From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751500Ab0DLM2H (ORCPT ); Mon, 12 Apr 2010 08:28:07 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:56201 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751031Ab0DLM2D (ORCPT ); Mon, 12 Apr 2010 08:28:03 -0400 Date: Mon, 12 Apr 2010 13:27:45 +0100 From: Russell King To: David VomLehn Cc: to@dvomlehn-lnx2.corp.sa.net, "linux-arch@vger.kernel.org"@cisco.com, linux-arch@vger.kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, maint_arch@dvomlehn-lnx2.corp.sa.net Subject: Re: [PATCH 1/23] Make register values available to panic notifiers Message-ID: <20100412122745.GC28208@flint.arm.linux.org.uk> Mail-Followup-To: David VomLehn , to@dvomlehn-lnx2.corp.sa.net, "linux-arch@vger.kernel.org"@cisco.com, linux-arch@vger.kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, maint_arch@dvomlehn-lnx2.corp.sa.net References: <20100412060609.GA25273@dvomlehn-lnx2.corp.sa.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100412060609.GA25273@dvomlehn-lnx2.corp.sa.net> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 11, 2010 at 11:06:09PM -0700, David VomLehn wrote: > This patch makes panic() and die() registers available to, for example, > panic notifier functions. Panic notifier functions are quite useful > for recording crash information, but they don't get passed the register > values. This makes it hard to print register contents, do stack > backtraces, etc. The changes in this patch save the register state when > panic() is called and introduce a function for die() to call that allows > it to pass in the registers it was passed. Can you explain why you want this? I'm wondering about the value of saving the registers; normally when a panic occurs, it's because of a well defined reason, and not because something went wrong in some CPU register; to put it another way, a panic() is a more controlled exception than a BUG() or a bad pointer dereference. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: