From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932633Ab0BYOBc (ORCPT ); Thu, 25 Feb 2010 09:01:32 -0500 Received: from eddie.linux-mips.org ([78.24.191.182]:45883 "EHLO eddie.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932357Ab0BYOBa (ORCPT ); Thu, 25 Feb 2010 09:01:30 -0500 Date: Thu, 25 Feb 2010 15:01:21 +0100 From: Ralf Baechle To: Jason Wessel Cc: linux-kernel@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, mingo@elte.hu Subject: Re: [PATCH 19/28] mips,kgdb: kdb low level trap catch and stack trace Message-ID: <20100225140121.GA5616@linux-mips.org> References: <1266014143-29444-1-git-send-email-jason.wessel@windriver.com> <1266014143-29444-20-git-send-email-jason.wessel@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1266014143-29444-20-git-send-email-jason.wessel@windriver.com> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 12, 2010 at 04:35:34PM -0600, Jason Wessel wrote: > The only way the debugger can handle a trap in inside rcu_lock, > notify_die, or atomic_notifier_call_chain without a recursive fault is > to have a low level "first opportunity handler" do_trap_or_bp() handler. > > Generally this will be something the vast majority of folks will not > need, but for those who need it, it is added as a kernel .config > option called KGDB_LOW_LEVEL_TRAP. > > Also added was a die notification for oops such that kdb can catch an > oops for analysis. > > There appeared to be no obvious way to pass the struct pt_regs from > the original exception back to the stack back tracer, so a special > case was added to show_stack() for when kdb is active because you > generally desire to generally look at the back trace of the original > exception. > > CC: Ralf Baechle > Signed-off-by: Jason Wessel Acked-by: Ralf Baechle Ralf