From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964790AbVJZPty (ORCPT ); Wed, 26 Oct 2005 11:49:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964794AbVJZPty (ORCPT ); Wed, 26 Oct 2005 11:49:54 -0400 Received: from ns1.suse.de ([195.135.220.2]:28592 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S964790AbVJZPtx (ORCPT ); Wed, 26 Oct 2005 11:49:53 -0400 From: Andi Kleen To: "Jan Beulich" Subject: Re: DIE_GPF vs. DIE_PAGE_FAULT/DIE_TRAP Date: Wed, 26 Oct 2005 17:50:44 +0200 User-Agent: KMail/1.8.2 Cc: linux-kernel@vger.kernel.org, discuss@x86-64.org References: <435FB26B.76F0.0078.0@novell.com> <200510261701.52611.ak@suse.de> <435FBB1A.76F0.0078.0@novell.com> In-Reply-To: <435FBB1A.76F0.0078.0@novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200510261750.44501.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 26 October 2005 17:21, Jan Beulich wrote: > Hmm, then this isn't really useful for a debugger. There ought to be a > chance to filter exceptions early (i.e. debugger accesses to non-mapped > memory or non-existing MSRs) and a chance to detect bad faults (note > that the kernel normal exception recovery mechanism may not be usable > here because for example page faults first try to service the fault > before scanning the fixup tables, but a debugger will normally not want > a page-in to happen behind its back). I thought the latter was what gets > reported as DIE_OOPS, while the former would be the filtering occasions > (and I actually took the "grossly misnamed" comment in asm/kdebug.h as > additional indication for that). All you want is a hook early in GPF, right? I guess that should be ok. I can see that it's useful on x86-64 due to the non canonical address fault resulting in GPFs mess. Just send a patch. -Andi