Received: by 2002:ac0:a5a7:0:0:0:0:0 with SMTP id m36-v6csp872411imm; Mon, 9 Jul 2018 12:12:55 -0700 (PDT) X-Google-Smtp-Source: AAOMgpcfck/snaWIJRBRlu6yVrEqntXI74YMLxZYEdCVfJ+ftZ4PiZg76vlgr+4T/lqIzaQGpZFP X-Received: by 2002:a63:c44a:: with SMTP id m10-v6mr20036739pgg.416.1531163575339; Mon, 09 Jul 2018 12:12:55 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531163575; cv=none; d=google.com; s=arc-20160816; b=ONT46QPA8VkDO8wlnzdlahNZQal8IInczv6quSRHIB67H0IGTr5Z1bC/2REzkHe2iE i3IwWJfMpACOI/8hibaZ6BSQWyw/gqXnDRGav7DXIBPlsozvJGnRyUalf4Y0dwY5FKob jGX2jCIuzKAuqi2Stc06xoQ53keRRjroxxjqXz5tdkiNY3SBEiHlMrFXXMp0teiIOWw9 SH5TPVGKyWEARa8GBz/GN3ypH4yCUDsodZutJCr6zlMh1xhHqNLUDakgQJw+OlwKXD0R fCI8KXJh+KXRBaymR+BUF9L4SC3iTZOLMCAHuI2OOHwKw1cBFOn5AThbU5eY5r4QhnC6 VXpg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=RCTrX4xl3KTer4TiFoPxXmHKnaHnK+CTp7XaDR7CjO8=; b=KV1wN0qjLKDqqjBSsR/yUFNOct+63sWLS+hWlSdIzBRbvbas+jUhVx4aZvfRPcfYyP T//8QW9TQ97QQ/l3Kcnzdfr7w5NPgxlLINnZhjkBM0iO4gwS+cPVetc2WR/FM0Vlmf3H UJPGC0hBs4fj93XBnPIdkjKCECVUmzHoR4r2oJl/IrJsA2Js/kWRsZ11AfDDCdhzqwhf UrMS7LFvMBpxCN3wpser5Td+GHBveHXBUWaH1eF8Z2pWl8db2uk1VEiyH4vBJVUYZ3Gc ozZk6jfr5V5LwcS0gd1flYY34Bd5bk4cAu2UKSrAcDf4RUbhGzcS4B3AEQndOpPd4vAW POSg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r11-v6si14175422pgs.274.2018.07.09.12.12.40; Mon, 09 Jul 2018 12:12:55 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933352AbeGITMB (ORCPT + 99 others); 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