Cregit: Linux 6.3: tty

Contributors: 6
Author	Tokens	Token Proportion	Commits	Commit Proportion
Alan Cox	75	40.11%	4	26.67%
Arnd Bergmann	47	25.13%	1	6.67%
Peter Hurley	41	21.93%	5	33.33%
Linus Torvalds (pre-git)	15	8.02%	2	13.33%
Jiri Slaby	5	2.67%	1	6.67%
Greg Kroah-Hartman	4	2.14%	2	13.33%
Total	187		15

// SPDX-License-Identifier: GPL-2.0
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/semaphore.h>
#include <linux/sched.h>
#include "tty.h"

/* Legacy tty mutex glue */

/*
 * Getting the big tty mutex.
 */

void tty_lock(struct tty_struct *tty)
{
	tty_kref_get(tty);
	mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);

int tty_lock_interruptible(struct tty_struct *tty)
{
	int ret;

	tty_kref_get(tty);
	ret = mutex_lock_interruptible(&tty->legacy_mutex);
	if (ret)
		tty_kref_put(tty);
	return ret;
}

void tty_unlock(struct tty_struct *tty)
{
	mutex_unlock(&tty->legacy_mutex);
	tty_kref_put(tty);
}
EXPORT_SYMBOL(tty_unlock);

void tty_lock_slave(struct tty_struct *tty)
{
	if (tty && tty != tty->link)
		tty_lock(tty);
}

void tty_unlock_slave(struct tty_struct *tty)
{
	if (tty && tty != tty->link)
		tty_unlock(tty);
}

void tty_set_lock_subclass(struct tty_struct *tty)
{
	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
}

tty_mutex.c