Commit Graph

7664 Commits

Author SHA1 Message Date
Hugo Villeneuve
e635f65269 serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFO
commit dbf4ab8218 upstream.

The SC16IS7XX IC supports a burst mode to access the FIFOs where the
initial register address is sent ($00), followed by all the FIFO data
without having to resend the register address each time. In this mode, the
IC doesn't increment the register address for each R/W byte.

The regmap_raw_read() and regmap_raw_write() are functions which can
perform IO over multiple registers. They are currently used to read/write
from/to the FIFO, and although they operate correctly in this burst mode on
the SPI bus, they would corrupt the regmap cache if it was not disabled
manually. The reason is that when the R/W size is more than 1 byte, these
functions assume that the register address is incremented and handle the
cache accordingly.

Convert FIFO R/W functions to use the regmap _noinc_ versions in order to
remove the manual cache control which was a workaround when using the
_raw_ versions. FIFO registers are properly declared as volatile so
cache will not be used/updated for FIFO accesses.

Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-6-hugo@hugovil.com
Cc: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:19:30 +02:00
Rickard x Andersson
142a01435c tty: serial: imx: Fix broken RS485
commit 672448ccf9 upstream.

When about to transmit the function imx_uart_start_tx is called and in
some RS485 configurations this function will call imx_uart_stop_rx. The
problem is that imx_uart_stop_rx will enable loopback in order to
release the RS485 bus, but when loopback is enabled transmitted data
will just be looped to RX.

This patch fixes the above problem by not enabling loopback when about
to transmit.

This driver now works well when used for RS485 half duplex master
configurations.

Fixes: 79d0224f6b ("tty: serial: imx: Handle RS485 DE signal active high")
Cc: stable <stable@kernel.org>
Signed-off-by: Rickard x Andersson <rickaran@axis.com>
Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Link: https://lore.kernel.org/r/20240221115304.509811-1-rickaran@axis.com
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:18:47 +02:00
Nicolas Pitre
0190d19d76 vt: fix unicode buffer corruption when deleting characters
commit 1581dafaf0 upstream.

This is the same issue that was fixed for the VGA text buffer in commit
39cdb68c64 ("vt: fix memory overlapping when deleting chars in the
buffer"). The cure is also the same i.e. replace memcpy() with memmove()
due to the overlaping buffers.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Fixes: 81732c3b2f ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:18:46 +02:00
Sherry Sun
fed1f00e48 tty: serial: fsl_lpuart: avoid idle preamble pending if CTS is enabled
commit 74cb7e0355 upstream.

If the remote uart device is not connected or not enabled after booting
up, the CTS line is high by default. At this time, if we enable the flow
control when opening the device(for example, using “stty -F /dev/ttyLP4
crtscts” command), there will be a pending idle preamble(first writing 0
and then writing 1 to UARTCTRL_TE will queue an idle preamble) that
cannot be sent out, resulting in the uart port fail to close(waiting for
TX empty), so the user space stty will have to wait for a long time or
forever.

This is an LPUART IP bug(idle preamble has higher priority than CTS),
here add a workaround patch to enable TX CTS after enabling UARTCTRL_TE,
so that the idle preamble does not get stuck due to CTS is deasserted.

Fixes: 380c966c09 ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20240305015706.1050769-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:18:45 +02:00
Peter Collingbourne
bbf72db11f serial: Lock console when calling into driver before registration
[ Upstream commit 801410b26a ]

During the handoff from earlycon to the real console driver, we have
two separate drivers operating on the same device concurrently. In the
case of the 8250 driver these concurrent accesses cause problems due
to the driver's use of banked registers, controlled by LCR.DLAB. It is
possible for the setup(), config_port(), pm() and set_mctrl() callbacks
to set DLAB, which can cause the earlycon code that intends to access
TX to instead access DLL, leading to missed output and corruption on
the serial line due to unintended modifications to the baud rate.

In particular, for setup() we have:

univ8250_console_setup()
-> serial8250_console_setup()
-> uart_set_options()
-> serial8250_set_termios()
-> serial8250_do_set_termios()
-> serial8250_do_set_divisor()

For config_port() we have:

serial8250_config_port()
-> autoconfig()

For pm() we have:

serial8250_pm()
-> serial8250_do_pm()
-> serial8250_set_sleep()

For set_mctrl() we have (for some devices):

serial8250_set_mctrl()
-> omap8250_set_mctrl()
-> __omap8250_set_mctrl()

To avoid such problems, let's make it so that the console is locked
during pre-registration calls to these callbacks, which will prevent
the earlycon driver from running concurrently.

Remove the partial solution to this problem in the 8250 driver
that locked the console only during autoconfig_irq(), as this would
result in a deadlock with the new approach. The console continues
to be locked during autoconfig_irq() because it can only be called
through uart_configure_port().

