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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 27F1AC2D0DD for ; Tue, 31 Dec 2019 06:20:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E52BB206E4 for ; Tue, 31 Dec 2019 06:20:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="D/2eJDch" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725890AbfLaGUn (ORCPT ); Tue, 31 Dec 2019 01:20:43 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:45378 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbfLaGUn (ORCPT ); Tue, 31 Dec 2019 01:20:43 -0500 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBV6EFnD019748 for ; Mon, 30 Dec 2019 22:20:42 -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=Mss/54ct8ahkDtgAW7RfTQxuUbcUFM4oiLzqwJ0Ax2o=; b=D/2eJDchmEAPVbcx5BxJcrhKGw7317qpTeUur2ix0KCf6GFH8IT9BxUSBWAXlDIcS1c9 DaP7Yts0y2sj0+3Kk1lPjQ4fSvKdINZBcRj8WF6pulMTTQHSL/C3w0hhOA7GFstyWD1C pKx8On2ovbPW/Ew1fEaCqDjqe+PXlJwX3Oc= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2x6qxd6y9c-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Mon, 30 Dec 2019 22:20:42 -0800 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::126) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Mon, 30 Dec 2019 22:20:41 -0800 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 569A4294410B; Mon, 30 Dec 2019 22:20:38 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Martin KaFai Lau Smtp-Origin-Hostname: devbig005.ftw2.facebook.com To: CC: Alexei Starovoitov , Daniel Borkmann , David Miller , , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next v3 00/11] Introduce BPF STRUCT_OPS Date: Mon, 30 Dec 2019 22:20:37 -0800 Message-ID: <20191231062037.280596-1-kafai@fb.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-30_08:2019-12-27,2019-12-30 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 adultscore=0 clxscore=1015 impostorscore=0 bulkscore=0 spamscore=0 lowpriorityscore=0 mlxscore=0 suspectscore=13 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912310050 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This series introduces BPF STRUCT_OPS. It is an infra to allow implementing some specific kernel's function pointers in BPF. The first use case included in this series is to implement TCP congestion control algorithm in BPF (i.e. implement struct tcp_congestion_ops in BPF). There has been attempt to move the TCP CC to the user space (e.g. CCP in TCP). The common arguments are faster turn around, get away from long-tail kernel versions in production...etc, which are legit points. BPF has been the continuous effort to join both kernel and userspace upsides together (e.g. XDP to gain the performance advantage without bypassing the kernel). The recent BPF advancements (in particular BTF-aware verifier, BPF trampoline, BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc) possible in BPF. The idea is to allow implementing tcp_congestion_ops in bpf. It allows a faster turnaround for testing algorithm in the production while leveraging the existing (and continue growing) BPF feature/framework instead of building one specifically for userspace TCP CC. Please see individual patch for details. The bpftool support will be posted in follow-up patches. v3: - Fix kbuild error by considering CONFIG_BPF_SYSCALL (kbuild) - Support anonymous bitfield in patch 4 (Andrii, Yonghong) - Push boundary safety check to a specific arch's trampoline function (in patch 6) (Yonghong). Reuse the WANR_ON_ONCE check in arch_prepare_bpf_trampoline() in x86. - Check module field is 0 in udata in patch 6 (Yonghong) - Check zero holes