net_sched: fix call_rcu() race on act_sample module removal
authorCong Wang <xiyou.wangcong@gmail.com>
Fri, 27 Oct 2017 01:24:41 +0000 (18:24 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sun, 29 Oct 2017 13:49:31 +0000 (22:49 +0900)
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 <yotamg@mellanox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sched/act_sample.c

index ec986ae528089081ecdf8528437bbd82b7e840e1..a9f9a2ccc66454196dc275d8825acb847661d7a7 100644 (file)
@@ -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);
 }