forge/linux-uconsole
1
0
Fork 0
Code Issues 1 Pull requests Projects Releases Packages Wiki Activity Actions

futex: fix handling of read-only-mapped hugepages

Browse source 
commit f12d5bfceb upstream.

The hugepage code had the exact same bug that regular pages had in
commit 7485d0d375 ("futexes: Remove rw parameter from
get_futex_key()").

The regular page case was fixed by commit 9ea71503a8 ("futex: Fix
regression with read only mappings"), but the transparent hugepage case
(added in a5b338f2b0: "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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Torvalds 2013-12-12 09:38:42 -08:00 • committed by Greg Kroah-Hartman
commit 13bb709cbe
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
kernel/futex.c
View file

@ -287,7 +287,7 @@ 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