From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sergey Organov <sorganov@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
linux-serial@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 033/101] serial: imx: fix locking in set_termios()
Date: Fri, 19 Jul 2019 00:06:24 -0400 [thread overview]
Message-ID: <20190719040732.17285-33-sashal@kernel.org> (raw)
In-Reply-To: <20190719040732.17285-1-sashal@kernel.org>
From: Sergey Organov <sorganov@gmail.com>
[ Upstream commit 4e828c3e09201512be5ee162393f334321f7cf01 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/imx.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 0f67197a3783..105de92b0b3b 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -382,6 +382,7 @@ 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);
@@ -390,6 +391,7 @@ 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;
@@ -399,6 +401,7 @@ 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;
@@ -1554,6 +1557,16 @@ 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
@@ -1597,16 +1610,6 @@ 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);
--
2.20.1
next prev parent reply other threads:[~2019-07-19 4:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190719040732.17285-1-sashal@kernel.org>
2019-07-19 4:05 ` [PATCH AUTOSEL 4.19 006/101] tty: max310x: Fix invalid baudrate divisors calculator Sasha Levin
2019-07-19 4:05 ` [PATCH AUTOSEL 4.19 008/101] tty: serial: cpm_uart - fix init when SMC is relocated Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 023/101] tty/serial: digicolor: Fix digicolor-usart already registered warning Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 024/101] tty: serial: msm_serial: avoid system lockup condition Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 025/101] serial: 8250: Fix TX interrupt handling condition Sasha Levin
2019-07-19 4:06 ` Sasha Levin [this message]
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 034/101] tty: serial_core: Set port active bit in uart_port_activate Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 040/101] serial: mctrl_gpio: Check if GPIO property exisits before requesting it Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 059/101] serial: sh-sci: Terminate TX DMA during buffer flushing Sasha Levin
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 060/101] serial: sh-sci: Fix TX DMA buffer flushing and workqueue races Sasha Levin
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