From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [BRIDGE] Unaligned access on IA64 when comparing ethernet addresses Date: Tue, 17 Apr 2007 13:37:23 -0700 Message-ID: <20070417133723.00031f82@mini> References: <4624B44A.9040509@sw.ru> <20070417.123135.56861973.davem@davemloft.net> <4625263D.1000709@linux-foundation.org> <20070417.130929.59470175.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: xemul@sw.ru, netdev@vger.kernel.org, bridge@lists.osdl.org, devel@openvz.org To: David Miller Return-path: Received: from smtp.osdl.org ([65.172.181.24]:34501 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752997AbXDQUiG (ORCPT ); Tue, 17 Apr 2007 16:38:06 -0400 In-Reply-To: <20070417.130929.59470175.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The previous patch relied on the bridge id being aligned by the compiler (which happens as a side effect). So please use this instead. compare_ether_addr() implicitly requires that the addresses passed are 2-bytes aligned in memory. This is not true for br_stp_change_bridge_id() and br_stp_recalculate_bridge_id() in which one of the addresses is unsigned char *, and thus may not be 2-bytes aligned. Signed-off-by: Evgeny Kravtsunov Signed-off-by: Kirill Korotaev Signed-off-by: Pavel Emelianov Signed-off-by: Stephen Hemminger --- --- linux-2.6.orig/net/bridge/br_stp_if.c 2007-04-16 20:03:04.000000000 -0700 +++ linux-2.6/net/bridge/br_stp_if.c 2007-04-17 13:25:52.000000000 -0700 @@ -126,23 +126,22 @@ /* called under bridge lock */ void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr) { - unsigned char oldaddr[6]; + bridge_id old_id; struct net_bridge_port *p; int wasroot; wasroot = br_is_root_bridge(br); - memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); + old_id = br->bridge_id; memcpy(br->bridge_id.addr, addr, ETH_ALEN); memcpy(br->dev->dev_addr, addr, ETH_ALEN); list_for_each_entry(p, &br->port_list, list) { - if (!compare_ether_addr(p->designated_bridge.addr, oldaddr)) + if (!compare_ether_addr(p->designated_bridge.addr, old_id.addr)) memcpy(p->designated_bridge.addr, addr, ETH_ALEN); - if (!compare_ether_addr(p->designated_root.addr, oldaddr)) + if (!compare_ether_addr(p->designated_root.addr, old_id.addr)) memcpy(p->designated_root.addr, addr, ETH_ALEN); - } br_configuration_update(br); @@ -151,19 +150,17 @@ br_become_root_bridge(br); } -static const unsigned char br_mac_zero[6]; - /* called under bridge lock */ void br_stp_recalculate_bridge_id(struct net_bridge *br) { - const unsigned char *addr = br_mac_zero; + static const bridge_id id_zero; + const unsigned char *addr = id_zero.addr; struct net_bridge_port *p; list_for_each_entry(p, &br->port_list, list) { - if (addr == br_mac_zero || + if (addr == id_zero.addr || memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0) addr = p->dev->dev_addr; - } if (compare_ether_addr(br->bridge_id.addr, addr)) --- linux-2.6.orig/net/bridge/br_private.h 2007-04-17 13:26:48.000000000 -0700 +++ linux-2.6/net/bridge/br_private.h 2007-04-17 13:30:29.000000000 -0700 @@ -36,7 +36,7 @@ { unsigned char prio[2]; unsigned char addr[6]; -}; +} __attribute__((aligned(8))); struct mac_addr {