startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
The register is also accessed from write() callback.
If console were printing and startup()/shutdown() callback
gets called, its access to the register could be overwritten.
Add port->lock to startup()/shutdown() callbacks to make sure
their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
write() callback.
Fixes: 45c054d081 ("tty: serial: add driver for the SiFive UART")
Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Rule: add
Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This requirement was overeagerly loosened in commit 2f83e38a09
("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"), but as
it turns out,
(1) the logic I implemented there was inconsistent (apologies!),
(2) TIOCL_SELMOUSEREPORT might actually be a small security risk
after all, and
(3) TIOCL_SELMOUSEREPORT is only meant to be used by the mouse
daemon (GPM or Consolation), which runs as CAP_SYS_ADMIN
already.
In more detail:
1. The previous patch has inconsistent logic:
In commit 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes
without CAP_SYS_ADMIN"), we checked for sel_mode ==
TIOCL_SELMOUSEREPORT, but overlooked that the lower four bits of
this "mode" parameter were actually used as an additional way to
pass an argument. So the patch did actually still require
CAP_SYS_ADMIN, if any of the mouse button bits are set, but did not
require it if none of the mouse buttons bits are set.
This logic is inconsistent and was not intentional. We should have
the same policies for using TIOCL_SELMOUSEREPORT independent of the
value of the "hidden" mouse button argument.
I sent a separate documentation patch to the man page list with
more details on TIOCL_SELMOUSEREPORT:
https://lore.kernel.org/all/20250223091342.35523-2-gnoack3000@gmail.com/
2. TIOCL_SELMOUSEREPORT is indeed a potential security risk which can
let an attacker simulate "keyboard" input to command line
applications on the same terminal, like TIOCSTI and some other
TIOCLINUX "selection mode" IOCTLs.
By enabling mouse reporting on a terminal and then injecting mouse
reports through TIOCL_SELMOUSEREPORT, an attacker can simulate
mouse movements on the same terminal, similar to the TIOCSTI
keystroke injection attacks that were previously possible with
TIOCSTI and other TIOCL_SETSEL selection modes.
Many programs (including libreadline/bash) are then prone to
misinterpret these mouse reports as normal keyboard input because
they do not expect input in the X11 mouse protocol form. The
attacker does not have complete control over the escape sequence,
but they can at least control the values of two consecutive bytes
in the binary mouse reporting escape sequence.
I went into more detail on that in the discussion at
https://lore.kernel.org/all/20250221.0a947528d8f3@gnoack.org/
It is not equally trivial to simulate arbitrary keystrokes as it
was with TIOCSTI (commit 83efeeeb3d ("tty: Allow TIOCSTI to be
disabled")), but the general mechanism is there, and together with
the small number of existing legit use cases (see below), it would
be better to revert back to requiring CAP_SYS_ADMIN for
TIOCL_SELMOUSEREPORT, as it was already the case before
commit 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes without
CAP_SYS_ADMIN").
3. TIOCL_SELMOUSEREPORT is only used by the mouse daemons (GPM or
Consolation), and they are the only legit use case:
To quote console_codes(4):
The mouse tracking facility is intended to return
xterm(1)-compatible mouse status reports. Because the console
driver has no way to know the device or type of the mouse, these
reports are returned in the console input stream only when the
virtual terminal driver receives a mouse update ioctl. These
ioctls must be generated by a mouse-aware user-mode application
such as the gpm(8) daemon.
Jared Finder has also confirmed in
https://lore.kernel.org/all/491f3df9de6593df8e70dbe77614b026@finder.org/
that Emacs does not call TIOCL_SELMOUSEREPORT directly, and it
would be difficult to find good reasons for doing that, given that
it would interfere with the reports that GPM is sending.
More information on the interaction between GPM, terminals and the
kernel with additional pointers is also available in this patch:
https://lore.kernel.org/all/a773e48920aa104a65073671effbdee665c105fc.1603963593.git.tammo.block@gmail.com/
For background on who else uses TIOCL_SELMOUSEREPORT: Debian Code
search finds one page of results, the only two known callers are
the two mouse daemons GPM and Consolation. (GPM does not show up
in the search results because it uses literal numbers to refer to
TIOCLINUX-related enums. I looked through GPM by hand instead.
