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-rw-r--r--debian/patches-rt/0146-rtmutex-rwlock-preserve-state-like-a-sleeping-lock.patch33
1 files changed, 33 insertions, 0 deletions
diff --git a/debian/patches-rt/0146-rtmutex-rwlock-preserve-state-like-a-sleeping-lock.patch b/debian/patches-rt/0146-rtmutex-rwlock-preserve-state-like-a-sleeping-lock.patch
new file mode 100644
index 000000000..44b53bba1
--- /dev/null
+++ b/debian/patches-rt/0146-rtmutex-rwlock-preserve-state-like-a-sleeping-lock.patch
@@ -0,0 +1,33 @@
+From 0e2b5eb41fc6820a80428de4a73ede6f47d74cf0 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 146/347] rtmutex/rwlock: preserve state like a sleeping lock
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+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
+--
+2.36.1
+