Although this patch introduces more locking than strictly necessary
(and in particular it also locks during the call to rs485_config()
which is not affected by this issue as far as I can tell), it follows
the principle that it is the responsibility of the generic console
code to manage the earlycon handoff by ensuring that earlycon and real
console driver code cannot run concurrently, and not the individual
drivers.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10 16:18:38 +02:00
Andy Shevchenko
6c619223aa serial: 8250_exar: Don't remove GPIO device on suspend
[ Upstream commit 73b5a5c00b ]

It seems a copy&paste mistake that suspend callback removes the GPIO
device. There is no counterpart of this action, means once suspended
there is no more GPIO device available untile full unbind-bind cycle
is performed. Remove suspicious GPIO device removal in suspend.

Fixes: d0aeaa83f0 ("serial: exar: split out the exar code from 8250_pci")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240219150627.2101198-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:34 -04:00
Tudor Ambarus
c220378081 tty: serial: samsung: fix tx_empty() to return TIOCSER_TEMT
[ Upstream commit 314c2b3992 ]

The core expects for tx_empty() either TIOCSER_TEMT when the tx is
empty or 0 otherwise. s3c24xx_serial_txempty_nofifo() might return
0x4, and at least uart_get_lsr_info() tries to clear exactly
TIOCSER_TEMT (BIT(1)). Fix tx_empty() to return TIOCSER_TEMT.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20240119104526.1221243-2-tudor.ambarus@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:34 -04:00
Hugo Villeneuve
e6011abe0c serial: max310x: fix syntax error in IRQ error message
[ Upstream commit 8ede8c6f47 ]

Replace g with q.

Helpful when grepping thru source code or logs for
"request" keyword.

Fixes: f65444187a ("serial: New serial driver MAX310X")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240118152213.2644269-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:34 -04:00
Jiri Slaby (SUSE)
19b2131837 tty: vt: fix 20 vs 0x20 typo in EScsiignore
[ Upstream commit 0e6a92f67c ]

The if (c >= 20 && c <= 0x3f) test added in commit 7a99565f87 is
wrong.  20 is DC4 in ascii and it makes no sense to consider that as the
bottom limit. Instead, it should be 0x20 as in the other test in
the commit above. This is supposed to NOT change anything as we handle
interesting 20-0x20 asciis far before this if.

So for sakeness, change to 0x20 (which is SPACE).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Fixes: 7a99565f87 ("vt: ignore csi sequences with intermediate characters.")
Cc: Martin Hostettler <textshell@uchuujin.de>
Link: https://lore.kernel.org/all/ZaP45QY2WEsDqoxg@neutronstar.dyndns.org/
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:34 -04:00
Jan Kundrát
a1211bbf78 serial: max310x: fix IO data corruption in batched operations
[ Upstream commit 3f42b142ea ]

After upgrading from 5.16 to 6.1, our board with a MAX14830 started
producing lots of garbage data over UART. Bisection pointed out commit
285e76fc04 as the culprit. That patch tried to replace hand-written
code which I added in 2b4bac48c1 ("serial: max310x: Use batched reads
when reasonably safe") with the generic regmap infrastructure for
batched operations.

Unfortunately, the `regmap_raw_read` and `regmap_raw_write` which were
used are actually functions which perform IO over *multiple* registers.
That's not what is needed for accessing these Tx/Rx FIFOs; the
appropriate functions are the `_noinc_` versions, not the `_raw_` ones.

Fix this regression by using `regmap_noinc_read()` and
`regmap_noinc_write()` along with the necessary `regmap_config` setup;
with this patch in place, our board communicates happily again. Since
our board uses SPI for talking to this chip, the I2C part is completely
untested.

Fixes: 285e76fc04 ("serial: max310x: use regmap methods for SPI batch operations")
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/79db8e82aadb0e174bc82b9996423c3503c8fb37.1680732084.git.jan.kundrat@cesnet.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:24 -04:00
Cosmin Tanislav
0ba485f90d serial: max310x: make accessing revision id interface-agnostic
[ Upstream commit b3883ab5e9 ]

SPI can only use 5 address bits, since one bit is reserved for
specifying R/W and 2 bits are used to specify the UART port.
To access registers that have addresses past 0x1F, an extended
register space can be enabled by writing to the GlobalCommand
register (address 0x1F).

I2C uses 8 address bits. The R/W bit is placed in the slave
address, and so is the UART port. Because of this, registers
that have addresses higher than 0x1F can be accessed normally.

To access the RevID register, on SPI, 0xCE must be written to
the 0x1F address to enable the extended register space, after
which the RevID register is accessible at address 0x5. 0xCD
must be written to the 0x1F address to disable the extended
register space.

On I2C, the RevID register is accessible at address 0x25.

Create an interface config struct, and add a method for
toggling the extended register space and a member for the RevId
register address. Implement these for SPI.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-4-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 3f42b142ea ("serial: max310x: fix IO data corruption in batched operations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:23 -04:00
Hugo Villeneuve
0afbf40c01 serial: max310x: prevent infinite while() loop in port startup
[ Upstream commit b35f8dbbce ]

If there is a problem after resetting a port, the do/while() loop that
checks the default value of DIVLSB register may run forever and spam the
I2C bus.

Add a delay before each read of DIVLSB, and a maximum number of tries to
prevent that situation from happening.

