linux/debian/patches-rt/0136-rtmutex-Add-rtmutex_lock_killable.patch

From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 9 Jun 2011 11:43:52 +0200
Subject: [PATCH 136/290] rtmutex: Add rtmutex_lock_killable()
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=d10ccdda6815a479f62a22fdbe86b733a8f0fe79

Add "killable" type to rtmutex. We need this since rtmutex are used as
"normal" mutexes which do use this type.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/rtmutex.h  |  1 +
 kernel/locking/rtmutex.c | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index 6fd615a0eea9..81ece6a8291a 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -115,6 +115,7 @@ extern void rt_mutex_lock(struct rt_mutex *lock);
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_timed_lock(struct rt_mutex *lock,
 			       struct hrtimer_sleeper *timeout);
 
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 1c3f56d3d9b6..a4b2af7718f8 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1562,6 +1562,25 @@ int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
 	return __rt_mutex_slowtrylock(lock);
 }
 
+/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock:              the rt_mutex to be locked
+ * @detect_deadlock:   deadlock detection on/off
+ *
+ * Returns:
+ *  0          on success
+ * -EINTR      when interrupted by a signal
+ * -EDEADLK    when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+	might_sleep();
+
+	return rt_mutex_fastlock(lock, TASK_KILLABLE, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
 /**
  * rt_mutex_timed_lock - lock a rt_mutex interruptible
  *			the timeout structure is provided