From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964787AbbLOEuW (ORCPT ); Mon, 14 Dec 2015 23:50:22 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37045 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933098AbbLOEuV (ORCPT ); Mon, 14 Dec 2015 23:50:21 -0500 User-Agent: K-9 Mail for Android In-Reply-To: References: <20151214234355.GA32730@localhost.localdomain> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [PATCH v2] Fix INT1 Exception with unregistered breakpoints From: "H. Peter Anvin" Date: Mon, 14 Dec 2015 20:49:40 -0800 To: Jeff Merkey , linux-kernel@vger.kernel.org CC: tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, peterz@infradead.org, luto@kernel.org Message-ID: <9ADACBE2-9CAA-4993-BF03-502DEF0D365D@zytor.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On December 14, 2015 4:49:51 PM PST, Jeff Merkey wrote: >On 12/14/15, Jeff Merkey wrote: >> Please consider the attached patch. >> >> SUMMARY >> >> This patch corrects a hard lockup failure of the system kernel if the >> operating system receives a breakpoint exception at a code execution >> address which was not registered with the operating system. The >patch >> allows kernel debuggers, application profiling and performance >modules, >> and external debugging tools to work better together at sharing the >> breakpoint registers on the platform in a way that they do not cause >> errors and system faults, and enables the full feature set in the >> breakpoint API. If a kernel application triggers a breakpoint >> or programs one in error, this patch will catch the condition and >report >> it to the system log without the operating system experiencing a >system >> fault. There are several consumers of the Linux Breakpoint API and >all >> of them can and sometimes do cause the condition this patch corrects. >> > >Peter, > >Is that the type of summary that meets the standards. I tried to be >concise. > >Jeff It would be good if you could be a bit more precise. In particular, explain how and why the condition can appear rather than just explain that it can. -- Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.