From 13817dd589f426aee9c36e3670e7cb2a7f067d23 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 4 Feb 2020 08:56:41 -0800 Subject: 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 --- kernel/rcu/tree_plugin.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 384651915d74..70b3c0f4ea37 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); } -- cgit