Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [PATCH v11 36/39] perf tools: Attach eBPF program to perf event | Date | Wed, 8 Jul 2015 13:14:25 +0000 |
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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.c ls
In this patch 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 <wangnan0@huawei.com> --- tools/perf/util/evsel.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index fe80047..73c17f3 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1216,6 +1216,22 @@ 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; /* -- 1.8.3.4
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