6957 Commits

Author SHA1 Message Date
Johan Hovold
493a275c04 serial: owl: drop low-latency workaround
The owl driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
been removed years before the driver was added by commit fc60a8b675bd
("tty: serial: owl: Implement console driver").

Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-18-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
c0a6c9f79e serial: msm_serial: drop low-latency workaround
Commit f77232dab25b ("tty: serial: msm: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-17-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
6e560913aa serial: mpc52xx_uart: drop low-latency workaround
Commit fbe543b412ce ("Fix a potential issue in mpc52xx uart driver")
worked around the infamous low_latency behaviour of
tty_flip_buffer_push() by simply dropping and reacquiring the port lock
in the interrupt handler.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-16-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
b8555963ca serial: meson: drop low-latency workaround
The meson driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
already been removed by the time the driver was added by commit
ff7693d079e5 ("ARM: meson: serial: add MesonX SoC on-chip uart driver").

Specifically, since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-15-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
5d148754da serial: mcf: drop low-latency workaround
Commit 5275ad70fed3 ("tty: serial: mcf: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-14-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
46a2675e8f serial: lpc32xx_hs: drop low-latency workaround
Commit ec128510905c ("tty: serial: lpc32xx_hs: drop uart_port->lock
before calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-13-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
4eec66e4b2 serial: icom: drop low-latency workaround
Commit 5faf75d7fed2 ("tty: serial: icom: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-12-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
acf4843631 serial: bcm63xx: drop low-latency workaround
Commit b4d499241c34 ("tty: serial: bcm63xx: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-11-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
983fe58ad7 serial: atmel_serial: drop low-latency workaround
Commit 1ecc26bd2789 ("atmel_serial: split the interrupt handler") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
dropping and reacquiring the port lock in the tasklet callback.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-10-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
e9af7e363a serial: arc_uart: drop low-latency workaround
Commit 3fa1200851c7 ("tty: serial: arc: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
80d43febac serial: ar933x: drop low-latency workaround
Commit b16c8e3eed12 ("tty: serial: ar933x: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
d0aa2820b9 serial: apbuart: drop low-latency workaround
Commit 78d34d75c84d ("tty: serial: apbuart: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-7-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
02d5364007 serial: amba-pl011: drop low-latency workaround
Commit ead76f329f77 ("ARM: 6763/1: pl011: add optional RX DMA to PL011
v2") added RX DMA support and also reproduced the workaround for the
infamous low_latency behaviour of tty_flip_buffer_push() by dropping and
reacquiring the port lock during receive processing.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Note that the port lock is also dropped in the PIO path
(see pl011_rx_chars), but it is not clear whether this is still needed
by the DMA code added by the aforementioned commit.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
173d37fc59 serial: amba-pl010: drop low-latency workaround
Commit 2389b272168c ("[ARM] 4417/1: Serial: Fix AMBA drivers locking")
worked around the infamous low_latency behaviour of
tty_flip_buffer_push() by simply dropping and reacquiring the port lock
in the interrupt handler.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
d26595d188 serial: altera_uart: drop low-latency workaround
Commit dd085ed8ef6c ("tty: serial: altera: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
f22dd43fc1 serial: altera_jtaguart: drop low-latency workaround
Commit 53dd0ba7a6f4 ("tty: serial: altera_jtag: drop uart_port->lock
before calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
02ca144fa4 tty: mxser: drop low-latency workaround
Commit 67d2bc58afdd ("Char: mxser_new, fix recursive locking") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
simply dropping and reacquiring the port lock in the interrupt handler.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Link: https://lore.kernel.org/lkml/3018694794025219@wsc.cz/T/#m06b04c640a7b6f41afb3d34a4cf29b1df4935d3a
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Dario Binacchi
e2a5e8448e serial: omap: fix rs485 half-duplex filtering
Data received during half-duplex transmission must be filtered.
If the target device responds quickly, emptying the FIFO at the end of
the transmission can erase not only the echo characters but also part of
the response message.
By keeping the receive interrupt enabled even during transmission, it
allows you to filter each echo character and only in a number equal to
those transmitted.
The issue was generated by a target device that started responding
240us later having received a request in communication at 115200bps.
Sometimes, some messages received by the target were missing some of the
first bytes.

