linux-stable.git/drivers/tty/serial, branch v5.4.232 Linux kernel stable tree serial: 8250_dma: Fix DMA Rx rearm race 2023-02-22T11:50:29+00:00 Ilpo Järvinen ilpo.jarvinen@linux.intel.com 2023-01-30T11:48:41+00:00 fc8548c75c033a9a332143768d4bfe5299fc0d26 commit 57e9af7831dcf211c5c689c2a6f209f4abdf0bce upstream. As DMA Rx can be completed from two places, it is possible that DMA Rx completes before DMA completion callback had a chance to complete it. Once the previous DMA Rx has been completed, a new one can be started on the next UART interrupt. The following race is possible (uart_unlock_and_check_sysrq_irqrestore() replaced with spin_unlock_irqrestore() for simplicity/clarity): CPU0 CPU1 dma_rx_complete() serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma_flush() __dma_rx_complete() dma->rx_running = 0 // Complete DMA Rx spin_unlock_irqrestore(&port->lock) serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma() dma->rx_running = 1 // Setup a new DMA Rx spin_unlock_irqrestore(&port->lock) spin_lock_irqsave(&port->lock) // sees dma->rx_running = 1 __dma_rx_complete() dma->rx_running = 0 // Incorrectly complete // running DMA Rx This race seems somewhat theoretical to occur for real but handle it correctly regardless. Check what is the DMA status before complething anything in __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 57e9af7831dcf211c5c689c2a6f209f4abdf0bce upstream.

As DMA Rx can be completed from two places, it is possible that DMA Rx
completes before DMA completion callback had a chance to complete it.
Once the previous DMA Rx has been completed, a new one can be started
on the next UART interrupt. The following race is possible
(uart_unlock_and_check_sysrq_irqrestore() replaced with
spin_unlock_irqrestore() for simplicity/clarity):

CPU0					CPU1
					dma_rx_complete()
serial8250_handle_irq()
  spin_lock_irqsave(&port->lock)
  handle_rx_dma()
    serial8250_rx_dma_flush()
      __dma_rx_complete()
        dma->rx_running = 0
        // Complete DMA Rx
  spin_unlock_irqrestore(&port->lock)

serial8250_handle_irq()
  spin_lock_irqsave(&port->lock)
  handle_rx_dma()
    serial8250_rx_dma()
      dma->rx_running = 1
      // Setup a new DMA Rx
  spin_unlock_irqrestore(&port->lock)

					  spin_lock_irqsave(&port->lock)
					  // sees dma->rx_running = 1
					  __dma_rx_complete()
					    dma->rx_running = 0
					    // Incorrectly complete
					    // running DMA Rx

This race seems somewhat theoretical to occur for real but handle it
correctly regardless. Check what is the DMA status before complething
anything in __dma_rx_complete().

Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250_dma: Fix DMA Rx completion race 2023-02-22T11:50:29+00:00 Ilpo Järvinen ilpo.jarvinen@linux.intel.com 2023-01-30T11:48:40+00:00 71d6b277c4e573fe3e1fcc39790eec1e5c6e13c0 commit 31352811e13dc2313f101b890fd4b1ce760b5fe7 upstream. __dma_rx_complete() is called from two places: - Through the DMA completion callback dma_rx_complete() - From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT The former does not hold port's lock during __dma_rx_complete() which allows these two to race and potentially insert the same data twice. Extend port's lock coverage in dma_rx_complete() to prevent the race and check if the DMA Rx is still pending completion before calling into __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 31352811e13dc2313f101b890fd4b1ce760b5fe7 upstream.

__dma_rx_complete() is called from two places:
  - Through the DMA completion callback dma_rx_complete()
  - From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT
The former does not hold port's lock during __dma_rx_complete() which
allows these two to race and potentially insert the same data twice.

Extend port's lock coverage in dma_rx_complete() to prevent the race
and check if the DMA Rx is still pending completion before calling
into __dma_rx_complete().

Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: atmel: fix incorrect baudrate setup 2023-01-24T06:18:01+00:00 Tobias Schramm t.schramm@manjaro.org 2023-01-09T07:29:40+00:00 b4461af0a5e69eb9de806049065e97842522d822 commit 5bfdd3c654bd879bff50c2e85e42f85ae698b42f upstream. Commit ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup") changed uart_set_options to select the correct baudrate configuration based on the absolute error between requested baudrate and available standard baudrate settings. Prior to that commit the baudrate was selected based on which predefined standard baudrate did not exceed the requested baudrate. This change of selection logic was never reflected in the atmel serial driver. Thus the comment left in the atmel serial driver is no longer accurate. Additionally the manual rounding up described in that comment and applied via (quot - 1) requests an incorrect baudrate. Since uart_set_options uses tty_termios_encode_baud_rate to determine the appropriate baudrate flags this can cause baudrate selection to fail entirely because tty_termios_encode_baud_rate will only select a baudrate if relative error between requested and selected baudrate does not exceed +/-2%. Fix that by requesting actual, exact baudrate used by the serial. Fixes: ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup") Cc: stable <stable@kernel.org> Signed-off-by: Tobias Schramm <t.schramm@manjaro.org> Acked-by: Richard Genoud <richard.genoud@gmail.com> Link: https://lore.kernel.org/r/20230109072940.202936-1-t.schramm@manjaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5bfdd3c654bd879bff50c2e85e42f85ae698b42f upstream.

