From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B20C3C46464 for ; Thu, 9 Aug 2018 11:26:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 500F52157F for ; Thu, 9 Aug 2018 11:26:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 500F52157F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730999AbeHINvF (ORCPT ); Thu, 9 Aug 2018 09:51:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:35696 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730707AbeHINvF (ORCPT ); Thu, 9 Aug 2018 09:51:05 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E4672AEC9; Thu, 9 Aug 2018 11:26:37 +0000 (UTC) Date: Thu, 9 Aug 2018 13:26:35 +0200 From: Joerg Roedel To: Kees Cook Cc: Joerg Roedel , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , X86 ML , LKML , Linux-MM , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , Anthony Liguori , Daniel Gruss , Hugh Dickins , Andrea Arcangeli , Waiman Long , Pavel Machek , "David H . Gutteridge" Subject: Re: [PATCH] x86/mm/pti: Move user W+X check into pti_finalize() Message-ID: <20180809112635.5nafpey7c2nowir7@suse.de> References: <1533727000-9172-1-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kees, On Wed, Aug 08, 2018 at 01:33:01PM -0700, Kees Cook wrote: > I'm slightly nervous about complicating this and splitting up the > check. I have a mild preference that all the checks get moved later, > so that all architectures have the checks happening at the same time > during boot. Splitting this up could give us some weird differences > between architectures, etc. As fas as I can see the checks are implemented on x86, arm, and arm64. I agree that it would be better to run the checks at a unified place across architectures and can send a patch-set for set once the dust around the 32-bit PTI implementation for x86 has settled. But currently the call-places are architecture specific and with that in mind the split-up on x86 is the right thing to do. I'll change that back when I implement your idea above. Regards, Joerg