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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 7E06FC282CB for ; Tue, 5 Feb 2019 22:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F1022175B for ; Tue, 5 Feb 2019 22:46:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RNGdFSsd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730590AbfBEWq3 (ORCPT ); Tue, 5 Feb 2019 17:46:29 -0500 Received: from merlin.infradead.org ([205.233.59.134]:51994 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730297AbfBEWqV (ORCPT ); Tue, 5 Feb 2019 17:46:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5XJRIrdkjENJb3QKmYgGMjGqndnRXzAHnf6fe8/YMzw=; b=RNGdFSsdVUtMmIkFrYmy3oKzg+ xoPbhs0n0J7XnWShg1UA+eJmnI3jxCUvDrXbONLN9qtwr6s/oJtyp7N+wXtnPIcUiAyZaXvs9t6Lj 7Bb3rwWZM42Q+MDpoFJfaVKNx1MLY+ot3Z8DhUrOpC7ErAx9P+ngztVPydYQb+R8/LSNbiCtYyJMX ODRkE2g6j3LOs9LekxM7xUD0EyTZMRGo5HGEcyAZ+ZnsMrL5EOZVMlQ+bEW+obNBXVZXFk4UzGZbc SSMUDSS6iqVsdpyRFh3KkXyFTBjC7GSkXpKcm26dcMXongllBdY9Ymf+3DLh213kXMzWEXDekIYLb 39aO04zg==; Received: from static-50-53-52-16.bvtn.or.frontiernet.net ([50.53.52.16] helo=midway.dunlab) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gr9Tr-0007DD-P9; Tue, 05 Feb 2019 22:46:16 +0000 Subject: Re: [PATCH v5 01/13] taint: Introduce a new taint flag (insecure) To: Andrew Morton , Andy Lutomirski Cc: "Chang S. Bae" , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andi Kleen , Markus T Metzger , Ravi Shankar , LKML References: <20190201205319.15995-1-chang.seok.bae@intel.com> <20190201205319.15995-2-chang.seok.bae@intel.com> <20190205132146.2e61b3df9e7be49e22b7d903@linux-foundation.org> From: Randy Dunlap Message-ID: Date: Tue, 5 Feb 2019 14:46:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20190205132146.2e61b3df9e7be49e22b7d903@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/5/19 1:21 PM, Andrew Morton wrote: > On Fri, 1 Feb 2019 18:42:29 -0800 Andy Lutomirski wrote: > >> On Fri, Feb 1, 2019 at 12:54 PM Chang S. Bae wrote: >>> >>> For testing (or root-only) purposes, the new flag will serve to tag the >>> kernel taint accurately. >>> >>> When adding a new feature support, patches need to be incrementally >>> applied and tested with temporal parameters. Currently, there is no flag >>> for this usage. >> >> I think this should be reviewed by someone like akpm. akpm, for >> background, this is part of an x86 patch series. If only part of the >> series is applied, the kernel will be blatantly insecure (but still >> functional and useful for testing and bisection), and this taint flag >> will be set if this kernel is booted. With the whole series applied, >> there are no users of the taint flag in the kernel. >> >> Do you think this is a good idea? > > What does "temporal parameters" mean? A complete description of this > testing process would help. > > I sounds a bit strange. You mean it assumes that people will partially > apply the series to test its functionality? That would be inconvenient. Ack. I don't think we need to (or should) worry about that kind of muckup. > - Can the new and now-unused taint flag be removed again at > end-of-series? > > - It would be a lot more convenient if we had some means of testing > after the whole series is applied, on a permanent basis - some > debugfs flag, perhaps? > -- ~Randy