don't copy back if an error was returned.

diff --git a/linux-core/drm_drv.c b/linux-core/drm_drv.c
index 5d2745e..e991f11 100644 (file)
--- a/linux-core/drm_drv.c
+++ b/linux-core/drm_drv.c
@@ -660,7 +660,7 @@ long drm_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                retcode = func(dev, kdata, file_priv);
        }
 
-       if (cmd & IOC_OUT) {
+       if ((retcode == 0) && cmd & IOC_OUT) {
                if (copy_to_user((void __user *)arg, kdata,
                                 _IOC_SIZE(cmd)) != 0)
                        retcode = -EACCES;