From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933547Ab0HXXCy (ORCPT ); Tue, 24 Aug 2010 19:02:54 -0400 Received: from kroah.org ([198.145.64.141]:41157 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933511Ab0HXXCo (ORCPT ); Tue, 24 Aug 2010 19:02:44 -0400 X-Mailbox-Line: From gregkh@clark.site Tue Aug 24 15:45:06 2010 Message-Id: <20100824224506.548013948@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 24 Aug 2010 15:45:06 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Stephen Hemminger , "David S. Miller" Subject: [061/114] bridge: add rcu_read_lock on transmit In-Reply-To: <20100824224610.GA5424@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Stephen Hemminger [ 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 Tested-by: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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 @@ -22,7 +22,7 @@ #include #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_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 * 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 @@ -37,7 +37,7 @@ 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; @@ -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 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)