From patchwork Wed Mar 10 04:04:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 397272 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=-12.0 required=3.0 tests=BAYES_00,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 70106C4360C for ; Wed, 10 Mar 2021 04:05:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4693964FE3 for ; Wed, 10 Mar 2021 04:05:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232268AbhCJEE4 convert rfc822-to-8bit (ORCPT ); Tue, 9 Mar 2021 23:04:56 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:13406 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231992AbhCJEEs (ORCPT ); Tue, 9 Mar 2021 23:04:48 -0500 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12A3tdOW028568 for ; Tue, 9 Mar 2021 20:04:48 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 376c07kkd5-7 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 09 Mar 2021 20:04:48 -0800 Received: from intmgw001.05.ash7.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 9 Mar 2021 20:04:43 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 454B52ED1C92; Tue, 9 Mar 2021 20:04:33 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 00/10] BPF static linking Date: Tue, 9 Mar 2021 20:04:21 -0800 Message-ID: <20210310040431.916483-1-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369, 18.0.761 definitions=2021-03-10_03:2021-03-09,2021-03-10 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=979 mlxscore=0 clxscore=1015 lowpriorityscore=0 phishscore=0 suspectscore=0 adultscore=0 bulkscore=0 malwarescore=0 spamscore=0 impostorscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103100017 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch set adds new libbpf APIs and their bpftool integration that allows to perform static linking of BPF object files. Currently no extern resolution across object files is performed. This is going to be the focus of the follow up patches. But, given amount of code and logic necessary to perform just basic functionality of linking together mostly independent BPF object files, it was decided to land basic BPF linker code and logic first and extend it afterwards. The motivation for BPF static linking is to provide the functionality that is naturally assumed for user-space development process: ability to structure application's code without artificial restrictions of having all the code and data (variables and maps) inside a single source code file. This enables better engineering practices of splitting code into well-encapsulated parts. It provides ability to hide internal state from other parts of the code base through static variables and maps. It is also a first steps towards having generic reusable BPF libraries. Please see individual patches (mostly #5 and #6) for more details. Patch #9 passes all test_progs' individual BPF .o files through BPF static linker, which is supposed to be a no-op operation, so is essentially validating that BPF static linker doesn't produce corrupted ELF object files. Patch #10 adds Makefile infra to be able to specify multi-file BPF object files and adds the first multi-file test to validate correctness. Andrii Nakryiko (10): libbpf: expose btf_type_by_id() internally libbpf: add internal helper to get raw BTF strings section libbpf: generalize BTF and BTF.ext type ID and strings iteration libbpf: add generic BTF type shallow copy API libbpf: add BPF static linker APIs libbpf: add BPF static linker BTF and BTF.ext support bpftool: add `gen bpfo` command to perform BPF static linking selftests/bpf: re-generate vmlinux.h and BPF skeletons if bpftool changed selftests/bpf: pass all BPF .o's through BPF static linker selftests/bpf: add multi-file statically linked BPF object file test tools/bpf/bpftool/gen.c | 46 +- tools/lib/bpf/Build | 2 +- tools/lib/bpf/btf.c | 454 ++-- tools/lib/bpf/btf.h | 2 + tools/lib/bpf/libbpf.c | 11 +- tools/lib/bpf/libbpf.h | 13 + tools/lib/bpf/libbpf.map | 5 + tools/lib/bpf/libbpf_internal.h | 33 + tools/lib/bpf/linker.c | 1945 +++++++++++++++++ tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 21 +- .../selftests/bpf/prog_tests/static_linked.c | 40 + .../selftests/bpf/progs/test_static_linked1.c | 30 + .../selftests/bpf/progs/test_static_linked2.c | 31 + 14 files changed, 2444 insertions(+), 190 deletions(-) create mode 100644 tools/lib/bpf/linker.c create mode 100644 tools/testing/selftests/bpf/prog_tests/static_linked.c create mode 100644 tools/testing/selftests/bpf/progs/test_static_linked1.c create mode 100644 tools/testing/selftests/bpf/progs/test_static_linked2.c