Add perf exporter (#1274)

Signed-off-by: Daniel Hodges <hodges.daniel.scott@gmail.com>

vendor/github.com/hodgesds/perf-utils/bpf.go

@@ -0,0 +1,22 @@
+// +build linux
+
+package perf
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+// BPFProfiler is a Profiler that allows attaching a Berkeley
+// Packet Filter (BPF) program to an existing kprobe tracepoint event.
+// You need CAP_SYS_ADMIN privileges to use this interface. See:
+// https://lwn.net/Articles/683504/
+type BPFProfiler interface {
+	Profiler
+	AttachBPF(int) error
+}
+
+// AttachBPF is used to attach a BPF program to a profiler by using the file
+// descriptor of the BPF program.
+func (p *profiler) AttachBPF(fd int) error {
+	return unix.IoctlSetInt(p.fd, unix.PERF_EVENT_IOC_SET_BPF, fd)
+}