Also fail probe if port reset is unsuccessful.

Fixes: 10d8b34a42 ("serial: max310x: Driver rework")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240116213001.3691629-5-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:20 -04:00
Cosmin Tanislav
2fbf2c767b serial: max310x: use a separate regmap for each port
[ Upstream commit 6ef281daf0 ]

The driver currently does manual register manipulation in
multiple places to talk to a specific UART port.

In order to talk to a specific UART port over SPI, the bits U1
and U0 of the register address can be set, as explained in the
Command byte configuration section of the datasheet.

Make this more elegant by creating regmaps for each UART port
and setting the read_flag_mask and write_flag_mask
accordingly.

All communcations regarding global registers are done on UART
port 0, so replace the global regmap entirely with the port 0
regmap.

Also, remove the 0x1f masks from reg_writeable(), reg_volatile()
and reg_precious() methods, since setting the U1 and U0 bits of
the register address happens inside the regmap core now.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-3-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: b35f8dbbce ("serial: max310x: prevent infinite while() loop in port startup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:20 -04:00
Cosmin Tanislav
2161c5411d serial: max310x: use regmap methods for SPI batch operations
[ Upstream commit 285e76fc04 ]

The SPI batch read/write operations can be implemented as simple
regmap raw read and write, which will also try to do a gather
write just as it is done here.

Use the regmap raw read and write methods.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-2-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: b35f8dbbce ("serial: max310x: prevent infinite while() loop in port startup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:20 -04:00
Ilpo Järvinen
3517b6d614 serial: 8250: Remove serial_rs485 sanitization from em485
[ Upstream commit 84f2faa785 ]

Serial core handles serial_rs485 sanitization.

When em485 init fails, there are two possible paths of entry:

  1) uart_rs485_config (init path) that fully clears port->rs485 on
     error.

  2) ioctl path with a pre-existing, valid port->rs485 unto which the
     kernel falls back on error and port->rs485 should therefore be
     kept untouched. The temporary rs485 struct is not returned to
     userspace in case of error so its flag don't matter.

...Thus SER_RS485_ENABLED clearing on error can/should be dropped.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-37-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:21:53 +01:00
Lino Sanfilippo
f4fab74cb8 serial: amba-pl011: Fix DMA transmission in RS485 mode
commit 3b69e32e15 upstream.

When DMA is used in RS485 mode make sure that the UARTs tx section is
enabled before the DMA buffers are queued for transmission.

Cc: stable@vger.kernel.org
Fixes: 8d47923772 ("serial: amba-pl011: add RS485 support")
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20240216224709.9928-2-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:21:49 +01:00
Lino Sanfilippo
48a09969e4 serial: 8250_exar: Set missing rs485_supported flag
[ Upstream commit 0c2a5f471c ]

The UART supports an auto-RTS mode in which the RTS pin is automatically
activated during transmission. So mark this mode as being supported even
if RTS is not controlled by the driver but the UART.

Also the serial core expects now at least one of both modes rts-on-send or
rts-after-send to be supported. This is since during sanitization
unsupported flags are deleted from a RS485 configuration set by userspace.
However if the configuration ends up with both flags unset, the core prints
a warning since it considers such a configuration invalid (see
uart_sanitize_serial_rs485()).

Cc:  <stable@vger.kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-8-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23 08:55:12 +01:00
Ilpo Järvinen
9ef7419bc2 serial: 8250_exar: Fill in rs485_supported
[ Upstream commit 59c221f8e1 ]

Add information on supported serial_rs485 features.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 0c2a5f471c ("serial: 8250_exar: Set missing rs485_supported flag")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23 08:55:12 +01:00
Hugo Villeneuve
72bf8760ad serial: max310x: fail probe if clock crystal is unstable
commit 8afa6c6dec upstream.

A stable clock is really required in order to use this UART, so log an
error message and bail out if the chip reports that the clock is not
stable.

Fixes: 4cf9a888fd ("serial: max310x: Check the clock readiness")
Cc: stable@vger.kernel.org
Suggested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://www.spinics.net/lists/linux-serial/msg35773.html
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240116213001.3691629-4-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:55:08 +01:00
Hugo Villeneuve
b67b421a82 serial: max310x: improve crystal stable clock detection
commit 93cd256ab2 upstream.

Some people are seeing a warning similar to this when using a crystal:

    max310x 11-006c: clock is not stable yet

The datasheet doesn't mention the maximum time to wait for the clock to be
stable when using a crystal, and it seems that the 10ms delay in the driver
is not always sufficient.

Jan Kundrát reported that it took three tries (each separated by 10ms) to
get a stable clock.

Modify behavior to check stable clock ready bit multiple times (20), and
waiting 10ms between each try.

Note: the first draft of the driver originally used a 50ms delay, without
checking the clock stable bit.
Then a loop with 1000 retries was implemented, each time reading the clock
stable bit.

