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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham 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 B3913C6783C for ; Fri, 12 Oct 2018 14:58:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78F6020865 for ; Fri, 12 Oct 2018 14:58:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78F6020865 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codemonkey.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729034AbeJLWa7 (ORCPT ); Fri, 12 Oct 2018 18:30:59 -0400 Received: from scorn.kernelslacker.org ([45.56.101.199]:43728 "EHLO scorn.kernelslacker.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728860AbeJLWa7 (ORCPT ); Fri, 12 Oct 2018 18:30:59 -0400 X-Greylist: delayed 1548 seconds by postgrey-1.27 at vger.kernel.org; Fri, 12 Oct 2018 18:30:59 EDT Received: from [2601:196:4600:5b90:ae9e:17ff:feb7:72ca] (helo=wopr.kernelslacker.org) by scorn.kernelslacker.org with esmtp (Exim 4.89) (envelope-from ) id 1gAyUN-0002hU-Ov; Fri, 12 Oct 2018 10:32:27 -0400 Received: by wopr.kernelslacker.org (Postfix, from userid 1026) id 764F4560660; Fri, 12 Oct 2018 10:32:27 -0400 (EDT) Date: Fri, 12 Oct 2018 10:32:27 -0400 From: Dave Jones To: Cong Wang Cc: Meelis Roos , LKML , Linux Kernel Network Developers Subject: Re: netconsole warning in 4.19.0-rc7 Message-ID: <20181012143227.rauhvaxi6jtvneiq@codemonkey.org.uk> Mail-Followup-To: Dave Jones , Cong Wang , Meelis Roos , LKML , Linux Kernel Network Developers References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 10, 2018 at 10:34:49PM -0700, Cong Wang wrote: > (Cc'ing Dave) > > On Wed, Oct 10, 2018 at 5:14 AM Meelis Roos wrote: > > > > Thies 4.19-rc7 on a bunch of test machines and got this warning from one. > > It is reproducible and I have not noticed it before. > > > [...] > > [ 9.914805] WARNING: CPU: 0 PID: 0 at kernel/softirq.c:168 __local_bh_enable_ip+0x2e/0x44 > > [ 9.914806] Modules linked in: > > [ 9.914808] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc7 #210 > > [ 9.914810] Hardware name: MicroLink /D850MV , BIOS MV85010A.86A.0067.P24.0304081124 04/08/2003 > > [ 9.914811] EIP: __local_bh_enable_ip+0x2e/0x44 > > [ 9.914813] Code: cc 02 5f c8 a9 00 00 0f 00 75 1f 83 ea 01 f7 da 01 15 cc 02 5f c8 a1 cc 02 5f c8 a9 00 ff 1f 00 74 0c ff 0d cc 02 5f c8 5d c3 <0f> 0b eb dd 66 a1 80 cd 5e c8 66 85 c0 74 e9 e8 87 ff ff ff eb e2 > > [ 9.914814] EAX: 80010200 EBX: f602b000 ECX: 36346270 EDX: 00000200 > > [ 9.914815] ESI: f620ecc0 EDI: f620ebac EBP: f600de40 ESP: f600de40 > > [ 9.914816] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 EFLAGS: 00010006 > > [ 9.914817] CR0: 80050033 CR2: b7f5f000 CR3: 36389000 CR4: 000006d0 > > [ 9.914818] Call Trace: > > [ 9.914819] > > [ 9.914820] netpoll_send_skb_on_dev+0xa5/0x1b0 > > This is exactly what I mentioned in my review here: > https://marc.info/?l=linux-netdev&m=153816136624679&w=2 > > "But irq is disabled here, so not sure if rcu_read_lock_bh() > could cause trouble... " ugh, what a mess. I'm travelling right now so not going to get to look into this more for a week or so. Unless someone has a quick-fix, should we revert ? We've traded one warning for another, which doesn't really feel like progress. Dave