/* And here is where the userspace process can look up the cookie value
* to retrieve the path.
*/
-asmlinkage long sys_lookup_dcookie(u64 cookie64, char * buf, size_t len)
+asmlinkage long sys_lookup_dcookie(u64 cookie64, char __user * buf, size_t len)
{
unsigned long cookie = (unsigned long)cookie64;
int err = -EINVAL;