Fixes: 3a13884abea0 ("tty/serial: omap: empty the RX FIFO at the end of half-duplex TX")
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Link: https://lore.kernel.org/r/20210418094705.27014-1-dariobin@libero.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:07:07 +02:00
Dario Binacchi
45f6b6db53 serial: omap: don't disable rs485 if rts gpio is missing
There are rs485 transceivers (e.g. MAX13487E/MAX13488E) which
automatically disable or enable the driver and receiver to keep the bus
in the correct state.
In these cases we don't need a GPIO for flow control.

Fixes: 4a0ac0f55b18 ("OMAP: add RS485 support")
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Link: https://lore.kernel.org/r/20210415210945.25863-1-dariobin@libero.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:06:59 +02:00
Johan Hovold
cea37afd28 serial: stm32: defer sysrq processing
Use the uart_unlock_and_check_sysrq() helper to defer sysrq processing
until receive processing is done and the port lock has been released.

This allows cleaning up the console_write() implementation by not having
to work around the recursive sysrq case (by dropping locking completely)
and also makes the console code work with PREEMPT_RT by no longer
relying on local_irq_save().

Reviewed-by: Valentin Caron<valentin.caron@foss.st.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Johan Hovold
e359b4411c serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.

Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.

Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.

Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.

Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable@vger.kernel.org      # 4.9
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Cc: Gerald Baeza <gerald.baeza@st.com>
Reviewed-by: Valentin Caron<valentin.caron@foss.st.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Johan Hovold
75f4e830fa serial: do not restore interrupt state in sysrq helper
The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.

Since commit 81e2073c175b ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.

Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.

Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Colin Ian King
86eb032675 tty: synclink_gt: remove redundant initialization of variable count
The variable count is being initialized with a value that is
never read and it is being updated later with a new value.  The
initialization is redundant and can be removed.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210420105718.377086-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:01:59 +02:00
Ulrich Hecht
f9f5498300 serial: sh-sci: remove obsolete latency workaround
Since the transition to hrtimers there is no more need to set a minimum
RX timeout to work around latency issues.

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/20210415093547.21639-1-uli+renesas@fpond.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 12:59:16 +02:00
Greg Kroah-Hartman
5ffa6e344a tty: clean include/linux/tty.h up
There are a lot of tty-core-only functions that are listed in
include/linux/tty.h.  Move them to drivers/tty/tty.h so that no one else
can accidentally call them or think that they are public functions.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:32:17 +02:00
Greg Kroah-Hartman
9f72cab159 tty: move some tty-only functions to drivers/tty/tty.h
The flow change and restricted_tty_write() logic is internal to the tty
core only, so move it out of the include/linux/tty.h file.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:30:18 +02:00
Greg Kroah-Hartman
dd9f611442 tty: make tty_release_redirect() static
No one calls this outside of the tty_io.c file, so mark this static and
do not export the symbol anymore.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-11-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:28:30 +02:00
Greg Kroah-Hartman
6c80c0b94b tty: move some internal tty lock enums and functions out of tty.h
Move the TTY_LOCK_* enums and tty_ldisc lock functions out of the global
tty.h into the local header file to clean things up.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:26:58 +02:00
Greg Kroah-Hartman
da5d669e00 tty: audit: move some local functions out of tty.h
The functions tty_audit_add_data() and tty_audit_tiocsti() are local to
the tty core code, and do not need to be in a "kernel-wide" header file
so move them to drivers/tty/tty.h

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-9-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:24:58 +02:00
Greg Kroah-Hartman
4d5a64cbc7 tty: tty.h: remove tty_info()
No one is calling this macro, and no one should, so remove it from the
.h file.

Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:23:08 +02:00
Greg Kroah-Hartman
98602c010c tty: create internal tty.h file
There are a number of functions and #defines in include/linux/tty.h that
do not belong there as they are private to the tty core code.

Create an initial drivers/tty/tty.h file and copy the odd "tty logging"
macros into it to seed the file with some initial things that we know
nothing outside of the tty core should be calling.

Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:22:17 +02:00
Hillf Danton
0a360e8b65 tty: n_gsm: check error while registering tty devices
Add the error path for registering tty devices and roll back in case of error
in bid to avoid the UAF like the below one reported.

