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
 8/* Legacy tty mutex glue */
 
 
 
 
 
 
 
 
 
 
 9
10/*
11 * Getting the big tty mutex.
12 */
13
14void tty_lock(struct tty_struct *tty)
15{
16	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
17		return;
18	tty_kref_get(tty);
19	mutex_lock(&tty->legacy_mutex);
20}
21EXPORT_SYMBOL(tty_lock);
22
23int tty_lock_interruptible(struct tty_struct *tty)
24{
25	int ret;
26
27	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
28		return -EIO;
29	tty_kref_get(tty);
30	ret = mutex_lock_interruptible(&tty->legacy_mutex);
31	if (ret)
32		tty_kref_put(tty);
33	return ret;
34}
35
36void tty_unlock(struct tty_struct *tty)
37{
38	if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
39		return;
40	mutex_unlock(&tty->legacy_mutex);
41	tty_kref_put(tty);
42}
43EXPORT_SYMBOL(tty_unlock);
44
45void tty_lock_slave(struct tty_struct *tty)
46{
47	if (tty && tty != tty->link)
48		tty_lock(tty);
49}
50
51void tty_unlock_slave(struct tty_struct *tty)
52{
53	if (tty && tty != tty->link)
54		tty_unlock(tty);
55}
56
57void tty_set_lock_subclass(struct tty_struct *tty)
58{
59	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
60}

 
 1#include <linux/tty.h>
 2#include <linux/module.h>
 3#include <linux/kallsyms.h>
 4#include <linux/semaphore.h>
 5#include <linux/sched.h>
 6
 7/*
 8 * The 'big tty mutex'
 9 *
10 * This mutex is taken and released by tty_lock() and tty_unlock(),
11 * replacing the older big kernel lock.
12 * It can no longer be taken recursively, and does not get
13 * released implicitly while sleeping.
14 *
15 * Don't use in new code.
16 */
17static DEFINE_MUTEX(big_tty_mutex);
18
19/*
20 * Getting the big tty mutex.
21 */
22void __lockfunc tty_lock(void)
 
23{
24	mutex_lock(&big_tty_mutex);
 
 
 
25}
26EXPORT_SYMBOL(tty_lock);
27
28void __lockfunc tty_unlock(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
29{
30	mutex_unlock(&big_tty_mutex);
 
 
 
31}
32EXPORT_SYMBOL(tty_unlock);