Commit ba47f97a18f2 ("serial: core: remove baud_rates when serial console
setup") changed uart_set_options to select the correct baudrate
configuration based on the absolute error between requested baudrate and
available standard baudrate settings.
Prior to that commit the baudrate was selected based on which predefined
standard baudrate did not exceed the requested baudrate.
This change of selection logic was never reflected in the atmel serial
driver. Thus the comment left in the atmel serial driver is no longer
accurate.
Additionally the manual rounding up described in that comment and applied
via (quot - 1) requests an incorrect baudrate. Since uart_set_options uses
tty_termios_encode_baud_rate to determine the appropriate baudrate flags
this can cause baudrate selection to fail entirely because
tty_termios_encode_baud_rate will only select a baudrate if relative error
between requested and selected baudrate does not exceed +/-2%.
Fix that by requesting actual, exact baudrate used by the serial.

Fixes: ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup")
Cc: stable <stable@kernel.org>
Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20230109072940.202936-1-t.schramm@manjaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: pch_uart: Pass correct sg to dma_unmap_sg() 2023-01-24T06:18:01+00:00 Ilpo Järvinen ilpo.jarvinen@linux.intel.com 2023-01-03T09:34:35+00:00 5d99369685a6eda2e062e2a8f32507202fc6373d commit e8914b52e5b024e4af3d810a935fe0805eee8a36 upstream. A local variable sg is used to store scatterlist pointer in pch_dma_tx_complete(). The for loop doing Tx byte accounting before dma_unmap_sg() alters sg in its increment statement. Therefore, the pointer passed into dma_unmap_sg() won't match to the one given to dma_map_sg(). To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg() instead of the local variable. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e8914b52e5b024e4af3d810a935fe0805eee8a36 upstream.

A local variable sg is used to store scatterlist pointer in
pch_dma_tx_complete(). The for loop doing Tx byte accounting before
dma_unmap_sg() alters sg in its increment statement. Therefore, the
pointer passed into dma_unmap_sg() won't match to the one given to
dma_map_sg().

To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg()
instead of the local variable.

Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: tegra: Handle RX transfer in PIO mode if DMA wasn't started 2023-01-18T10:42:06+00:00 Dmitry Osipenko digetx@gmail.com 2020-02-09T16:44:15+00:00 38b5d7054d75aad80651f37c2ba6c3092d977d4e commit 1f69a1273b3f204a9c00dc3bbdcc4afcd0787428 upstream. It is possible to get an instant RX timeout or end-of-transfer interrupt before RX DMA was started, if transaction is less than 16 bytes. Transfer should be handled in PIO mode in this case because DMA can't handle it. This patch brings back the original behaviour of the driver that was changed by accident by a previous commit, it fixes occasional Bluetooth HW initialization failures which I started to notice recently. Fixes: d5e3fadb7012 ("tty: serial: tegra: Activate RX DMA transfer by request") Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Link: https://lore.kernel.org/r/20200209164415.9632-1-digetx@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1f69a1273b3f204a9c00dc3bbdcc4afcd0787428 upstream.

It is possible to get an instant RX timeout or end-of-transfer interrupt
before RX DMA was started, if transaction is less than 16 bytes. Transfer
should be handled in PIO mode in this case because DMA can't handle it.
This patch brings back the original behaviour of the driver that was
changed by accident by a previous commit, it fixes occasional Bluetooth HW
initialization failures which I started to notice recently.

Fixes: d5e3fadb7012 ("tty: serial: tegra: Activate RX DMA transfer by request")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200209164415.9632-1-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sunsab: Fix error handling in sunsab_init() 2023-01-18T10:41:23+00:00 Yuan Can yuancan@huawei.com 2022-11-23T06:12:12+00:00 98c01a728b468148adea5f0f91065b2076741338 [ Upstream commit 1a6ec673fb627c26e2267ca0a03849f91dbd9b40 ] The sunsab_init() returns the platform_driver_register() directly without checking its return value, if platform_driver_register() failed, the allocated sunsab_ports is leaked. Fix by free sunsab_ports and set it to NULL when platform_driver_register() failed. Fixes: c4d37215a824 ("[SERIAL] sunsab: Convert to of_driver framework.") Signed-off-by: Yuan Can <yuancan@huawei.com> Link: https://lore.kernel.org/r/20221123061212.52593-1-yuancan@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1a6ec673fb627c26e2267ca0a03849f91dbd9b40 ]

The sunsab_init() returns the platform_driver_register() directly without
checking its return value, if platform_driver_register() failed, the
allocated sunsab_ports is leaked.
Fix by free sunsab_ports and set it to NULL when platform_driver_register()
failed.