Fixes: 4cf9a888fd ("serial: max310x: Check the clock readiness")
Cc: stable@vger.kernel.org
Suggested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://www.spinics.net/lists/linux-serial/msg35773.html
Link: https://lore.kernel.org/all/20240110174015.6f20195fde08e5c9e64e5675@hugovil.com/raw
Link: e5dfe3e4a7
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240116213001.3691629-3-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:55:07 +01:00
Hugo Villeneuve
2e8b2b9180 serial: max310x: set default value when reading clock ready bit
commit 0419373333 upstream.

If regmap_read() returns a non-zero value, the 'val' variable can be left
uninitialized.

Clear it before calling regmap_read() to make sure we properly detect
the clock ready bit.

Fixes: 4cf9a888fd ("serial: max310x: Check the clock readiness")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240116213001.3691629-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:55:07 +01:00
Adrian Reber
ef86cdc688 tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE
[ Upstream commit e0f25b8992 ]

The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root
users to checkpoint and restore processes as non-root with CRIU.

This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option
'--shell-job' as non-root. CRIU's man-page describes the '--shell-job'
option like this:

  Allow one to dump shell jobs. This implies the restored task will
  inherit session and process group ID from the criu itself. This option
  also allows to migrate a single external tty connection, to migrate
  applications like top.

TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and
this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE.

With this change it is possible to checkpoint and restore processes
which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is
set.

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Adrian Reber <areber@redhat.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23 08:54:51 +01:00
Christoph Niedermaier
763c67e96b serial: imx: Correct clock error message in function probe()
[ Upstream commit 3e189470ca ]

Correct the clock error message by changing the clock name.

Fixes: 1e512d4533 ("serial: imx: add error messages when .probe fails")
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231224093209.2612-1-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:52 -08:00
Oliver Neukum
013d7878c7 usb: cdc-acm: return correct error code on unsupported break
[ Upstream commit 66aad7d8d3 ]

In ACM support for sending breaks to devices is optional.
If a device says that it doenot support sending breaks,
the host must respect that.
Given the number of optional features providing tty operations
for each combination is not practical and errors need to be
returned dynamically if unsupported features are requested.

In case a device does not support break, we want the tty layer
to treat that like it treats drivers that statically cannot
support sending a break. It ignores the inability and does nothing.
This patch uses EOPNOTSUPP to indicate that.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 9e98966c7b ("tty: rework break handling")
Link: https://lore.kernel.org/r/20231207132639.18250-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:52 -08:00
Jiri Slaby (SUSE)
c50f88954c tty: use 'if' in send_break() instead of 'goto'
[ Upstream commit 24f2cd0199 ]

Now, the "jumped-over" code is simple enough to be put inside an 'if'.
Do so to make it 'goto'-less.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-16-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3 ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:51 -08:00
Jiri Slaby (SUSE)
a222bd01ca tty: don't check for signal_pending() in send_break()
[ Upstream commit fd99392b64 ]

msleep_interruptible() will check on its own. So no need to do the check
in send_break() before calling the above.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-15-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3 ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:51 -08:00
Jiri Slaby (SUSE)
370b18aefe tty: early return from send_break() on TTY_DRIVER_HARDWARE_BREAK
[ Upstream commit 66619686d1 ]

If the driver sets TTY_DRIVER_HARDWARE_BREAK, we leave ops->break_ctl()
to the driver and return from send_break(). But we do it using a local
variable and keep the code flowing through the end of the function.
Instead, do 'return' immediately with the ops->break_ctl()'s return
value.

This way, we don't have to stuff the 'else' branch of the 'if' with the
software break handling. And we can re-indent the function too.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3 ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:51 -08:00
Jiri Slaby (SUSE)
6f98751fa4 tty: change tty_write_lock()'s ndelay parameter to bool
[ Upstream commit af81533655 ]

It's a yes-no parameter, so convert it to bool to be obvious.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3 ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:51 -08:00
Paul Geurts
ff168d4fdb serial: imx: fix tx statemachine deadlock
[ Upstream commit 78d60dae9a ]

When using the serial port as RS485 port, the tx statemachine is used to
control the RTS pin to drive the RS485 transceiver TX_EN pin. When the
TTY port is closed in the middle of a transmission (for instance during
userland application crash), imx_uart_shutdown disables the interface
and disables the Transmission Complete interrupt. afer that,
imx_uart_stop_tx bails on an incomplete transmission, to be retriggered
by the TC interrupt. This interrupt is disabled and therefore the tx
statemachine never transitions out of SEND. The statemachine is in
deadlock now, and the TX_EN remains low, making the interface useless.

imx_uart_stop_tx now checks for incomplete transmission AND whether TC
interrupts are enabled before bailing to be retriggered. This makes sure
the state machine handling is reached, and is properly set to
WAIT_AFTER_SEND.