TIOCL_SELMOUSEREPORT is also not used from libgpm.)
https://codesearch.debian.net/search?q=TIOCL_SELMOUSEREPORT
Cc: Jared Finder <jared@finder.org>
Cc: Jann Horn <jannh@google.com>
Cc: Hanno Böck <hanno@hboeck.de>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: stable <stable@kernel.org>
Fixes: 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN")
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250411070144.3959-2-gnoack3000@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MSM UART DM controller supports different working modes, e.g. DMA or
the "single-character mode", where all reads/writes operate on a single
character rather than 4 chars (32-bit) at once. When using earlycon,
__msm_console_write() always writes 4 characters at a time, but we don't
know which mode the bootloader was using and we don't set the mode either.
This causes garbled output if the bootloader was using the single-character
mode, because only every 4th character appears in the serial console, e.g.
"[ 00oni pi 000xf0[ 00i s 5rm9(l)l s 1 1 SPMTA 7:C 5[ 00A ade k d[
00ano:ameoi .Q1B[ 00ac _idaM00080oo'"
If the bootloader was using the DMA ("DM") mode, output would likely fail
entirely. Later, when the full serial driver probes, the port is
re-initialized and output works as expected.
Fix this also for earlycon by clearing the DMEN register and
reset+re-enable the transmitter to apply the change. This ensures the
transmitter is in the expected state before writing any output.
Cc: stable <stable@kernel.org>
Fixes: 0efe729634 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Here is the big set of serial and tty driver updates for 6.15-rc1.
Include in here are the following:
- more great tty layer cleanups from Jiri. Someday this will be done,
but that's not going to be any year soon...
- kdb debug driver reverts to fix a reported issue
- lots of .dts binding updates for different devices with serial
devices
- lots of tiny updates and tweaks and a few bugfixes for different
serial drivers.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the big set of serial and tty driver updates for 6.15-rc1.
Include in here are the following:
- more great tty layer cleanups from Jiri. Someday this will be done,
but that's not going to be any year soon...
- kdb debug driver reverts to fix a reported issue
- lots of .dts binding updates for different devices with serial
devices
- lots of tiny updates and tweaks and a few bugfixes for different
serial drivers.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits)
tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning
serial: stm32: do not deassert RS485 RTS GPIO prematurely
serial: 8250: add driver for NI UARTs
dt-bindings: serial: snps-dw-apb-uart: document RZ/N1 binding without DMA
serial: icom: fix code format problems
serial: sh-sci: Save and restore more registers
tty: serial: pl011: remove incorrect of_match_ptr annotation
dt-bindings: serial: snps-dw-apb-uart: Add support for rk3562
tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register
tty: caif: removed unused function debugfs_tx()
serial: 8250_dma: terminate correct DMA in tx_dma_flush()
tty: serial: fsl_lpuart: rename register variables more specifically
tty: serial: fsl_lpuart: use port struct directly to simply code
tty: serial: fsl_lpuart: Use u32 and u8 for register variables
tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers
tty: serial: 8250: Add Brainboxes XC devices
dt-bindings: serial: fsl-lpuart: support i.MX94
tty: serial: 8250: Add some more device IDs
dt-bindings: serial: samsung: add exynos7870-uart compatible
serial: 8250_dw: Comment possible corner cases in serial_out() implementation
...
