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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 B180BECE58C for ; Fri, 11 Oct 2019 09:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81BB021D6C for ; Fri, 11 Oct 2019 09:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570785112; bh=drscdF8WjY/Kmi+jyxmoVaWt127a15am0W2ZZzsR4do=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=kF1RM6cDSBOKhJxLRiw5kzYccxZ5h97EZ3q4mF5x5y3abEDivaNbJturlxt06sjte ZgBsXYxEJ8XmGeTuFJgYNl9FCuvTynwlxKJ5RA9KYwpHFOZltuDjxWw2NaV7FvdIMz 1oecS6i+6WlhV7w2W5WT8dPU4fxxb0myABdXKxXc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727538AbfJKJLv (ORCPT ); Fri, 11 Oct 2019 05:11:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:60408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726585AbfJKJLv (ORCPT ); Fri, 11 Oct 2019 05:11:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 463892084C; Fri, 11 Oct 2019 09:11:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570785110; bh=drscdF8WjY/Kmi+jyxmoVaWt127a15am0W2ZZzsR4do=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=h7Re/GW+CtZsvnmM3bm7h2jiAzZsk+TqLrNBAQfy8AkWWO7orLMkxcY6IhYazEkOJ 0Bd1DDwi723m6RiIgiJ+rNoiaoMU8C2hARBFbkfwXrLUFBlLfusEvlr9Cd+4sH4Kc+ ydN5MnhqKyFTorWIqEXQ3FfDUEBoMNB6yT7pxLMA= Date: Fri, 11 Oct 2019 11:11:48 +0200 From: Greg KH To: Lei Chen Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: Re: ipv6 UNH-IOL Intact test cases failure on kernel 4.4.178 Message-ID: <20191011091148.GB1124173@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Oct 11, 2019 at 05:00:32PM +0800, Lei Chen wrote: > Hi David, > Thanks in advance for reading my message. > > We are running UNH-IOL test on our product which is based on kernel > 4.4.178. The INTACT test cases failed on ipv6 verification. The same test > cases just got pass on 4.4.153. (Sorry, the INTACT suite does not look to > be open sourced. Hence I don't really know what the cases were indeed > doing.) > > Our verification engineer also mentioned: "The pattern of failures look > eerily similar to a regression we recently discovered in SLES 12. I.e., > Failures related to “Parameter Problems”, as well as “Fragmentation“." We > have tried to back out the defragment related patch: > > commit 5f2d68b6b5a439c3223d8fa6ba20736f91fc58d8 > Author: Florian Westphal > Date: Wed Oct 10 12:30:10 2018 -0700 > > ipv6: defrag: drop non-last frags smaller than min mtu > > commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6 upstream. > > don't bother with pathological cases, they only waste cycles. > IPv6 requires a minimum MTU of 1280 so we should never see fragments > smaller than this (except last frag). > > > But it doesn't help. Could you please shed a light on which patch between > 4.4.153 and 4.4.178 could have caused such a regression? Thanks again. As you can run the test, why can't you run 'git bisect' to find the offending patch? thanks, greg k-h