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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 01D95C433E9 for ; Thu, 4 Feb 2021 23:49:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B718E64FB2 for ; Thu, 4 Feb 2021 23:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231265AbhBDXtV (ORCPT ); Thu, 4 Feb 2021 18:49:21 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:55052 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231231AbhBDXtU (ORCPT ); Thu, 4 Feb 2021 18:49:20 -0500 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 114NkYIs007848 for ; Thu, 4 Feb 2021 15:48:39 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : content-type : content-transfer-encoding : mime-version; s=facebook; bh=NjqJJp2Jp5aHJBp1l9VQMpOiKqbbaKqk6YF2UD7DMrQ=; b=q+G4lsv0npuYnIQciFoZor837RuMAhYB/m/bi2AAuKnQMVJYJptsAjVNgJfF0pP9oG7J KU2j8x5WSVOgwo/bbOejxWtusabwunfEkNRwDgR/LoH7znUq+Pv7v6okK4IcwEodgzGk /96YaRrE7fe0xMTOT0iFv9EcAynu0EfEZP4= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 36fh1uvqer-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 04 Feb 2021 15:48:39 -0800 Received: from intmgw001.38.frc1.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 4 Feb 2021 15:48:39 -0800 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id B50D23704E75; Thu, 4 Feb 2021 15:48:27 -0800 (PST) From: Yonghong Song To: CC: Alexei Starovoitov , Cong Wang , Daniel Borkmann , Subject: [PATCH bpf-next 0/8] bpf: add bpf_for_each_map_elem() helper Date: Thu, 4 Feb 2021 15:48:27 -0800 Message-ID: <20210204234827.1628857-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 X-FB-Internal: Safe Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.737 definitions=2021-02-04_13:2021-02-04,2021-02-04 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=1 malwarescore=0 clxscore=1015 phishscore=0 mlxlogscore=218 bulkscore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 priorityscore=1501 mlxscore=1 impostorscore=0 spamscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102040144 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This patch set introduced bpf_for_each_map_elem() helper. The helper permits bpf program iterates through all elements for a particular map. The work originally inspired by an internal discussion where firewall rules are kept in a map and bpf prog wants to check packet 5 tuples against all rules in the map. A bounded loop can be used but it has a few drawbacks. As the loop iteration goes up, verification time goes up too. For really large maps, verification may fail. A helper which abstracts out the loop itself will not have verification time issue. A recent discussion in [1] involves to iterate all hash map elements in bpf program. Currently iterating all hashmap elements in bpf program is not easy if key space is really big. Having a helper to abstract out the loop itself is even more meaningful. The proposed helper signature looks like: long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags) where callback_fn is a static function and callback_ctx is a piece of data allocated on the caller stack which can be accessed by the callback_fn. The callback_fn signature might be different for different maps. For example, for hash/array maps, the signature might be long callback_fn(map, key, val, callback_ctx) In the rest of series, Patch 1 did some refactoring. Patch 2 implemented core kernel support for the helper. Patches 3 and 4 added hashmap and arraymap support. Patches 5 and 6 added libbpf and bpftool support. Patches 7 and 8 added selftests for hashmap and arraymap. [1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gma= il.com/ Yonghong Song (8): bpf: refactor BPF_PSEUDO_CALL checking as a helper function bpf: add bpf_for_each_map_elem() helper bpf: add hashtab support for bpf_for_each_map_elem() helper bpf: add arraymap support for bpf_for_each_map_elem() helper libbpf: support local function pointer relocation bpftool: print local function pointer properly selftests/bpf: add hashmap test for bpf_for_each_map_elem() helper selftests/bpf: add arraymap test for bpf_for_each_map_elem() helper include/linux/bpf.h | 18 ++ include/linux/bpf_verifier.h | 3 + include/uapi/linux/bpf.h | 28 ++ kernel/bpf/arraymap.c | 36 +++ kernel/bpf/bpf_iter.c | 16 + kernel/bpf/hashtab.c | 57 ++++ kernel/bpf/helpers.c | 2 + kernel/bpf/verifier.c | 299 ++++++++++++++++-- kernel/trace/bpf_trace.c | 2 + tools/bpf/bpftool/xlated_dumper.c | 3 + tools/include/uapi/linux/bpf.h | 28 ++ tools/lib/bpf/libbpf.c | 33 +- .../selftests/bpf/prog_tests/for_each.c | 145 +++++++++ .../bpf/progs/for_each_array_map_elem.c | 71 +++++ .../bpf/progs/for_each_hash_map_elem.c | 103 ++++++ 15 files changed, 811 insertions(+), 33 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/for_each.c create mode 100644 tools/testing/selftests/bpf/progs/for_each_array_map_el= em.c create mode 100644 tools/testing/selftests/bpf/progs/for_each_hash_map_ele= m.c --=20 2.24.1