[PATCH 3.2 137/140] media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors

Ben Hutchings
2018-02-28T17:43:42Z

From: Hans Verkuil <hans.verkuil@cisco.com>

commit d83a8243aaefe62ace433e4384a4f077bed86acb upstream.

Some ioctls need to copy back the result even if the ioctl returned
an error. However, don't do this for the error code -ENOTTY.
It makes no sense in that cases.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/video/v4l2-compat-ioctl32.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/media/video/v4l2-compat-ioctl32.c
+++ b/drivers/media/video/v4l2-compat-ioctl32.c
@@ -885,6 +885,9 @@ static long do_video_ioctl(struct file *
set_fs(old_fs);
}

+ if (err == -ENOTTY)
+ return err;
+
/* Special case: even after an error we need to put the
results back for these ioctls since the error_idx will
contain information on which control failed. */