From patchwork Mon Apr 27 20:12:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 220469 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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 8060AC4CECC for ; Mon, 27 Apr 2020 20:13:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 600CA20728 for ; Mon, 27 Apr 2020 20:13:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="MjI8PPEa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbgD0UNB (ORCPT ); Mon, 27 Apr 2020 16:13:01 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:51394 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726881AbgD0UM5 (ORCPT ); Mon, 27 Apr 2020 16:12:57 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03RK1sOw011056 for ; Mon, 27 Apr 2020 13:12:55 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=e6sUKVJE4TRn+OgxVb/za2wlkWSbdOe4ULxFFsDU+0w=; b=MjI8PPEaCRGxJHuZp4PRnmiLpKg588K0StKgpbcXUq4lsb8xdRy2Ioj1h+hnrnxG02nj NfbZsTAH5kCMeGewF5NjLtLCsy88rAeRvZQuto9QG3dwKfiSu1Sg4ps9LvOzAH64CRzC zSHwFMSz9yx26Lrr9TjsvjrbIoXQVP+1sY4= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 30mk1gdyeq-14 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 27 Apr 2020 13:12:55 -0700 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Mon, 27 Apr 2020 13:12:53 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id B8AC73700871; Mon, 27 Apr 2020 13:12:52 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Yonghong Song Smtp-Origin-Hostname: devbig003.ftw2.facebook.com To: Andrii Nakryiko , , Martin KaFai Lau , CC: Alexei Starovoitov , Daniel Borkmann , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next v1 15/19] tools/libbpf: add bpf_iter support Date: Mon, 27 Apr 2020 13:12:52 -0700 Message-ID: <20200427201252.2996037-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200427201235.2994549-1-yhs@fb.com> References: <20200427201235.2994549-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-04-27_15:2020-04-27,2020-04-27 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 suspectscore=2 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 mlxscore=0 malwarescore=0 bulkscore=0 spamscore=0 adultscore=0 clxscore=1015 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004270161 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Three new libbpf APIs are added to support bpf_iter: - bpf_program__attach_iter Given a bpf program and additional parameters, which is none now, returns a bpf_link. - bpf_link__create_iter Given a bpf_link, create a bpf_iter and return a fd so user can then do read() to get seq_file output data. - bpf_iter_create syscall level API to create a bpf iterator. Two macros, BPF_SEQ_PRINTF0 and BPF_SEQ_PRINTF, are also introduced. These two macros can help bpf program writers with nicer bpf_seq_printf syntax similar to the kernel one. Signed-off-by: Yonghong Song --- tools/lib/bpf/bpf.c | 11 +++++++ tools/lib/bpf/bpf.h | 2 ++ tools/lib/bpf/bpf_tracing.h | 23 ++++++++++++++ tools/lib/bpf/libbpf.c | 60 +++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 11 +++++++ tools/lib/bpf/libbpf.map | 7 +++++ 6 files changed, 114 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 5cc1b0785d18..7ffd6c0ad95f 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -619,6 +619,17 @@ int bpf_link_update(int link_fd, int new_prog_fd, return sys_bpf(BPF_LINK_UPDATE, &attr, sizeof(attr)); } +int bpf_iter_create(int link_fd, unsigned int flags) +{ + union bpf_attr attr; + + memset(&attr, 0, sizeof(attr)); + attr.iter_create.link_fd = link_fd; + attr.iter_create.flags = flags; + + return sys_bpf(BPF_ITER_CREATE, &attr, sizeof(attr)); +} + int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) { diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 46d47afdd887..db9df303090e 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -187,6 +187,8 @@ struct bpf_link_update_opts { LIBBPF_API int bpf_link_update(int link_fd, int new_prog_fd, const struct bpf_link_update_opts *opts); +LIBBPF_API int bpf_iter_create(int link_fd, unsigned int flags); + struct bpf_prog_test_run_attr { int prog_fd; int repeat; diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index f3f3c3fb98cb..4a6dffaa7e57 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -413,4 +413,27 @@ typeof(name(0)) name(struct pt_regs *ctx) \ } \ static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args) +/* + * BPF_SEQ_PRINTF to wrap bpf_seq_printf to-be-printed values + * in a structure. BPF_SEQ_PRINTF0 is a simple wrapper for + * bpf_seq_printf(). + */ +#define BPF_SEQ_PRINTF0(seq, fmt) \ + ({ \ + int ret = bpf_seq_printf(seq, fmt, sizeof(fmt), \ + (void *)0, 0); \ + ret; \ + }) + +#define BPF_SEQ_PRINTF(seq, fmt, args...) \ + ({ \ + _Pragma("GCC diagnostic push") \ + _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \ + __u64 param[___bpf_narg(args)] = { args }; \ + _Pragma("GCC diagnostic pop") \ + int ret = bpf_seq_printf(seq, fmt, sizeof(fmt), \ + param, sizeof(param)); \ + ret; \ + }) + #endif diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8e1dc6980fac..ffdc4d8e0cc0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6366,6 +6366,9 @@ static const struct bpf_sec_def section_defs[] = { .is_attach_btf = true, .expected_attach_type = BPF_LSM_MAC, .attach_fn = attach_lsm), + SEC_DEF("iter/", TRACING, + .expected_attach_type = BPF_TRACE_ITER, + .is_attach_btf = true), BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), @@ -6629,6 +6632,7 @@ static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj, #define BTF_TRACE_PREFIX "btf_trace_" #define BTF_LSM_PREFIX "bpf_lsm_" +#define BTF_ITER_PREFIX "__bpf_iter__" #define BTF_MAX_NAME_SIZE 128 static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix, @@ -6659,6 +6663,9 @@ static inline int __find_vmlinux_btf_id(struct btf *btf, const char *name, else if (attach_type == BPF_LSM_MAC) err = find_btf_by_prefix_kind(btf, BTF_LSM_PREFIX, name, BTF_KIND_FUNC); + else if (attach_type == BPF_TRACE_ITER) + err = find_btf_by_prefix_kind(btf, BTF_ITER_PREFIX, name, + BTF_KIND_FUNC); else err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); @@ -7617,6 +7624,59 @@ bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd) return link; } +struct bpf_link * +bpf_program__attach_iter(struct bpf_program *prog, + const struct bpf_iter_attach_opts *opts) +{ + enum bpf_attach_type attach_type; + char errmsg[STRERR_BUFSIZE]; + struct bpf_link *link; + int prog_fd, link_fd; + + if (!OPTS_VALID(opts, bpf_iter_attach_opts)) + return ERR_PTR(-EINVAL); + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warn("program '%s': can't attach before loaded\n", + bpf_program__title(prog, false)); + return ERR_PTR(-EINVAL); + } + + link = calloc(1, sizeof(*link)); + if (!link) + return ERR_PTR(-ENOMEM); + link->detach = &bpf_link__detach_fd; + + attach_type = bpf_program__get_expected_attach_type(prog); + link_fd = bpf_link_create(prog_fd, 0, attach_type, NULL); + if (link_fd < 0) { + link_fd = -errno; + free(link); + pr_warn("program '%s': failed to attach to iterator: %s\n", + bpf_program__title(prog, false), + libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg))); + return ERR_PTR(link_fd); + } + link->fd = link_fd; + return link; +} + +int bpf_link__create_iter(struct bpf_link *link, unsigned int flags) +{ + char errmsg[STRERR_BUFSIZE]; + int iter_fd; + + iter_fd = bpf_iter_create(bpf_link__fd(link), flags); + if (iter_fd < 0) { + iter_fd = -errno; + pr_warn("failed to create an iterator: %s\n", + libbpf_strerror_r(iter_fd, errmsg, sizeof(errmsg))); + } + + return iter_fd; +} + struct bpf_link *bpf_program__attach(struct bpf_program *prog) { const struct bpf_sec_def *sec_def; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index f1dacecb1619..abe5786fcab3 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -258,6 +258,17 @@ struct bpf_map; LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map); +struct bpf_iter_attach_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ +}; +#define bpf_iter_attach_opts__last_field sz + +LIBBPF_API struct bpf_link * +bpf_program__attach_iter(struct bpf_program *prog, + const struct bpf_iter_attach_opts *opts); +LIBBPF_API int +bpf_link__create_iter(struct bpf_link *link, unsigned int flags); + struct bpf_insn; /* diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index bb8831605b25..1cea36f9f2e2 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -254,3 +254,10 @@ LIBBPF_0.0.8 { bpf_program__set_lsm; bpf_set_link_xdp_fd_opts; } LIBBPF_0.0.7; + +LIBBPF_0.0.9 { + global: + bpf_link__create_iter; + bpf_program__attach_iter; + bpf_iter_create; +} LIBBPF_0.0.8;