btf__add_datasec
LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
id = btf__add_datasec(btf, sec->sec_name, sec->sec_sz);
btf__add_datasec(btf, "datasec1", 12); /* [21] datasec datasec1 */
id = btf__add_datasec(btf, "datasec1", 12);