static bool check_ids(u32 old_id, u32 cur_id, struct bpf_id_pair *idmap)
{
	unsigned int i;

	for (i = 0; i < BPF_ID_MAP_SIZE; i++) {
		if (!idmap[i].old) {
			/* Reached an empty slot; haven't seen this id before */
			idmap[i].old = old_id;
			idmap[i].cur = cur_id;
			return true;
		}
		if (idmap[i].old == old_id)
			return idmap[i].cur == cur_id;
	}
	/* We ran out of idmap slots, which should be impossible */
	WARN_ON_ONCE(1);
	return false;
}