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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT 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 9D879C2D0A6 for ; Thu, 3 Sep 2020 20:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7953A20678 for ; Thu, 3 Sep 2020 20:37:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="NZ43jkcw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729538AbgICUf5 (ORCPT ); Thu, 3 Sep 2020 16:35:57 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:9046 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729273AbgICUfz (ORCPT ); Thu, 3 Sep 2020 16:35:55 -0400 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 083KWgLX032306 for ; Thu, 3 Sep 2020 13:35:54 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=xJmp28btJh24nQluHJ6E+yjOaTdt15okri30qMaZNxY=; b=NZ43jkcwc/mfee2RxliKq+gY8wOtPhZVjLfhCKN5Cjyjg/kEkwkteJavUEi3tECSSAy5 tOrdK7oWcINWWrtx1nkS6lMZJEtLDYcW5J7tftjCsrre4H/z96t8jl8z3Umj5OkB0Oah 9v+BLnw8eWdOwFmrhy164pCdb+iEGnTVaEg= Received: from mail.thefacebook.com ([163.114.132.120]) by m0001303.ppops.net with ESMTP id 33b4crs702-10 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 03 Sep 2020 13:35:53 -0700 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 3 Sep 2020 13:35:50 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 596F72EC6814; Thu, 3 Sep 2020 13:35:43 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , , Andrii Nakryiko Subject: [PATCH v3 bpf-next 00/14] Add libbpf full support for BPF-to-BPF calls Date: Thu, 3 Sep 2020 13:35:28 -0700 Message-ID: <20200903203542.15944-1-andriin@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-03_13:2020-09-03,2020-09-03 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 mlxscore=0 clxscore=1015 lowpriorityscore=0 suspectscore=8 priorityscore=1501 phishscore=0 bulkscore=0 malwarescore=0 spamscore=0 impostorscore=0 mlxlogscore=783 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009030183 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Currently, libbpf supports a limited form of BPF-to-BPF subprogram calls.= The restriction is that entry-point BPF program should use *all* of defined sub-programs in BPF .o file. If any of the subprograms is not used, such entry-point BPF program will be rejected by verifier as containing unreac= hable dead code. This is not a big limitation for cases with single entry-point= BPF programs, but is quite a heavy restriction for multi-programs that use on= ly partially overlapping set of subprograms. This patch set removes all such restrictions and adds complete support fo= r using BPF sub-program calls on BPF side. This is achieved through libbpf tracking subprograms individually and detecting which subprograms are use= d by any given entry-point BPF program, and subsequently only appending and relocating code for just those used subprograms. In addition, libbpf now also supports multiple entry-point BPF programs w= ithin the same ELF section. This allows to structure code so that there are few variants of BPF programs of the same type and attaching to the same targe= t (e.g., for tracepoints and kprobes) without the need to worry about ELF section name clashes. This patch set opens way for more wider adoption of BPF subprogram calls, especially for real-world production use-cases with complicated net of subprograms. This will allow to further scale BPF verification process th= rough good use of global functions, which can be verified independently. This i= s also important prerequisite for static linking which allows static BPF libraries to not worry about naming clashes for section names, as well as= use static non-inlined functions (subprograms) without worries of verifier rejecting program due to dead code. Patch set is structured as follows: - patched 1-6 contain all the libbpf changes necessary to support multi-p= rog sections and bpf2bpf subcalls; - patch 7 adds dedicated selftests validating all combinations of possibl= e sub-calls (within and across sections, static vs global functions); - patch 8 deprecated bpf_program__title() in favor of bpf_program__section_name(). The intent was to also deprecate bpf_object__find_program_by_title() as it's now non-sensical with multi= ple programs per section. But there were too many selftests uses of this an= d I didn't want to delay this patches further and make it even bigger, so= left it for a follow up cleanup; - patches 9-10 remove uses for title-related APIs from bpftool and bpf_program__title() use from selftests; - patch 11 is converting fexit_bpf2bpf to have explicit subtest (it does contain 4 subtests, which are not handled as sub-tests); - patches 12-14 convert few complicated BPF selftests to use __noinline functions to further validate correctness of libbpf's bpf2bpf processin= g logic. =20 v2->v3: - explained subprog relocation algorithm in more details (Alexei); - pyperf, strobelight and cls_redirect got new subprog variants, leavin= g other modes intact (Alexei); v1->v2: - rename DEPRECATED to LIBBPF_DEPRECATED to avoid name clashes; - fix test_subprogs build; - convert a bunch of complicated selftests to __noinline (Alexei). Andrii Nakryiko (14): libbpf: ensure ELF symbols table is found before further ELF processing libbpf: parse multi-function sections into multiple BPF programs libbpf: support CO-RE relocations for multi-prog sections libbpf: make RELO_CALL work for multi-prog sections and sub-program calls libbpf: implement generalized .BTF.ext func/line info adjustment libbpf: add multi-prog section support for struct_ops selftests/bpf: add selftest for multi-prog sections and bpf-to-bpf calls tools/bpftool: replace bpf_program__title() with bpf_program__section_name() selftests/bpf: don't use deprecated libbpf APIs libbpf: deprecate notion of BPF program "title" in favor of "section name" selftests/bpf: turn fexit_bpf2bpf into test with subtests selftests/bpf: add subprogs to pyperf, strobemeta, and l4lb_noinline tests selftests/bpf: modernize xdp_noinline test w/ skeleton and __noinline selftests/bpf: add __noinline variant of cls_redirect selftest tools/bpf/bpftool/prog.c | 4 +- tools/lib/bpf/btf.h | 18 +- tools/lib/bpf/libbpf.c | 1287 +++++++++++------ tools/lib/bpf/libbpf.h | 5 +- tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_common.h | 2 + .../selftests/bpf/flow_dissector_load.h | 8 +- .../bpf/prog_tests/bpf_verif_scale.c | 4 + .../selftests/bpf/prog_tests/cls_redirect.c | 72 +- .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 21 +- .../selftests/bpf/prog_tests/l4lb_all.c | 9 +- .../bpf/prog_tests/reference_tracking.c | 2 +- .../selftests/bpf/prog_tests/subprogs.c | 31 + .../selftests/bpf/prog_tests/xdp_noinline.c | 49 +- tools/testing/selftests/bpf/progs/pyperf.h | 11 +- .../selftests/bpf/progs/pyperf_subprogs.c | 5 + .../testing/selftests/bpf/progs/strobemeta.h | 30 +- .../selftests/bpf/progs/strobemeta_subprogs.c | 10 + .../selftests/bpf/progs/test_cls_redirect.c | 105 +- .../bpf/progs/test_cls_redirect_subprogs.c | 2 + .../selftests/bpf/progs/test_l4lb_noinline.c | 41 +- .../selftests/bpf/progs/test_subprogs.c | 103 ++ .../selftests/bpf/progs/test_xdp_noinline.c | 36 +- .../selftests/bpf/test_socket_cookie.c | 2 +- 24 files changed, 1247 insertions(+), 611 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/subprogs.c create mode 100644 tools/testing/selftests/bpf/progs/pyperf_subprogs.c create mode 100644 tools/testing/selftests/bpf/progs/strobemeta_subprogs= .c create mode 100644 tools/testing/selftests/bpf/progs/test_cls_redirect_s= ubprogs.c create mode 100644 tools/testing/selftests/bpf/progs/test_subprogs.c --=20 2.24.1