- Add sorting of mcount locations at build time
- Rework uaccess functions with C exception handling to shorten inline
assembly size and enable full inlining. This yields near-optimal code
for small constant copies with a ~40kb kernel size increase
- Add support for a configurable STRICT_MM_TYPECHECKS which allows to
generate better code, but also allows to have type checking for
debug builds
- Optimize get_lowcore() for common callers with alternatives that
nearly revert to the pre-relocated lowcore code, while also slightly
reducing syscall entry and exit time
- Convert MACHINE_HAS_* checks for single facility tests into cpu_has_*
style macros that call test_facility(), and for features with additional
conditions, add a new ALT_TYPE_FEATURE alternative to provide a static
branch via alternative patching. Also, move machine feature detection
to the decompressor for early patching and add debugging functionality
to easily show which alternatives are patched
- Add exception table support to early boot / startup code to get rid
of the open coded exception handling
- Use asm_inline for all inline assemblies with EX_TABLE or ALTERNATIVE
to ensure correct inlining and unrolling decisions
- Remove 2k page table leftovers now that s390 has been switched to
always allocate 4k page tables
- Split kfence pool into 4k mappings in arch_kfence_init_pool() and
remove the architecture-specific kfence_split_mapping()
- Use READ_ONCE_NOCHECK() in regs_get_kernel_stack_nth() to silence
spurious KASAN warnings from opportunistic ftrace argument tracing
- Force __atomic_add_const() variants on s390 to always return void,
ensuring compile errors for improper usage
- Remove s390's ioremap_wt() and pgprot_writethrough() due to mismatched
semantics and lack of known users, relying on asm-generic fallbacks
- Signal eventfd in vfio-ap to notify userspace when the guest AP
configuration changes, including during mdev removal
- Convert mdev_types from an array to a pointer in vfio-ccw and vfio-ap
drivers to avoid fake flex array confusion
- Cleanup trap code
- Remove references to the outdated linux390@de.ibm.com address
- Other various small fixes and improvements all over the code
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Merge tag 's390-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Add sorting of mcount locations at build time
- Rework uaccess functions with C exception handling to shorten inline
assembly size and enable full inlining. This yields near-optimal code
for small constant copies with a ~40kb kernel size increase
- Add support for a configurable STRICT_MM_TYPECHECKS which allows to
generate better code, but also allows to have type checking for debug
builds
- Optimize get_lowcore() for common callers with alternatives that
nearly revert to the pre-relocated lowcore code, while also slightly
reducing syscall entry and exit time
- Convert MACHINE_HAS_* checks for single facility tests into cpu_has_*
style macros that call test_facility(), and for features with
additional conditions, add a new ALT_TYPE_FEATURE alternative to
provide a static branch via alternative patching. Also, move machine
feature detection to the decompressor for early patching and add
debugging functionality to easily show which alternatives are patched
- Add exception table support to early boot / startup code to get rid
of the open coded exception handling
- Use asm_inline for all inline assemblies with EX_TABLE or ALTERNATIVE
to ensure correct inlining and unrolling decisions
- Remove 2k page table leftovers now that s390 has been switched to
always allocate 4k page tables
- Split kfence pool into 4k mappings in arch_kfence_init_pool() and
remove the architecture-specific kfence_split_mapping()
- Use READ_ONCE_NOCHECK() in regs_get_kernel_stack_nth() to silence
spurious KASAN warnings from opportunistic ftrace argument tracing
- Force __atomic_add_const() variants on s390 to always return void,
ensuring compile errors for improper usage
- Remove s390's ioremap_wt() and pgprot_writethrough() due to
mismatched semantics and lack of known users, relying on asm-generic
fallbacks
- Signal eventfd in vfio-ap to notify userspace when the guest AP
configuration changes, including during mdev removal
- Convert mdev_types from an array to a pointer in vfio-ccw and vfio-ap
drivers to avoid fake flex array confusion
- Cleanup trap code
- Remove references to the outdated linux390@de.ibm.com address
- Other various small fixes and improvements all over the code
* tag 's390-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (78 commits)
s390: Use inline qualifier for all EX_TABLE and ALTERNATIVE inline assemblies
s390/kfence: Split kfence pool into 4k mappings in arch_kfence_init_pool()
s390/ptrace: Avoid KASAN false positives in regs_get_kernel_stack_nth()
s390/boot: Ignore vmlinux.map
s390/sysctl: Remove "vm/allocate_pgste" sysctl
s390: Remove 2k vs 4k page table leftovers
s390/tlb: Use mm_has_pgste() instead of mm_alloc_pgste()
s390/lowcore: Use lghi instead llilh to clear register
s390/syscall: Merge __do_syscall() and do_syscall()
s390/spinlock: Implement SPINLOCK_LOCKVAL with inline assembly
s390/smp: Implement raw_smp_processor_id() with inline assembly
s390/current: Implement current with inline assembly
s390/lowcore: Use inline qualifier for get_lowcore() inline assembly
s390: Move s390 sysctls into their own file under arch/s390
s390/syscall: Simplify syscall_get_arguments()
s390/vfio-ap: Notify userspace that guest's AP config changed when mdev removed
s390: Remove ioremap_wt() and pgprot_writethrough()
s390/mm: Add configurable STRICT_MM_TYPECHECKS
s390/mm: Convert pgste_val() into function
s390/mm: Convert pgprot_val() into function
...
