This is a note to let you know that I've just added the patch titled
serial: omap: do not override settings for RS485 support
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 51f93776b84dee23e44a7be880736669a01cec2b Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:17 +0100
Subject: serial: omap: do not override settings for RS485 support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The drivers RS485 support is deactivated if there is no RTS GPIO available.
This is done by nullifying the ports rs485_supported struct. After that
however the settings in serial_omap_rs485_supported are assigned to the
same structure unconditionally, which results in an unintended reactivation
of RS485 support.
Fix this by moving the assignment to the beginning of
serial_omap_probe_rs485() and thus before uart_get_rs485_mode() gets
called.
Also replace the assignment of rs485_config() to have the complete RS485
setup in one function.
Fixes: e2752ae3cfc9 ("serial: omap: Disallow RS-485 if rts-gpio is not specified")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com>
Link: https://lore.kernel.org/r/20240103061818.564-7-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/omap-serial.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 730755621879..f5a0b401af63 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1483,6 +1483,13 @@ static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
return omap_up_info;
}
+static const struct serial_rs485 serial_omap_rs485_supported = {
+ .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+ SER_RS485_RX_DURING_TX,
+ .delay_rts_before_send = 1,
+ .delay_rts_after_send = 1,
+};
+
static int serial_omap_probe_rs485(struct uart_omap_port *up,
struct device *dev)
{
@@ -1497,6 +1504,9 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
if (!np)
return 0;
+ up->port.rs485_config = serial_omap_config_rs485;
+ up->port.rs485_supported = serial_omap_rs485_supported;
+
ret = uart_get_rs485_mode(&up->port);
if (ret)
return ret;
@@ -1531,13 +1541,6 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
return 0;
}
-static const struct serial_rs485 serial_omap_rs485_supported = {
- .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
- SER_RS485_RX_DURING_TX,
- .delay_rts_before_send = 1,
- .delay_rts_after_send = 1,
-};
-
static int serial_omap_probe(struct platform_device *pdev)
{
struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
@@ -1604,17 +1607,11 @@ static int serial_omap_probe(struct platform_device *pdev)
dev_info(up->port.dev, "no wakeirq for uart%d\n",
up->port.line);
- ret = serial_omap_probe_rs485(up, &pdev->dev);
- if (ret < 0)
- goto err_rs485;
-
sprintf(up->name, "OMAP UART%d", up->port.line);
up->port.mapbase = mem->start;
up->port.membase = base;
up->port.flags = omap_up_info->flags;
up->port.uartclk = omap_up_info->uartclk;
- up->port.rs485_config = serial_omap_config_rs485;
- up->port.rs485_supported = serial_omap_rs485_supported;
if (!up->port.uartclk) {
up->port.uartclk = DEFAULT_CLK_SPEED;
dev_warn(&pdev->dev,
@@ -1622,6 +1619,10 @@ static int serial_omap_probe(struct platform_device *pdev)
DEFAULT_CLK_SPEED);
}
+ ret = serial_omap_probe_rs485(up, &pdev->dev);
+ if (ret < 0)
+ goto err_rs485;
+
up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
--
2.43.0
This is a note to let you know that I've just added the patch titled
usb: dwc: ep0: Update request status in dwc3_ep0_stall_restart
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From e9d40b215e38480fd94c66b06d79045717a59e9c Mon Sep 17 00:00:00 2001
From: Uttkarsh Aggarwal <quic_uaggarwa(a)quicinc.com>
Date: Fri, 22 Dec 2023 15:17:04 +0530
Subject: usb: dwc: ep0: Update request status in dwc3_ep0_stall_restart
Current implementation blocks the running operations when Plug-out and
Plug-In is performed continuously, process gets stuck in
dwc3_thread_interrupt().
Code Flow:
CPU1
->Gadget_start
->dwc3_interrupt
->dwc3_thread_interrupt
->dwc3_process_event_buf
->dwc3_process_event_entry
->dwc3_endpoint_interrupt
->dwc3_ep0_interrupt
->dwc3_ep0_inspect_setup
->dwc3_ep0_stall_and_restart
By this time if pending_list is not empty, it will get the next request
on the given list and calls dwc3_gadget_giveback which will unmap request
and call its complete() callback to notify upper layers that it has
completed. Currently dwc3_gadget_giveback status is set to -ECONNRESET,
whereas it should be -ESHUTDOWN based on condition if not dwc->connected
is true.
