From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by kanga.kvack.org (Postfix) with ESMTP id DF1796B05EB for ; Thu, 8 Nov 2018 07:05:21 -0500 (EST) Received: by mail-qk1-f198.google.com with SMTP id 67so36624139qkj.18 for ; Thu, 08 Nov 2018 04:05:21 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id l2si2913910qvo.45.2018.11.08.04.05.20 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 08 Nov 2018 04:05:21 -0800 (PST) From: Florian Weimer Subject: pkeys: Reserve PKEY_DISABLE_READ Date: Thu, 08 Nov 2018 13:05:09 +0100 Message-ID: <877ehnbwqy.fsf@oldenburg.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: linux-api@vger.kernel.org, linux-mm@kvack.org Cc: dave.hansen@intel.com, linuxram@us.ibm.com Would it be possible to reserve a bit for PKEY_DISABLE_READ? I think the POWER implementation can disable read access at the hardware level, but not write access, and that cannot be expressed with the current PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE bits. My upcoming POWER implementation of pkey_set and pkey_get in glibc would benefit from this. Thanks, Florian