From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751860AbZEHPaX (ORCPT ); Fri, 8 May 2009 11:30:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752929AbZEHPaI (ORCPT ); Fri, 8 May 2009 11:30:08 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:15667 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753229AbZEHPaH convert rfc822-to-8bit (ORCPT ); Fri, 8 May 2009 11:30:07 -0400 Message-Id: <4A046C3F.76EA.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.0 Date: Fri, 08 May 2009 16:30:39 +0100 From: "Jan Beulich" To: "Jeremy Fitzhardinge" Cc: "Ingo Molnar" , "the arch/x86 maintainers" , "Linus Torvalds" , "Xen-devel" , "Linux Kernel Mailing List" Subject: Re: [Xen-devel] [PATCH 2/5] xen/x86-64: clean up warnings aboutIST-usingtraps References: <4A032EE0.9030607@goop.org> <4A03F947.76EA.0078.0@novell.com> <4A044E55.20803@goop.org> In-Reply-To: <4A044E55.20803@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> Jeremy Fitzhardinge 08.05.09 17:23 >>> >Jan Beulich wrote: >>> else if (addr == (unsigned long)int3) >>> addr = (unsigned long)xen_int3; >>> - else >>> - WARN_ON(val->ist != 0); >>> + else if (addr == (unsigned long)double_fault || >>> + addr == (unsigned long)stack_segment) { >>> >> >> I don't think you want to exclude handling stack faults: Ordinary memory >> references using rsp or rbp as the base register will cause these instead >> of general protection faults when the resulting effective address is non- >> canonical. >> > >So even usermode memory accesses? Ew. Yes, just try it out - you'll observe them generate SIGBUS instead of SIGSEGV. Jan