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Merge tag 'printk-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- New option "printk.debug_non_panic_cpus" allows to store printk
messages from non-panic CPUs during panic. It might be useful when
panic() fails. It is disabled by default because it increases the
chance to see the messages printed before panic() and on the
panic-CPU.
- New build option "CONFIG_NULL_TTY_DEFAULT_CONSOLE" allows to build
kernel without the virtual terminal support which prefers ttynull
over serial console.
- Do not unblank suspended consoles.
- Some code clean up.
* tag 'printk-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk/panic: Add option to allow non-panic CPUs to write to the ring buffer.
printk: Add an option to allow ttynull to be a default console device
printk: Check CON_SUSPEND when unblanking a console
printk: Rename console_start to console_resume
printk: Rename console_stop to console_suspend
printk: Rename resume_console to console_resume_all
printk: Rename suspend_console to console_suspend_all
If stm32_usart_start_tx is called with an empty xmit buffer, RTS GPIO
could be deasserted prematurely, as bytes in TX FIFO are still
transmitting.
So this patch remove rts disable when xmit buffer is empty.
Fixes: d7c7671616 ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode")
Cc: stable <stable@kernel.org>
Signed-off-by: Cheick Traore <cheick.traore@foss.st.com>
Link: https://lore.kernel.org/r/20250320152540.709091-1-cheick.traore@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The National Instruments (NI) 16550 is a 16550-like UART with larger
FIFOs and embedded RS-232/RS-485 transceiver control circuitry. This
patch adds a driver that can operate this UART, which is used for
onboard serial ports in several NI embedded controller designs.
Portions of this driver were originally written by Jaeden Amero and
Karthik Manamcheri, with extensive cleanups and refactors since by
Brenda Streiff.
Cc: Gratian Crisan <gratian.crisan@emerson.com>
Co-developed-by: Jason Smith <jason.smith@emerson.com>
Signed-off-by: Jason Smith <jason.smith@emerson.com>
Signed-off-by: Chaitanya Vadrevu <chaitanya.vadrevu@emerson.com>
Link: https://lore.kernel.org/r/a3b0df6d-1dd5-4cc4-a7e1-4ed51fb9e4cc@emerson.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix below inconsistent indenting smatch warning.
smatch warnings:
drivers/tty/serial/icom.c:1768 icom_probe() warn: inconsistent indenting
Removed that useless (void *), the code would fit on a single 100c line
Removed '{' and '}'.
Signed-off-by: Charles Han <hanchunchao@inspur.com>
Link: https://lore.kernel.org/r/20250305095120.7518-1-hanchunchao@inspur.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there
are multiple ways to configure the requested serial speed. If firmware
uses a different method than Linux, and if any debug info is printed
after the Bit Rate Register (SCBRR) is restored, but before termios is
reconfigured (which configures the alternative method), the system may
lock-up during resume.
Fix this by saving and restoring the contents of the BRG Frequency
Division (SCDL) and Clock Select (SCCKS) registers as well.
Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which
configures the sampling point, and the SCIFA/SCIFB's Serial Port Control
and Data Registers (SCPCR/SCPDR), which configure the optional control
flow signals.
After this, all registers that are not saved/restored are either:
- read-only,
- write-only,
- status registers containing flags with clear-after-set semantics,
- FIFO Data Count Trigger registers, which do not matter much for
the serial console.
Fixes: 22a6984c5b ("serial: sh-sci: Update the suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Building with W=1 shows a warning about sbsa_uart_of_match being unused when
CONFIG_OF is disabled:
drivers/tty/serial/amba-pl011.c:2945:34: error: unused variable 'sbsa_uart_of_match' [-Werror,-Wunused-const-variable]
The driver is not actually used on any machines that are built
with CONFIG_OF disabled, so using of_match_ptr() won't save any
actual memory, and it can be best removed.
The corresponding ACPI_PTR() annotation does save a few bytes on
32-bit arm since CONFIG_ACPI is not available, but for consistency
it seems better to remove both along with the __maybe_unused
annotation on the ACPI table.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250225163556.4169086-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No need to overwrite the whole UARTMODIR register before waiting the
transmit engine complete, actually our target here is only to disable
CTS flow control to avoid the dirty data in TX FIFO may block the
transmit engine complete.
Also delete the following duplicate CTS disable configuration.
Fixes: d5a2e08343 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When flushing transmit side DMA, it is the transmit channel that should
be terminated, not the receive channel.
