[PATCH 4.6 043/203] uvc: Forward compat ioctls to their handlers directly

Greg Kroah-Hartman
2016-07-25T22:25:34Z

From: Andy Lutomirski <luto@kernel.org>

commit a44323e2a8f342848bb77e8e04fcd85fcb91b3b4 upstream.

The current code goes through a lot of indirection just to call a
known handler. Simplify it: just call the handlers directly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/uvc/uvc_v4l2.c | 39 ++++++++++++++++++---------------------
1 file changed, 18 insertions(+), 21 deletions(-)

--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1408,47 +1408,44 @@ static int uvc_v4l2_put_xu_query(const s
static long uvc_v4l2_compat_ioctl32(struct file *file,
unsigned int cmd, unsigned long arg)
{
+ struct uvc_fh *handle = file->private_data;
union {
struct uvc_xu_control_mapping xmap;
struct uvc_xu_control_query xqry;
} karg;
void __user *up = compat_ptr(arg);
- mm_segment_t old_fs;
long ret;

switch (cmd) {
case UVCIOC_CTRL_MAP32:
- cmd = UVCIOC_CTRL_MAP;
ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
+ if (ret)
+ return ret;
+ ret = uvc_ioctl_ctrl_map(handle->chain, &karg.xmap);
+ if (ret)
+ return ret;
+ ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
+ if (ret)
+ return ret;
+
break;

case UVCIOC_CTRL_QUERY32:
- cmd = UVCIOC_CTRL_QUERY;
ret = uvc_v4l2_get_xu_query(&karg.xqry, up);
+ if (ret)
+ return ret;
+ ret = uvc_xu_ctrl_query(handle->chain, &karg.xqry);
+ if (ret)
+ return ret;
+ ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
+ if (ret)
+ return ret;
break;

default:
return -ENOIOCTLCMD;
}

- old_fs = get_fs();
- set_fs(KERNEL_DS);
- ret = video_ioctl2(file, cmd, (unsigned long)&karg);
- set_fs(old_fs);
-
- if (ret < 0)
- return ret;
-
- switch (cmd) {
- case UVCIOC_CTRL_MAP:
- ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
- break;
-
- case UVCIOC_CTRL_QUERY:
- ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
- break;
- }
-
return ret;
}
#endif