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=-7.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 DFF4BC433E7 for ; Thu, 3 Sep 2020 09:46:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A00E820709 for ; Thu, 3 Sep 2020 09:46:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727825AbgICJqj (ORCPT ); Thu, 3 Sep 2020 05:46:39 -0400 Received: from foss.arm.com ([217.140.110.172]:57742 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725984AbgICJqi (ORCPT ); Thu, 3 Sep 2020 05:46:38 -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 46C25101E; Thu, 3 Sep 2020 02:46:37 -0700 (PDT) Received: from [10.57.7.89] (unknown [10.57.7.89]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2B47E3F68F; Thu, 3 Sep 2020 02:46:35 -0700 (PDT) Subject: Re: [PATCH 0/4] kselftests/arm64: add PAuth tests To: Dave Martin Cc: linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , boian4o1@gmail.com, Catalin Marinas , amit.kachhap@arm.com, vincenzo.frascino@arm.com, Shuah Khan References: <20200828131606.7946-1-boyan.karatotev@arm.com> <20200902164825.GH6642@arm.com> From: Boyan Karatotev Message-ID: <7ed52c37-a448-55c9-4ec8-b803ec62ecf6@arm.com> Date: Thu, 3 Sep 2020 10:46:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200902164825.GH6642@arm.com> 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 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? > [...] > > Cheers > ---Dave > -- Regards, Boyan