Fixes: 9e512eaaf8 ("serial: 8250: Fix fifo underflow on flush")
Cc: stable <stable@kernel.org>
Reported-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are many fuzzy register variables in the lpuart driver, such as
temp, tmp, val, reg. Let's give these register variables more specific
names.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-4-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Most lpuart functions have the parameter struct uart_port *port, but
still use the &sport->port to get the uart_port instead of use it
directly, let's simply the code logic, directly use this struct instead
of covert it from struct sport.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use u32 and u8 rather than unsigned long or unsigned char for register
variables for clarity and consistency.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to the LPUART reference manual, TXRTSE and TXRTSPOL of MODIR
register only can be changed when the transmitter is disabled.
So disable the transmitter before changing RS485 related registers and
re-enable it after the change is done.
Fixes: 67b0183786 ("tty: serial: lpuart: Add RS485 support for 32-bit uart flavour")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250312022503.1342990-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
8250 DesignWare driver uses a few custom implementations of the serial_out().
These implementations are carefully made to avoid infinite loops. But this is
not obvious from looking at the code. Comment the possible corner cases in
the respective functions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250317094021.1201512-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
change_irq and change_port are boolean variables. Mark them as such
(instead of uint).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-32-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Return immediately from the error locations or switch-case ends. It is
therefore easier to see the flow.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-31-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is unnecessary here and makes the code harder to follow. Invert the
condition and drop the goto+label.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-30-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Use already defined 'port' for fetching start/offset, and size.
* Return from the switch immediately -- so it is clear what is returned
and when.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-29-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are serial_port_in/out() helpers to be used instead of direct
p->serial_in/out(). Use them in various 8250 drivers.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
--
[v2]
* Use serial_port_in/out() and not serial_in/out() [Andy]
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # 8250_dw
Link: https://lore.kernel.org/r/20250317070046.24386-28-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_line_info() wants to work with struct uart_state. Do not pass a
driver and an index. Pass the precomputed struct directly.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-27-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The linking is done implicitly by tty_port_register_device_attr_serdev()
few lines below. So drop this explicit tty_port_link_device().
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-26-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
They are simple wrappers around serial_{in/out}() without actually
pausing the execution. Since ever. So drop these useless wrappers.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/r/20250317070046.24386-24-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These ioctls are undocumented and not exposed -- they are defined
locally. Given they need a special tty_port just for them, this is very
ugly. So drop this whole functionality. It is barely used for something
real. (And if it is, we'd need a common functionality to all drivers.)
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-21-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I doubt anyone actually uses this driver (unlike mxser.c and serial
moxa driven devices). Even less there is anyone with a moxa ISA card.
The newer mxser dropped the support for ISA in 2021. Let this moxa
follow now.
Good diet.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-20-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The arbitrary MOXA_VERSION is dumped to the logs when the driver is
loaded. Avoid this as a driver should be silent unless something breaks.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-19-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In particular, serdev_device_write_room() is not called, so the whole
serdev's write_room() can go.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-17-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__tty_alloc_driver()'s kernel-doc needed some care: describe the return
value using the standard "Returns:", and use the new enum tty_driver_flag
for @flags.
Then, the tty_alloc_driver() macro was undocumented, but referenced many
times in the docs. Copy the docs from the above (except the @owner
parameter, obviously).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-15-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_tty_read() contains "we need more data" handling deep in that
function. And there is also a label (more_to_be_read) as we handle this
situation from two places.
It makes more sense to have all "return"s accumulated at the end of
functions. And "goto" from multiple places there. Therefore, do this
with the "more_to_be_read" label in n_tty_read().
After this and the previous changes, n_tty_read() is now much more
easier to follow.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-12-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_tty_read() is a very long function doing too much of different stuff.
Extract the "wait for input" to a separate function:
n_tty_wait_for_input(). It returns an error (< 0), no input (0), or has
potential input (1).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-11-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_tty_read() is a very long function doing too much of different stuff.
Extract the "cookie" (continuation read) handling to a separate
function: n_tty_continue_cookie().
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-10-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This n_tty_trace() is an always disabled debugging macro. It comes from
commit 32f13521ca ("n_tty: Line copy to user buffer in canonical
mode").
Drop it as it is dead for over a decade.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-9-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Use guard(mutex), which results in:
- the function can return directly when "space == 0".
- "i" can now be "unsigned" as it is no longer abused to hold a retval
from tty->ops->write(). Note the compared-to "nr" is already
"unsigned".
