[PATCH 6.17 03/35] sched_ext: Sync error_irq_work before freeing scx_sched

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tejun Heo <tj@kernel.org>

[ Upstream commit efeeaac9ae9763f9c953e69633c86bc3031e39b5 ]

By the time scx_sched_free_rcu_work() runs, the scx_sched is no longer
reachable. However, a previously queued error_irq_work may still be pending or
running. Ensure it completes before proceeding with teardown.

Fixes: bff3b5aec1b7 ("sched_ext: Move disable machinery into scx_sched")
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/sched/ext.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 46029050b170f..f89894476e51f 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3537,7 +3537,9 @@ static void scx_sched_free_rcu_work(struct work_struct *work)
 	struct scx_dispatch_q *dsq;
 	int node;
 
+	irq_work_sync(&sch->error_irq_work);
 	kthread_stop(sch->helper->task);
+
 	free_percpu(sch->pcpu);
 
 	for_each_node_state(node, N_POSSIBLE)
-- 
2.51.0