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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3D32EC433DF for ; Tue, 16 Jun 2020 01:51:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 232B7206F1 for ; Tue, 16 Jun 2020 01:51:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726419AbgFPBvd (ORCPT ); Mon, 15 Jun 2020 21:51:33 -0400 Received: from mga04.intel.com ([192.55.52.120]:18586 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbgFPBvc (ORCPT ); Mon, 15 Jun 2020 21:51:32 -0400 IronPort-SDR: Iog+5KIJ7x7HcREwl57FJ6AWPpylwiXjMeEm8xrRrCdC1MrSI31ReS+GBQTVqbKY+7Jb+hHj7O lazIXsh81a0g== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2020 18:51:31 -0700 IronPort-SDR: MhTL47sbS+pRc/kLZQKHQ0AQ/M0ggkjhNBL+Z0Cal3rc4x4rO0tukFSHpVcJA3lhdBbyc3DpB6 i/ucjTf5/PWw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,517,1583222400"; d="scan'208";a="276757754" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.152]) by orsmga006.jf.intel.com with ESMTP; 15 Jun 2020 18:51:31 -0700 Date: Mon, 15 Jun 2020 18:51:31 -0700 From: Sean Christopherson To: Prarit Bhargava Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Tony Luck , "Peter Zijlstra (Intel)" , Rahul Tanwar , Xiaoyao Li , Ricardo Neri , Dave Hansen Subject: Re: [PATCH v3] x86/split_lock: Sanitize userspace and guest error output Message-ID: <20200616015131.GA26491@linux.intel.com> References: <20200615113900.35697-1-prarit@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200615113900.35697-1-prarit@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 15, 2020 at 07:39:00AM -0400, Prarit Bhargava wrote: > There are two problems with kernel messages in fatal mode that were found > during testing of guests and userspace programs. > > The first is that no kernel message is output when the split lock detector > is triggered with a userspace program. As a result the userspace process > dies from receiving SIGBUS with no indication to the user of what caused > the process to die. > > The second problem is that only the first triggering guest causes a kernel > message to be output because the message is output with pr_warn_once(). > This also results in a loss of information to the user. > > While fixing these I noticed that the same message was being output > three times so I'm cleaning that up too. > > Fix fatal mode output, and use consistent messages for fatal and > warn modes for both userspace and guests. > > Signed-off-by: Prarit Bhargava > Signed-off-by: Sean Christopherson This needs a Co-developed-by for me, and your SOB should come last, e.g. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Prarit Bhargava See "12) When to use Acked-by:, Cc:, and Co-developed-by:" in Documentation/process/submitting-patches.rst for more details.