From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756069AbZHYT64 (ORCPT ); Tue, 25 Aug 2009 15:58:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754127AbZHYT6z (ORCPT ); Tue, 25 Aug 2009 15:58:55 -0400 Received: from mail-bw0-f219.google.com ([209.85.218.219]:52654 "EHLO mail-bw0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750873AbZHYT6z convert rfc822-to-8bit (ORCPT ); Tue, 25 Aug 2009 15:58:55 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=TFq+T8xUzxJbJQltRI8xzZoV4vqWVnmQ0XVZKXOaoqphfGrNFOs2Z0L7ySLwmIRzou omu7l1d4AiMtcHiUdtVW/DUkxHe/MVVh6w5RNwoS+DBYIADJcIEB9umewq0lYupn2Crg FXr6azhvIDmFXgnHoIT1YBO+uGu4sPmzCxoII= MIME-Version: 1.0 In-Reply-To: <4A94411E.708@goop.org> References: <1251227779-24347-1-git-send-email-penberg@cs.helsinki.fi> <4A943CBD.60808@goop.org> <1251229085.25686.2.camel@penberg-laptop> <4A94411E.708@goop.org> Date: Tue, 25 Aug 2009 22:58:55 +0300 X-Google-Sender-Auth: 0fe2754f23808e79 Message-ID: <84144f020908251258p71d5ad2fx7d31361c243a698e@mail.gmail.com> Subject: Re: [PATCH] x86: Execute WP test after interrupts are enabled From: Pekka Enberg To: Jeremy Fitzhardinge Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, Arnd Hannemann , Brian Gerst Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 25, 2009 at 10:53 PM, Jeremy Fitzhardinge wrote: > On 08/25/09 12:38, Pekka Enberg wrote: >> On Tue, 2009-08-25 at 12:34 -0700, Jeremy Fitzhardinge wrote: >> >>> I don't think this is the real fix, and it seems a bit ugly.  I'm OK >>> with it as a workaround, but I think it will end up getting reverted if >>> applied. >>> >> Yeah, I'm fine with that. It's just that we're really late in the >> release cycle now so I'd like to keep the fix as simple as possible. > > Yeah, that's fine, but I think something like this would be simpler. > Arnd, could you test it please? > > From: Jeremy Fitzhardinge > Date: Tue, 25 Aug 2009 12:47:17 -0700 > Subject: [PATCH] xen: suppress WP test > > Xen always runs on CPUs which properly support WP enforcement in > privileged mode, so there's no need to test for it. > > This also works around a crash reported by Arnd Hannemann, though > I think its just a band-aid for that case. > > Reported-by: Arnd Hannemann > Signed-off-by: Jeremy Fitzhardinge > Cc: Pekka Enberg > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 16d0d70..e5b903b 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1069,6 +1069,7 @@ asmlinkage void __init xen_start_kernel(void) >        /* set up basic CPUID stuff */ >        cpu_detect(&new_cpu_data); >        new_cpu_data.hard_math = 1; > +       new_cpu_data.wp_works_ok = 1; >        new_cpu_data.x86_capability[0] = cpuid_edx(1); >  #endif Yeah, this is even better assuming it works. :-) Acked-by: Pekka Enberg