Commit f309532b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

tty: Revert the tty locking series, it needs more work 



This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d31 - tty: add lockdep annotations
  8f6576ad - tty: fix ldisc lock inversion trace
  d3ca8b64 - pty: Fix lock inversion
  b1d679af - tty: drop the pty lock during hangup
  abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef3 - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 233e562e

drivers/tty/amiserial.c

+7 −7
Original line number Diff line number Diff line
@@ -1033,7 +1033,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state, 
	if (!retinfo)

		return -EFAULT;

	memset(&tmp, 0, sizeof(tmp));

	tty_lock(tty);

	tty_lock();

	tmp.line = tty->index;

	tmp.port = state->port;

	tmp.flags = state->tport.flags;
@@ -1042,7 +1042,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state, 
	tmp.close_delay = state->tport.close_delay;

	tmp.closing_wait = state->tport.closing_wait;

	tmp.custom_divisor = state->custom_divisor;

	tty_unlock(tty);

	tty_unlock();

	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))

		return -EFAULT;

	return 0;
@@ -1059,12 +1059,12 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, 
	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))

		return -EFAULT;



	tty_lock(tty);

	tty_lock();

	change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) ||

		new_serial.custom_divisor != state->custom_divisor;

	if (new_serial.irq || new_serial.port != state->port ||

			new_serial.xmit_fifo_size != state->xmit_fifo_size) {

		tty_unlock(tty);

		tty_unlock();

		return -EINVAL;

	}
@@ -1074,7 +1074,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, 
		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||

		    ((new_serial.flags & ~ASYNC_USR_MASK) !=

		     (port->flags & ~ASYNC_USR_MASK))) {

			tty_unlock(tty);

			tty_unlock();

			return -EPERM;

		}

		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
@@ -1084,7 +1084,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, 
	}



	if (new_serial.baud_base < 9600) {

		tty_unlock(tty);

		tty_unlock();

		return -EINVAL;

	}
@@ -1116,7 +1116,7 @@ check_and_exit: 
		}

	} else

		retval = startup(tty, state);

	tty_unlock(tty);

	tty_unlock();

	return retval;

}

drivers/tty/cyclades.c

+1 −1
Original line number Diff line number Diff line
@@ -1599,7 +1599,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp) 
	 * If the port is the middle of closing, bail out now

	 */

	if (tty_hung_up_p(filp) || (info->port.flags & ASYNC_CLOSING)) {

		wait_event_interruptible_tty(tty, info->port.close_wait,

		wait_event_interruptible_tty(info->port.close_wait,

				!(info->port.flags & ASYNC_CLOSING));

		return (info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN: -ERESTARTSYS;

	}

drivers/tty/n_r3964.c

+5 −6
Original line number Diff line number Diff line
@@ -1065,8 +1065,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, 


	TRACE_L("read()");



	/* FIXME: should use a private lock */

	tty_lock(tty);

	tty_lock();



	pClient = findClient(pInfo, task_pid(current));

	if (pClient) {
@@ -1078,7 +1077,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, 
				goto unlock;

			}

			/* block until there is a message: */

			wait_event_interruptible_tty(tty, pInfo->read_wait,

			wait_event_interruptible_tty(pInfo->read_wait,

					(pMsg = remove_msg(pInfo, pClient)));

		}
@@ -1108,7 +1107,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, 
	}

	ret = -EPERM;

unlock:

	tty_unlock(tty);

	tty_unlock();

	return ret;

}
@@ -1157,7 +1156,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, 
	pHeader->locks = 0;

	pHeader->owner = NULL;



	tty_lock(tty);

	tty_lock();



	pClient = findClient(pInfo, task_pid(current));

	if (pClient) {
@@ -1176,7 +1175,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, 
	add_tx_queue(pInfo, pHeader);

	trigger_transmit(pInfo);



	tty_unlock(tty);

	tty_unlock();



	return 0;

}

drivers/tty/pty.c

+11 −14
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ static void pty_close(struct tty_struct *tty, struct file *filp) 
	wake_up_interruptible(&tty->read_wait);

	wake_up_interruptible(&tty->write_wait);

	tty->packet = 0;

	/* Review - krefs on tty_link ?? */

	if (!tty->link)

		return;

	tty->link->packet = 0;
@@ -63,9 +62,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp) 
		        mutex_unlock(&devpts_mutex);

		}

#endif

		tty_unlock(tty);

		tty_unlock();

		tty_vhangup(tty->link);

		tty_lock(tty);

		tty_lock();

	}

}
@@ -623,27 +622,26 @@ static int ptmx_open(struct inode *inode, struct file *filp) 
		return retval;



	/* find a device that is not in use. */

	mutex_lock(&devpts_mutex);

	tty_lock();

	index = devpts_new_index(inode);

	tty_unlock();

	if (index < 0) {

		retval = index;

		goto err_file;

	}



	mutex_unlock(&devpts_mutex);



	mutex_lock(&tty_mutex);

	mutex_lock(&devpts_mutex);

	tty = tty_init_dev(ptm_driver, index);

	mutex_unlock(&devpts_mutex);

	tty_lock();

	mutex_unlock(&tty_mutex);



	if (IS_ERR(tty)) {

		retval = PTR_ERR(tty);

		goto out;

	}



	/* The tty returned here is locked so we can safely

	   drop the mutex */

	mutex_unlock(&tty_mutex);



	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */



	tty_add_file(tty, filp);
@@ -656,17 +654,16 @@ static int ptmx_open(struct inode *inode, struct file *filp) 
	if (retval)

		goto err_release;



	tty_unlock(tty);

	tty_unlock();

	return 0;

err_release:

	tty_unlock(tty);

	tty_unlock();

	tty_release(inode, filp);

	return retval;

out:

	mutex_unlock(&tty_mutex);

	devpts_kill_index(inode, index);

	tty_unlock();

err_file:

        mutex_unlock(&devpts_mutex);

	tty_free_file(filp);

	return retval;

}

drivers/tty/serial/crisv10.c

+4 −4
Original line number Diff line number Diff line
@@ -3976,7 +3976,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp, 
	 */

	if (tty_hung_up_p(filp) ||

	    (info->flags & ASYNC_CLOSING)) {

		wait_event_interruptible_tty(tty, info->close_wait,

		wait_event_interruptible_tty(info->close_wait,

			!(info->flags & ASYNC_CLOSING));

#ifdef SERIAL_DO_RESTART

		if (info->flags & ASYNC_HUP_NOTIFY)
@@ -4052,9 +4052,9 @@ block_til_ready(struct tty_struct *tty, struct file * filp, 
		printk("block_til_ready blocking: ttyS%d, count = %d\n",

		       info->line, info->count);

#endif

		tty_unlock(tty);

		tty_unlock();

		schedule();

		tty_lock(tty);

		tty_lock();

	}

	set_current_state(TASK_RUNNING);

	remove_wait_queue(&info->open_wait, &wait);
@@ -4115,7 +4115,7 @@ rs_open(struct tty_struct *tty, struct file * filp) 
	 */

	if (tty_hung_up_p(filp) ||

	    (info->flags & ASYNC_CLOSING)) {

		wait_event_interruptible_tty(tty, info->close_wait,

		wait_event_interruptible_tty(info->close_wait,

			!(info->flags & ASYNC_CLOSING));

#ifdef SERIAL_DO_RESTART

		return ((info->flags & ASYNC_HUP_NOTIFY) ?

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