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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 96389C4320E for ; Thu, 26 Aug 2021 03:22:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 763AA610C9 for ; Thu, 26 Aug 2021 03:22:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237055AbhHZDXY (ORCPT ); Wed, 25 Aug 2021 23:23:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231720AbhHZDXV (ORCPT ); Wed, 25 Aug 2021 23:23:21 -0400 Received: from mail-ot1-x32d.google.com (mail-ot1-x32d.google.com [IPv6:2607:f8b0:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 787B0C061757; Wed, 25 Aug 2021 20:22:34 -0700 (PDT) Received: by mail-ot1-x32d.google.com with SMTP id c19-20020a9d6153000000b0051829acbfc7so1681302otk.9; Wed, 25 Aug 2021 20:22:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bUeZZcRUwgsVKTg9hbUOFpXsEAgjIJCFQuo9JR/6uzc=; b=Cd+PYR/CcyaKB2Dv5SB33p47LhOGWZXNOHn1EdmwVk1xcpzdrlZ6xHmaxnv2H1iPGf RWtP8SHbN3xokld1eM/pm5ttcqP5oEVT3y2TUXHs9mzHYDOL5ViUCwYYIhEstqF70Xfp WJuv/0dJdP/tOW4nFPoUoYJVY8ksZK6uTBcL2dfkCvEqvr9MPxqLKenyIHOEOED7k9fP mE1OcurZBALiFsM6WDqfM97C0n+lhT/e6Q4pbTF5SCAfMxtOP/qx8KGfQiJ1ujkQVkgf 7i9VtdHZ42y7O9CHoQnhHn5VTuFgre5r3KC01v84y3Q2g+/0/OiXLFD9PY+X/ZGfUQCJ TbtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bUeZZcRUwgsVKTg9hbUOFpXsEAgjIJCFQuo9JR/6uzc=; b=SRU+e5ThTLTMXDX4pKMR7WK33IC2oQIhNX84Ez8lTRZLi6mx6iGfRdgGSoo+MOFPBs RyEnlE4e5XZr+jNQhNSKJ9NIy2bnlWtAOOC5TB0TWOZKZ+fkCjdfp391nj6ZVpmATuwb dr8q+VufwfYc2IkO/HJoYTmeTWYhAtSmailOWtjjR1cS17hS8hqGvH+EAxBib9z6U1BZ OnMZnHX7Ty38mJvlNAYzmUdvzWyNQSjfDU72mKjEQdapMFsNIW2VWqJdhnuTIG2TVuxc J/H+75arsNBhEBPSFXscEK9PzibGU/NSJkMJpdOVXacXRQ0NgggeCs2mNH09beK6jKhC 936w== X-Gm-Message-State: AOAM530MPrf5WSBKNrF55IJnGJEvqqwsImurjUU3BHIAQIpvlC5UrAzT HtClxLCYPOFGnmh+KuMpvYM711kdOTaVaC3Wj8g= X-Google-Smtp-Source: ABdhPJxgk1EqPZK7qA7ih/uquKPxaLzFqjR5sZ54uxK1N75LUQxoav/lMAWNN1uN0WKcEyzI+s06wNoInRxtLucaEAY= X-Received: by 2002:a05:6830:20d0:: with SMTP id z16mr1331201otq.330.1629948153918; Wed, 25 Aug 2021 20:22:33 -0700 (PDT) MIME-Version: 1.0 References: <20210824071926.68019-1-benbjiang@gmail.com> In-Reply-To: From: Jiang Biao Date: Thu, 26 Aug 2021 11:22:23 +0800 Message-ID: Subject: Re: [PATCH] ipv4/mptcp: fix divide error To: Mat Martineau 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 26 Aug 2021 at 01:56, Mat Martineau wrote: > > > 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 > ok, I'll try and give you feedback. Regards, Jiang