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linux-next/drivers/tty/tty_mutex.c
Peter Hurley 6d029c68de tty: Merge conditional + error message + WARN_ON()
WARN() does all of these things in one statement.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13 19:59:48 -08:00

47 lines
931 B
C

#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 (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return;
tty_kref_get(tty);
mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);
void __lockfunc 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 __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);
}