acquire_reference
int id = acquire_reference(env, insn_idx, 0);
id = acquire_reference(env, insn_idx, 0);
ret = aux->ctx_arg_info[i].refcounted ? acquire_reference(env, 0, 0) : 0;
static int acquire_reference(struct bpf_verifier_env *env, int insn_idx, int parent_id);
id = acquire_reference(env, insn_idx, parent_id);
id = acquire_reference(env, insn_idx, 0);