Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755372AbZJFAgn (ORCPT ); Mon, 5 Oct 2009 20:36:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753560AbZJFAgn (ORCPT ); Mon, 5 Oct 2009 20:36:43 -0400 Received: from claw.goop.org ([74.207.240.146]:50064 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753428AbZJFAgm (ORCPT ); Mon, 5 Oct 2009 20:36:42 -0400 Message-ID: <4ACA90F2.1060909@goop.org> Date: Mon, 05 Oct 2009 17:36:02 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Bastian Blank , Ingo Molnar , the arch/x86 maintainers , Stable Kernel , Linux Kernel Mailing List , Xen-devel Subject: Re: [Xen-devel] Re: [PATCH] xen: Disable stack protector for irq helper References: <20091004183013.GA26101@wavehammer.waldi.eu.org> <4AC92A65.40806@goop.org> <20091005013517.GA6081@wavehammer.waldi.eu.org> <4ACA2AFD.4080305@goop.org> <20091005224310.GA32144@wavehammer.waldi.eu.org> In-Reply-To: <20091005224310.GA32144@wavehammer.waldi.eu.org> X-Enigmail-Version: 0.97a Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1126 Lines: 31 On 10/05/09 15:43, Bastian Blank wrote: > On Mon, Oct 05, 2009 at 10:21:01AM -0700, Jeremy Fitzhardinge wrote: > >>> Save all caller-saved registers on x86_32 for the paravirt callee saved >>> registers. >>> >> That looks better, but it is still overkill. We only need to save the >> set of registers the ABI requires the callee to preserve. What >> additional register(s) gets clobbered by stack-protector that need to be >> saved? >> > Well, exactly the two, ecx and edx. eax is still clobbered by the return > value. Anyway, it works in praxis. I'm confused. It already saves ecx, so what else needs saving? Besides, most of the code in that file isn't used unless you're using a very old version of Xen; it will generally prefer to use the ones in xen-asm_X.S. I have the feeling we haven't really found the root cause of your problem yet. Thanks, J -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/