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: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sergey Organov 2019-06-11 15:05:24 +03:00 committed by Greg Kroah-Hartman
parent da0f843e6e
commit 4e828c3e09
1 changed files with 13 additions and 10 deletions

View File

@ -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);