rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE()
This commit applies ACCESS_ONCE() to an outside-of-lock access to
->gp_flags. Although it is hard to imagine any sane compiler messing
this particular case up, the documentation benefits are substantial.
Plus the definition of "sane compiler" grows ever looser.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 62b67b7..6d028fd 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1481,7 +1481,7 @@
/* Handle grace-period start. */
for (;;) {
wait_event_interruptible(rsp->gp_wq,
- rsp->gp_flags &
+ ACCESS_ONCE(rsp->gp_flags) &
RCU_GP_FLAG_INIT);
if (rcu_gp_init(rsp))
break;