From 2febdb632bb96235b94b8fccaf882a78f8f4b2bb Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 5 Nov 2014 12:13:02 -0500 Subject: tty: Preset lock subclass for nested tty locks Eliminate the requirement of specifying the tty lock nesting at lock time; instead, set the lock subclass for slave ptys at pty install (normal ttys and master ptys use subclass 0). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_mutex.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'drivers/tty/tty_mutex.c') diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c index f43e995c7a0f..4486741190c4 100644 --- a/drivers/tty/tty_mutex.c +++ b/drivers/tty/tty_mutex.c @@ -13,15 +13,14 @@ enum { TTY_MUTEX_NORMAL, - TTY_MUTEX_NESTED, + TTY_MUTEX_SLAVE, }; /* * Getting the big tty mutex. */ -static void __lockfunc tty_lock_nested(struct tty_struct *tty, - unsigned int subclass) +void __lockfunc tty_lock(struct tty_struct *tty) { if (tty->magic != TTY_MAGIC) { pr_err("L Bad %p\n", tty); @@ -29,12 +28,7 @@ static void __lockfunc tty_lock_nested(struct tty_struct *tty, return; } tty_kref_get(tty); - mutex_lock_nested(&tty->legacy_mutex, subclass); -} - -void __lockfunc tty_lock(struct tty_struct *tty) -{ - return tty_lock_nested(tty, TTY_MUTEX_NORMAL); + mutex_lock(&tty->legacy_mutex); } EXPORT_SYMBOL(tty_lock); @@ -56,7 +50,7 @@ void __lockfunc tty_lock_slave(struct tty_struct *tty) WARN_ON(!mutex_is_locked(&tty->link->legacy_mutex) || !tty->driver->type == TTY_DRIVER_TYPE_PTY || !tty->driver->type == PTY_TYPE_SLAVE); - tty_lock_nested(tty, TTY_MUTEX_NESTED); + tty_lock(tty); } } @@ -65,3 +59,8 @@ 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_MUTEX_SLAVE); +} -- cgit v1.2.3