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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 3201FC43461 for ; Mon, 7 Sep 2020 10:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0594B21481 for ; Mon, 7 Sep 2020 10:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728857AbgIGK3e (ORCPT ); Mon, 7 Sep 2020 06:29:34 -0400 Received: from foss.arm.com ([217.140.110.172]:60142 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728739AbgIGK3E (ORCPT ); Mon, 7 Sep 2020 06:29:04 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F3606106F; Mon, 7 Sep 2020 03:29:03 -0700 (PDT) Received: from arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3B2A3F66E; Mon, 7 Sep 2020 03:29:02 -0700 (PDT) Date: Mon, 7 Sep 2020 11:29:00 +0100 From: Dave Martin To: Boyan Karatotev Cc: Shuah Khan , boian4o1@gmail.com, Catalin Marinas , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, amit.kachhap@arm.com, vincenzo.frascino@arm.com, Will Deacon , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/4] kselftests/arm64: add PAuth tests Message-ID: <20200907102900.GN6642@arm.com> References: <20200828131606.7946-1-boyan.karatotev@arm.com> <20200902164825.GH6642@arm.com> <7ed52c37-a448-55c9-4ec8-b803ec62ecf6@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7ed52c37-a448-55c9-4ec8-b803ec62ecf6@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 03, 2020 at 10:46:33AM +0100, Boyan Karatotev wrote: > On 02/09/2020 17:48, Dave Martin wrote: > > On Fri, Aug 28, 2020 at 02:16:02PM +0100, Boyan Karatotev wrote: > >> Pointer Authentication (PAuth) is a security feature introduced in ARMv8.3. > >> It introduces instructions to sign addresses and later check for potential > >> corruption using a second modifier value and one of a set of keys. The > >> signature, in the form of the Pointer Authentication Code (PAC), is stored > >> in some of the top unused bits of the virtual address (e.g. [54: 49] if > >> TBID0 is enabled and TnSZ is set to use a 48 bit VA space). A set of > >> controls are present to enable/disable groups of instructions (which use > >> certain keys) for compatibility with libraries that do not utilize the > >> feature. PAuth is used to verify the integrity of return addresses on the > >> stack with less memory than the stack canary. > >> > >> This patchset adds kselftests to verify the kernel's configuration of the > >> feature and its runtime behaviour. There are 7 tests which verify that: > >> * an authentication failure leads to a SIGSEGV > >> * the data/instruction instruction groups are enabled > >> * the generic instructions are enabled > >> * all 5 keys are unique for a single thread > >> * exec() changes all keys to new unique ones > >> * context switching preserves the 4 data/instruction keys > >> * context switching preserves the generic keys > >> > >> The tests have been verified to work on qemu without a working PAUTH > >> Implementation and on ARM's FVP with a full or partial PAuth > >> implementation. > >> > >> Note: This patchset is only verified for ARMv8.3 and there will be some > >> changes required for ARMv8.6. More details can be found here [1]. Once > >> ARMv8.6 PAuth is merged the first test in this series will required to be > >> updated. > > > > Nit: is it worth running checkpatch over this series? > > > > Although this is not kernel code, there are a number of formatting > > weirdnesses and surplus blank lines etc. that checkpatch would probably > > warn about. > > > I ran it through checkpatch and it came out clean except for some > MAINTAINERS warnings. I see that when I add --strict it does complain > about multiple blank lines which I can fix for the next version. Are > there any other flags I should be running checkpatch with? Hmmm, probably not. I had thought checkpatch was generally noisier about that kind of thing. Since the issues were all minor and nobody else objected, I would suggest not to worry about them. Cheers ---Dave