1// SPDX-License-Identifier: GPL-2.0 2#include <linux/tty.h> 3#include <linux/module.h> 4#include <linux/kallsyms.h> 5#include <linux/semaphore.h> 6#include <linux/sched.h> 7#include "tty.h" 8 9/* Legacy tty mutex glue */ 10 11/* 12 * Getting the big tty mutex. 13 */ 14 15void tty_lock(struct tty_struct *tty) 16{ 17 tty_kref_get(tty); 18 mutex_lock(&tty->legacy_mutex); 19} 20EXPORT_SYMBOL(tty_lock); 21 22int tty_lock_interruptible(struct tty_struct *tty) 23{ 24 int ret; 25 26 tty_kref_get(tty); 27 ret = mutex_lock_interruptible(&tty->legacy_mutex); 28 if (ret) 29 tty_kref_put(tty); 30 return ret; 31} 32 33void tty_unlock(struct tty_struct *tty) 34{ 35 mutex_unlock(&tty->legacy_mutex); 36 tty_kref_put(tty); 37} 38EXPORT_SYMBOL(tty_unlock); 39 40void tty_lock_slave(struct tty_struct *tty) 41{ 42 if (tty && tty != tty->link) 43 tty_lock(tty); 44} 45 46void tty_unlock_slave(struct tty_struct *tty) 47{ 48 if (tty && tty != tty->link) 49 tty_unlock(tty); 50} 51 52void tty_set_lock_subclass(struct tty_struct *tty) 53{ 54 lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE); 55} 56