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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 51C79C43381 for ; Tue, 5 Mar 2019 14:30:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 266BF20848 for ; Tue, 5 Mar 2019 14:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727760AbfCEO37 (ORCPT ); Tue, 5 Mar 2019 09:29:59 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51812 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726190AbfCEO37 (ORCPT ); Tue, 5 Mar 2019 09:29:59 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x25EENga074191 for ; Tue, 5 Mar 2019 09:29:57 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2r1tmdgxx0-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 05 Mar 2019 09:29:57 -0500 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 5 Mar 2019 14:29:51 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x25ETpqn16449572 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 5 Mar 2019 14:29:51 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EBF0BA405B; Tue, 5 Mar 2019 14:29:50 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 99816A4054; Tue, 5 Mar 2019 14:29:50 +0000 (GMT) Received: from [9.152.212.90] (unknown [9.152.212.90]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 5 Mar 2019 14:29:50 +0000 (GMT) Subject: Re: [PATCH v3 0/3] gcov: add Clang support To: Tri Vo Cc: ghackmann@android.com, ndesaulniers@google.com, linux-kernel@vger.kernel.org, kernel-team@android.com, yamada.masahiro@socionext.com, Andrew Morton References: <20190122233749.42220-1-trong@android.com> From: Peter Oberparleiter Date: Tue, 5 Mar 2019 15:29:51 +0100 MIME-Version: 1.0 In-Reply-To: <20190122233749.42220-1-trong@android.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19030514-4275-0000-0000-0000031729BD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19030514-4276-0000-0000-000038257D25 Message-Id: <7c7b4521-d747-d064-0506-4e3d6746877e@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-05_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903050096 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23.01.2019 00:37, Tri Vo wrote: > This patch series adds Clang supoprt for gcov. > > Patch 1 refactors existing code in preparation for Clang support. > Patch 2 implements necessary LLVM runtime hooks and gcov kernel interfaces. > Patch 3 updates documentation. Thanks for the updates! I've provided suggestions for some minor improvements in my other review e-mails. With those changes applied, the patch set is in my opinion ready for inclusion into the mainline kernel. My suggestion would be to re-post the resulting version while putting Andrew Morton on CC as gcov changes are typically integrated via his tree. Also I've successfully re-tested this patch set version on s390 using GCC 7.3.0 to ensure that the existing GCC support is still working. Unfortunately I wasn't able to test the Clang version due to some compile problems on s390 (unrelated to this patch set). If you haven't done so, I would like to suggest to run the following tests with the Clang gcov-kernel version that should catch problems in some corner cases: 1. Unload a module, then use llvm-cov on the associated coverage file. Expectation: correct llvm-cov output including coverage of module exit code. 2. Unload a module, modify its source, re-compile it and load it again, then use llvm-cov on the associated coverage file. Expectation: kernel message "discarding saved data", correct llvm-cov output with no coverage of module exit code. 3. Unload a module, then reset all coverage data by writing to /sys/kernel/debug/gcov/reset. Expectation: all coverage files associated with the module are removed from debugfs. -- Peter Oberparleiter Linux on Z Development - IBM Germany