void __start_tty(struct tty_struct *tty)
{
	if (!tty->stopped || tty->flow_stopped)
		return;
	tty->stopped = 0;
	if (tty->ops->start)
		tty->ops->start(tty);
	tty_wakeup(tty);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.