Cc: <stable(a)vger.kernel.org>
Fixes: d742220b3577 ("usb: dwc3: ep0: giveback requests on stall_and_restart")
Signed-off-by: Uttkarsh Aggarwal <quic_uaggarwa(a)quicinc.com>
Link: https://lore.kernel.org/r/20231222094704.20276-1-quic_uaggarwa@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/dwc3/ep0.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index b94243237293..6ae8a36f21cf 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -238,7 +238,10 @@ void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
struct dwc3_request *req;
req = next_request(&dep->pending_list);
- dwc3_gadget_giveback(dep, req, -ECONNRESET);
+ if (!dwc->connected)
+ dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
+ else
+ dwc3_gadget_giveback(dep, req, -ECONNRESET);
}
dwc->eps[0]->trb_enqueue = 0;
--
2.43.0
This is a note to let you know that I've just added the patch titled
serial: core, imx: do not set RS485 enabled if it is not supported
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 74eab89b26ac433ad857292f4707b43c1a8f0209 Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:16 +0100
Subject: serial: core, imx: do not set RS485 enabled if it is not supported
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
If the imx driver cannot support RS485 it nullifies the ports
rs485_supported structure. But it still calls uart_get_rs485_mode() which
may set the RS485_ENABLED flag nevertheless.
This may lead to an attempt to configure RS485 even if it is not supported
when the flag is evaluated in uart_configure_port() at port startup.
Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED
flag is not supported by the caller.
With this fix a check for RTS availability is now obsolete in the imx
driver, since it can not evaluate to true any more. So remove this check.
Furthermore the explicit nullifcation of rs485_supported is not needed,
since the memory has already been set to zeros at allocation. So remove
this, too.
Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported")
Cc: Shawn Guo <shawnguo(a)kernel.org>
Cc: Sascha Hauer <s.hauer(a)pengutronix.de>
Cc: <stable(a)vger.kernel.org>
Suggested-by: Uwe Kleine-König <u.kleine-koenig(a)pengutronix.de>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com>
Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/imx.c | 7 -------
drivers/tty/serial/serial_core.c | 3 +++
2 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 8b7d9c5a7455..4aa72d5aeafb 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2211,7 +2211,6 @@ static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
return HRTIMER_NORESTART;
}
-static const struct serial_rs485 imx_no_rs485 = {}; /* No RS485 if no RTS */
static const struct serial_rs485 imx_rs485_supported = {
.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
SER_RS485_RX_DURING_TX,
@@ -2295,8 +2294,6 @@ static int imx_uart_probe(struct platform_device *pdev)
/* RTS is required to control the RS485 transmitter */
if (sport->have_rtscts || sport->have_rtsgpio)
sport->port.rs485_supported = imx_rs485_supported;
- else
- sport->port.rs485_supported = imx_no_rs485;
sport->port.flags = UPF_BOOT_AUTOCONF;
timer_setup(&sport->timer, imx_uart_timeout, 0);
@@ -2331,10 +2328,6 @@ static int imx_uart_probe(struct platform_device *pdev)
if (ret)
goto err_clk;
- if (sport->port.rs485.flags & SER_RS485_ENABLED &&
- (!sport->have_rtscts && !sport->have_rtsgpio))
- dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
-
/*
* If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
* signal cannot be set low during transmission in case the
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index b9606db78c92..b56ed8c376b2 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3607,6 +3607,9 @@ int uart_get_rs485_mode(struct uart_port *port)
u32 rs485_delay[2];
int ret;
+ if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
+ return 0;
+
ret = device_property_read_u32_array(dev, "rs485-rts-delay",
rs485_delay, 2);
if (!ret) {
--
2.43.0
This is a note to let you know that I've just added the patch titled
serial: core: make sure RS485 cannot be enabled when it is not
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From c73986913fa47e71e0b1ad7f039f6444915e8810 Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:15 +0100
Subject: serial: core: make sure RS485 cannot be enabled when it is not
supported
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Some uart drivers specify a rs485_config() function and then decide later
to disable RS485 support for some reason (e.g. imx and ar933).
