From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S934223AbcCNLfM (ORCPT <rfc822;w@1wt.eu>);
	Mon, 14 Mar 2016 07:35:12 -0400
Received: from mail-wm0-f41.google.com ([74.125.82.41]:34649 "EHLO
	mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752020AbcCNLfF (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 14 Mar 2016 07:35:05 -0400
Date: Mon, 14 Mar 2016 11:35:02 +0000
From: Matt Fleming <matt@codeblueprint.co.uk>
To: Ingo Molnar <mingo@kernel.org>
Cc: Scott Ashcroft <scott.ashcroft@talk21.com>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Matthew Garrett <mjg59@srcf.ucam.org>, Borislav Petkov <bp@alien8.de>,
        Ben Hutchings <ben@decadent.org.uk>,
        Raphael Hertzog <hertzog@debian.org>,
        Roger Shimizu <rogershimizu@gmail.com>,
        Alexis Murzeau <amurzeau@gmail.com>
Subject: Re: [PATCH] x86/efi: Always map boot service regions into new EFI
 page tables
Message-ID: <20160314113502.GC2619@codeblueprint.co.uk>
References: <1457695163-29632-1-git-send-email-matt@codeblueprint.co.uk>
 <1457695163-29632-2-git-send-email-matt@codeblueprint.co.uk>
 <1457888975.3884.9.camel@talk21.com>
 <20160313215847.GA2619@codeblueprint.co.uk>
 <20160313230736.GB2619@codeblueprint.co.uk>
 <20160314103019.GA32573@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20160314103019.GA32573@gmail.com>
User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 14 Mar, at 11:30:19AM, Ingo Molnar wrote:
> 
> * Matt Fleming <matt@codeblueprint.co.uk> wrote:
> 
> > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> > index 8fee5b6f8f66..af74849e8c0f 100644
> > --- a/arch/x86/mm/pageattr.c
> > +++ b/arch/x86/mm/pageattr.c
> > @@ -1055,7 +1055,7 @@ static int populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
> >  	/*
> >  	 * Map everything starting from the Gb boundary, possibly with 1G pages
> >  	 */
> > -	while (end - start >= PUD_SIZE) {
> > +	while (cpu_has_gbpages && end - start >= PUD_SIZE) {
> >  		set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
> >  				   massage_pgprot(pud_pgprot)));
> 
> Btw., can 'cpa->pfn << PAGE_SHIFT' possibly work on 32-bit systems?
> 
> cpa->pfn is unsigned long, so the result gets truncated to 32 bits ...
> 
> cpa->pfn should be u64.

That is a nice catch.

Note that we never run this code on 32-bit right now. Moving 32-bit to
this code and away from the old_map scheme is on my TODO list.