diff options
| -rw-r--r-- | kernel/time/timer_migration.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index c8a8ea2e5b98..371a62a749aa 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -534,8 +534,13 @@ static void __walk_groups(up_f up, struct tmigr_walk *data, break; child = group; - group = group->parent; + /* + * Pairs with the store release on group connection + * to make sure group initialization is visible. + */ + group = READ_ONCE(group->parent); data->childmask = child->groupmask; + WARN_ON_ONCE(!data->childmask); } while (group); } @@ -1578,7 +1583,12 @@ static void tmigr_connect_child_parent(struct tmigr_group *child, child->groupmask = BIT(parent->num_children++); } - child->parent = parent; + /* + * Make sure parent initialization is visible before publishing it to a + * racing CPU entering/exiting idle. This RELEASE barrier enforces an + * address dependency that pairs with the READ_ONCE() in __walk_groups(). + */ + smp_store_release(&child->parent, parent); raw_spin_unlock(&parent->lock); raw_spin_unlock_irq(&child->lock); |