Fixes: cb1a609236 ("serial: imx: implement rts delaying for rs485")
Signed-off-by: Paul Geurts <paul_geurts@live.nl>
Tested-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Tested-by: Eberhard Stoll <eberhard.stoll@gmx.de>
Link: https://lore.kernel.org/r/AM0PR09MB26758F651BC1B742EB45775995B8A@AM0PR09MB2675.eurprd09.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:51 -08:00
Uwe Kleine-König
828cd82948 serial: 8250: omap: Don't skip resource freeing if pm_runtime_resume_and_get() failed
[ Upstream commit ad90d0358b ]

Returning an error code from .remove() makes the driver core emit the
little helpful error message:

	remove callback returned a non-zero value. This will be ignored.

and then remove the device anyhow. So all resources that were not freed
are leaked in this case. Skipping serial8250_unregister_port() has the
potential to keep enough of the UART around to trigger a use-after-free.

So replace the error return (and with it the little helpful error
message) by a more useful error message and continue to cleanup.

Fixes: e3f0c638f4 ("serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231110152927.70601-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 14:52:50 -08:00
Hugo Villeneuve
fc7c3be665 serial: sc16is7xx: set safe default SPI clock frequency
commit 3ef79cd141 upstream.

15 MHz is supported only by 76x variants.

If the SPI clock frequency is not specified, use a safe default clock value
of 4 MHz that is supported by all variants.

Also use HZ_PER_MHZ macro to improve readability.

Fixes: 2c837a8a8f ("sc16is7xx: spi interface is added")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231221231823.2327894-4-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25 14:52:49 -08:00
Hugo Villeneuve
160ef3fc35 serial: sc16is7xx: add check for unsupported SPI modes during probe
commit 6d710b769c upstream.

The original comment is confusing because it implies that variants other
than the SC16IS762 supports other SPI modes beside SPI_MODE_0.

Extract from datasheet:
    The SC16IS762 differs from the SC16IS752 in that it supports SPI clock
    speeds up to 15 Mbit/s instead of the 4 Mbit/s supported by the
    SC16IS752... In all other aspects, the SC16IS762 is functionally and
    electrically the same as the SC16IS752.

The same is also true of the SC16IS760 variant versus the SC16IS740 and
SC16IS750 variants.

For all variants, only SPI mode 0 is supported.

Change comment and abort probing if the specified SPI mode is not
SPI_MODE_0.

Fixes: 2c837a8a8f ("sc16is7xx: spi interface is added")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231221231823.2327894-3-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25 14:52:49 -08:00
Christoph Niedermaier
314cf7c2dd serial: imx: Ensure that imx_uart_rs485_config() is called with enabled clock
commit 7c45eaa813 upstream.

There are register accesses in the function imx_uart_rs485_config(). The
clock must be enabled for these accesses. This was ensured by calling it
via the function uart_rs485_config() in the probe() function within the
range where the clock is enabled. With the commit 7c7f9bc986 ("serial:
Deassert Transmit Enable on probe in driver-specific way") it was removed
from the probe() function and is now only called through the function
uart_add_one_port() which is located at the end of the probe() function.
But the clock is already switched off in this area. To ensure that the
clock is enabled during register access, move the disabling of the clock
to the very end of the probe() function. To avoid leaking enabled clocks
on error also add an error path for exiting with disabling the clock.

Fixes: 7c7f9bc986 ("serial: Deassert Transmit Enable on probe in driver-specific way")
Cc: stable <stable@kernel.org>
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20231226113647.39376-1-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25 14:52:47 -08:00
Ronald Wahl
e5731380b7 serial: 8250_omap: Add earlycon support for the AM654 UART controller
commit 8e42c301ce upstream.

Currently there is no support for earlycon on the AM654 UART
controller. This commit adds it.

Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20231031131242.15516-1-rwahl@gmx.de
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:36:49 +01:00
Ronald Wahl
17c2ed9a99 serial: 8250: 8250_omap: Do not start RX DMA on THRI interrupt
commit c6bb057418 upstream.

Starting RX DMA on THRI interrupt is too early because TX may not have
finished yet.

This change is inspired by commit 90b8596ac4 ("serial: 8250: Prevent
starting up DMA Rx on THRI interrupt") and fixes DMA issues I had with
an AM62 SoC that is using the 8250 OMAP variant.

Cc: stable@vger.kernel.org
Fixes: c26389f998 ("serial: 8250: 8250_omap: Add DMA support for UARTs on K3 SoCs")
Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20231101171431.16495-1-rwahl@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:36:49 +01:00
Ronald Wahl
8718c0ab94 serial: 8250: 8250_omap: Clear UART_HAS_RHR_IT_DIS bit
commit 8973ab7a24 upstream.

This fixes commit 439c7183e5 ("serial: 8250: 8250_omap: Disable RX
interrupt after DMA enable") which unfortunately set the
UART_HAS_RHR_IT_DIS bit in the UART_OMAP_IER2 register and never
cleared it.

Cc: stable@vger.kernel.org
Fixes: 439c7183e5 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable")
Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20231031110909.11695-1-rwahl@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:36:49 +01:00
Daniel Mack
9bf8bc456f serial: sc16is7xx: address RX timeout interrupt errata
commit 08ce9a1b72 upstream.

This device has a silicon bug that makes it report a timeout interrupt
but no data in the FIFO.

