linux/drivers/tty/tty_mutex.c
Greg Kroah-Hartman 6c80c0b94b tty: move some internal tty lock enums and functions out of tty.h
Move the TTY_LOCK_* enums and tty_ldisc lock functions out of the global
tty.h into the local header file to clean things up.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:26:58 +02:00

62 lines
1.2 KiB
C

// 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)
{
if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return;
tty_kref_get(tty);
mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);
int tty_lock_interruptible(struct tty_struct *tty)
{
int ret;
if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return -EIO;
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)
{
if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
return;
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);
}