[PATCH for v4.14 11/13] media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors

From: Hans Verkuil <hverkuil@xs4all.nl>
To: stable@vger.kernel.org
Cc: linux-media@vger.kernel.org,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Mauro Carvalho Chehab <mchehab@s-opensource.com>
Subject: [PATCH for v4.14 11/13] media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors
Date: Wed, 14 Feb 2018 12:44:32 +0100	[thread overview]
Message-ID: <20180214114434.26842-12-hverkuil@xs4all.nl> (raw)
In-Reply-To: <20180214114434.26842-1-hverkuil@xs4all.nl>

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>
---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index bef9c990c9bd..5603c7c1edd5 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -968,6 +968,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		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. */
-- 
2.15.1
