The boost_starttime shared variable has conflicting unmarked C-language
accesses, which are dangerous at best. This commit therefore adds
appropriate marking. This was found by KCSAN.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcutorture.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 422f7e4cc08de..829ae0b7d3c04 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -997,7 +997,7 @@ static int rcu_torture_boost(void *arg)
goto checkwait;
/* Wait for the next test interval. */
- oldstarttime = boost_starttime;
+ oldstarttime = READ_ONCE(boost_starttime);
while (time_before(jiffies, oldstarttime)) {
schedule_timeout_interruptible(oldstarttime - jiffies);
if (stutter_wait("rcu_torture_boost"))
@@ -1041,10 +1041,11 @@ static int rcu_torture_boost(void *arg)
* interval. Besides, we are running at RT priority,
* so delays should be relatively rare.
*/
- while (oldstarttime == boost_starttime && !kthread_should_stop()) {
+ while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) {
if (mutex_trylock(&boost_mutex)) {
if (oldstarttime == boost_starttime) {
- boost_starttime = jiffies + test_boost_interval * HZ;
+ WRITE_ONCE(boost_starttime,
+ jiffies + test_boost_interval * HZ);
n_rcu_torture_boosts++;
}
mutex_unlock(&boost_mutex);
--
2.31.1.189.g2e36527f23
