uvc: Forward compat ioctls to their handlers directly

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

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>

1 files changed, 18 insertions, 21 deletions

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index d7723ce772b3..12690c1ea8f8 100644
--- 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 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 = 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