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 tty_lock(struct tty_struct * tty)15void tty_lock(struct tty_struct *tty) 16 { 17 tty_kref_get(tty); 18 mutex_lock(&tty->legacy_mutex); 19 } 20 EXPORT_SYMBOL(tty_lock); 21 tty_lock_interruptible(struct tty_struct * tty)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 tty_unlock(struct tty_struct * tty)33void tty_unlock(struct tty_struct *tty) 34 { 35 mutex_unlock(&tty->legacy_mutex); 36 tty_kref_put(tty); 37 } 38 EXPORT_SYMBOL(tty_unlock); 39 tty_lock_slave(struct tty_struct * tty)40void tty_lock_slave(struct tty_struct *tty) 41 { 42 if (tty && tty != tty->link) 43 tty_lock(tty); 44 } 45 tty_unlock_slave(struct tty_struct * tty)46void tty_unlock_slave(struct tty_struct *tty) 47 { 48 if (tty && tty != tty->link) 49 tty_unlock(tty); 50 } 51 tty_set_lock_subclass(struct tty_struct * tty)52void tty_set_lock_subclass(struct tty_struct *tty) 53 { 54 lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE); 55 } 56