void protect_control_stack_guard_page(pid_t t_id, int protect_p) {
struct thread *th= find_thread_by_pid(t_id);
+#if 0
os_protect(CONTROL_STACK_GUARD_PAGE(th),
os_vm_page_size,protect_p ?
(OS_VM_PROT_READ|OS_VM_PROT_EXECUTE) : OS_VM_PROT_ALL);
+#endif
}