C C-LB+rl-deref-o-rul+o-sync-o.litmus

{
	a=x;
}

P0(int **a)
{
	int *r1;
	int r2;

	rcu_read_lock();
	r1 = rcu_dereference(*a);
	r2 = READ_ONCE(*r1);
	rcu_read_unlock();
}

P1(int **a, int *x, int *y)
{
	WRITE_ONCE(*a, y);
	synchronize_rcu();
	WRITE_ONCE(*x, 1);  /* Emulate kfree(). */
}

exists
(0:r1=x /\ 0:r2=1)