Warn in the case it is called with cpu == -1. This does not appear
to happen anywhere.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 kernel/workqueue.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 003474c9a77d..0954b778b315 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -7562,6 +7562,8 @@ notrace void wq_watchdog_touch(int cpu)
 {
 	if (cpu >= 0)
 		per_cpu(wq_watchdog_touched_cpu, cpu) = jiffies;
+	else
+		WARN_ONCE(1, "%s should be called with valid CPU", __func__);
 
 	wq_watchdog_touched = jiffies;
 }
-- 
2.45.1