Index: sys/geom/geom_dev.c
===================================================================
--- sys/geom/geom_dev.c
+++ sys/geom/geom_dev.c
@@ -712,8 +712,10 @@
                         * time can be is likewise.  We make this ioctl
                         * interruptible by checking for signals for each bio.
                         */
-                       if (SIGPENDING(td))
+                       if (length > 0 && SIGPENDING(td)) {
+                               error = EINTR;
                                break;
+                       }
                }
                break;
        case DIOCGIDENT: