static void mark_all_scalars_precise(struct bpf_verifier_env *env,
				     struct bpf_verifier_state *st)
{
	struct bpf_func_state *func;
	struct bpf_reg_state *reg;
	int i, j;

	/* big hammer: mark all scalars precise in this path.
	 * pop_stack may still get !precise scalars.
	 */
	for (; st; st = st->parent)
		for (i = 0; i <= st->curframe; i++) {
			func = st->frame[i];
			for (j = 0; j < BPF_REG_FP; j++) {
				reg = &func->regs[j];
				if (reg->type != SCALAR_VALUE)
					continue;
				reg->precise = true;
			}
			for (j = 0; j < func->allocated_stack / BPF_REG_SIZE; j++) {
				if (!is_spilled_reg(&func->stack[j]))
					continue;
				reg = &func->stack[j].spilled_ptr;
				if (reg->type != SCALAR_VALUE)
					continue;
				reg->precise = true;
			}
		}
}