From c0d378ef1266546a39f2df00a56ff1f74166a2b7 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 26 Oct 2017 18:24:36 -0700 Subject: net_sched: use tcf_queue_work() in u32 filter Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi Cc: Daniel Borkmann Cc: Jiri Pirko Cc: John Fastabend Cc: Jamal Hadi Salim Cc: "Paul E. McKenney" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_u32.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 10b8d851fc6b..dadd1b344497 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -68,7 +68,10 @@ struct tc_u_knode { u32 __percpu *pcpu_success; #endif struct tcf_proto *tp; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; /* The 'sel' field MUST be the last field in structure to allow for * tc_u32_keys allocated at end of structure. */ @@ -418,11 +421,21 @@ static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n, * this the u32_delete_key_rcu variant does not free the percpu * statistics. */ +static void u32_delete_key_work(struct work_struct *work) +{ + struct tc_u_knode *key = container_of(work, struct tc_u_knode, work); + + rtnl_lock(); + u32_destroy_key(key->tp, key, false); + rtnl_unlock(); +} + static void u32_delete_key_rcu(struct rcu_head *rcu) { struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu); - u32_destroy_key(key->tp, key, false); + INIT_WORK(&key->work, u32_delete_key_work); + tcf_queue_work(&key->work); } /* u32_delete_key_freepf_rcu is the rcu callback variant @@ -432,11 +445,21 @@ static void u32_delete_key_rcu(struct rcu_head *rcu) * for the variant that should be used with keys return from * u32_init_knode() */ +static void u32_delete_key_freepf_work(struct work_struct *work) +{ + struct tc_u_knode *key = container_of(work, struct tc_u_knode, work); + + rtnl_lock(); + u32_destroy_key(key->tp, key, true); + rtnl_unlock(); +} + static void u32_delete_key_freepf_rcu(struct rcu_head *rcu) { struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu); - u32_destroy_key(key->tp, key, true); + INIT_WORK(&key->work, u32_delete_key_freepf_work); + tcf_queue_work(&key->work); } static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key) -- cgit v1.2.3