The datasheet states the following in the errata section 18.1.4:

  "If the host reads the receive FIFO at the same time as a
  time-out interrupt condition happens, the host might read 0xCC
  (time-out) in the Interrupt Indication Register (IIR), but bit 0
  of the Line Status Register (LSR) is not set (means there is no
  data in the receive FIFO)."

The errata description seems to indicate it concerns only polled mode of
operation when reading bit 0 of the LSR register. However, tests have
shown and NXP has confirmed that the RXLVL register also yields 0 when
the bug is triggered, and hence the IRQ driven implementation in this
driver is equally affected.

This bug has hit us on production units and when it does, sc16is7xx_irq()
would spin forever because sc16is7xx_port_irq() keeps seeing an
interrupt in the IIR register that is not cleared because the driver
does not call into sc16is7xx_handle_rx() unless the RXLVL register
reports at least one byte in the FIFO.

Fix this by always reading one byte from the FIFO when this condition
is detected in order to clear the interrupt. This approach was
confirmed to be correct by NXP through their support channels.

Tested by: Hugo Villeneuve <hvilleneuve@dimonoff.com>

Signed-off-by: Daniel Mack <daniel@zonque.org>
Co-Developed-by: Maxim Popov <maxim.snafu@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231123072818.1394539-1-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:36:49 +01:00
Arnd Bergmann
87ac270412 ARM: PL011: Fix DMA support
commit 58ac1b3799 upstream.

Since there is no guarantee that the memory returned by
dma_alloc_coherent() is associated with a 'struct page', using the
architecture specific phys_to_page() is wrong, but using
virt_to_page() would be as well.

Stop using sg lists altogether and just use the *_single() functions
instead. This also simplifies the code a bit since the scatterlists in
this driver always have only one entry anyway.

https://lore.kernel.org/lkml/86db0fe5-930d-4cbb-bd7d-03367da38951@app.fastmail.com/
    Use consistent names for dma buffers

gc: Add a commit log from the initial thread:
https://lore.kernel.org/lkml/86db0fe5-930d-4cbb-bd7d-03367da38951@app.fastmail.com/
    Use consistent names for dma buffers

Fixes: cb06ff102e ("ARM: PL011: Add support for Rx DMA buffer polling.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20231122171503.235649-1-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13 18:36:48 +01:00
Pavel Krasavin
0c49e74e95 tty: serial: meson: fix hard LOCKUP on crtscts mode
[ Upstream commit 2a1d728f20 ]

There might be hard lockup if we set crtscts mode on port without RTS/CTS configured:

# stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6
[   95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[   95.890857] rcu:     3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984
[   95.900212] rcu:     (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4)
[   95.906972] Task dump for CPU 3:
[   95.910178] task:bash            state:R  running task     stack:0     pid:205   ppid:1      flags:0x00000202
[   95.920059] Call trace:
[   95.922485]  __switch_to+0xe4/0x168
[   95.925951]  0xffffff8003477508
[   95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3
[   95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc

Possible solution would be to not allow to setup crtscts on such port.

Tested on S905X3 based board.

Fixes: ff7693d079 ("ARM: meson: serial: add MesonX SoC on-chip uart driver")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Dmitry Rokosov <ddrokosov@salutedevices.com>

v6: stable tag added
v5: https://lore.kernel.org/lkml/OF43DA36FF.2BD3BB21-ON00258A47.005A8125-00258A47.005A9513@gdc.ru/
added missed Reviewed-by tags, Fixes tag added according to Dmitry and Neil notes
v4: https://lore.kernel.org/lkml/OF55521400.7512350F-ON00258A47.003F7254-00258A47.0040E15C@gdc.ru/
More correct patch subject according to Jiri's note
v3: https://lore.kernel.org/lkml/OF6CF5FFA0.CCFD0E8E-ON00258A46.00549EDF-00258A46.0054BB62@gdc.ru/
"From:" line added to the mail
v2: https://lore.kernel.org/lkml/OF950BEF72.7F425944-ON00258A46.00488A76-00258A46.00497D44@gdc.ru/
braces for single statement removed according to Dmitry's note
v1: https://lore.kernel.org/lkml/OF28B2B8C9.5BC0CD28-ON00258A46.0037688F-00258A46.0039155B@gdc.ru/
Link: https://lore.kernel.org/r/OF66360032.51C36182-ON00258A48.003F656B-00258A48.0040092C@gdc.ru

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:56:32 +00:00
Lad Prabhakar
6f26b6a61b serial: meson: Use platform_get_irq() to get the interrupt
[ Upstream commit 5b68061983 ]

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-5-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 2a1d728f20 ("tty: serial: meson: fix hard LOCKUP on crtscts mode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:56:32 +00:00
David Woodhouse
01975bee0a hvc/xen: fix event channel handling for secondary consoles
commit ef5dd8ec88 upstream.

The xencons_connect_backend() function allocates a local interdomain
event channel with xenbus_alloc_evtchn(), then calls
bind_interdomain_evtchn_to_irq_lateeoi() to bind to that port# on the
*remote* domain.

