From fa17e8511d2f284ca4d1bebe5744ec1e41ce1803 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 11 Jan 2019 21:16:31 +0100
Subject: [PATCH 147/283] rtmutex/rwlock: preserve state like a sleeping lock

The rwlock is spinning while acquiring a lock. Therefore it must become
a sleeping lock on RT and preserve its task state while sleeping and
waiting for the lock to become available.

Reported-by: Joe Korty <Joe.Korty@concurrent-rt.com>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/locking/rwlock-rt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c
index aebb7ce25bc6..8f90afe111ce 100644
--- a/kernel/locking/rwlock-rt.c
+++ b/kernel/locking/rwlock-rt.c
@@ -128,7 +128,7 @@ void __sched __read_rt_lock(struct rt_rw_lock *lock)
 	 * That would put Reader1 behind the writer waiting on
 	 * Reader2 to call read_unlock() which might be unbound.
 	 */
-	rt_mutex_init_waiter(&waiter, false);
+	rt_mutex_init_waiter(&waiter, true);
 	rt_spin_lock_slowlock_locked(m, &waiter, flags);
 	/*
 	 * The slowlock() above is guaranteed to return with the rtmutex is
-- 
2.20.1

