c3c upstream.
The hugepage code had the exact same bug that regular pages had in commit 7485d0d3758e ("futexes: Remove rw parameter from get_futex_key()").
The regular page case was fixed by commit 9ea71503a8ed ("futex: Fix regression with read only mappings"), but the transparent hugepage case (added in a5b338f2b0b1: "thp: update futex compound knowledge") case remained broken.
Found by Dave Jones and his trinity tool.
Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/futex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/futex.c b/kernel/futex.c index f0ee318..e564a9a 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -285,7 +285,7 @@ again: put_page(page); /* serialize against __split_huge_page_splitting() */ local_irq_disable(); - if (likely(__get_user_pages_fast(address, 1, 1, &page) == 1)) { + if (likely(__get_user_pages_fast(address, 1, !ro, &page) == 1)) { page_head = compound_head(page); /* * page_head is valid pointer but we must pin -- 1.8.3.2
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