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| author |   Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2019-09-19 13:36:59 -0400 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-09-25 17:42:30 +0200 |
| commit | fc0d77387cb5ae883fd774fc559e056a8dde024c (patch) | |
| tree | 0976ac4e9a319e4688ef2a14030512576c2c60f0 /kernel | |
| parent | tasks, sched/core: RCUify the assignment of rq->curr (diff) | |
| download | linux-dev-fc0d77387cb5ae883fd774fc559e056a8dde024c.tar.xz linux-dev-fc0d77387cb5ae883fd774fc559e056a8dde024c.zip | |
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 <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-2-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/membarrier.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index b14250a11608..d48b95fc4026 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) |