From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932255Ab2B1Blg (ORCPT ); Mon, 27 Feb 2012 20:41:36 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:46792 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176Ab2B1BGO (ORCPT ); Mon, 27 Feb 2012 20:06:14 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of gregkh@linuxfoundation.org designates 10.68.241.170 as permitted sender) smtp.mail=gregkh@linuxfoundation.org MIME-Version: 1.0 Message-Id: <20120228010207.185235117@linuxfoundation.org> User-Agent: quilt/0.51-17.1 Date: Mon, 27 Feb 2012 17:02:22 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Dumazet , Shlomo Pongratz , Roland Dreier , Or Gerlitz , Herbert Xu , Sean Hefty , "David S. Miller" Subject: [ 19/73] gro: more generic L2 header check In-Reply-To: <20120228010246.GA24299@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 5ca3b72c5da47d95b83857b768def6172fbc080a ] Shlomo Pongratz reported GRO L2 header check was suited for Ethernet only, and failed on IB/ipoib traffic. He provided a patch faking a zeroed header to let GRO aggregates frames. Roland Dreier, Herbert Xu, and others suggested we change GRO L2 header check to be more generic, ie not assuming L2 header is 14 bytes, but taking into account hard_header_len. __napi_gro_receive() has special handling for the common case (Ethernet) to avoid a memcmp() call and use an inline optimized function instead. Signed-off-by: Eric Dumazet Reported-by: Shlomo Pongratz Cc: Roland Dreier Cc: Or Gerlitz Cc: Herbert Xu Tested-by: Sean Hefty Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3434,14 +3434,20 @@ static inline gro_result_t __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb) { struct sk_buff *p; + unsigned int maclen = skb->dev->hard_header_len; for (p = napi->gro_list; p; p = p->next) { unsigned long diffs; diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; diffs |= p->vlan_tci ^ skb->vlan_tci; - diffs |= compare_ether_header(skb_mac_header(p), - skb_gro_mac_header(skb)); + if (maclen == ETH_HLEN) + diffs |= compare_ether_header(skb_mac_header(p), + skb_gro_mac_header(skb)); + else if (!diffs) + diffs = memcmp(skb_mac_header(p), + skb_gro_mac_header(skb), + maclen); NAPI_GRO_CB(p)->same_flow = !diffs; NAPI_GRO_CB(p)->flush = 0; }