Fixes: c4d37215a824 ("[SERIAL] sunsab: Convert to of_driver framework.")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221123061212.52593-1-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: altera_uart: fix locking in polling mode 2023-01-18T10:41:23+00:00 Gabriel Somlo gsomlo@gmail.com 2022-11-22T20:04:26+00:00 61f4146a7e5f2956d0b4153f2dca9864cc78e3c0 [ Upstream commit 1307c5d33cce8a41dd77c2571e4df65a5b627feb ] Since altera_uart_interrupt() may also be called from a poll timer in "serving_softirq" context, use spin_[lock_irqsave|unlock_irqrestore] variants, which are appropriate for both softirq and hardware interrupt contexts. Fixes: 2f8b9c15cd88 ("altera_uart: Add support for polling mode (IRQ-less)") Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Link: https://lore.kernel.org/r/20221122200426.888349-1-gsomlo@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1307c5d33cce8a41dd77c2571e4df65a5b627feb ]

Since altera_uart_interrupt() may also be called from
a poll timer in "serving_softirq" context, use
spin_[lock_irqsave|unlock_irqrestore] variants, which
are appropriate for both softirq and hardware interrupt
contexts.

Fixes: 2f8b9c15cd88 ("altera_uart: Add support for polling mode (IRQ-less)")
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Link: https://lore.kernel.org/r/20221122200426.888349-1-gsomlo@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: altera_uart_{r,t}x_chars() need only uart_port 2023-01-18T10:41:23+00:00 Jiri Slaby jslaby@suse.cz 2022-09-20T05:20:43+00:00 ce40c44e62bc3bbdf5f8d55df4585a0d5db2027a [ Upstream commit 3af44d9bb0539d5fa27d6159d696fda5f3747bff ] Both altera_uart_{r,t}x_chars() need only uart_port, not altera_uart. So pass the former from altera_uart_interrupt() directly. Apart it maybe saves a dereference, this makes the transition of altera_uart_tx_chars() easier to follow in the next patch. Cc: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220920052049.20507-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3af44d9bb0539d5fa27d6159d696fda5f3747bff ]

Both altera_uart_{r,t}x_chars() need only uart_port, not altera_uart. So
pass the former from altera_uart_interrupt() directly.

Apart it maybe saves a dereference, this makes the transition of
altera_uart_tx_chars() easier to follow in the next patch.

Cc: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: clean up stop-tx part in altera_uart_tx_chars() 2023-01-18T10:41:23+00:00 Jiri Slaby jslaby@suse.cz 2022-09-20T05:20:42+00:00 071bb9e36327859999ea53c1eb9671a7c10f9187 [ Upstream commit d9c128117da41cf4cb0e80ae565b5d3ac79dffac ] The "stop TX" path in altera_uart_tx_chars() is open-coded, so: * use uart_circ_empty() to check if the buffer is empty, and * when true, call altera_uart_stop_tx(). Cc: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220920052049.20507-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit d9c128117da41cf4cb0e80ae565b5d3ac79dffac ]

The "stop TX" path in altera_uart_tx_chars() is open-coded, so:
* use uart_circ_empty() to check if the buffer is empty, and
* when true, call altera_uart_stop_tx().

Cc: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: pch: Fix PCI device refcount leak in pch_request_dma() 2023-01-18T10:41:23+00:00 Xiongfeng Wang wangxiongfeng2@huawei.com 2022-11-22T11:45:59+00:00 d165388227aa7e46a9751b90bae6337b5335cdbb [ Upstream commit 8be3a7bf773700534a6e8f87f6ed2ed111254be5 ] As comment of pci_get_slot() says, it returns a pci_device with its refcount increased. The caller must decrement the reference count by calling pci_dev_put(). Since 'dma_dev' is only used to filter the channel in filter(), we can call pci_dev_put() before exiting from pch_request_dma(). Add the missing pci_dev_put() for the normal and error path. Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver") Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8be3a7bf773700534a6e8f87f6ed2ed111254be5 ]

As comment of pci_get_slot() says, it returns a pci_device with its
refcount increased. The caller must decrement the reference count by
calling pci_dev_put().

Since 'dma_dev' is only used to filter the channel in filter(), we can
call pci_dev_put() before exiting from pch_request_dma(). Add the
missing pci_dev_put() for the normal and error path.

Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>