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Commit 19225135 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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tty: serial - fix various misuses/mishandlings of port->tty 



Make it robust against hang up events. In most cases we can do this simply
by passing the right things in the first place.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent a360fae6

drivers/serial/serial_core.c

+60 −49
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ static struct lock_class_key port_lock_key; 
#define uart_console(port)	(0)

#endif



static void uart_change_speed(struct uart_state *state,

static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,

					struct ktermios *old_termios);

static void uart_wait_until_sent(struct tty_struct *tty, int timeout);

static void uart_change_pm(struct uart_state *state, int pm_state);
@@ -137,7 +137,7 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) 
 * Startup the port.  This will be called once per open.  All calls

 * will be serialised by the per-port mutex.

 */

static int uart_startup(struct uart_state *state, int init_hw)

static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)

{

	struct uart_port *uport = state->uart_port;

	struct tty_port *port = &state->port;
@@ -152,7 +152,7 @@ static int uart_startup(struct uart_state *state, int init_hw) 
	 * once we have successfully opened the port.  Also set

	 * up the tty->alt_speed kludge

	 */

	set_bit(TTY_IO_ERROR, &port->tty->flags);

	set_bit(TTY_IO_ERROR, &tty->flags);



	if (uport->type == PORT_UNKNOWN)

		return 0;
@@ -177,26 +177,26 @@ static int uart_startup(struct uart_state *state, int init_hw) 
			/*

			 * Initialise the hardware port settings.

			 */

			uart_change_speed(state, NULL);

			uart_change_speed(tty, state, NULL);



			/*

			 * Setup the RTS and DTR signals once the

			 * port is open and ready to respond.

			 */

			if (port->tty->termios->c_cflag & CBAUD)

			if (tty->termios->c_cflag & CBAUD)

				uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);

		}



		if (port->flags & ASYNC_CTS_FLOW) {

			spin_lock_irq(&uport->lock);

			if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))

				port->tty->hw_stopped = 1;

				tty->hw_stopped = 1;

			spin_unlock_irq(&uport->lock);

		}



		set_bit(ASYNCB_INITIALIZED, &port->flags);



		clear_bit(TTY_IO_ERROR, &port->tty->flags);

		clear_bit(TTY_IO_ERROR, &tty->flags);

	}



	if (retval && capable(CAP_SYS_ADMIN))
@@ -210,11 +210,10 @@ static int uart_startup(struct uart_state *state, int init_hw) 
 * DTR is dropped if the hangup on close termio flag is on.  Calls to

 * uart_shutdown are serialised by the per-port semaphore.

 */

static void uart_shutdown(struct uart_state *state)

static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)

{

	struct uart_port *uport = state->uart_port;

	struct tty_port *port = &state->port;

	struct tty_struct *tty = port->tty;



	/*

	 * Set the TTY IO error marker
@@ -430,11 +429,10 @@ uart_get_divisor(struct uart_port *port, unsigned int baud) 
EXPORT_SYMBOL(uart_get_divisor);



/* FIXME: Consistent locking policy */

static void

uart_change_speed(struct uart_state *state, struct ktermios *old_termios)

static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,

					struct ktermios *old_termios)

{

	struct tty_port *port = &state->port;

	struct tty_struct *tty = port->tty;

	struct uart_port *uport = state->uart_port;

	struct ktermios *termios;
@@ -463,8 +461,8 @@ uart_change_speed(struct uart_state *state, struct ktermios *old_termios) 
	uport->ops->set_termios(uport, termios, old_termios);

}



static inline int

__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)

static inline int __uart_put_char(struct uart_port *port,

				struct circ_buf *circ, unsigned char c)

{

	unsigned long flags;

	int ret = 0;
@@ -494,8 +492,8 @@ static void uart_flush_chars(struct tty_struct *tty) 
	uart_start(tty);

}



static int

uart_write(struct tty_struct *tty, const unsigned char *buf, int count)

static int uart_write(struct tty_struct *tty,

					const unsigned char *buf, int count)

{

	struct uart_state *state = tty->driver_data;

	struct uart_port *port;
@@ -675,7 +673,7 @@ static int uart_get_info(struct uart_state *state, 
	return 0;

}



static int uart_set_info(struct uart_state *state,

static int uart_set_info(struct tty_struct *tty, struct uart_state *state,

			 struct serial_struct __user *newinfo)

{

	struct serial_struct new_serial;
@@ -770,7 +768,7 @@ static int uart_set_info(struct uart_state *state, 
		 * We need to shutdown the serial port at the old

		 * port/type/irq combination.

		 */

		uart_shutdown(state);

		uart_shutdown(tty, state);

	}



	if (change_port) {
@@ -869,25 +867,27 @@ static int uart_set_info(struct uart_state *state, 
				       "is deprecated.\n", current->comm,

				       tty_name(port->tty, buf));

			}

			uart_change_speed(state, NULL);

			uart_change_speed(tty, state, NULL);

		}

	} else

		retval = uart_startup(state, 1);

		retval = uart_startup(tty, state, 1);

 exit:

	mutex_unlock(&port->mutex);

	return retval;

}





/*

 * uart_get_lsr_info - get line status register info.

/**

 *	uart_get_lsr_info	-	get line status register info

 *	@tty: tty associated with the UART

 *	@state: UART being queried

 *	@value: returned modem value

 *

 *	Note: uart_ioctl protects us against hangups.

