+static const int nfs_set_port_min = 0;
+static const int nfs_set_port_max = 65535;
+
+static int param_set_port(const char *val, struct kernel_param *kp)
+{
+ char *endp;
+ int num = simple_strtol(val, &endp, 0);
+ if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
+ return -EINVAL;
+ *((int *)kp->arg) = num;
+ return 0;
+}
+
+module_param_call(callback_tcpport, param_set_port, param_get_int,
+ &nfs_callback_set_tcpport, 0644);