Commit d594231a authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcutorture: Verify RCU reader prevents full polling from completing 



This commit adds a test to rcu_torture_writer() that verifies that a
->get_gp_state_full() and ->poll_gp_state_full() polled grace-period
sequence does not claim that a grace period elapsed within the confines
of the corresponding read-side critical section.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent ed7d2f1a

kernel/rcu/rcutorture.c

+16 −3
Original line number Diff line number Diff line
@@ -1309,6 +1309,8 @@ rcu_torture_writer(void *arg) 
			atomic_inc(&rcu_torture_wcount[i]);

			WRITE_ONCE(old_rp->rtort_pipe_count,

				   old_rp->rtort_pipe_count + 1);



			// Make sure readers block polled grace periods.

			if (cur_ops->get_gp_state && cur_ops->poll_gp_state) {

				idx = cur_ops->readlock();

				cookie = cur_ops->get_gp_state();
@@ -1325,10 +1327,21 @@ rcu_torture_writer(void *arg) 
				}

				cur_ops->readunlock(idx);

			}

			if (cur_ops->get_gp_completed_full && cur_ops->poll_gp_state_full) {

			if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) {

				idx = cur_ops->readlock();

				cur_ops->get_gp_state_full(&cookie_full);

				WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full),

					  "%s: Cookie check 5 failed %s(%d) online %*pbl\n",

					  __func__,

					  rcu_torture_writer_state_getname(),

					  rcu_torture_writer_state,

					  cpumask_pr_args(cpu_online_mask));

				if (cur_ops->get_gp_completed_full) {

					cur_ops->get_gp_completed_full(&cookie_full);

					WARN_ON_ONCE(!cur_ops->poll_gp_state_full(&cookie_full));

				}

				cur_ops->readunlock(idx);

			}

			switch (synctype[torture_random(&rand) % nsynctypes]) {

			case RTWS_DEF_FREE:

				rcu_torture_writer_state = RTWS_DEF_FREE;