root/tools/testing/selftests/bpf/progs/tracing_multi_bench.c 
// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>

char _license[] SEC("license") = "GPL";

SEC("fentry.multi")
int BPF_PROG(bench)
{
        return 0;
}