From patchwork Thu Jun 20 23:09:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1119878 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="flooIDXO"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45VHbd2syfz9s6w for ; Fri, 21 Jun 2019 09:10:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726059AbfFTXKU (ORCPT ); Thu, 20 Jun 2019 19:10:20 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:64864 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726073AbfFTXKT (ORCPT ); Thu, 20 Jun 2019 19:10:19 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5KN39vT031709 for ; Thu, 20 Jun 2019 16:10:18 -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=Y1FWKdBI5j0avkYfXEmpyA8NTajFIFgoZI9ySoULmg8=; b=flooIDXOYP65Ma2lpxW2EQrFXkbPnZ9Jm03O2DFRInPoqoE6UorAW7EX1yxkXxIHjIiK D3nrKUk8SR4uoOBVWSAkdtccXXwoRevtKu2CDI4O1beIMdDSHEYwK1h8Z5C7O8D2l9Kh mM1VhJTOLYBwwUnYDOnxSzDJdsF2lcXqVX4= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2t8gch8pue-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 20 Jun 2019 16:10:18 -0700 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Thu, 20 Jun 2019 16:10:17 -0700 Received: by dev101.prn2.facebook.com (Postfix, from userid 137359) id 34DE486173D; Thu, 20 Jun 2019 16:10:16 -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 bpf-next 2/7] libbpf: add ability to attach/detach BPF to perf event Date: Thu, 20 Jun 2019 16:09:46 -0700 Message-ID: <20190620230951.3155955-3-andriin@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190620230951.3155955-1-andriin@fb.com> References: <20190620230951.3155955-1-andriin@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-20_15:, , signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 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-1906200163 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, providing most generic and most low-level way to attach BPF programs. libbpf_perf_event_disable_and_close API is added to disable and close existing perf event by its FD. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 41 ++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 4 ++++ tools/lib/bpf/libbpf.map | 2 ++ 3 files changed, 47 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8ce3beba8551..2bb1fa008be3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -3928,6 +3929,46 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, return 0; } +int libbpf_perf_event_disable_and_close(int pfd) +{ + int err; + + if (pfd < 0) + return 0; + + err = ioctl(pfd, PERF_EVENT_IOC_DISABLE, 0); + close(pfd); + return err; +} + +int bpf_program__attach_perf_event(struct bpf_program *prog, int pfd) +{ + char errmsg[STRERR_BUFSIZE]; + int bpf_fd, err; + + bpf_fd = bpf_program__fd(prog); + if (bpf_fd < 0) { + pr_warning("program '%s': can't attach before loaded\n", + bpf_program__title(prog, false)); + return -EINVAL; + } + if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, bpf_fd) < 0) { + err = -errno; + 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; + } + if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { + err = -errno; + 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; + } + return 0; +} + 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 d639f47e3110..76db1bbc0dac 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -165,6 +165,10 @@ LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); LIBBPF_API void bpf_program__unload(struct bpf_program *prog); +LIBBPF_API int libbpf_perf_event_disable_and_close(int pfd); +LIBBPF_API int 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 2c6d835620d2..d27406982b5a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -172,5 +172,7 @@ LIBBPF_0.0.4 { btf_dump__new; btf__parse_elf; bpf_object__load_xattr; + bpf_program__attach_perf_event; libbpf_num_possible_cpus; + libbpf_perf_event_disable_and_close; } LIBBPF_0.0.3;