helper_id
int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id helper_id,
BPF_EMIT_CALL((__u32)helper_id),
enum bpf_func_id helper_id;
res = libbpf_probe_bpf_helper(d->prog_type, d->helper_id, NULL);
.helper_id = BPF_FUNC_ ## helper, \