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,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 8E764C5CFEB for ; Mon, 9 Jul 2018 19:12:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46BE0208A5 for ; Mon, 9 Jul 2018 19:12:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46BE0208A5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 S933370AbeGITMB (ORCPT ); Mon, 9 Jul 2018 15:12:01 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:55524 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932789AbeGITMA (ORCPT ); Mon, 9 Jul 2018 15:12:00 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4686380401B6; Mon, 9 Jul 2018 19:12:00 +0000 (UTC) Received: from treble (ovpn-120-114.rdu2.redhat.com [10.10.120.114]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AAA212166BA2; Mon, 9 Jul 2018 19:11:59 +0000 (UTC) Date: Mon, 9 Jul 2018 14:11:57 -0500 From: Josh Poimboeuf To: Peter Zijlstra Cc: Tetsuo Handa , Ingo Molnar , mingo@redhat.com, linux-kernel@vger.kernel.org, Andy Lutomirski , Borislav Petkov , Linus Torvalds , Thomas Gleixner Subject: Re: [PATCH] x86: Avoid pr_cont() in show_opcodes() Message-ID: <20180709191034.pyadc3cy7ulwaf2o@treble> References: <1530943625-3288-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20180707111209.GA27768@gmail.com> <20180709084953.GB2476@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180709084953.GB2476@hirez.programming.kicks-ass.net> User-Agent: NeoMutt/20180323 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 09 Jul 2018 19:12:00 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 09 Jul 2018 19:12:00 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jpoimboe@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 09, 2018 at 10:49:53AM +0200, Peter Zijlstra wrote: > On Sat, Jul 07, 2018 at 10:54:28PM +0900, Tetsuo Handa wrote: > > >> Since syzbot is confused by concurrent printk() messages [1], > > >> this patch changes show_opcodes() to use snprintf(). > > But how big of a problem is that really? We can't very well remove all > pr_cont stuff from the kernel. I'd say we should try to make oopses as legible as possible. Also KERN_CONT is inherently broken, and we should avoid using it in general, IMO. -- Josh