rcutorture: Add reader-side tests of polling grace-period API

This commit adds reader-side testing of the polling grace-period API.
This testing verifies that a cookie obtained in an SRCU read-side critical
section does not get a true return from poll_state_synchronize_srcu()
within that same critical section.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Paul E. McKenney 2020-11-15 12:45:57 -08:00
parent 0fd0548db1
commit bc480a6354

View File

@ -1429,6 +1429,7 @@ rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp,
*/
static bool rcu_torture_one_read(struct torture_random_state *trsp)
{
unsigned long cookie;
int i;
unsigned long started;
unsigned long completed;
@ -1444,6 +1445,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp)
WARN_ON_ONCE(!rcu_is_watching());
newstate = rcutorture_extend_mask(readstate, trsp);
rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++);
if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
cookie = cur_ops->get_gp_state();
started = cur_ops->get_gp_seq();
ts = rcu_trace_clock_local();
p = rcu_dereference_check(rcu_torture_current,
@ -1480,6 +1483,13 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp)
}
__this_cpu_inc(rcu_torture_batch[completed]);
preempt_enable();
if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
WARN_ONCE(cur_ops->poll_gp_state(cookie),
"%s: Cookie check 3 failed %s(%d) %lu->%lu\n",
__func__,
rcu_torture_writer_state_getname(),
rcu_torture_writer_state,
cookie, cur_ops->get_gp_state());
rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK);
// This next splat is expected behavior if leakpointer, especially