In these cases userspace may be able to activate RS485 via TIOCSRS485
nevertheless, since in uart_set_rs485_config() an existing rs485_config()
function indicates that RS485 is supported.
Make sure that this is not longer possible by checking the uarts
rs485_supported.flags instead and bailing out if SER_RS485_ENABLED is not
set.
Furthermore instead of returning an empty structure return -ENOTTY if the
RS485 configuration is requested via TIOCGRS485 but RS485 is not supported.
This has a small impact on userspace visibility but it is consistent with
the -ENOTTY error for TIOCGRS485.
Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported")
Fixes: 55e18c6b6d42 ("serial: imx: Remove serial_rs485 sanitization")
Cc: Shawn Guo <shawnguo(a)kernel.org>
Cc: Sascha Hauer <s.hauer(a)pengutronix.de>
Cc: <stable(a)vger.kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-5-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/serial_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index cd8c3a70455e..b9606db78c92 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1474,7 +1474,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
int ret;
unsigned long flags;
- if (!port->rs485_config)
+ if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
return -ENOTTY;
if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
--
2.43.0
This is a note to let you know that I've just added the patch titled
serial: core: fix sanitizing check for RTS settings
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 4afeced55baa391490b61ed9164867e2927353ed Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:14 +0100
Subject: serial: core: fix sanitizing check for RTS settings
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Among other things uart_sanitize_serial_rs485() tests the sanity of the RTS
settings in a RS485 configuration that has been passed by userspace.
If RTS-on-send and RTS-after-send are both set or unset the configuration
is adjusted and RTS-after-send is disabled and RTS-on-send enabled.
This however makes only sense if both RTS modes are actually supported by
the driver.
With commit be2e2cb1d281 ("serial: Sanitize rs485_struct") the code does
take the driver support into account but only checks if one of both RTS
modes are supported. This may lead to the errorneous result of RTS-on-send
being set even if only RTS-after-send is supported.
Fix this by changing the implemented logic: First clear all unsupported
flags in the RS485 configuration, then adjust an invalid RTS setting by
taking into account which RTS mode is supported.
Cc: <stable(a)vger.kernel.org>
Fixes: be2e2cb1d281 ("serial: Sanitize rs485_struct")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-4-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/serial_core.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 850f24cc53e5..cd8c3a70455e 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1376,20 +1376,28 @@ static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs4
return;
}
- /* Pick sane settings if the user hasn't */
- if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) &&
- !(rs485->flags & SER_RS485_RTS_ON_SEND) ==
- !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
- dev_warn_ratelimited(port->dev,
- "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
- port->name, port->line);
- rs485->flags |= SER_RS485_RTS_ON_SEND;
- rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
- supported_flags |= SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND;
- }
-
rs485->flags &= supported_flags;
+ /* Pick sane settings if the user hasn't */
+ if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+ !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
+ if (supported_flags & SER_RS485_RTS_ON_SEND) {
+ rs485->flags |= SER_RS485_RTS_ON_SEND;
+ rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
+
+ dev_warn_ratelimited(port->dev,
+ "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
+ port->name, port->line);
+ } else {
+ rs485->flags |= SER_RS485_RTS_AFTER_SEND;
+ rs485->flags &= ~SER_RS485_RTS_ON_SEND;
+
+ dev_warn_ratelimited(port->dev,
+ "%s (%d): invalid RTS setting, using RTS_AFTER_SEND instead\n",
+ port->name, port->line);
+ }
+ }
+
uart_sanitize_serial_rs485_delays(port, rs485);
/* Return clean padding area to userspace */
--
2.43.0
This is a note to let you know that I've just added the patch titled
serial: core: set missing supported flag for RX during TX GPIO
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 1a33e33ca0e80d485458410f149265cdc0178cfa Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:13 +0100
Subject: serial: core: set missing supported flag for RX during TX GPIO
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
If the RS485 feature RX-during-TX is supported by means of a GPIO set the
according supported flag. Otherwise setting this feature from userspace may
not be possible, since in uart_sanitize_serial_rs485() the passed RS485
configuration is matched against the supported features and unsupported
settings are thereby removed and thus take no effect.