 */

static int uart_get_lsr_info(struct uart_state *state,

			     unsigned int __user *value)

static int uart_get_lsr_info(struct tty_struct *tty,

			struct uart_state *state, unsigned int __user *value)

{

	struct uart_port *uport = state->uart_port;

	struct tty_port *port = &state->port;

	unsigned int result;



	result = uport->ops->tx_empty(uport);
@@ -900,7 +900,7 @@ static int uart_get_lsr_info(struct uart_state *state, 
	 */

	if (uport->x_char ||

	    ((uart_circ_chars_pending(&state->xmit) > 0) &&

	     !port->tty->stopped && !port->tty->hw_stopped))

	     !tty->stopped && !tty->hw_stopped))

		result &= ~TIOCSER_TEMT;



	return put_user(result, value);
@@ -961,7 +961,7 @@ static int uart_break_ctl(struct tty_struct *tty, int break_state) 
	return 0;

}



static int uart_do_autoconfig(struct uart_state *state)

static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)

{

	struct uart_port *uport = state->uart_port;

	struct tty_port *port = &state->port;
@@ -980,7 +980,7 @@ static int uart_do_autoconfig(struct uart_state *state) 


	ret = -EBUSY;

	if (tty_port_users(port) == 1) {

		uart_shutdown(state);

		uart_shutdown(tty, state);



		/*

		 * If we already have a port type configured,
@@ -999,7 +999,7 @@ static int uart_do_autoconfig(struct uart_state *state) 
		 */

		uport->ops->config_port(uport, flags);



		ret = uart_startup(state, 1);

		ret = uart_startup(tty, state, 1);

	}

	mutex_unlock(&port->mutex);

	return ret;
@@ -1122,11 +1122,11 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, 
		break;



	case TIOCSSERIAL:

		ret = uart_set_info(state, uarg);

		ret = uart_set_info(tty, state, uarg);

		break;



	case TIOCSERCONFIG:

		ret = uart_do_autoconfig(state);

		ret = uart_do_autoconfig(tty, state);

		break;



	case TIOCSERGWILD: /* obsolete */
@@ -1172,7 +1172,7 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, 
	 */

	switch (cmd) {

	case TIOCSERGETLSR: /* Get line status register */

		ret = uart_get_lsr_info(state, uarg);

		ret = uart_get_lsr_info(tty, state, uarg);

		break;



	default: {
@@ -1219,7 +1219,7 @@ static void uart_set_termios(struct tty_struct *tty, 
		return;

	}



	uart_change_speed(state, old_termios);

	uart_change_speed(tty, state, old_termios);



	/* Handle transition to B0 status */

	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
@@ -1335,7 +1335,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
		uart_wait_until_sent(tty, uport->timeout);

	}



	uart_shutdown(state);

	uart_shutdown(tty, state);

	uart_flush_buffer(tty);



	tty_ldisc_flush(tty);
@@ -1436,7 +1436,7 @@ static void uart_hangup(struct tty_struct *tty) 
	mutex_lock(&port->mutex);

	if (port->flags & ASYNC_NORMAL_ACTIVE) {

		uart_flush_buffer(tty);

		uart_shutdown(state);

		uart_shutdown(tty, state);

		port->count = 0;

		clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);

		tty_port_tty_set(port, NULL);
@@ -1446,15 +1446,19 @@ static void uart_hangup(struct tty_struct *tty) 
	mutex_unlock(&port->mutex);

}



/*

/**

 *	uart_update_termios	-	update the terminal hw settings

 *	@tty: tty associated with UART

 *	@state: UART to update

 *

 *	Copy across the serial console cflag setting into the termios settings

 *	for the initial open of the port.  This allows continuity between the

 *	kernel settings, and the settings init adopts when it opens the port

 *	for the first time.

 */

static void uart_update_termios(struct uart_state *state)

static void uart_update_termios(struct tty_struct *tty,

						struct uart_state *state)

{

	struct tty_struct *tty = state->port.tty;

	struct uart_port *port = state->uart_port;



	if (uart_console(port) && port->cons->cflag) {
@@ -1471,7 +1475,7 @@ static void uart_update_termios(struct uart_state *state) 
		/*

		 * Make termios settings take effect.

		 */

		uart_change_speed(state, NULL);

		uart_change_speed(tty, state, NULL);



		/*

		 * And finally enable the RTS and DTR signals.
@@ -1668,7 +1672,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp) 
	/*

	 * Start up the serial port.

	 */

	retval = uart_startup(state, 0);

	retval = uart_startup(tty, state, 0);



	/*

	 * If we succeeded, wait until the port is ready.
@@ -1683,7 +1687,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp) 
	if (retval == 0 && !(port->flags & ASYNC_NORMAL_ACTIVE)) {

		set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);



		uart_update_termios(state);

		uart_update_termios(tty, state);

	}



fail:
@@ -2010,9 +2014,13 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) 
	struct tty_port *port = &state->port;

	struct device *tty_dev;

	struct uart_match match = {uport, drv};

	struct tty_struct *tty;



	mutex_lock(&port->mutex);



	/* Must be inside the mutex lock until we convert to tty_port */

	tty = port->tty;



	tty_dev = device_find_child(uport->dev, &match, serial_match_port);

	if (device_may_wakeup(tty_dev)) {

		enable_irq_wake(uport->irq);
@@ -2105,9 +2113,12 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) 
		ops->set_mctrl(uport, 0);

		spin_unlock_irq(&uport->lock);

		if (console_suspend_enabled || !uart_console(uport)) {

			/* Protected by port mutex for now */

			struct tty_struct *tty = port->tty;

			ret = ops->startup(uport);

			if (ret == 0) {

				uart_change_speed(state, NULL);

				if (tty)

					uart_change_speed(tty, state, NULL);

				spin_lock_irq(&uport->lock);

				ops->set_mctrl(uport, uport->mctrl);

				ops->start_tx(uport);
@@ -2119,7 +2130,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) 
				 * Clear the "initialized" flag so we won't try

				 * to call the low level drivers shutdown method.

				 */

				uart_shutdown(state);

				uart_shutdown(tty, state);

			}

		}