Plus syzbot reported general protection fault in cdev_del() on Sep 24, 2020
and both cases are down to the kobject_put() in tty_cdev_add().

 ------------[ cut here ]------------
 refcount_t: underflow; use-after-free.
 WARNING: CPU: 1 PID: 8923 at lib/refcount.c:28
 refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28
 Modules linked in:
 CPU: 1 PID: 8923 Comm: executor Not tainted 5.12.0-rc5+ #8
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
 1.13.0-1ubuntu1.1 04/01/2014
 RIP: 0010:refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28
 Code: 4f ff ff ff e8 32 fa b5 fe 48 c7 c7 3d f8 f6 86 e8 d6 ab c6 fe
 c6 05 7c 34 67 04 01 48 c7 c7 68 f8 6d 86 31 c0 e8 81 2e 9d fe <0f> 0b
 e9 22 ff ff ff e8 05 fa b5 fe 48 c7 c7 3e f8 f6 86 e8 a9 ab
 RSP: 0018:ffffc90001633c60 EFLAGS: 00010246
 RAX: 15d08b2e34b77800 RBX: 0000000000000003 RCX: ffff88804c056c80
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: 0000000000000003 R08: ffffffff813767aa R09: 0001ffffffffffff
 R10: 0001ffffffffffff R11: ffff88804c056c80 R12: ffff888040b7d000
 R13: ffff88804c206938 R14: ffff88804c206900 R15: ffff888041b18488
 FS:  00000000022c9940(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f9f9b122008 CR3: 0000000044b4b000 CR4: 0000000000750ee0
 PKRU: 55555554
 Call Trace:
  __refcount_sub_and_test -origin/./include/linux/refcount.h:283 [inline]
  __refcount_dec_and_test -origin/./include/linux/refcount.h:315 [inline]
  refcount_dec_and_test -origin/./include/linux/refcount.h:333 [inline]
  kref_put -origin/./include/linux/kref.h:64 [inline]
  kobject_put+0x17b/0x180 -origin/lib/kobject.c:753
  cdev_del+0x4b/0x50 -origin/fs/char_dev.c:597
  tty_unregister_device+0x99/0xd0 -origin/drivers/tty/tty_io.c:3343
  gsmld_detach_gsm -origin/drivers/tty/n_gsm.c:2409 [inline]
  gsmld_close+0x6c/0x140 -origin/drivers/tty/n_gsm.c:2478
  tty_ldisc_close -origin/drivers/tty/tty_ldisc.c:488 [inline]
  tty_ldisc_kill -origin/drivers/tty/tty_ldisc.c:636 [inline]
  tty_ldisc_release+0x1b6/0x400 -origin/drivers/tty/tty_ldisc.c:809
  tty_release_struct+0x19/0xb0 -origin/drivers/tty/tty_io.c:1714
  tty_release+0x9ad/0xa00 -origin/drivers/tty/tty_io.c:1885
  __fput+0x260/0x4e0 -origin/fs/file_table.c:280
  ____fput+0x11/0x20 -origin/fs/file_table.c:313
  task_work_run+0x8e/0x110 -origin/kernel/task_work.c:140
  tracehook_notify_resume -origin/./include/linux/tracehook.h:189 [inline]
  exit_to_user_mode_loop -origin/kernel/entry/common.c:174 [inline]
  exit_to_user_mode_prepare+0x16b/0x1a0 -origin/kernel/entry/common.c:208
  __syscall_exit_to_user_mode_work -origin/kernel/entry/common.c:290 [inline]
  syscall_exit_to_user_mode+0x20/0x40 -origin/kernel/entry/common.c:301
  do_syscall_64+0x45/0x80 -origin/arch/x86/entry/common.c:56
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: syzbot+c49fe6089f295a05e6f8@syzkaller.appspotmail.com
Reported-and-tested-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Link: https://lore.kernel.org/r/20210412035758.1974-1-hdanton@sina.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:19:30 +02:00
Zev Weiss
ca03042f0f serial: 8250_aspeed_vuart: add aspeed, lpc-io-reg and aspeed, lpc-interrupts DT properties
These allow describing all the Aspeed VUART attributes currently
available via sysfs.  aspeed,lpc-interrupts provides a replacement for
the deprecated aspeed,sirq-polarity-sense property.

