Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D672C433F5 for ; Fri, 3 Dec 2021 02:29:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378055AbhLCCct (ORCPT ); Thu, 2 Dec 2021 21:32:49 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:15689 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234029AbhLCCcs (ORCPT ); Thu, 2 Dec 2021 21:32:48 -0500 Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4J4xXb5rHXzZdNW; Fri, 3 Dec 2021 10:26:39 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 3 Dec 2021 10:29:23 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.20; Fri, 3 Dec 2021 10:29:23 +0800 Message-ID: <4cd6d815-aaf2-2d62-cff9-8fb4fae3781d@huawei.com> Date: Fri, 3 Dec 2021 10:29:22 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v3] arm64: Enable KCSAN Content-Language: en-US To: Mark Rutland , Marco Elver CC: Catalin Marinas , Will Deacon , , , References: <20211202143331.15259-1-wangkefeng.wang@huawei.com> From: Kefeng Wang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggeme712-chm.china.huawei.com (10.1.199.108) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/12/2 22:44, Mark Rutland wrote: > On Thu, Dec 02, 2021 at 03:36:06PM +0100, Marco Elver wrote: >> On Thu, 2 Dec 2021 at 15:23, Kefeng Wang wrote: >>> This patch enables KCSAN for arm64, with updates to build rules >>> to not use KCSAN for several incompatible compilation units. >>> >>> Resent GCC version(at least GCC10) made outline-atomics as the >> s/Resent/Recent/ >> >>> default option(unlike Clang), which will cause linker errors >>> for kernel/kcsan/core.o. Disables the out-of-line atomics by >>> no-outline-atomics to fix the linker errors. >>> >>> Meanwhile, as Mark said[1], there is a specific issue on arm64 >>> about ARM64_BTI with Clang 11 if KCSAN enabled, which is fixed >>> by Clang 12, add CLANG_VERSION check. And also some latent issues >>> are need to be fixed which isn't just a KCSAN problem, we make >>> the KCSAN depends on EXPERT for now. >>> >>> Tested selftest and kcsan_test(built with GCC11 and Clang 13), >>> and all passed. >>> >>> [1] https://lkml.org/lkml/2021/12/1/354 >> Please use lore/kernel.org permalinks. For this one it'd be: >> https://lkml.kernel.org/r/YadiUPpJ0gADbiHQ@FVFF77S0Q05N >> >> (But I think if this is the final version of the patch, hopefully a >> maintainer can amend the commit message.) >> >>> Signed-off-by: Kefeng Wang >> Acked-by: Marco Elver # kernel/kcsan >> >> is still valid, given nothing changed there. I leave the rest to Mark. > I want to do some compiler / config testing before I ack this (just to > make sure there isn't some latent issue I've forgotten about), but > otherwise I think this should be fine. > > I'll try to have that done in the next few days. I will wait for some time, thanks Marco/Mark. > > Any other review/testing would be appreciated! As Nathan points, commit 8cdd23c23c3d ("arm64: Restrict ARM64_BTI_KERNEL to clang 12.0.0 and newer"), so need to add Clang version check, which is v2 does. is there some other requirement that we need this check, what's your option, thanks. > > Thanks, > Mark. > >