(7.0.z) custom java security permission does not work

  grant principal org.jboss.security.SimplePrincipal "admin" {
    permission org.jboss.example.CustomPermission "/Hello";
  };

    javax.security.auth.Subject subj = (javax.security.auth.Subject) javax.security.jacc.PolicyContext.getContext("javax.security.auth.Subject.container");  

    org.jboss.example.CustomPermission permission = new org.jboss.example.CustomPermission("/Hello");

    try {
      Subject.doAsPrivileged(subj, new PrivilegedAction() {
        public Object run() {
          AccessController.checkPermission(p);
          return null;
        }
      }, null);
      return true;
    } catch (SecurityException se) {
      log.warn("AuthUtils.permitted(): Subject " + subj + " not authorized for permission " + p);
      return false;
    }