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 S935884AbeCHTaf (ORCPT <rfc822;w@1wt.eu>);
        Thu, 8 Mar 2018 14:30:35 -0500
Received: from mga01.intel.com ([192.55.52.88]:37109 "EHLO mga01.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S932076AbeCHTac (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 8 Mar 2018 14:30:32 -0500
X-Amp-Result: SKIPPED(no attachment in message)
X-Amp-File-Uploaded: False
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.47,442,1515484800";
   d="scan'208";a="32386422"
Subject: Re: mm, x86, powerpc: pkey semantics for key-0 ?
To: Ram Pai <linuxram@us.ibm.com>
References: <1519257138-23797-1-git-send-email-linuxram@us.ibm.com>
 <1519257138-23797-4-git-send-email-linuxram@us.ibm.com>
 <2a7737cf-a5ba-c814-fdc7-45b5cdd47376@intel.com>
 <20180308182517.GO1060@ram.oc3035372033.ibm.com>
Cc: mpe@ellerman.id.au, mingo@redhat.com, akpm@linux-foundation.org,
        linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org,
        linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
        benh@kernel.crashing.org, paulus@samba.org,
        khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com,
        bsingharora@gmail.com, hbabu@us.ibm.com, mhocko@kernel.org,
        bauerman@linux.vnet.ibm.com, ebiederm@xmission.com, corbet@lwn.net,
        arnd@arndb.de, fweimer@redhat.com, msuchanek@suse.com,
        Ulrich.Weigand@de.ibm.com
From: Dave Hansen <dave.hansen@intel.com>
Message-ID: <1bfaa8c0-cd9c-b590-9930-e9584dfb928d@intel.com>
Date: Thu, 8 Mar 2018 11:30:29 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.6.0
MIME-Version: 1.0
In-Reply-To: <20180308182517.GO1060@ram.oc3035372033.ibm.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 03/08/2018 10:25 AM, Ram Pai wrote:
> Is there a reason why the default key; key-0, is not allowed to be
> explicitly associated with pages using pkey_mprotect()?

No, it's a bug if it is not permitted.  I have a vague recollection of
knowing about this and having a patch.