From patchwork Tue Dec 10 01:14:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1206851 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="Iuf5z6ag"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47X2DD0tWcz9s4Y for ; Tue, 10 Dec 2019 12:15:08 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727473AbfLJBOv (ORCPT ); Mon, 9 Dec 2019 20:14:51 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:6432 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727350AbfLJBOu (ORCPT ); Mon, 9 Dec 2019 20:14:50 -0500 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id xBA1CZLc019814 for ; Mon, 9 Dec 2019 17:14:49 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=facebook; bh=miRau5+VJsH9JKRajjt8/XhGdNhygJx0xHfmp88I5a4=; b=Iuf5z6agaVu5UWPfUJ39MlFng/j2W0LKAnmMTQlBLueBkuyZYWa7MEiRgacrc7J6h3Ub 73bOcSNMacpC3Ilzf5QfZkz6HMllBWvqHp/0jXDErUu32bBrTb40Al+BXX+tQkcMxspW McUdWtZaJXuxw64q3Dm8VtYJdfv/OMUbrlE= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by m0001303.ppops.net with ESMTP id 2wrbemkjg0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Mon, 09 Dec 2019 17:14:49 -0800 Received: from intmgw001.05.ash5.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::128) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Mon, 9 Dec 2019 17:14:48 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id CA5E92EC16B5; Mon, 9 Dec 2019 17:14:46 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 00/15] Add code-generated BPF object skeleton support Date: Mon, 9 Dec 2019 17:14:23 -0800 Message-ID: <20191210011438.4182911-1-andriin@fb.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95, 18.0.572 definitions=2019-12-09_05:2019-12-09, 2019-12-09 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 suspectscore=8 mlxlogscore=999 priorityscore=1501 clxscore=1015 phishscore=0 malwarescore=0 bulkscore=0 spamscore=0 adultscore=0 impostorscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912100009 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch set introduces an alternative and complimentary to existing libbpf API interface for working with BPF objects, maps, programs, and global data from userspace side. This approach is relying on code generation. bpftool produces a struct (a.k.a. skeleton) tailored and specific to provided BPF object file. It includes hard-coded fields and data structures for every map, program, link, and global data present. Altogether this approach significantly reduces amount of userspace boilerplate code required to open, load, attach, and work with BPF objects. It improves attach/detach story, by providing pre-allocated space for bpf_links, and ensuring they are properly detached on shutdown. It allows to do away with by name/title lookups of maps and programs, because libbpf's skeleton API, in conjunction with generated code from bpftool, is filling in hard-coded fields with actual pointers to corresponding struct bpf_map/bpf_program/bpf_link. Also, thanks to BPF array mmap() support, working with global data (variables) from userspace is now as natural as it is from BPF side: each variable is just a struct field inside skeleton struct. Furthermore, this allows to have a natural way for userspace to pre-initialize global data (including previously impossible to initialize .rodata) by just assigning values to the same per-variable fields. Libbpf will carefully take into account this initialization image, will use it to pre-populate BPF maps at creation time, and will re-mmap() BPF map's contents at exactly the same userspace memory address such that it can continue working with all the same pointers without any interruptions. If kernel doesn't support mmap(), global data will still be successfully initialized, but after map creation global data structures inside skeleton will be NULL-ed out. This allows userspace application to gracefully handle lack of mmap() support, if necessary. A bunch of selftests are also converted to using skeletons, demonstrating significant simplification of userspace part of test and reduction in amount of code necessary. rfc->v1: - runqslower moved out into separate patch set waiting for vmlinux.h improvements; - skeleton generation code deals with unknown internal maps more gracefully. Andrii Nakryiko (15): libbpf: don't require root for bpf_object__open() libbpf: add generic bpf_program__attach() libbpf: move non-public APIs from libbpf.h to libbpf_internal.h libbpf: add BPF_EMBED_OBJ macro for embedding BPF .o files libbpf: expose field/var declaration emitting API internally libbpf: expose BPF program's function name libbpf: refactor global data map initialization libbpf: postpone BTF ID finding for TRACING programs to load phase libbpf: reduce log level of supported section names dump libbpf: add experimental BPF object skeleton support bpftool: add skeleton codegen command selftests/bpf: add BPF skeletons selftests and convert attach_probe.c selftests/bpf: convert few more selftest to skeletons selftests/bpf: add test validating data section to struct convertion layout bpftool: add `gen skeleton` BASH completions tools/bpf/bpftool/Makefile | 2 +- tools/bpf/bpftool/bash-completion/bpftool | 11 + tools/bpf/bpftool/gen.c | 530 ++++++++++++++++ tools/bpf/bpftool/main.c | 3 +- tools/bpf/bpftool/main.h | 1 + tools/bpf/bpftool/net.c | 1 + tools/lib/bpf/btf_dump.c | 61 +- tools/lib/bpf/libbpf.c | 583 ++++++++++++++---- tools/lib/bpf/libbpf.h | 63 +- tools/lib/bpf/libbpf.map | 4 + tools/lib/bpf/libbpf_internal.h | 61 ++ tools/testing/selftests/bpf/.gitignore | 2 + tools/testing/selftests/bpf/Makefile | 36 +- .../selftests/bpf/prog_tests/attach_probe.c | 154 +---- .../selftests/bpf/prog_tests/fentry_fexit.c | 105 ++-- .../selftests/bpf/prog_tests/fentry_test.c | 72 +-- tools/testing/selftests/bpf/prog_tests/mmap.c | 58 +- .../selftests/bpf/prog_tests/probe_user.c | 6 +- .../selftests/bpf/prog_tests/rdonly_maps.c | 11 +- .../selftests/bpf/prog_tests/skeleton.c | 47 ++ .../bpf/prog_tests/stacktrace_build_id.c | 79 +-- .../bpf/prog_tests/stacktrace_build_id_nmi.c | 84 +-- .../selftests/bpf/progs/test_attach_probe.c | 34 +- .../selftests/bpf/progs/test_skeleton.c | 36 ++ 24 files changed, 1444 insertions(+), 600 deletions(-) create mode 100644 tools/bpf/bpftool/gen.c create mode 100644 tools/testing/selftests/bpf/prog_tests/skeleton.c create mode 100644 tools/testing/selftests/bpf/progs/test_skeleton.c Acked-by: Martin KaFai Lau