in patch 6 (Andrii) - s/_btf_vmlinux/btf/ in patch 5 and 7 (Andrii) - s/check_xxx/is_xxx/ in patch 7 (Andrii) - Use "struct_ops/" convention in patch 11 (Andrii) - Use the skel instead of bpf_object in patch 11 (Andrii) - libbpf: Decide BPF_PROG_TYPE_STRUCT_OPS at open phase by using find_sec_def() - libbpf: Avoid a debug message at open phase (Andrii) - libbpf: Add bpf_program__(is|set)_struct_ops() for consistency (Andrii) - libbpf: Add "struct_ops" to section_defs (Andrii) - libbpf: Some code shuffling in init_kern_struct_ops() (Andrii) - libbpf: A few safety checks (Andrii) v2: - Dropped cubic for now. They will be reposted once there are more clarity in "jiffies" on both bpf side (about the helper) and tcp_cubic side (some of jiffies usages are being replaced by tp->tcp_mstamp) - Remove unnecssary check on bitfield support from btf_struct_access() (Yonghong) - BTF_TYPE_EMIT macro (Yonghong, Andrii) - value_name's length check to avoid an unlikely type match during truncation case (Yonghong) - BUILD_BUG_ON to ensure no trampoline-image overrun in the future (Yonghong) - Simplify get_next_key() (Yonghong) - Added comment to explain how to check mandatory func ptr in net/ipv4/bpf_tcp_ca.c (Yonghong) - Rename "__bpf_" to "bpf_struct_ops_" for value prefix (Andrii) - Add comment to highlight the bpf_dctcp.c is not necessarily the same as tcp_dctcp.c. (Alexei, Eric) - libbpf: Renmae "struct_ops" to ".struct_ops" for elf sec (Andrii) - libbpf: Expose struct_ops as a bpf_map (Andrii) - libbpf: Support multiple struct_ops in SEC(".struct_ops") (Andrii) - libbpf: Add bpf_map__attach_struct_ops() (Andrii) Martin KaFai Lau (11): bpf: Save PTR_TO_BTF_ID register state when spilling to stack bpf: Avoid storing modifier to info->btf_id bpf: Add enum support to btf_ctx_access() bpf: Support bitfield read access in btf_struct_access bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS bpf: tcp: Support tcp_congestion_ops in bpf bpf: Add BPF_FUNC_tcp_send_ack helper bpf: Synch uapi bpf.h to tools/ bpf: libbpf: Add STRUCT_OPS support bpf: Add bpf_dctcp example arch/x86/net/bpf_jit_comp.c | 18 +- include/linux/bpf.h | 79 ++- include/linux/bpf_types.h | 7 + include/linux/btf.h | 47 ++ include/linux/filter.h | 2 + include/net/tcp.h | 1 + include/uapi/linux/bpf.h | 19 +- kernel/bpf/Makefile | 3 + kernel/bpf/bpf_struct_ops.c | 617 +++++++++++++++++ kernel/bpf/bpf_struct_ops_types.h | 9 + kernel/bpf/btf.c | 163 +++-- kernel/bpf/map_in_map.c | 3 +- kernel/bpf/syscall.c | 66 +- kernel/bpf/trampoline.c | 8 +- kernel/bpf/verifier.c | 140 +++- net/core/filter.c | 2 +- net/ipv4/Makefile | 4 + net/ipv4/bpf_tcp_ca.c | 250 +++++++ net/ipv4/tcp_cong.c | 14 +- net/ipv4/tcp_ipv4.c | 6 +- net/ipv4/tcp_minisocks.c | 4 +- net/ipv4/tcp_output.c | 4 +- tools/include/uapi/linux/bpf.h | 19 +- tools/lib/bpf/bpf.c | 10 +- tools/lib/bpf/bpf.h | 5 +- tools/lib/bpf/libbpf.c | 650 +++++++++++++++++- tools/lib/bpf/libbpf.h | 5 +- tools/lib/bpf/libbpf.map | 3 + tools/lib/bpf/libbpf_probes.c | 2 + tools/testing/selftests/bpf/bpf_tcp_helpers.h | 228 ++++++ .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 187 +++++ tools/testing/selftests/bpf/progs/bpf_dctcp.c | 210 ++++++ 32 files changed, 2639 insertions(+), 146 deletions(-) create mode 100644 kernel/bpf/bpf_struct_ops.c create mode 100644 kernel/bpf/bpf_struct_ops_types.h create mode 100644 net/ipv4/bpf_tcp_ca.c create mode 100644 tools/testing/selftests/bpf/bpf_tcp_helpers.h create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c create mode 100644 tools/testing/selftests/bpf/progs/bpf_dctcp.c -- 2.17.1