From 8db610c3bd93e6929348f6e5271f2f905f80d82e Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 23 Feb 2024 17:07:24 -0800 Subject: rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE() Because the Tasks RCU ->rtp_exit_list is initialized at rcu_init() time while there is only one CPU running with interrupts disabled, it is not possible for an exiting task to encounter an uninitialized list. This commit therefore replaces the conditional initialization with a WARN_ON_ONCE(). Reported-by: Frederic Weisbecker Closes: https://lore.kernel.org/all/ZdiNXmO3wRvmzPsr@lothringen/ Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/tasks.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/rcu/tasks.h') diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 82e458ea0728..78d74c81cc24 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1203,8 +1203,7 @@ void exit_tasks_rcu_start(void) rtpcp = this_cpu_ptr(rcu_tasks.rtpcpu); t->rcu_tasks_exit_cpu = smp_processor_id(); raw_spin_lock_irqsave_rcu_node(rtpcp, flags); - if (!rtpcp->rtp_exit_list.next) - INIT_LIST_HEAD(&rtpcp->rtp_exit_list); + WARN_ON_ONCE(!rtpcp->rtp_exit_list.next); list_add(&t->rcu_tasks_exit_list, &rtpcp->rtp_exit_list); raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags); preempt_enable(); -- cgit v1.2.3