The following commit has been merged into the core/rcu branch of tip: Commit-ID: 0050c7b2d27c3cc126df59bd8094fb3d25b00ade Gitweb: https://git.kernel.org/tip/0050c7b2d27c3cc126df59bd8094fb3d25b00ade Author: Paul E. McKenney <paulmck@xxxxxxxxxx> AuthorDate: Fri, 03 Jan 2020 15:59:12 -08:00 Committer: Paul E. McKenney <paulmck@xxxxxxxxxx> CommitterDate: Thu, 20 Feb 2020 15:58:22 -08:00 locking/rtmutex: rcu: Add WRITE_ONCE() to rt_mutex ->owner The rt_mutex structure's ->owner field is read locklessly, so this commit adds the WRITE_ONCE() to an update in order to provide proper documentation and READ_ONCE()/WRITE_ONCE() pairing. This data race was reported by KCSAN. Not appropriate for backporting due to failure being unlikely. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> --- kernel/locking/rtmutex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 851bbb1..c9f090d 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -57,7 +57,7 @@ rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner) if (rt_mutex_has_waiters(lock)) val |= RT_MUTEX_HAS_WAITERS; - lock->owner = (struct task_struct *)val; + WRITE_ONCE(lock->owner, (struct task_struct *)val); } static inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
|