From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755463AbZFGKEL (ORCPT ); Sun, 7 Jun 2009 06:04:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753275AbZFGKEA (ORCPT ); Sun, 7 Jun 2009 06:04:00 -0400 Received: from mx2.redhat.com ([66.187.237.31]:45425 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020AbZFGKD7 (ORCPT ); Sun, 7 Jun 2009 06:03:59 -0400 Message-ID: <4A2B9086.20309@redhat.com> Date: Sun, 07 Jun 2009 13:03:50 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Tetsuo Handa CC: guillaume.thouvenin@ext.bull.net, linux-kernel@vger.kernel.org Subject: Re: [2.6.30-rc8 KVM] gcc 3.3 dies at emulate_2op_cl(). References: <4A2B7A79.4060600@redhat.com> <200906071747.FFJ57396.MSOOQFVHtFOJLF@I-love.SAKURA.ne.jp> <4A2B8201.8050904@redhat.com> <200906071839.DFB51529.JFHLOFtMFOSVQO@I-love.SAKURA.ne.jp> <4A2B8B22.3020602@redhat.com> <200906071900.GED43277.OtJOQFOFSMHVFL@I-love.SAKURA.ne.jp> In-Reply-To: <200906071900.GED43277.OtJOQFOFSMHVFL@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tetsuo Handa wrote: > Avi Kivity wrote: > >> I can eliminate _tmp by using lahf/sahf, but it's not going to be a >> trivial patch. >> > > I don't know what's happening here. > > If I comment out (_dst).bytes == 2 , it compiles. > The problem happens only "w" + "unsigned short" case. > > # diff -urp arch/x86/kvm/x86_emulate.c~ arch/x86/kvm/x86_emulate.c > --- arch/x86/kvm/x86_emulate.c~ 2009-06-03 12:07:25.000000000 +0900 > +++ arch/x86/kvm/x86_emulate.c 2009-06-07 17:52:05.591542272 +0900 > @@ -461,8 +461,8 @@ static u32 group2_table[] = { > do { \ > switch ((_dst).bytes) { \ > case 2: \ > - __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ > - "w", unsigned short); \ > + /* __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ > + "w", unsigned short); */ \ > break; \ > case 4: \ > __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ > It's a gcc register allocator bug. Bugs don't have to be reasonable. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.