From: Paul E. McKenney Date: Wed, 16 May 2012 22:51:08 +0000 (-0700) Subject: rcu: Remove return value from rcu_assign_pointer() X-Git-Tag: upstream/snapshot3+hdmi~7040^2^2~2^3~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e9023c4061054cbf59c5288068118a4d0b152f01;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.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 Reported-by: Josh Triplett Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- 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