Cc: <stable(a)vger.kernel.org>
Fixes: 163f080eb717 ("serial: core: Add option to output RS485 RX_DURING_TX state via GPIO")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-3-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/serial_core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 8d381c283cec..850f24cc53e5 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3649,6 +3649,8 @@ int uart_get_rs485_mode(struct uart_port *port)
if (IS_ERR(desc))
return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-rx-during-tx-gpios\n");
port->rs485_rx_during_tx_gpio = desc;
+ if (port->rs485_rx_during_tx_gpio)
+ port->rs485_supported.flags |= SER_RS485_RX_DURING_TX;
return 0;
}
--
2.43.0
This is a note to let you know that I've just added the patch titled
serial: Do not hold the port lock when setting rx-during-tx GPIO
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 07c30ea5861fb26a77dade8cdc787252f6122fb1 Mon Sep 17 00:00:00 2001
From: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Date: Wed, 3 Jan 2024 07:18:12 +0100
Subject: serial: Do not hold the port lock when setting rx-during-tx GPIO
Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config().
Since this function is called with the port lock held, this can be a
problem in case that setting the GPIO line can sleep (e.g. if a GPIO
expander is used which is connected via SPI or I2C).
Avoid this issue by moving the GPIO setting outside of the port lock into
the serial core and thus making it a generic feature.
Also with commit c54d48543689 ("serial: stm32: Add support for rs485
RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a
rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too.
Furthermore reset old GPIO settings in case that changing the RS485
configuration failed.
Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO")
Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO")
Cc: Shawn Guo <shawnguo(a)kernel.org>
Cc: Sascha Hauer <s.hauer(a)pengutronix.de>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Lino Sanfilippo <l.sanfilippo(a)kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/tty/serial/imx.c | 4 ----
drivers/tty/serial/serial_core.c | 26 ++++++++++++++++++++++++--
drivers/tty/serial/stm32-usart.c | 8 ++------
3 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index a0fcf18cbeac..8b7d9c5a7455 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1948,10 +1948,6 @@ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termio
rs485conf->flags & SER_RS485_RX_DURING_TX)
imx_uart_start_rx(port);
- if (port->rs485_rx_during_tx_gpio)
- gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
- !!(rs485conf->flags & SER_RS485_RX_DURING_TX));
-
return 0;
}
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index cc866da50b81..8d381c283cec 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1407,6 +1407,16 @@ static void uart_set_rs485_termination(struct uart_port *port,
!!(rs485->flags & SER_RS485_TERMINATE_BUS));
}
+static void uart_set_rs485_rx_during_tx(struct uart_port *port,
+ const struct serial_rs485 *rs485)
+{
+ if (!(rs485->flags & SER_RS485_ENABLED))
+ return;
+
+ gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+ !!(rs485->flags & SER_RS485_RX_DURING_TX));
+}
+
static int uart_rs485_config(struct uart_port *port)
{
struct serial_rs485 *rs485 = &port->rs485;
@@ -1418,12 +1428,17 @@ static int uart_rs485_config(struct uart_port *port)
uart_sanitize_serial_rs485(port, rs485);
uart_set_rs485_termination(port, rs485);
+ uart_set_rs485_rx_during_tx(port, rs485);
uart_port_lock_irqsave(port, &flags);
ret = port->rs485_config(port, NULL, rs485);
uart_port_unlock_irqrestore(port, flags);
- if (ret)
+ if (ret) {
memset(rs485, 0, sizeof(*rs485));
+ /* unset GPIOs */
+ gpiod_set_value_cansleep(port->rs485_term_gpio, 0);
+ gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0);