* The end label is now dubbed "do_write" as that is what happens there.
Unlike the uncertain "break_out" name.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_write_room() returns an "unsigned int". So in case some insane
driver (like my tty test driver) returns (legitimate) UINT_MAX from its
tty_operations::write_room(), n_tty is confused on several places.
For example, in process_output_block(), the result of tty_write_room()
is stored into (signed) "int". So this UINT_MAX suddenly becomes -1. And
that is extended to ssize_t and returned from process_output_block().
This causes a write() to such a node to receive -EPERM (which is -1).
Fix that by using proper "unsigned int" and proper "== 0" test. And
return 0 constant directly in that "if", so that it is immediately clear
what is returned ("space" equals to 0 at that point).
Similarly for process_output() and __process_echoes().
Note this does not fix any in-tree driver as of now.
If you want "Fixes: something", it would be commit 03b3b1a240 ("tty:
make tty_operations::write_room return uint"). I intentionally do not
mark this patch by a real tag below.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"N_TTY_BUF_SIZE" is private to n_tty and shall not be exposed to the
world. Definitely not in tty.h somewhere in the middle of "struct
tty_struct".
This is a remnant of moving "read_flags" to "struct n_tty_data" in
commit 3fe780b379 ("TTY: move ldisc data from tty_struct: bitmaps").
But some cleanup was needed first (in previous patches).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
N_TTY_BUF_SIZE -- as the name suggests -- is the N_TTY's buffer size.
There is no reason to couple that to audit's buffer size, so define an
own TTY_AUDIT_BUF_SIZE macro (with the same size).
N_TTY_BUF_SIZE is private and will be moved to n_tty.c later.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The new option is CONFIG_NULL_TTY_DEFAULT_CONSOLE.
if enabled, and CONFIG_VT is disabled, ttynull will become the default
primary console device.
ttynull will be the only console device usually with this option enabled.
Some architectures do call add_preferred_console() which may add another
console though.
Motivation:
Many distributions ship with CONFIG_VT enabled. On tested desktop hardware
if CONFIG_VT is disabled, the default console device falls back to
/dev/ttyS0 instead of /dev/tty.
This could cause issues in user space, and hardware problems:
1. The user space issues include the case where /dev/ttyS0 is
disconnected, and the TCGETS ioctl, which some user space libraries use
as a probe to determine if a file is a tty, is called on /dev/console and
fails. Programs that call isatty() on /dev/console and get an incorrect
false value may skip expected logging to /dev/console.
2. The hardware issues include the case if a user has a science instrument
or other device connected to the /dev/ttyS0 port, and they were to upgrade
to a kernel that is disabling the CONFIG_VT option, kernel logs will then
be sent to the device connected to /dev/ttyS0 unless they edit their
kernel command line manually.
The new CONFIG_NULL_TTY_DEFAULT_CONSOLE option will give users and
distribution maintainers an option to avoid this. Disabling CONFIG_VT and
enabling CONFIG_NULL_TTY_DEFAULT_CONSOLE will ensure the default kernel
console behavior is not dependent on hardware configuration by default, and
avoid unexpected new behavior on devices connected to the /dev/ttyS0 serial
port.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Adam Simonelli <adamsimonelli@gmail.com>
Link: https://lore.kernel.org/r/20250314160749.3286153-2-adamsimonelli@gmail.com
[pmladek@suse.com: Fixed indentation of the commit message.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
The intent of console_start was to resume a previously suspended console,
so rename it accordingly.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-4-0b878577f2e6@suse.com
[pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
The intent of console_stop was in fact to suspend it, so rename the
function accordingly.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-3-0b878577f2e6@suse.com
[pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Move machine type detection to the decompressor and use static branches
to implement and use machine_is_[lpar|vm|kvm]() instead of a runtime check
via MACHINE_IS_[LPAR|VM|KVM].
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Ryo Takakura
Günther Noack
Stephan Gerhold
Thomas Gleixner
Linus Torvalds
Petr Mladek
Sherry Sun
Cheick Traore
Chaitanya Vadrevu
Charles Han
Geert Uytterhoeven
Arnd Bergmann
John Keeping
Cameron Williams
Andy Shevchenko
Jiri Slaby (SUSE)
Adam Simonelli
Marcos Paulo de Souza
Heiko Carstens