[PATCH v2] uwb: properly check kthread_run return value

[Andrey Konovalov]

uwbd_start() calls kthread_run() and checks that the return value is
not NULL. But the return value is not NULL in case kthread_run() fails,
it takes the form of ERR_PTR(-EINTR).

Use IS_ERR() instead.

Also add a check to uwbd_stop().

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
 drivers/uwb/uwbd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/uwb/uwbd.c b/drivers/uwb/uwbd.c
index 01c20a260a8b..2a3cc48d837c 100644
--- a/drivers/uwb/uwbd.c
+++ b/drivers/uwb/uwbd.c
@@ -303,7 +303,7 @@ static int uwbd(void *param)
 void uwbd_start(struct uwb_rc *rc)
 {
 	rc->uwbd.task = kthread_run(uwbd, rc, "uwbd");
-	if (rc->uwbd.task == NULL)
+	if (IS_ERR(rc->uwbd.task))
 		printk(KERN_ERR "UWB: Cannot start management daemon; "
 		       "UWB won't work\n");
 	else
@@ -313,7 +313,8 @@ void uwbd_start(struct uwb_rc *rc)
 /* Stop the UWB daemon and free any unprocessed events */
 void uwbd_stop(struct uwb_rc *rc)
 {
-	kthread_stop(rc->uwbd.task);
+	if (!IS_ERR(rc->uwbd.task))
+		kthread_stop(rc->uwbd.task);
 	uwbd_flush(rc);
 }
 
-- 
2.14.1.581.gf28d330327-goog