From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753723AbbJNMvn (ORCPT ); Wed, 14 Oct 2015 08:51:43 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:50234 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753526AbbJNMmp (ORCPT ); Wed, 14 Oct 2015 08:42:45 -0400 From: Wang Nan To: , , CC: , , , , , , , , , , , , Wang Nan , Arnaldo Carvalho de Melo Subject: [PATCH 07/31] perf tools: Attach eBPF program to perf event Date: Wed, 14 Oct 2015 12:41:18 +0000 Message-ID: <1444826502-49291-8-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1444826502-49291-1-git-send-email-wangnan0@huawei.com> References: <1444826502-49291-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is the final patch which makes basic BPF filter work. After applying this patch, users are allowed to use BPF filter like: # perf record --event ./hello_world.o ls A bpf_fd field is appended to 'struct evsel', and setup during the callback function add_bpf_event() for each 'probe_trace_event'. PERF_EVENT_IOC_SET_BPF ioctl is used to attach eBPF program to a newly created perf event. The file descriptor of the eBPF program is passed to perf record using previous patches, and stored into evsel->bpf_fd. It is possible that different perf event are created for one kprobe events for different CPUs. In this case, when trying to call the ioctl, EEXIST will be return. This patch doesn't treat it as an error. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org --- tools/perf/util/evsel.c | 17 +++++++++++++++++ tools/perf/util/evsel.h | 1 + tools/perf/util/parse-events.c | 6 ++++++ 3 files changed, 24 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 8be867c..7d12af5 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -208,6 +208,7 @@ void perf_evsel__init(struct perf_evsel *evsel, evsel->unit = ""; evsel->scale = 1.0; evsel->evlist = NULL; + evsel->bpf_fd = -1; INIT_LIST_HEAD(&evsel->node); INIT_LIST_HEAD(&evsel->config_terms); perf_evsel__object.init(evsel); @@ -1346,6 +1347,22 @@ retry_open: err); goto try_fallback; } + + if (evsel->bpf_fd >= 0) { + int evt_fd = FD(evsel, cpu, thread); + int bpf_fd = evsel->bpf_fd; + + err = ioctl(evt_fd, + PERF_EVENT_IOC_SET_BPF, + bpf_fd); + if (err && errno != EEXIST) { + pr_err("failed to attach bpf fd %d: %s\n", + bpf_fd, strerror(errno)); + err = -EINVAL; + goto out_close; + } + } + set_rlimit = NO_CHANGE; /* diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 02a5fed..a60b5d5 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -121,6 +121,7 @@ struct perf_evsel { char *group_name; bool cmdline_group_boundary; struct list_head config_terms; + int bpf_fd; }; union u64_swap { diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 61c7a47..5087023 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -542,6 +542,7 @@ static int add_bpf_event(struct probe_trace_event *tev, int fd, struct __add_bpf_event_param *param = _param; struct parse_events_evlist *evlist = param->data; struct list_head *list = param->list; + struct perf_evsel *pos; int err; pr_debug("add bpf event %s:%s and attach bpf program %d\n", @@ -562,6 +563,11 @@ static int add_bpf_event(struct probe_trace_event *tev, int fd, } pr_debug("adding %s:%s\n", tev->group, tev->event); + list_for_each_entry(pos, &new_evsels, node) { + pr_debug("adding %s:%s to %p\n", + tev->group, tev->event, pos); + pos->bpf_fd = fd; + } list_splice(&new_evsels, list); return 0; } -- 1.8.3.4