rcu: Make rcu_assign_pointer's assignment volatile and type-safe

The rcu_assign_pointer() primitive needs to use ACCESS_ONCE to make
the assignment to the destination pointer volatile, to protect against
compilers too clever for their own good.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 00ad28168ef0..97853cd2d7b4 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -551,7 +551,7 @@ static inline void rcu_preempt_sleep_check(void)
 #define __rcu_assign_pointer(p, v, space) \
         do { \
                 smp_wmb(); \
-                (p) = (typeof(*v) __force space *)(v); \
+                ACCESS_ONCE(p) = (typeof(*(v)) __force space *)(v); \
         } while (0)