This reverts commit
b9ca5f8560af244489b4a1bc1ae88b341f24bc95 as 0-day
shows it has a circular locking dependency.
Fixes: b9ca5f8560af ("tty: pty: Fix race condition between release_one_tty and pty_write")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Sahara <keun-o.park@darkmatter.ae>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
if (tty->stopped)
return 0;
- mutex_lock(&tty_mutex);
- if (to->magic != TTY_MAGIC) {
- mutex_unlock(&tty_mutex);
- return -EIO;
- }
-
if (c > 0) {
spin_lock_irqsave(&to->port->lock, flags);
/* Stuff the data into the input queue of the other end */
tty_flip_buffer_push(to->port);
spin_unlock_irqrestore(&to->port->lock, flags);
}
- mutex_unlock(&tty_mutex);
return c;
}
struct tty_driver *driver = tty->driver;
struct module *owner = driver->owner;
- mutex_lock(&tty_mutex);
if (tty->ops->cleanup)
tty->ops->cleanup(tty);
tty->magic = 0;
- mutex_unlock(&tty_mutex);
-
tty_driver_kref_put(driver);
module_put(owner);