The sync_sched_exp_online_cleanup() is called from rcutree_online_cpu(),
which can be invoked with interrupts enabled. This means that
the ->cpu_no_qs.b.exp field is subject to data races from the
rcu_exp_handler() IPI handler, so this commit marks the load from
that field.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree_exp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index fc2ee326a6f73..12f1a18d7b6d6 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -759,7 +759,7 @@ static void sync_sched_exp_online_cleanup(int cpu)
my_cpu = get_cpu();
/* Quiescent state either not needed or already requested, leave. */
if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) ||
- rdp->cpu_no_qs.b.exp) {
+ READ_ONCE(rdp->cpu_no_qs.b.exp)) {
put_cpu();
return;
}
--
2.31.1.189.g2e36527f23
