From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C87DFC4320A for ; Wed, 25 Aug 2021 17:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA41E6023E for ; Wed, 25 Aug 2021 17:56:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242418AbhHYR5L (ORCPT ); Wed, 25 Aug 2021 13:57:11 -0400 Received: from mga03.intel.com ([134.134.136.65]:42586 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235032AbhHYR5K (ORCPT ); Wed, 25 Aug 2021 13:57:10 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10087"; a="217614869" X-IronPort-AV: E=Sophos;i="5.84,351,1620716400"; d="scan'208";a="217614869" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2021 10:56:24 -0700 X-IronPort-AV: E=Sophos;i="5.84,351,1620716400"; d="scan'208";a="527422217" Received: from jambrizm-mobl1.amr.corp.intel.com ([10.212.224.56]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2021 10:56:23 -0700 Date: Wed, 25 Aug 2021 10:56:14 -0700 (PDT) From: Mat Martineau To: Jiang Biao cc: Matthieu Baerts , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel , Jiang Biao , Jiang Biao , Paolo Abeni Subject: Re: [PATCH] ipv4/mptcp: fix divide error In-Reply-To: Message-ID: References: <20210824071926.68019-1-benbjiang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 24 Aug 2021, Jiang Biao wrote: > Hi, > > On Tue, 24 Aug 2021 at 15:36, Matthieu Baerts > wrote: >> >> Hi Jiang, >> >> On 24/08/2021 09:19, Jiang Biao wrote: >> >> (...) >> >>> There is a fix divide error reported, >>> divide error: 0000 [#1] PREEMPT SMP KASAN >>> RIP: 0010:tcp_tso_autosize build/../net/ipv4/tcp_output.c:1975 [inline] >>> RIP: 0010:tcp_tso_segs+0x14f/0x250 build/../net/ipv4/tcp_output.c:1992 >> >> Thank you for this patch and validating MPTCP on your side! >> >> This issue is actively tracked on our Github project [1] and a patch is >> already in our tree [2] but still under validation. >>> It's introduced by non-initialized info->mss_now in __mptcp_push_pending. >>> Fix it by adding protection in mptcp_push_release. >> >> Indeed, you are right, info->mss_now can be set to 0 in some cases but >> that's not normal. >> >> Instead of adding a protection here, we preferred fixing the root cause, >> see [2]. Do not hesitate to have a look at the other patch and comment >> there if you don't agree with this version. >> Except if [2] is difficult to backport, I think we don't need your extra >> protection. WDYT? >> > Agreed, fixing the root cause is much better. > Thanks for the reply. > Hi Jiang - Could you try cherry-picking this commit to see if it eliminates the error in your system? https://github.com/multipath-tcp/mptcp_net-next/commit/9ef5aea5a794f4a369e26ed816e9c80cdc5a5f86 Thanks! -- Mat Martineau Intel