From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 401gx269JszF09n for ; Thu, 15 Mar 2018 05:58:43 +1100 (AEDT) Subject: Re: [PATCH 1/1 v2] x86: pkey-mprotect must allow pkey-0 To: Ram Pai References: <1521013574-27041-1-git-send-email-linuxram@us.ibm.com> <18b155e3-07e9-5a4b-1f95-e1667078438c@intel.com> <20180314171448.GA1060@ram.oc3035372033.ibm.com> <5027ca9e-63c8-47ab-960d-a9c4466d7075@intel.com> <20180314185452.GB1060@ram.oc3035372033.ibm.com> Cc: mingo@redhat.com, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.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 From: Dave Hansen Message-ID: <3f7c9ee7-46db-723f-177d-7505d0ac1e41@intel.com> Date: Wed, 14 Mar 2018 11:58:29 -0700 MIME-Version: 1.0 In-Reply-To: <20180314185452.GB1060@ram.oc3035372033.ibm.com> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/14/2018 11:54 AM, Ram Pai wrote: >>> (e) it bypasses key-permission checks when assigned. >> I don't think this is necessary. I think the only rule we *need* is: >> >> pkey-0 is allocated implicitly at execve() time. You do not >> need to call pkey_alloc() to allocate it. > And can be explicitly associated with any address range ? Yes, it should ideally be available for use just like any other key when allocated.