sched_ext: Track @p's rq lock across set_cpus_allowed_scx -> ops.set_cpumask

[ Upstream commit 9fb4570 ]

The SCX_CALL_OP_TASK call site passes rq=NULL incorrectly, leaving
scx_locked_rq() unset. Pass task_rq(p) instead so update_locked_rq()
reflects reality.

v2: Add Fixes: tag (Andrea Righi).

Fixes: 18853ba ("sched_ext: Track currently locked rq")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: htejun

kernel/sched/ext.c

@@ -2606,7 +2606,7 @@ static void set_cpus_allowed_scx(struct task_struct *p,
 	 * designation pointless. Cast it away when calling the operation.
 	 */
 	if (SCX_HAS_OP(sch, set_cpumask))
-		SCX_CALL_OP_TASK(sch, SCX_KF_REST, set_cpumask, NULL,
+		SCX_CALL_OP_TASK(sch, SCX_KF_REST, set_cpumask, task_rq(p),
 				 p, (struct cpumask *)p->cpus_ptr);
 }