Patchwork uwb: properly check kthread_run return value

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Submitter Andrey Konovalov
Date Sept. 13, 2017, 3:06 p.m.
Message ID <eaad1afda975d3dac217de3d9a5e5ca83da74f48.1505315045.git.andreyknvl@google.com>
Download mbox | patch
Permalink /patch/9951517/
State New
Headers show

Comments

Andrey Konovalov - Sept. 13, 2017, 3:06 p.m.
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.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/uwb/uwbd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Andrey Konovalov - Sept. 13, 2017, 3:59 p.m.
On Wed, Sep 13, 2017 at 5:06 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> 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.

This uncovers another issue, there's no check of rc->uwbd.task in
uwbd_stop(). Will mail v2.

>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  drivers/uwb/uwbd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/uwb/uwbd.c b/drivers/uwb/uwbd.c
> index 01c20a260a8b..9f615b303576 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
> --
> 2.14.1.581.gf28d330327-goog
>

Patch

diff --git a/drivers/uwb/uwbd.c b/drivers/uwb/uwbd.c
index 01c20a260a8b..9f615b303576 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