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path: root/drivers/tty/tty_mutex.c
blob: 0efcf713b756e5e7eaf95bf7b5f2a744fc7f6dc0 (plain)
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#include <linux/tty.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/semaphore.h>
#include <linux/sched.h>

/* Legacy tty mutex glue */

/*
 * Getting the big tty mutex.
 */

void __lockfunc tty_lock(struct tty_struct *tty)
{
	if (tty->magic != TTY_MAGIC) {
		pr_err("L Bad %p\n", tty);
		WARN_ON(1);
		return;
	}
	tty_kref_get(tty);
	mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);

void __lockfunc tty_unlock(struct tty_struct *tty)
{
	if (tty->magic != TTY_MAGIC) {
		pr_err("U Bad %p\n", tty);
		WARN_ON(1);
		return;
	}
	mutex_unlock(&tty->legacy_mutex);
	tty_kref_put(tty);
}
EXPORT_SYMBOL(tty_unlock);

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

void __lockfunc 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);
}
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