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=-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=unavailable 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 BD738C5B577 for ; Sat, 29 Jun 2019 03:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96B082075B for ; Sat, 29 Jun 2019 03:49:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="CsFLMhN9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726862AbfF2DtT (ORCPT ); Fri, 28 Jun 2019 23:49:19 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:44738 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726851AbfF2DtT (ORCPT ); Fri, 28 Jun 2019 23:49:19 -0400 Received: from pps.filterd (m0044008.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5T3n5AR010196 for ; Fri, 28 Jun 2019 20:49:17 -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-type; s=facebook; bh=p1yUPCvwpMddoWVoZBvVkMwCRtvFEfV3k675Sbx4UyU=; b=CsFLMhN9qRDer2mJp31Ipimz1LroJv0YZxCp2yrPbVejJeQB++u6XUdXGd1qRd/BFlyf f5ztJyhUMZ3BlQ9OcZpV9MHPMTdIfFE29zjHSz2ULn+CwBmB1Mq3LPiGQL9jj0Y0gyBN FnAFleAbw5VRxgV03lY5oKTEmESNgDJErJA= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2tdu5p8s63-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 28 Jun 2019 20:49:17 -0700 Received: from mx-out.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 28 Jun 2019 20:49:16 -0700 Received: by dev101.prn2.facebook.com (Postfix, from userid 137359) id DA188860E3E; Fri, 28 Jun 2019 20:49:13 -0700 (PDT) Smtp-Origin-Hostprefix: dev From: Andrii Nakryiko Smtp-Origin-Hostname: dev101.prn2.facebook.com To: , , , , , , , CC: Andrii Nakryiko Smtp-Origin-Cluster: prn2c23 Subject: [PATCH v4 bpf-next 3/9] libbpf: add ability to attach/detach BPF program to perf event Date: Fri, 28 Jun 2019 20:49:00 -0700 Message-ID: <20190629034906.1209916-4-andriin@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190629034906.1209916-1-andriin@fb.com> References: <20190629034906.1209916-1-andriin@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-29_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906290044 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org bpf_program__attach_perf_event allows to attach BPF program to existing perf event hook, providing most generic and most low-level way to attach BPF programs. It returns struct bpf_link, which should be passed to bpf_link__destroy to detach and free resources, associated with a link. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 61 ++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 3 ++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 65 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 455795e6f8af..98c155ec3bfa 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -3958,6 +3959,66 @@ int bpf_link__destroy(struct bpf_link *link) return err; } +struct bpf_link_fd { + struct bpf_link link; /* has to be at the top of struct */ + int fd; /* hook FD */ +}; + +static int bpf_link__destroy_perf_event(struct bpf_link *link) +{ + struct bpf_link_fd *l = (void *)link; + int err; + + if (l->fd < 0) + return 0; + + err = ioctl(l->fd, PERF_EVENT_IOC_DISABLE, 0); + if (err) + err = -errno; + + close(l->fd); + return err; +} + +struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, + int pfd) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link_fd *link; + int prog_fd, err; + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warning("program '%s': can't attach before loaded\n", + bpf_program__title(prog, false)); + return ERR_PTR(-EINVAL); + } + + link = malloc(sizeof(*link)); + if (!link) + return ERR_PTR(-ENOMEM); + link->link.destroy = &bpf_link__destroy_perf_event; + link->fd = pfd; + + if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { + err = -errno; + free(link); + pr_warning("program '%s': failed to attach to pfd %d: %s\n", + bpf_program__title(prog, false), pfd, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return ERR_PTR(err); + } + if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { + err = -errno; + free(link); + pr_warning("program '%s': failed to enable pfd %d: %s\n", + bpf_program__title(prog, false), pfd, + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + return ERR_PTR(err); + } + return (struct bpf_link *)link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5082a5ebb0c2..1bf66c4a9330 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -169,6 +169,9 @@ struct bpf_link; LIBBPF_API int bpf_link__destroy(struct bpf_link *link); +LIBBPF_API struct bpf_link * +bpf_program__attach_perf_event(struct bpf_program *prog, int pfd); + struct bpf_insn; /* diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 3cde850fc8da..756f5aa802e9 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -169,6 +169,7 @@ LIBBPF_0.0.4 { global: bpf_link__destroy; bpf_object__load_xattr; + bpf_program__attach_perf_event; btf_dump__dump_type; btf_dump__free; btf_dump__new; -- 2.17.1