[PATCH v4 20/20] sched/core: Add a few check for valid CPU in inc/dec of preferred CPUs

[Shrikanth Hegde]

Add few cpumask_check where cpu is expected to be a a valid one.

Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
---
v3->v4:
- new patch.

 kernel/sched/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 57d52973ef0d..9342aae315ca 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11417,6 +11417,9 @@ void arch_dec_preferred_cpus(struct steal_monitor_t *sm, u64 steal_ratio)
 
 	last_cpu = cpumask_last(cpu_preferred_mask);
 
+	/* mask can't be null */
+	cpumask_check(last_cpu);
+
 	/*
 	 * If the core belongs to the housekeeping CPUs, no action is
 	 * taken. This leaves at least one core preferred always.
@@ -11505,6 +11508,9 @@ void sched_trigger_steal_computation(int cpu)
 					     cpu_active_mask);
 	ktime_t now;
 
+	/* at least one housekeeping CPU must be active */
+	cpumask_check(first_hk_cpu);
+
 	/* Done by first active housekeeping CPU only */
 	if (likely(cpu != first_hk_cpu))
 		return;
-- 
2.47.3