list_for_each (entry, &__stack_user) { struct pthread *curp;
list_for_each (entry, &stack_used) { struct pthread *curp;
    list_for_each (entry, &__stack_user)      {	struct pthread *curp;	curp = list_entry (entry, struct pthread, list);	if (curp == pd)	  {	    result = curp;	    break;	  }      }