C auto/C-RW-R+RW-G+RW-R
{
}

P0(int *x, int *y)
{
	rcu_read_lock();
	r1 = READ_ONCE(*y);
	WRITE_ONCE(*x, 1);
	rcu_read_unlock();
}

P1(int *x, int *z)
{
	r2 = READ_ONCE(*x);
	synchronize_rcu();
	WRITE_ONCE(*z, 1);
}

P2(int *z, int *y)
{
	rcu_read_lock();
	r3 = READ_ONCE(*z);
	WRITE_ONCE(*y, 1);
	rcu_read_unlock();
}

exists
(0:r1=1 /\ 1:r2=1 /\ 2:r3=1)