From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: [PATCH][BRIDGE] Properly dereference the br_should_route_hook Date: Tue, 27 Nov 2007 19:12:11 +0300 Message-ID: <474C41DB.4080007@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: bridge@lists.osdl.org, Linux Netdev List , devel@openvz.org To: Herbert Xu , Stephen Hemminger Return-path: Received: from sacred.ru ([62.205.161.221]:49959 "EHLO sacred.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754099AbXK0QMg (ORCPT ); Tue, 27 Nov 2007 11:12:36 -0500 Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This hook is protected with the RCU, so simple if (br_should_route_hook) br_should_route_hook(...) is not enough on some architectures. Use the rcu_dereference/rcu_assign_pointer in this case. Signed-off-by: Pavel Emelyanov --- diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 3cedd4e..b42b192 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -122,6 +122,7 @@ static inline int is_link_local(const unsigned char *dest) struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) { const unsigned char *dest = eth_hdr(skb)->h_dest; + typeof(br_should_route_hook) rhook; if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) goto drop; @@ -147,9 +148,9 @@ struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) switch (p->state) { case BR_STATE_FORWARDING: - - if (br_should_route_hook) { - if (br_should_route_hook(skb)) + rhook = rcu_dereference(br_should_route_hook); + if (rhook != NULL) { + if (rhook(skb)) return skb; dest = eth_hdr(skb)->h_dest; } diff --git a/net/bridge/netfilter/ebtable_broute.c b/net/bridge/netfilter/ebtable_broute.c index e44519e..be6f186 100644 --- a/net/bridge/netfilter/ebtable_broute.c +++ b/net/bridge/netfilter/ebtable_broute.c @@ -70,13 +70,13 @@ static int __init ebtable_broute_init(void) if (ret < 0) return ret; /* see br_input.c */ - br_should_route_hook = ebt_broute; + rcu_assign_pointer(br_should_route_hook, ebt_broute); return ret; } static void __exit ebtable_broute_fini(void) { - br_should_route_hook = NULL; + rcu_assign_pointer(br_should_route_hook, NULL); synchronize_net(); ebt_unregister_table(&broute_table); }