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 <wangn...@huawei.com> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: David Ahern <dsah...@gmail.com> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Kaixu Xia <xiaka...@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngk...@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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
