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 abf44d89c6ce37e78a7fabe67a4670307b2fb013..fb8e6db511d771f3e24a4086db41320c48a9170b 100644 (file)
--- 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