+ }
return ret;
}
@@ -1462,6 +1477,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
return ret;
uart_sanitize_serial_rs485(port, &rs485);
uart_set_rs485_termination(port, &rs485);
+ uart_set_rs485_rx_during_tx(port, &rs485);
uart_port_lock_irqsave(port, &flags);
ret = port->rs485_config(port, &tty->termios, &rs485);
@@ -1473,8 +1489,14 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
port->ops->set_mctrl(port, port->mctrl);
}
uart_port_unlock_irqrestore(port, flags);
- if (ret)
+ if (ret) {
+ /* restore old GPIO settings */
+ gpiod_set_value_cansleep(port->rs485_term_gpio,
+ !!(port->rs485.flags & SER_RS485_TERMINATE_BUS));
+ gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+ !!(port->rs485.flags & SER_RS485_RX_DURING_TX));
return ret;
+ }
if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
return -EFAULT;
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 9781c143def2..794b77512740 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -226,12 +226,6 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
- if (port->rs485_rx_during_tx_gpio)
- gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
- !!(rs485conf->flags & SER_RS485_RX_DURING_TX));
- else
- rs485conf->flags |= SER_RS485_RX_DURING_TX;
-
if (rs485conf->flags & SER_RS485_ENABLED) {
cr1 = readl_relaxed(port->membase + ofs->cr1);
cr3 = readl_relaxed(port->membase + ofs->cr3);
@@ -256,6 +250,8 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
writel_relaxed(cr3, port->membase + ofs->cr3);
writel_relaxed(cr1, port->membase + ofs->cr1);
+
+ rs485conf->flags |= SER_RS485_RX_DURING_TX;
} else {
stm32_usart_clr_bits(port, ofs->cr3,
USART_CR3_DEM | USART_CR3_DEP);
--
2.43.0
In mon_bin_vma_fault():
offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= rp->b_size)
return VM_FAULT_SIGBUS;
chunk_idx = offset / CHUNK_SIZE;
pageptr = rp->b_vec[chunk_idx].pg;
The code is executed without holding any lock.
In mon_bin_vma_close():
spin_lock_irqsave(&rp->b_lock, flags);
rp->mmap_active--;
spin_unlock_irqrestore(&rp->b_lock, flags);
In mon_bin_ioctl():
spin_lock_irqsave(&rp->b_lock, flags);
if (rp->mmap_active) {
...
} else {
...
kfree(rp->b_vec);
rp->b_vec = vec;
rp->b_size = size;
...
}
spin_unlock_irqrestore(&rp->b_lock, flags);
Concurrent execution of mon_bin_vma_fault() with mon_bin_vma_close() and
mon_bin_ioctl() could lead to atomicity violations. mon_bin_vma_fault()
accesses rp->b_size and rp->b_vec without locking, risking array
out-of-bounds access or use-after-free bugs due to possible modifications
in mon_bin_ioctl().
This possible bug is found by an experimental static analysis tool
developed by our team, BassCheck[1]. This tool analyzes the locking APIs
to extract function pairs that can be concurrently executed, and then
analyzes the instructions in the paired functions to identify possible
concurrency bugs including data races and atomicity violations. The above
possible bug is reported when our tool analyzes the source code of
Linux 6.2.
To address this issue, it is proposed to add a spin lock pair in
mon_bin_vma_fault() to ensure atomicity. With this patch applied, our tool
never reports the possible bug, with the kernel configuration allyesconfig
for x86_64. Due to the lack of associated hardware, we cannot test the
patch in runtime testing, and just verify it according to the code logic.
[1] https://sites.google.com/view/basscheck/
Fixes: 19e6317d24c25 ("usb: mon: Fix a deadlock in usbmon between ...")
Cc: stable(a)vger.kernel.org
Reported-by: BassCheck <bass(a)buaa.edu.cn>
Signed-off-by: Gui-Dong Han <2045gemini(a)gmail.com>
---
v2:
* In this patch v2, we've added some information of the static analysis
tool used, as per the researcher guidelines. Also, we've added a cc in the
signed-off-by area, according to the stable-kernel-rules.
Thank Greg KH for helpful advice.
