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=-2.5 required=3.0 tests=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 0F9E5C46499 for ; Fri, 5 Jul 2019 14:22:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4A7620828 for ; Fri, 5 Jul 2019 14:22:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725763AbfGEOWH (ORCPT ); Fri, 5 Jul 2019 10:22:07 -0400 Received: from www62.your-server.de ([213.133.104.62]:51766 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725497AbfGEOWH (ORCPT ); Fri, 5 Jul 2019 10:22:07 -0400 Received: from [78.46.172.2] (helo=sslproxy05.your-server.de) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1hjP6D-00046A-OJ; Fri, 05 Jul 2019 16:22:05 +0200 Received: from [2a02:1205:5069:fce0:c5f9:cd68:79d4:446d] (helo=linux.home) by sslproxy05.your-server.de with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1hjP6D-000NNK-Ey; Fri, 05 Jul 2019 16:22:05 +0200 Subject: Re: [PATCH v2 bpf-next] selftests/bpf: do not ignore clang failures To: Ilya Leoshkevich , bpf@vger.kernel.org, liu.song.a23@gmail.com, andrii.nakryiko@gmail.com References: <20190701184025.25731-1-iii@linux.ibm.com> From: Daniel Borkmann Message-ID: Date: Fri, 5 Jul 2019 16:22:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20190701184025.25731-1-iii@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.100.3/25501/Fri Jul 5 10:01:52 2019) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 07/01/2019 08:40 PM, Ilya Leoshkevich wrote: > Am 01.07.2019 um 17:31 schrieb Andrii Nakryiko : >> Do we still need clang | llc pipeline with new clang? Could the same >> be achieved with single clang invocation? That would solve the problem >> of not detecting pipeline failures. > > I’ve experimented with this a little, and found that new clang: > > - Does not understand -march, but -target is sufficient. > - Understands -mcpu. > - Understands -Xclang -target-feature -Xclang +foo as a replacement for > -mattr=foo. > > However, there are two issues with that: > > - Don’t older clangs need to be supported? For example, right now alu32 > progs are built conditionally. We usually require latest clang to be able to test most recent features like BTF such that it helps to catch potential bugs in either of the projects before release. > - It does not seem to be possible to build test_xdp.o without -target > bpf. For everything non-tracing, it does not make sense to invoke clang w/o the -target bpf flag, see also Documentation/bpf/bpf_devel_QA.rst +573 for more explanation, so this needs to be present for building test_xdp.o. Thanks, Daniel