Commit eeaf61d8 authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

bridge: add rcu_read_lock on transmit 



Long ago, when bridge was converted to RCU, rcu lock was equivalent
to having preempt disabled. RCU has changed a lot since then and
bridge code was still assuming the since transmit was called with
bottom half disabled, it was RCU safe.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Tested-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ff847ac2

net/bridge/br_device.c

+3 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 
#include <asm/uaccess.h>

#include "br_private.h"



/* net device transmit always called with no BH (preempt_disabled) */

/* net device transmit always called with BH disabled */

netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct net_bridge *br = netdev_priv(dev);
@@ -46,6 +46,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 
	skb_reset_mac_header(skb);

	skb_pull(skb, ETH_HLEN);



	rcu_read_lock();

	if (is_multicast_ether_addr(dest)) {

		if (br_multicast_rcv(br, NULL, skb))

			goto out;
@@ -61,6 +62,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 
		br_flood_deliver(br, skb);



out:

	rcu_read_unlock();

	return NETDEV_TX_OK;

}

net/bridge/br_fdb.c

+1 −1
Original line number Diff line number Diff line
@@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_bridge *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)

{

net/bridge/br_input.c

+3 −3
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ static int br_pass_frame_up(struct sk_buff *skb) 
		       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;
@@ -108,7 +108,7 @@ 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 = rcu_dereference(skb->dev->br_port);
@@ -133,7 +133,7 @@ static inline int is_link_local(const unsigned char *dest) 
/*

 * Called via br_handle_frame_hook.

 * Return NULL if skb is handled

 * note: already called with rcu_read_lock (preempt_disabled)

 * note: already called with rcu_read_lock

 */

struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)

{

net/bridge/br_stp_bpdu.c

+1 −1
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_port *p) 
/*

 * 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)

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