[Patch net 14/16] net_sched: fix call_rcu() race on act_sample module removal

[Cong Wang]

Similar to commit c78e1746d3ad
("net: sched: fix call_rcu() race on classifier module unloads"),
we need to wait for flying RCU callback tcf_sample_cleanup_rcu().

Cc: Yotam Gigi <yot...@mellanox.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Jiri Pirko <j...@resnulli.us>
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Cc: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 net/sched/act_sample.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index ec986ae52808..a9f9a2ccc664 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -264,6 +264,7 @@ static int __init sample_init_module(void)
 
 static void __exit sample_cleanup_module(void)
 {
+       rcu_barrier();
        tcf_unregister_action(&act_sample_ops, &sample_net_ops);
 }
 
-- 
2.13.0