[tip:core/rcu] rcu: Remove return value from rcu_assign_pointer()

["tip-bot for Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>]

Commit-ID:  e9023c4061054cbf59c5288068118a4d0b152f01
Gitweb:     http://git.kernel.org/tip/e9023c4061054cbf59c5288068118a4d0b152f01
Author:     Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Wed, 16 May 2012 15:51:08 -0700
Committer:  Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Mon, 2 Jul 2012 12:34:23 -0700

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@xxxxxxxxxxxx>
Reported-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
 include/linux/rcupdate.h |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index abf44d8..fb8e6db 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
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html