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-4-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:18:35 +02:00
Zev Weiss
3b44af4f9f serial: 8250_aspeed_vuart: refactor sirq and lpc address setting code
This splits dedicated aspeed_vuart_set_{sirq,lpc_address}() functions
out of the sysfs store functions in preparation for adding DT
properties that will be poking the same registers.  While we're at it,
these functions now provide some basic bounds-checking on their
arguments.

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-3-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:18:35 +02:00
Yu Kuai
63bbdb4ea0 tty: hvc: make symbol 'hvc_udbg_dev' static
The sparse tool complains as follows:

drivers/tty/hvc/hvc_udbg.c:20:19: warning:
 symbol 'hvc_udbg_dev' was not declared. Should it be static?

This symbol is not used outside of hvc_udbg.c, so this
commit marks it static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210407125826.4139130-1-yukuai3@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:41:40 +02:00
Bixuan Cui
9e5313acad serial: Add missing MODULE_DEVICE_TABLE
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Link: https://lore.kernel.org/r/20210410035048.11466-1-cuibixuan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:37:27 +02:00
Johan Hovold
79c5966cec serial: core: return early on unsupported ioctls
Drivers can return -ENOIOCTLCMD when an ioctl is not recognised to tell
the upper layers to continue looking for a handler.

This is not the case for the RS485 and ISO7816 ioctls whose handlers
should return -ENOTTY directly in case a serial driver does not
implement the corresponding methods.

Fixes: a5f276f10ff7 ("serial_core: Handle TIOC[GS]RS485 ioctls.")
Fixes: ad8c0eaa0a41 ("tty/serial_core: add ISO7816 infrastructure")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
8b57b3a123 serial: core: drop redundant TIOCGSERIAL memset
Since commit 5099d234a52a ("serial_core: switch to ->[sg]et_serial()")
the serial structure passed to uart_get_info() has already have been
cleared by the tty layer so drop the redundant memset.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
885c77d528 tty: refactor TIOCSSERIAL handling
Factor out the deprecated serial flags handling and tty-operation check
shared with the compat TIOCSSERIAL handler.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
1b7bc6b10a tty: use pr_warn_ratelimited() for deprecated serial flags
Use pr_warn_ratelimited() when warning about deprecated serial flags
instead of open coding.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
8871de06ff tty: fix return value for unsupported termiox ioctls
Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Support for termiox was added by commit 1d65b4a088de ("tty: Add
termiox") in 2008 but no driver support ever followed and it was
recently ripped out by commit e0efb3168d34 ("tty: Remove dead termiox
code").

Fix the return value for the unsupported termiox ioctls, which have
always returned -EINVAL, by explicitly returning -ENOTTY rather than
removing them completely and falling back to the default unrecognised-
ioctl handling.

Fixes: 1d65b4a088de ("tty: Add termiox")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
1b8b20868a tty: fix return value for unsupported ioctls
Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned
-EINVAL when a tty driver did not implement the corresponding
operations.

Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a
corresponding Fixes tag below.

Fixes: d281da7ff6f7 ("tty: Make tiocgicount a handler")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Xiaofei Tan
b895854618 tty: tty_ldisc: Remove the repeated word 'the'
Remove the repeated word 'the' following advice of checkpatch.pl

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-11-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
408795b025 tty: tty_ldisc: Do not use assignment in if condition
Do not use assignment in if condition following the advice of
checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-10-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
72a8dcd7bb tty: tty_ldisc: Fix coding style issues of block comments
Fix coding style issues of block comments, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-9-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
d72383591d tty: tty_ldisc: Add a blank line after declarations
Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-8-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
5d3945e84b tty: tty_ldisc: Fix an issue of code indent should use tabs
Fix an issue of code indent should use tabs, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-7-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
96d508259c tty: tty_jobctrl: Remove spaces before tabs
Remove spaces before tabs following the advice of checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-6-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
63eeafd439 tty: tty_jobctrl: Fix coding style issues of block comments
Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, do some expression optimization for the sentenses.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-5-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00
Xiaofei Tan
d4e1d903a3 tty: tty_jobctrl: Add a blank line after declarations
Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-4-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:33:00 +02:00