That doesn't work very well:

(qemu) device_add xen-console,id=con1,chardev=pty0
[   44.323872] xenconsole console-1: 2 xenbus_dev_probe on device/console/1
[   44.323995] xenconsole: probe of console-1 failed with error -2

Fix it to use bind_evtchn_to_irq_lateeoi(), which does the right thing
by just binding that *local* event channel to an irq. The backend will
do the interdomain binding.

This didn't affect the primary console because the setup for that is
special — the toolstack allocates the guest event channel and the guest
discovers it with HVMOP_get_param.

Fixes: fe415186b4 ("xen/console: harden hvc_xen against event channel storms")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-2-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:56:28 +00:00
David Woodhouse
cfd543c108 hvc/xen: fix error path in xen_hvc_init() to always register frontend driver
commit 2704c9a559 upstream.

The xen_hvc_init() function should always register the frontend driver,
even when there's no primary console — as there may be secondary consoles.
(Qemu can always add secondary consoles, but only the toolstack can add
the primary because it's special.)

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-3-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:56:28 +00:00
David Woodhouse
730e08cb91 hvc/xen: fix console unplug
commit a30badfd7c upstream.

On unplug of a Xen console, xencons_disconnect_backend() unconditionally
calls free_irq() via unbind_from_irqhandler(), causing a warning of
freeing an already-free IRQ:

(qemu) device_del con1
[   32.050919] ------------[ cut here ]------------
[   32.050942] Trying to free already-free IRQ 33
[   32.050990] WARNING: CPU: 0 PID: 51 at kernel/irq/manage.c:1895 __free_irq+0x1d4/0x330

It should be using evtchn_put() to tear down the event channel binding,
and let the Linux IRQ side of it be handled by notifier_del_irq() through
the HVC code.

On which topic... xencons_disconnect_backend() should call hvc_remove()
*first*, rather than tearing down the event channel and grant mapping
while they are in use. And then the IRQ is guaranteed to be freed by
the time it's torn down by evtchn_put().

Since evtchn_put() also closes the actual event channel, avoid calling
xenbus_free_evtchn() except in the failure path where the IRQ was not
successfully set up.

However, calling hvc_remove() at the start of xencons_disconnect_backend()
still isn't early enough. An unplug request is indicated by the backend
setting its state to XenbusStateClosing, which triggers a notification
to xencons_backend_changed(), which... does nothing except set its own
frontend state directly to XenbusStateClosed without *actually* tearing
down the HVC device or, you know, making sure it isn't actively in use.

So the backend sees the guest frontend set its state to XenbusStateClosed
and stops servicing the interrupt... and the guest spins for ever in the
domU_write_console() function waiting for the ring to drain.

Fix that one by calling hvc_remove() from xencons_backend_changed() before
signalling to the backend that it's OK to proceed with the removal.

Tested with 'dd if=/dev/zero of=/dev/hvc1' while telling Qemu to remove
the console device.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-4-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:56:27 +00:00
Muhammad Usama Anjum
fa0b93a3de tty/sysrq: replace smp_processor_id() with get_cpu()
commit dd976a97d1 upstream.

The smp_processor_id() shouldn't be called from preemptible code.
Instead use get_cpu() and put_cpu() which disables preemption in
addition to getting the processor id. Enable preemption back after
calling schedule_work() to make sure that the work gets scheduled on all
cores other than the current core. We want to avoid a scenario where
current core's stack trace is printed multiple times and one core's
stack trace isn't printed because of scheduling of current task.

This fixes the following bug:

[  119.143590] sysrq: Show backtrace of all active CPUs
[  119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873
[  119.144586] caller is debug_smp_processor_id+0x20/0x30
[  119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3
[  119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023
[  119.145053] Call trace:
[  119.145093]  dump_backtrace+0x0/0x1a0
[  119.145122]  show_stack+0x18/0x70
[  119.145141]  dump_stack+0xc4/0x11c
[  119.145159]  check_preemption_disabled+0x100/0x110
[  119.145175]  debug_smp_processor_id+0x20/0x30
[  119.145195]  sysrq_handle_showallcpus+0x20/0xc0
[  119.145211]  __handle_sysrq+0x8c/0x1a0
[  119.145227]  write_sysrq_trigger+0x94/0x12c
[  119.145247]  proc_reg_write+0xa8/0xe4
[  119.145266]  vfs_write+0xec/0x280
[  119.145282]  ksys_write+0x6c/0x100
[  119.145298]  __arm64_sys_write+0x20/0x30
[  119.145315]  el0_svc_common.constprop.0+0x78/0x1e4
[  119.145332]  do_el0_svc+0x24/0x8c
[  119.145348]  el0_svc+0x10/0x20
[  119.145364]  el0_sync_handler+0x134/0x140
[  119.145381]  el0_sync+0x180/0x1c0

Cc: jirislaby@kernel.org
Cc: stable@vger.kernel.org
Fixes: 47cab6a722 ("debug lockups: Improve lockup detection, fix generic arch fallback")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20231009162021.3607632-1-usama.anjum@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:56:27 +00:00
Yi Yang
6c80f48912 tty: vcc: Add check for kstrdup() in vcc_probe()
[ Upstream commit d81ffb87aa ]

Add check for the return value of kstrdup() and return the error, if it
fails in order to avoid NULL pointer dereference.

