From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id 3181B6B0005 for ; Fri, 9 Mar 2018 15:00:43 -0500 (EST) Received: by mail-qt0-f199.google.com with SMTP id x35so7609345qtx.5 for ; Fri, 09 Mar 2018 12:00:43 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id b4si1433580qkc.414.2018.03.09.12.00.39 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Mar 2018 12:00:39 -0800 (PST) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w29JuU6A083373 for ; Fri, 9 Mar 2018 15:00:38 -0500 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2gky5wuqhk-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Fri, 09 Mar 2018 15:00:38 -0500 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 9 Mar 2018 20:00:35 -0000 Date: Fri, 9 Mar 2018 12:00:17 -0800 From: Ram Pai Subject: Re: [PATCH] x86, powerpc : pkey-mprotect must allow pkey-0 Reply-To: Ram Pai References: <1520583161-11741-1-git-send-email-linuxram@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-Id: <20180309200017.GR1060@ram.oc3035372033.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Florian Weimer 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, dave.hansen@intel.com, 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, msuchanek@suse.com, Ulrich.Weigand@de.ibm.com On Fri, Mar 09, 2018 at 12:04:49PM +0100, Florian Weimer wrote: > On 03/09/2018 09:12 AM, Ram Pai wrote: > >Once an address range is associated with an allocated pkey, it cannot be > >reverted back to key-0. There is no valid reason for the above behavior. > > mprotect without a key does not necessarily use key 0, e.g. if > protection keys are used to emulate page protection flag combination > which is not directly supported by the hardware. > > Therefore, it seems to me that filtering out non-allocated keys is > the right thing to do. I am not sure, what you mean. Do you agree with the patch or otherwise? RP