The following commit has been merged into the core/rcu branch of tip:
Commit-ID: 13817dd589f426aee9c36e3670e7cb2a7f067d23
Gitweb: https://git.kernel.org/tip/13817dd589f426aee9c36e3670e7cb2a7f067d23
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate: Tue, 04 Feb 2020 08:56:41 -08:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Thu, 20 Feb 2020 15:58:23 -08:00
rcu: Tighten rcu_lockdep_assert_cblist_protected() check
The ->nocb_lock lockdep assertion is currently guarded by cpu_online(),
which is incorrect for no-CBs CPUs, whose callback lists must be
protected by ->nocb_lock regardless of whether or not the corresponding
CPU is online. This situation could result in failure to detect bugs
resulting from failing to hold ->nocb_lock for offline CPUs.
This commit therefore removes the cpu_online() guard.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree_plugin.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 3846519..70b3c0f 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1579,8 +1579,7 @@ static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp,
static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp)
{
lockdep_assert_irqs_disabled();
- if (rcu_segcblist_is_offloaded(&rdp->cblist) &&
- cpu_online(rdp->cpu))
+ if (rcu_segcblist_is_offloaded(&rdp->cblist))
lockdep_assert_held(&rdp->nocb_lock);
}
|