Signed-off-by: Yi Yang <yiyang13@huawei.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230904035220.48164-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:56:19 +00:00
Yi Yang
b77f7c025e tty: tty_jobctrl: fix pid memleak in disassociate_ctty()
[ Upstream commit 11e7f27b79 ]

There is a pid leakage:
------------------------------
unreferenced object 0xffff88810c181940 (size 224):
  comm "sshd", pid 8191, jiffies 4294946950 (age 524.570s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de  .............N..
    ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff  ....kkkk........
  backtrace:
    [<ffffffff814774e6>] kmem_cache_alloc+0x5c6/0x9b0
    [<ffffffff81177342>] alloc_pid+0x72/0x570
    [<ffffffff81140ac4>] copy_process+0x1374/0x2470
    [<ffffffff81141d77>] kernel_clone+0xb7/0x900
    [<ffffffff81142645>] __se_sys_clone+0x85/0xb0
    [<ffffffff8114269b>] __x64_sys_clone+0x2b/0x30
    [<ffffffff83965a72>] do_syscall_64+0x32/0x80
    [<ffffffff83a00085>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

It turns out that there is a race condition between disassociate_ctty() and
tty_signal_session_leader(), which caused this leakage.

The pid memleak is triggered by the following race:
task[sshd]                     task[bash]
-----------------------        -----------------------
                               disassociate_ctty();
                               spin_lock_irq(&current->sighand->siglock);
                               put_pid(current->signal->tty_old_pgrp);
                               current->signal->tty_old_pgrp = NULL;
                               tty = tty_kref_get(current->signal->tty);
                               spin_unlock_irq(&current->sighand->siglock);
tty_vhangup();
tty_lock(tty);
...
tty_signal_session_leader();
spin_lock_irq(&p->sighand->siglock);
...
if (tty->ctrl.pgrp) //tty->ctrl.pgrp is not NULL
p->signal->tty_old_pgrp = get_pid(tty->ctrl.pgrp); //An extra get
spin_unlock_irq(&p->sighand->siglock);
...
tty_unlock(tty);
                               if (tty) {
                                   tty_lock(tty);
                                   ...
                                   put_pid(tty->ctrl.pgrp);
                                   tty->ctrl.pgrp = NULL; //It's too late
                                   ...
                                   tty_unlock(tty);
                               }

The issue is believed to be introduced by commit c8bcd9c5be ("tty:
Fix ->session locking") who moves the unlock of siglock in
disassociate_ctty() above "if (tty)", making a small window allowing
tty_signal_session_leader() to kick in. It can be easily reproduced by
adding a delay before "if (tty)" and at the entrance of
tty_signal_session_leader().

To fix this issue, we move "put_pid(current->signal->tty_old_pgrp)" after
"tty->ctrl.pgrp = NULL".

Fixes: c8bcd9c5be ("tty: Fix ->session locking")
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Co-developed-by: GUO Zihua <guozihua@huawei.com>
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Link: https://lore.kernel.org/r/20230831023329.165737-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:08:25 +01:00
Cameron Williams
28b8ad8cce tty: 8250: Add Brainboxes Oxford Semiconductor-based quirks
commit e4876dacac upstream.

Some of the later revisions of the Brainboxes PX cards are based
on the Oxford Semiconductor chipset. Due to the chip's unique setup
these cards need to be initialised.
Previously these were tested against a reference card with the same broken
baudrate on another PC, cancelling out the effect. With this patch they
work and can transfer/receive find against an FTDI-based device.

Add all of the cards which require this setup to the quirks table.
Thanks to Maciej W. Rozycki for clarification on this chip.

Fixes: ef5a03a26c ("tty: 8250: Add support for Brainboxes PX cards.")
Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB7899D222A4AB2A4E8C57108FC4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08 17:26:51 +01:00
Cameron Williams
44c4dfac3f tty: 8250: Add support for Intashield IX cards
commit 62d2ec2ded upstream.

Add support for the IX-100, IX-200 and IX-400 serial cards.

Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB7899614E5837E82A03272A4BC4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08 17:26:51 +01:00
Cameron Williams
d541ccb34d tty: 8250: Add support for additional Brainboxes PX cards
commit 9604884e59 upstream.

Add support for some more of the Brainboxes PX (PCIe) range
of serial cards, namely
PX-275/PX-279, PX-475 (serial port, not LPT), PX-820,
PX-803/PX-857 (additional ID).

Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB78996BEC353FB346FC35444BC4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08 17:26:51 +01:00
Cameron Williams
60debc01fc tty: 8250: Fix up PX-803/PX-857
commit ee61337b93 upstream.

The PX-803/PX-857 are variants of each other, add a note.
Additionally fix up the port counts for the card (2, not 1).

Fixes: ef5a03a26c ("tty: 8250: Add support for Brainboxes PX cards.")
Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB789978C8ED872FB4B014E132C4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08 17:26:51 +01:00