mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
tty: add lockdep annotations
tty_lock_pair() do the right thing to avoid deadlocks, but should instruct LOCKDEP of this to avoid a splat. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
1d59d61f60
commit
fde86d3108
1 changed files with 15 additions and 4 deletions
|
@ -6,11 +6,17 @@
|
|||
|
||||
/* Legacy tty mutex glue */
|
||||
|
||||
enum {
|
||||
TTY_MUTEX_NORMAL,
|
||||
TTY_MUTEX_NESTED,
|
||||
};
|
||||
|
||||
/*
|
||||
* Getting the big tty mutex.
|
||||
*/
|
||||
|
||||
void __lockfunc tty_lock(struct tty_struct *tty)
|
||||
static void __lockfunc tty_lock_nested(struct tty_struct *tty,
|
||||
unsigned int subclass)
|
||||
{
|
||||
if (tty->magic != TTY_MAGIC) {
|
||||
printk(KERN_ERR "L Bad %p\n", tty);
|
||||
|
@ -18,7 +24,12 @@ void __lockfunc tty_lock(struct tty_struct *tty)
|
|||
return;
|
||||
}
|
||||
tty_kref_get(tty);
|
||||
mutex_lock(&tty->legacy_mutex);
|
||||
mutex_lock_nested(&tty->legacy_mutex, subclass);
|
||||
}
|
||||
|
||||
void __lockfunc tty_lock(struct tty_struct *tty)
|
||||
{
|
||||
return tty_lock_nested(tty, TTY_MUTEX_NORMAL);
|
||||
}
|
||||
EXPORT_SYMBOL(tty_lock);
|
||||
|
||||
|
@ -43,11 +54,11 @@ void __lockfunc tty_lock_pair(struct tty_struct *tty,
|
|||
{
|
||||
if (tty < tty2) {
|
||||
tty_lock(tty);
|
||||
tty_lock(tty2);
|
||||
tty_lock_nested(tty2, TTY_MUTEX_NESTED);
|
||||
} else {
|
||||
if (tty2 && tty2 != tty)
|
||||
tty_lock(tty2);
|
||||
tty_lock(tty);
|
||||
tty_lock_nested(tty, TTY_MUTEX_NESTED);
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL(tty_lock_pair);
|
||||
|
|
Loading…
Reference in a new issue