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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2C36C433EF for ; Fri, 3 Dec 2021 10:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351827AbhLCKtG (ORCPT ); Fri, 3 Dec 2021 05:49:06 -0500 Received: from foss.arm.com ([217.140.110.172]:47180 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231520AbhLCKtF (ORCPT ); Fri, 3 Dec 2021 05:49:05 -0500 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 A99831595; Fri, 3 Dec 2021 02:45:41 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.66.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 716C33F5A1; Fri, 3 Dec 2021 02:45:40 -0800 (PST) Date: Fri, 3 Dec 2021 10:41:02 +0000 From: Mark Rutland To: Kefeng Wang Cc: Marco Elver , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, joey.gouly@arm.com Subject: Re: [PATCH v3] arm64: Enable KCSAN Message-ID: References: <20211202143331.15259-1-wangkefeng.wang@huawei.com> <4cd6d815-aaf2-2d62-cff9-8fb4fae3781d@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4cd6d815-aaf2-2d62-cff9-8fb4fae3781d@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 03, 2021 at 10:29:22AM +0800, Kefeng Wang wrote: > > 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, I'm not immediately aware of another reason, so I'm fine with not checking that for KCSAN -- If I discover another reason I will let you know. Thanks, Mark. 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 12C8CC433EF for ; Fri, 3 Dec 2021 10:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=DtDKGr0L6exPTKRVsrL8RztDRcmxuZRhUJlYVn9zkpU=; b=Wb1biAkw+K40we 2D+4f2PhMLLDt88u6fhpv3QsssiwvR9O7fcHFkmYY6jNj9uuVL0ATYzIV2e60aF0Y7w/f8YYQRHJo mDsopP6LhvUUfhXo3SzrwgMlsVmoM3H9+qS5suQD5O8y0EUiwcQp56Mf1PjQYzGi/LgtUz7am2GzT pdIy9ruHELz7I8ZeGc1B/CUv47lDM66G7v/7l0WvY2BfYRGl2dZQU9jEAVVEQyf55vrWfyB/qN0bu zXYRjzKT7gcYCr5zRVCouJznL04wIETjV1nA5/ODm2/DV+ULL4gZdZbvpTx9gAaET1y9I53JnCSGq HfDITRptZRr2WT2V9bzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt64Z-00FE3G-SQ; Fri, 03 Dec 2021 10:45:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt64U-00FE1W-Vp for linux-arm-kernel@lists.infradead.org; Fri, 03 Dec 2021 10:45:44 +0000 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 A99831595; Fri, 3 Dec 2021 02:45:41 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.66.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 716C33F5A1; Fri, 3 Dec 2021 02:45:40 -0800 (PST) Date: Fri, 3 Dec 2021 10:41:02 +0000 From: Mark Rutland To: Kefeng Wang Cc: Marco Elver , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, joey.gouly@arm.com Subject: Re: [PATCH v3] arm64: Enable KCSAN Message-ID: References: <20211202143331.15259-1-wangkefeng.wang@huawei.com> <4cd6d815-aaf2-2d62-cff9-8fb4fae3781d@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4cd6d815-aaf2-2d62-cff9-8fb4fae3781d@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211203_024543_101282_1D4A1EE7 X-CRM114-Status: GOOD ( 30.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Dec 03, 2021 at 10:29:22AM +0800, Kefeng Wang wrote: > > 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, I'm not immediately aware of another reason, so I'm fine with not checking that for KCSAN -- If I discover another reason I will let you know. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel