From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751728Ab0ILGzZ (ORCPT ); Sun, 12 Sep 2010 02:55:25 -0400 Received: from [83.228.35.12] ([83.228.35.12]:35167 "EHLO fs.ru.acad.bg" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751435Ab0ILGzX (ORCPT ); Sun, 12 Sep 2010 02:55:23 -0400 Message-ID: <4C8C7957.7080207@fs.uni-ruse.bg> Date: Sun, 12 Sep 2010 09:55:19 +0300 From: Plamen Petrov User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; bg; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: David Miller , jarkao2@gmail.com, eric.dumazet@gmail.com, herbert@gondor.hengli.com.au, kernel-testers@vger.kernel.org, maciej.rutecki@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, stable@kernel.org Subject: Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum_dev References: <1283672983.3402.38.camel@edumazet-laptop> <20100908062004.GA6280@ff.dom.local> <20100908.103256.112592448.davem@davemloft.net> <201009082221.16356.rjw@sisk.pl> In-Reply-To: <201009082221.16356.rjw@sisk.pl> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org На 08.9.2010 г. 23:21, Rafael J. Wysocki написа: > On Wednesday, September 08, 2010, David Miller wrote: >> From: Jarek Poplawski >> Date: Wed, 8 Sep 2010 06:20:04 +0000 >> >>> We need both of them. I hope David could add this too: >>> >>> Tested-by: Plamen Petrov >> >> Done, and applied, thanks :-) > > Please kindly let me know when Linus gets them, so that I can close the bug. > > Rafael Now that both commits that fix my problems are in Linus' tree, the bug can be closed, but these fixes should go in 2.6.35.y, too. So, CCing -stable. Fix 1: > commit 3d3be4333fdf6faa080947b331a6a19bce1a4f57 > > gro: fix different skb headrooms > > Packets entering GRO might have different headrooms, even for a given > flow (because of implementation details in drivers, like copybreak). > We cant force drivers to deliver packets with a fixed headroom. > > 1) fix skb_segment() > > skb_segment() makes the false assumption headrooms of fragments are same > than the head. When CHECKSUM_PARTIAL is used, this can give csum_start > errors, and crash later in skb_copy_and_csum_dev() > > 2) allocate a minimal skb for head of frag_list > > skb_gro_receive() uses netdev_alloc_skb(headroom + skb_gro_offset(p)) to > allocate a fresh skb. This adds NET_SKB_PAD to a padding already > provided by netdevice, depending on various things, like copybreak. > > Use alloc_skb() to allocate an exact padding, to reduce cache line > needs: > NET_SKB_PAD + NET_IP_ALIGN > > bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626 > > Many thanks to Plamen Petrov, testing many debugging patches ! > With help of Jarek Poplawski. > > Reported-by: Plamen Petrov > Signed-off-by: Eric Dumazet > CC: Jarek Poplawski > Signed-off-by: David S. Miller Fix 2: > commit 64289c8e6851bca0e589e064c9a5c9fbd6ae5dd4 > > gro: Re-fix different skb headrooms > > The patch: "gro: fix different skb headrooms" in its part: > "2) allocate a minimal skb for head of frag_list" is buggy. The copied > skb has p->data set at the ip header at the moment, and skb_gro_offset > is the length of ip + tcp headers. So, after the change the length of > mac header is skipped. Later skb_set_mac_header() sets it into the > NET_SKB_PAD area (if it's long enough) and ip header is misaligned at > NET_SKB_PAD + NET_IP_ALIGN offset. There is no reason to assume the > original skb was wrongly allocated, so let's copy it as it was. > > bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626 > fixes commit: 3d3be4333fdf6faa080947b331a6a19bce1a4f57 > > Reported-by: Plamen Petrov > Signed-off-by: Jarek Poplawski > CC: Eric Dumazet > Acked-by: Eric Dumazet > Tested-by: Plamen Petrov > Signed-off-by: David S. Miller Thanks, Plamen