static void clean_func_state(struct bpf_verifier_env *env,
			     struct bpf_func_state *st)
{
	enum bpf_reg_liveness live;
	int i, j;

	for (i = 0; i < BPF_REG_FP; i++) {
		live = st->regs[i].live;
		/* liveness must not touch this register anymore */
		st->regs[i].live |= REG_LIVE_DONE;
		if (!(live & REG_LIVE_READ))
			/* since the register is unused, clear its state
			 * to make further comparison simpler
			 */
			__mark_reg_not_init(env, &st->regs[i]);
	}

	for (i = 0; i < st->allocated_stack / BPF_REG_SIZE; i++) {
		live = st->stack[i].spilled_ptr.live;
		/* liveness must not touch this stack slot anymore */
		st->stack[i].spilled_ptr.live |= REG_LIVE_DONE;
		if (!(live & REG_LIVE_READ)) {
			__mark_reg_not_init(env, &st->stack[i].spilled_ptr);
			for (j = 0; j < BPF_REG_SIZE; j++)
				st->stack[i].slot_type[j] = STACK_INVALID;
		}
	}
}