Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753074AbdLMPBE (ORCPT <rfc822;w@1wt.eu>);
        Wed, 13 Dec 2017 10:01:04 -0500
Received: from merlin.infradead.org ([205.233.59.134]:44302 "EHLO
        merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1750886AbdLMPBC (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 13 Dec 2017 10:01:02 -0500
Date: Wed, 13 Dec 2017 16:00:07 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Dan Williams <dan.j.williams@intel.com>,
        Dave Hansen <dave.hansen@intel.com>, Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Borislav Petkov <bpetkov@suse.de>,
        Greg KH <gregkh@linuxfoundation.org>, Kees Cook <keescook@google.com>,
        Hugh Dickins <hughd@google.com>, Brian Gerst <brgerst@gmail.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Denys Vlasenko <dvlasenk@redhat.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        David Laight <David.Laight@aculab.com>,
        Eduardo Valentin <eduval@amazon.com>, aliguori@amazon.com,
        Will Deacon <will.deacon@arm.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        kirill.shutemov@linux.intel.com, aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [patch 05/16] mm: Allow special mappings with user access cleared
Message-ID: <20171213150007.fonxub6yzjh2iu2c@hirez.programming.kicks-ass.net>
References: <20171212173221.496222173@linutronix.de>
 <20171212173333.669577588@linutronix.de>
 <CALCETrXLeGGw+g7GiGDmReXgOxjB-cjmehdryOsFK4JB5BJAFQ@mail.gmail.com>
 <20171213122211.bxcb7xjdwla2bqol@hirez.programming.kicks-ass.net>
 <20171213125739.fllckbl3o4nonmpx@node.shutemov.name>
 <20171213143455.oqigy6m53qhuu7k4@hirez.programming.kicks-ass.net>
 <20171213144339.ii5gk2arwg5ivr6b@node.shutemov.name>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20171213144339.ii5gk2arwg5ivr6b@node.shutemov.name>
User-Agent: NeoMutt/20170609 (1.8.3)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 471
Lines: 16

On Wed, Dec 13, 2017 at 05:43:39PM +0300, Kirill A. Shutemov wrote:
> > am I perchance looking at the wrong tee?
> 
> I'm looking at Linus' tree.

Clearly I'm not synced up enough... :/

> It was changed recently:
> 	5c9d2d5c269c ("mm: replace pte_write with pte_access_permitted in fault + gup paths")
> 

Indeed. So FOLL_GET should also get these tests and, as you said, the
other levels too.

I would like FOLL_POPULATE (doesn't have FOLL_GET) to be allowed
'access'.