Messages in this thread Patch in this message | | | From | paulmck@kernel ... | Subject | [PATCH tip/core/rcu 26/30] rcu: Tighten rcu_lockdep_assert_cblist_protected() check | Date | Fri, 14 Feb 2020 15:56:03 -0800 |
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From: "Paul E. McKenney" <paulmck@kernel.org>
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@kernel.org> --- 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); } -- 2.9.5
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