From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756241AbcGHVCw (ORCPT ); Fri, 8 Jul 2016 17:02:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43381 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753497AbcGHVCq (ORCPT ); Fri, 8 Jul 2016 17:02:46 -0400 Date: Fri, 8 Jul 2016 14:02:45 -0700 From: Andrew Morton To: Konstantin Khlebnikov Cc: linux-kernel@vger.kernel.org, Jiri Kosina , Ulrich Obergfell , Aaron Tomlin Subject: Re: [PATCH] kernel/watchdog: use nmi registers snapshot in hardlockup handler Message-Id: <20160708140245.6721f848bae1b8700a3e17fe@linux-foundation.org> In-Reply-To: <146771764784.86724.6006627197118544150.stgit@buzz> References: <146771764784.86724.6006627197118544150.stgit@buzz> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 05 Jul 2016 14:20:47 +0300 Konstantin Khlebnikov wrote: > NMI handler doesn't call set_irq_regs(), so get_irq_regs() returns NULL or > stale snapshot from beginning of IRQ interrupted by NMI. Registers from > argument are always here and points to interrupted instruction and state. Changelog is quite poor. Please send along a new one which describes in full detail how this patch alters kernel behaviour. Such a description will help others decide whether their kernel might need this patch and permits others to decide which kernel versions need the fix.