---
drivers/usb/mon/mon_bin.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 9ca9305243fe..509cd1b8ff13 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -1250,12 +1250,16 @@ static vm_fault_t mon_bin_vma_fault(struct vm_fault *vmf)
struct mon_reader_bin *rp = vmf->vma->vm_private_data;
unsigned long offset, chunk_idx;
struct page *pageptr;
-
+ unsigned long flags;
+ spin_lock_irqsave(&rp->b_lock, flags);
offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= rp->b_size)
+ if (offset >= rp->b_size) {
+ spin_unlock_irqrestore(&rp->b_lock, flags);
return VM_FAULT_SIGBUS;
+ }
chunk_idx = offset / CHUNK_SIZE;
pageptr = rp->b_vec[chunk_idx].pg;
+ spin_unlock_irqrestore(&rp->b_lock, flags);
get_page(pageptr);
vmf->page = pageptr;
return 0;
--
2.34.1
In mon_bin_vma_fault():
offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= rp->b_size)
return VM_FAULT_SIGBUS;
chunk_idx = offset / CHUNK_SIZE;
pageptr = rp->b_vec[chunk_idx].pg;
The code is executed without holding any lock.
In mon_bin_vma_close():
spin_lock_irqsave(&rp->b_lock, flags);
rp->mmap_active--;
spin_unlock_irqrestore(&rp->b_lock, flags);
In mon_bin_ioctl():
spin_lock_irqsave(&rp->b_lock, flags);
if (rp->mmap_active) {
...
} else {
...
kfree(rp->b_vec);
rp->b_vec = vec;
rp->b_size = size;
...
}
spin_unlock_irqrestore(&rp->b_lock, flags);
Concurrent execution of mon_bin_vma_fault() with mon_bin_vma_close() and
mon_bin_ioctl() could lead to atomicity violations. mon_bin_vma_fault()
accesses rp->b_size and rp->b_vec without locking, risking array
out-of-bounds access or use-after-free bugs due to possible modifications
in mon_bin_ioctl().
This possible bug is found by an experimental static analysis tool
developed by our team, BassCheck[1]. This tool analyzes the locking APIs
to extract function pairs that can be concurrently executed, and then
analyzes the instructions in the paired functions to identify possible
concurrency bugs including data races and atomicity violations. The above
possible bug is reported when our tool analyzes the source code of
Linux 6.2.
To address this issue, it is proposed to add a spin lock pair in
mon_bin_vma_fault() to ensure atomicity. With this patch applied, our tool
never reports the possible bug, with the kernel configuration allyesconfig
for x86_64. Due to the lack of associated hardware, we cannot test the
patch in runtime testing, and just verify it according to the code logic.
[1] https://sites.google.com/view/basscheck/
Fixes: 19e6317d24c2 ("usb: mon: Fix a deadlock in usbmon between ...")
Cc: stable(a)vger.kernel.org
Signed-off-by: Gui-Dong Han <2045gemini(a)gmail.com>
---
v2:
* In this patch v2, we've added some information of the static analysis
tool used, as per the researcher guidelines. Also, we've added a cc in the
signed-off-by area, according to the stable-kernel-rules.
Thank Greg KH for helpful advice.
---
v3:
* In this patch v3, we've added a necessary blank line and adjusted the
position of spin_unlock_irqrestore() following Greg KH's suggestions.
Thank Greg KH for helpful advice.
---
drivers/usb/mon/mon_bin.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 9ca9305243fe..fbc1a9c0b345 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -1250,14 +1250,19 @@ static vm_fault_t mon_bin_vma_fault(struct vm_fault *vmf)
struct mon_reader_bin *rp = vmf->vma->vm_private_data;
unsigned long offset, chunk_idx;
struct page *pageptr;
-
+ unsigned long flags;
+
+ spin_lock_irqsave(&rp->b_lock, flags);
offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= rp->b_size)
+ if (offset >= rp->b_size) {
+ spin_unlock_irqrestore(&rp->b_lock, flags);
return VM_FAULT_SIGBUS;
+ }
chunk_idx = offset / CHUNK_SIZE;
pageptr = rp->b_vec[chunk_idx].pg;
get_page(pageptr);
vmf->page = pageptr;
+ spin_unlock_irqrestore(&rp->b_lock, flags);
return 0;
}
--
2.34.1