From patchwork Thu Apr 7 19:25:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kui-Feng Lee X-Patchwork-Id: 12805642 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A2E7C433EF for ; Thu, 7 Apr 2022 19:26:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230042AbiDGT2o (ORCPT ); Thu, 7 Apr 2022 15:28:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230457AbiDGT2n (ORCPT ); Thu, 7 Apr 2022 15:28:43 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 720D4283F6A for ; Thu, 7 Apr 2022 12:26:33 -0700 (PDT) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 237IAgMG016907 for ; Thu, 7 Apr 2022 12:26:33 -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=BV1oHiYsXQTJrzAg5b8dYwyiKTRryO0K3tsvF+2GCt8=; b=cX2rMlJ+35V6EfOdcd5SB92qPE/3sxU9iNMKfOMsZ6Nscmi80fqNDwLgJVRypR9dswd7 20uvs/25T0XE32TyHVDpih5ddAVH1LUJfoBVCpQPhuON3SkxQBavRTQsz65DSnNdHEED 13oaQvHhBoE4FMQWVhZStynpk7sECCDHHyM= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3f9q7fx3kk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 07 Apr 2022 12:26:32 -0700 Received: from twshared29473.14.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Thu, 7 Apr 2022 12:26:31 -0700 Received: by devbig931.frc1.facebook.com (Postfix, from userid 460691) id 1A842200EE89; Thu, 7 Apr 2022 12:26:23 -0700 (PDT) From: Kui-Feng Lee To: , , , , CC: Kui-Feng Lee Subject: [PATCH bpf-next v3 4/5] lib/bpf: Assign cookies to links in libbpf. Date: Thu, 7 Apr 2022 12:25:51 -0700 Message-ID: <20220407192552.2343076-5-kuifeng@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220407192552.2343076-1-kuifeng@fb.com> References: <20220407192552.2343076-1-kuifeng@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: nYX5p2OhiyfZAFwxxww-cqNdUFx1KiHq X-Proofpoint-GUID: nYX5p2OhiyfZAFwxxww-cqNdUFx1KiHq X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-04-07_04,2022-04-07_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add a cookie field to the attributes of bpf_link_create(). Add bpf_program__attach_trace_opts() to attach a cookie to a link. Signed-off-by: Kui-Feng Lee --- tools/lib/bpf/bpf.c | 7 +++++++ tools/lib/bpf/bpf.h | 3 +++ tools/lib/bpf/libbpf.c | 33 +++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 12 ++++++++++++ tools/lib/bpf/libbpf.map | 1 + 5 files changed, 56 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index f69ce3a01385..1586f2e87964 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -854,6 +854,13 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, perf_event)) return libbpf_err(-EINVAL); break; + case BPF_TRACE_FENTRY: + case BPF_TRACE_FEXIT: + case BPF_MODIFY_RETURN: + attr.link_create.tracing.bpf_cookie = OPTS_GET(opts, tracing.bpf_cookie, 0); + if (!OPTS_ZEROED(opts, tracing)) + return libbpf_err(-EINVAL); + break; default: if (!OPTS_ZEROED(opts, flags)) return libbpf_err(-EINVAL); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 5253cb4a4c0a..e7df17277c8d 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -410,6 +410,9 @@ struct bpf_link_create_opts { __u32 iter_info_len; __u32 target_btf_id; union { + struct { + __u64 bpf_cookie; + } tracing; struct { __u64 bpf_cookie; } perf_event; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 43161fdd44bb..ab8cfb59073a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10611,6 +10611,39 @@ struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog) return bpf_program__attach_btf_id(prog); } +struct bpf_link *bpf_program__attach_trace_opts(const struct bpf_program *prog, + const struct bpf_trace_opts *opts) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link *link; + int prog_fd, pfd; + + LIBBPF_OPTS(bpf_link_create_opts, link_opts); + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warn("prog '%s': can't attach before loaded\n", prog->name); + return libbpf_err_ptr(-EINVAL); + } + + link = calloc(1, sizeof(*link)); + if (!link) + return libbpf_err_ptr(-ENOMEM); + link->detach = &bpf_link__detach_fd; + + link_opts.tracing.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + pfd = bpf_link_create(prog_fd, 0, prog->expected_attach_type, &link_opts); + if (pfd < 0) { + pfd = -errno; + free(link); + pr_warn("prog '%s': failed to attach: %s\n", + prog->name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return libbpf_err_ptr(pfd); + } + link->fd = pfd; + return (struct bpf_link *)link; +} + struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog) { return bpf_program__attach_btf_id(prog); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index c1b0c2ef14d8..42aff476bcb0 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -501,8 +501,20 @@ bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, LIBBPF_API struct bpf_link * bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, const char *tp_name); + +struct bpf_trace_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; +}; +#define bpf_trace_opts__last_field bpf_cookie + LIBBPF_API struct bpf_link * bpf_program__attach_trace(const struct bpf_program *prog); +LIBBPF_API struct bpf_link * +bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); + LIBBPF_API struct bpf_link * bpf_program__attach_lsm(const struct bpf_program *prog); LIBBPF_API struct bpf_link * diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index df1b947792c8..e2f592b2f6a9 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -424,6 +424,7 @@ LIBBPF_0.6.0 { LIBBPF_0.7.0 { global: bpf_btf_load; + bpf_program__attach_trace_opts; bpf_program__expected_attach_type; bpf_program__log_buf; bpf_program__log_level;