uvc: Forward compat ioctls to their handlers directly

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>
[bwh: Backported to 3.16: old code forwarded to uvc_v4l2_ioctl()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 378ae02e593b93a19bb9010a23f62175029bbefd..836c252c12f45c410a03f3431e682e1526df96b5 100644 (file)
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1279,47 +1279,44 @@ static int uvc_v4l2_put_xu_query(const struct uvc_xu_control_query *kp,
 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 = uvc_v4l2_ioctl(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