Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbbLRXIw (ORCPT ); Fri, 18 Dec 2015 18:08:52 -0500 Received: from mail-ig0-f181.google.com ([209.85.213.181]:37380 "EHLO mail-ig0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751932AbbLRXIv (ORCPT ); Fri, 18 Dec 2015 18:08:51 -0500 MIME-Version: 1.0 In-Reply-To: References: <56736BD1.5080700@linux.intel.com> <5673750B.606@linux.intel.com> <567453AF.5060808@linux.intel.com> <56746774.8000707@linux.intel.com> <567476CC.8080805@linux.intel.com> Date: Fri, 18 Dec 2015 15:08:50 -0800 X-Google-Sender-Auth: LVBeyBUiMrE1zQdTGmoZ9xfjJAk Message-ID: Subject: Re: Rethinking sigcontext's xfeatures slightly for PKRU's benefit? From: Linus Torvalds To: Andy Lutomirski Cc: Dave Hansen , "H. Peter Anvin" , Oleg Nesterov , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Brian Gerst , "linux-kernel@vger.kernel.org" , Christoph Hellwig Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 793 Lines: 20 On Fri, Dec 18, 2015 at 2:28 PM, Andy Lutomirski wrote: > > Apps that don't want to use the baseline_pkru mechanism could use > syscalls to claim ownership of protection keys but then manage them > purely with WRPKRU directly. We could optionally disallow > mprotect_key on keys that weren't allocated in advance. > > Does that seem sane? So everything seems sane except for the need for that baseline_pkru. I'm not seeing why it couldn't just be a fixed value. Is there any real downside to it? Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/