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Commit f7e57044 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

sch_teql: fix lockdep splat 



We need rcu_read_lock() protection before using dst_get_neighbour(), and
we must cache its value (pass it to __teql_resolve())

teql_master_xmit() is called under rcu_read_lock_bh() protection, its
not enough.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 15fc1f36

net/sched/sch_teql.c

+20 −11
Original line number Diff line number Diff line
@@ -225,11 +225,11 @@ static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt) 




static int

__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev)

__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res,

	       struct net_device *dev, struct netdev_queue *txq,

	       struct neighbour *mn)

{

	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);

	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);

	struct neighbour *mn = dst_get_neighbour(skb_dst(skb));

	struct teql_sched_data *q = qdisc_priv(txq->qdisc);

	struct neighbour *n = q->ncache;



	if (mn->tbl == NULL)
@@ -262,17 +262,26 @@ __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device * 
}



static inline int teql_resolve(struct sk_buff *skb,

			       struct sk_buff *skb_res, struct net_device *dev)

			       struct sk_buff *skb_res,

			       struct net_device *dev,

			       struct netdev_queue *txq)

{

	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);

	struct dst_entry *dst = skb_dst(skb);

	struct neighbour *mn;

	int res;



	if (txq->qdisc == &noop_qdisc)

		return -ENODEV;



	if (dev->header_ops == NULL ||

	    skb_dst(skb) == NULL ||

	    dst_get_neighbour(skb_dst(skb)) == NULL)

	if (!dev->header_ops || !dst)

		return 0;

	return __teql_resolve(skb, skb_res, dev);



	rcu_read_lock();

	mn = dst_get_neighbour(dst);

	res = mn ? __teql_resolve(skb, skb_res, dev, txq, mn) : 0;

	rcu_read_unlock();



	return res;

}



static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -307,7 +316,7 @@ static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev) 
			continue;

		}



		switch (teql_resolve(skb, skb_res, slave)) {

		switch (teql_resolve(skb, skb_res, slave, slave_txq)) {

		case 0:

			if (__netif_tx_trylock(slave_txq)) {

				unsigned int length = qdisc_pkt_len(skb);