From patchwork Tue Apr 12 16:55:54 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: 12810971 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 A8403C433EF for ; Tue, 12 Apr 2022 16:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232565AbiDLQ6z (ORCPT ); Tue, 12 Apr 2022 12:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353145AbiDLQ6y (ORCPT ); Tue, 12 Apr 2022 12:58:54 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6E5C5F8D8 for ; Tue, 12 Apr 2022 09:56:36 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 23CGQCvO000850 for ; Tue, 12 Apr 2022 09:56:36 -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=NHH6RviNAH6XZY+a20b/Nz6R9VCrU4Hm9x/69A7F1Zg=; b=AoIz9Nv7EaQUfWGkZB42UBYsgo8eidw0lcLsVM0FWUNRcUIjzY+4zwSla1odmWmjKliC scJTGmeW18H5e2pPBiotGF9xkBrrnfklFClHKJUGeaBgUhT4i6TfO87h6kSb9zPZvdr5 012ik3BD+BYX1Z/qTjllE+npjUZ94/KV6+4= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3fcy5qvaa2-9 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 12 Apr 2022 09:56:36 -0700 Received: from twshared13345.18.frc3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 12 Apr 2022 09:56:34 -0700 Received: by devbig931.frc1.facebook.com (Postfix, from userid 460691) id 63A512309166; Tue, 12 Apr 2022 09:56:25 -0700 (PDT) From: Kui-Feng Lee To: , , , , CC: Kui-Feng Lee Subject: [PATCH bpf-next v5 4/5] lib/bpf: Assign cookies to links in libbpf. Date: Tue, 12 Apr 2022 09:55:54 -0700 Message-ID: <20220412165555.4146407-5-kuifeng@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220412165555.4146407-1-kuifeng@fb.com> References: <20220412165555.4146407-1-kuifeng@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: fAfUamtYbcy73tz_2YOeIbHYr1eiyKNt X-Proofpoint-GUID: fAfUamtYbcy73tz_2YOeIbHYr1eiyKNt X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-04-12_06,2022-04-12_02,2022-02-23_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 cf27251adb92..c2454979c3c4 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -863,6 +863,13 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, kprobe_multi)) 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 f4b4afb6d4ba..4cdbabcccefc 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 bf4f7ac54ebf..8586e1efd780 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -11262,6 +11262,39 @@ 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 63d66f1adf1a..e0dd3f9a5aca 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -563,8 +563,20 @@ 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 82f6d62176dd..9235da802e31 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;