Messages in this thread Patch in this message | | | Date | Tue, 24 Aug 2010 15:42:13 -0700 | From | Greg KH <> | Subject | [51/91] bridge: add rcu_read_lock on transmit |
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2.6.34-stable review patch. If anyone has any objections, please let us know.
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From: Stephen Hemminger <shemminger@vyatta.com>
[ Upstream commit eeaf61d8891f9c9ed12c1a667e72bf83f0857954 ]
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: Stephen Hemminger <shemminger@vyatta.com> Tested-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- net/bridge/br_device.c | 4 +++- net/bridge/br_fdb.c | 2 +- net/bridge/br_input.c | 6 +++--- net/bridge/br_stp_bpdu.c | 2 +- 4 files changed, 8 insertions(+), 6 deletions(-)
--- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -19,7 +19,7 @@ #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); @@ -35,6 +35,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff * skb_reset_mac_header(skb); skb_pull(skb, ETH_HLEN); + rcu_read_lock(); if (dest[0] & 1) { if (br_multicast_rcv(br, NULL, skb)) goto out; @@ -50,6 +51,7 @@ 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 +++ b/net/bridge/br_fdb.c @@ -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 +++ b/net/bridge/br_input.c @@ -35,7 +35,7 @@ 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; @@ -106,7 +106,7 @@ 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); @@ -131,7 +131,7 @@ static inline int is_link_local(const un /* * 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) { --- a/net/bridge/br_stp_bpdu.c +++ b/net/bridge/br_stp_bpdu.c @@ -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)
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