- read_lock(&tasklist_lock); /* pin current->signal */
- ac.ac_tty = current->signal->tty ?
- old_encode_dev(tty_devnum(current->signal->tty)) : 0;
- read_unlock(&tasklist_lock);
+ mutex_lock(&tty_mutex);
+ tty = get_current_tty();
+ ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
+ mutex_unlock(&tty_mutex);