The following commit has been merged into the sched/urgent branch of tip: Commit-ID: fc0d77387cb5ae883fd774fc559e056a8dde024c Gitweb: https://git.kernel.org/tip/fc0d77387cb5ae883fd774fc559e056a8dde024c Author: Mathieu Desnoyers <[email protected]> AuthorDate: Thu, 19 Sep 2019 13:36:59 -04:00 Committer: Ingo Molnar <[email protected]> CommitterDate: Wed, 25 Sep 2019 17:42:30 +02:00
sched/membarrier: Fix private expedited registration check Fix a logic flaw in the way membarrier_register_private_expedited() handles ready state checks for private expedited sync core and private expedited registrations. If a private expedited membarrier registration is first performed, and then a private expedited sync_core registration is performed, the ready state check will skip the second registration when it really should not. Signed-off-by: Mathieu Desnoyers <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Eric W. Biederman <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Russell King - ARM Linux admin <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/membarrier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index b14250a..d48b95f 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -226,7 +226,7 @@ static int membarrier_register_private_expedited(int flags) * groups, which use the same mm. (CLONE_VM but not * CLONE_THREAD). */ - if (atomic_read(&mm->membarrier_state) & state) + if ((atomic_read(&mm->membarrier_state) & state) == state) return 0; atomic_or(MEMBARRIER_STATE_PRIVATE_EXPEDITED, &mm->membarrier_state); if (flags & MEMBARRIER_FLAG_SYNC_CORE)
