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Commit 4e828c3e authored by Sergey Organov's avatar Sergey Organov Committed by Greg Kroah-Hartman
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serial: imx: fix locking in set_termios() 



imx_uart_set_termios() called imx_uart_rts_active(), or
imx_uart_rts_inactive() before taking port->port.lock.

As a consequence, sport->port.mctrl that these functions modify
could have been changed without holding port->port.lock.

Moved locking of port->port.lock above the calls to fix the issue.

Signed-off-by: default avatarSergey Organov <sorganov@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent da0f843e

drivers/tty/serial/imx.c

+13 −10
Original line number Diff line number Diff line
@@ -383,6 +383,7 @@ static void imx_uart_ucrs_restore(struct imx_port *sport, 
}

#endif



/* called with port.lock taken and irqs caller dependent */

static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)

{

	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
@@ -391,6 +392,7 @@ static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2) 
	mctrl_gpio_set(sport->gpios, sport->port.mctrl);

}



/* called with port.lock taken and irqs caller dependent */

static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)

{

	*ucr2 &= ~UCR2_CTSC;
@@ -400,6 +402,7 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2) 
	mctrl_gpio_set(sport->gpios, sport->port.mctrl);

}



/* called with port.lock taken and irqs caller dependent */

static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)

{

	*ucr2 |= UCR2_CTSC;
@@ -1549,6 +1552,16 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, 
		old_csize = CS8;

	}



	del_timer_sync(&sport->timer);



	/*

	 * Ask the core to calculate the divisor for us.

	 */

	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);

	quot = uart_get_divisor(port, baud);



	spin_lock_irqsave(&sport->port.lock, flags);



	if ((termios->c_cflag & CSIZE) == CS8)

		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;

	else
@@ -1592,16 +1605,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, 
			ucr2 |= UCR2_PROE;

	}



	del_timer_sync(&sport->timer);



	/*

	 * Ask the core to calculate the divisor for us.

	 */

	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);

	quot = uart_get_divisor(port, baud);



	spin_lock_irqsave(&sport->port.lock, flags);



	sport->port.read_status_mask = 0;

	if (termios->c_iflag & INPCK)

		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);