uses __getname/__putname instead of getname. getname was deprecated
the new code calls __getname (which really is a specific type of 
memory allocator, then copies the string safely from user space
into the allocated buffer

--- vmblock-only/linux/control.c	2014-03-15 15:28:40.871076076 +0100
+++ vmblock-only/linux/control.c.new	2014-03-15 15:29:15.079074439 +0100
@@ -279,11 +279,17 @@
    int i;
    int retval;
 
-   name = getname(buf);
+   name = __getname();
    if (IS_ERR(name)) {
       return PTR_ERR(name);
    }
 
+   i = strncpy_from_user(name, buf, PATH_MAX);
+   if (i < 0 || i == PATH_MAX) {
+      __putname(name);
+      return -EINVAL;
+   }
+
    for (i = strlen(name) - 1; i >= 0 && name[i] == '/'; i--) {