Re: br_forward.c - rcu dereference warning
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2010-07-27 20:14:50
On Tue, 2010-07-27 at 11:26 -0700, Stephen Hemminger wrote:
-/* net device transmit always called with no BH (preempt_disabled) */ +/* net device transmit always called with no BH disabled */
"no BH disabled"?
quoted hunk ↗ jump to hunk
@@ -48,6 +48,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff * skb_reset_mac_header(skb); skb_pull(skb, ETH_HLEN); + rcu_read_lock(); if (is_multicast_ether_addr(dest)) { if (unlikely(netpoll_tx_running(dev))) { br_flood_deliver(br, skb);@@ -67,6 +68,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff * br_flood_deliver(br, skb); out: + rcu_read_unlock(); return NETDEV_TX_OK; } --- a/net/bridge/br_fdb.c 2010-07-27 11:18:30.815320981 -0700 +++ b/net/bridge/br_fdb.c 2010-07-27 11:18:59.597710975 -0700@@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_br spin_unlock_bh(&br->hash_lock); } -/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */ +/* No locking or refcounting, assumes caller has rcu_read_lock */ struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, const unsigned char *addr) { --- a/net/bridge/br_input.c 2010-07-27 11:19:05.266181492 -0700 +++ b/net/bridge/br_input.c 2010-07-27 11:19:29.148163149 -0700@@ -39,7 +39,7 @@ static int br_pass_frame_up(struct sk_bu netif_receive_skb); } -/* note: already called with rcu_read_lock (preempt_disabled) */ +/* note: already called with rcu_read_lock */ int br_handle_frame_finish(struct sk_buff *skb) { const unsigned char *dest = eth_hdr(skb)->h_dest;@@ -110,7 +110,7 @@ drop: goto out; } -/* note: already called with rcu_read_lock (preempt_disabled) */ +/* note: already called with rcu_read_lock */ static int br_handle_local_finish(struct sk_buff *skb) { struct net_bridge_port *p = br_port_get_rcu(skb->dev);@@ -133,8 +133,7 @@ static inline int is_link_local(const un /* * Return NULL if skb is handled - * note: already called with rcu_read_lock (preempt_disabled) from - * netif_receive_skb + * note: already called with rcu_read_lock from netif_receive_skb */ struct sk_buff *br_handle_frame(struct sk_buff *skb) { --- a/net/bridge/br_stp_bpdu.c 2010-07-27 11:19:34.092573294 -0700 +++ b/net/bridge/br_stp_bpdu.c 2010-07-27 11:19:40.725123403 -0700@@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_ /* * Called from llc. * - * NO locks, but rcu_read_lock (preempt_disabled) + * NO locks, but rcu_read_lock */ void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb, struct net_device *dev)
Did you want me to test the patch? johannes