From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 16 May 2012 22:51:08 +0000 (-0700)
Subject: rcu: Remove return value from rcu_assign_pointer()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e9023c4061054cbf59c5288068118a4d0b152f01;p=linux-beck.git

rcu: Remove return value from rcu_assign_pointer()

The return value from rcu_assign_pointer() is not used, and using it
would be quite ugly, for example:

	q = rcu_assign_pointer(global_p, p);

To prevent this sort of ugliness from spreading, this commit wraps
rcu_assign_pointer() in a do-while loop.

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index abf44d89c6ce..fb8e6db511d7 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -513,10 +513,10 @@ static inline void rcu_preempt_sleep_check(void)
 		(_________p1); \
 	})
 #define __rcu_assign_pointer(p, v, space) \
-	({ \
+	do { \
 		smp_wmb(); \
 		(p) = (typeof(*v) __force space *)(v); \
-	})
+	} while (0)
 
 
 /**
@@ -851,7 +851,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
  *
  * Assigns the specified value to the specified RCU-protected
  * pointer, ensuring that any concurrent RCU readers will see
- * any prior initialization.  Returns the value assigned.
+ * any prior initialization.
  *
  * Inserts memory barriers on architectures that require them
  * (which is most of them), and also prevents the compiler from