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2025-04-15serial: sifive: lock port in startup()/shutdown() callbacksRyo Takakura1-0/+6
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: 45c054d0815b ("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>
2025-04-11tty: Require CAP_SYS_ADMIN for all usages of TIOCL_SELMOUSEREPORTGünther Noack1-3/+2
This requirement was overeagerly loosened in commit 2f83e38a095f ("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 2f83e38a095f ("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 83efeeeb3d04 ("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 2f83e38a095f ("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: 2f83e38a095f ("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>
2025-04-11serial: msm: Configure correct working mode before starting earlyconStephan Gerhold1-0/+6
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: 0efe72963409 ("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>
2025-04-05treewide: Switch/rename to timer_delete[_sync]()Thomas Gleixner22-44/+44
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>
2025-04-03Merge tag 'tty-6.15-rc1' of ↵Linus Torvalds37-1248/+1953
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 ...
2025-03-29Merge tag 's390-6.15-1' of ↵Linus Torvalds1-3/+4
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 ...
2025-03-28Merge tag 'printk-for-6.15' of ↵Linus Torvalds2-4/+21
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
2025-03-27Merge branch 'for-6.15-console-suspend-api-cleanup' into for-linusPetr Mladek1-3/+3
2025-03-24tty: serial: fsl_lpuart: Fix unused variable 'sport' build warningSherry Sun1-3/+0
Remove the unused variable 'sport' to avoid the kernel build warning. Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/ Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20serial: stm32: do not deassert RS485 RTS GPIO prematurelyCheick Traore1-3/+1
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: d7c76716169d ("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>
2025-03-20serial: 8250: add driver for NI UARTsChaitanya Vadrevu3-0/+475
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>
2025-03-20serial: icom: fix code format problemsCharles Han1-5/+4
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>
2025-03-20serial: sh-sci: Save and restore more registersGeert Uytterhoeven1-0/+25
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: 22a6984c5b5df8ea ("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>
2025-03-20tty: serial: pl011: remove incorrect of_match_ptr annotationArnd Bergmann2-4/+4
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>
2025-03-20tty: serial: lpuart: only disable CTS instead of overwriting the whole ↵Sherry Sun1-5/+7
UARTMODIR register 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: d5a2e0834364 ("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>
2025-03-20serial: 8250_dma: terminate correct DMA in tx_dma_flush()John Keeping1-1/+1
When flushing transmit side DMA, it is the transmit channel that should be terminated, not the receive channel. Fixes: 9e512eaaf8f40 ("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>
2025-03-20tty: serial: fsl_lpuart: rename register variables more specificallySherry Sun1-110/+110
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>
2025-03-20tty: serial: fsl_lpuart: use port struct directly to simply codeSherry Sun1-108/+102
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>
2025-03-20tty: serial: fsl_lpuart: Use u32 and u8 for register variablesSherry Sun1-47/+46
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>
2025-03-20tty: serial: fsl_lpuart: disable transmitter before changing RS485 related ↵Sherry Sun1-0/+17
registers 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: 67b01837861c ("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>
2025-03-20tty: serial: 8250: Add Brainboxes XC devicesCameron Williams1-0/+30
These ExpressCard devices use the OxPCIE chip and can be used with this driver. Signed-off-by: Cameron Williams <cang1@live.co.uk> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/DB7PR02MB3802907A9360F27F6CD67AAFC4D62@DB7PR02MB3802.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20tty: serial: 8250: Add some more device IDsCameron Williams1-0/+16
These card IDs got missed the first time around. Cc: stable <stable@kernel.org> Signed-off-by: Cameron Williams <cang1@live.co.uk> Link: https://lore.kernel.org/r/DB7PR02MB380295BCC879CCF91315AC38C4C12@DB7PR02MB3802.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20serial: 8250_dw: Comment possible corner cases in serial_out() implementationAndy Shevchenko1-0/+17
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>
2025-03-20serial: switch change_irq and change_port to bool in uart_set_info()Jiri Slaby (SUSE)1-2/+2
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>
2025-03-20serial: 8250_port: simplify serial8250_request_std_resource()Jiri Slaby (SUSE)1-15/+10
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>
2025-03-20serial: 8250_port: do not use goto for UPQ_NO_TXEN_TEST code flowJiri Slaby (SUSE)1-18/+16
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>
2025-03-20serial: 8250_rsa: simplify rsa8250_{request/release}_resource()Jiri Slaby (SUSE)1-12/+9
* 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>
2025-03-20serial: 8250: use serial_port_in/out() helpersJiri Slaby (SUSE)3-13/+13
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>
2025-03-20serial: pass struct uart_state to uart_line_info()Jiri Slaby (SUSE)1-3/+2
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>
2025-03-20serial: remove redundant tty_port_link_device()Jiri Slaby (SUSE)1-1/+0
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>
2025-03-20tty: sunsu: remove unused serial_icr_read()Jiri Slaby (SUSE)1-14/+0
It is commented and never used. 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/20250317070046.24386-25-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20tty: sunsu: drop serial_{in,out}p()Jiri Slaby (SUSE)1-87/+77
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>
2025-03-20tty: moxa: carve out special ioctls and extra tty_portJiri Slaby (SUSE)1-145/+1
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>
2025-03-20tty: moxa: drop ISA supportJiri Slaby (SUSE)2-96/+6
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>
2025-03-20tty: moxa: drop version dump to logsJiri Slaby (SUSE)1-5/+0
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>
2025-03-20tty: serdev: drop serdev_controller_ops::write_room()Jiri Slaby (SUSE)2-20/+0
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>
2025-03-20tty: tty_driver: document both {,__}tty_alloc_driver() properlyJiri Slaby (SUSE)1-3/+5
__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>
2025-03-20tty: n_tty: move more_to_be_read to the end of n_tty_read()Jiri Slaby (SUSE)1-15/+14
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>
2025-03-20tty: n_tty: extract n_tty_wait_for_input()Jiri Slaby (SUSE)1-26/+31
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>
2025-03-20tty: n_tty: extract n_tty_continue_cookie() from n_tty_read()Jiri Slaby (SUSE)1-30/+36
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>
2025-03-20tty: n_tty: drop n_tty_trace()Jiri Slaby (SUSE)1-14/+0
This n_tty_trace() is an always disabled debugging macro. It comes from commit 32f13521ca68 ("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>
2025-03-20tty: n_tty: clean up process_output_block()Jiri Slaby (SUSE)1-16/+11
* 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>
2025-03-20tty: n_tty: simplify process_output()Jiri Slaby (SUSE)1-10/+4
Using guard(mutex), the function can be written in a much more efficient way. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250317070046.24386-7-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20tty: n_tty: use uint for space returned by tty_write_room()Jiri Slaby (SUSE)1-6/+7
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 03b3b1a2405c ("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>
2025-03-20tty: move N_TTY_BUF_SIZE to n_ttyJiri Slaby (SUSE)1-0/+2
"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 3fe780b379fa ("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>
2025-03-20tty: audit: do not use N_TTY_BUF_SIZEJiri Slaby (SUSE)1-4/+6
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>
2025-03-17printk: Add an option to allow ttynull to be a default console deviceAdam Simonelli1-1/+18
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>
2025-03-11printk: Rename console_start to console_resumeMarcos Paulo de Souza1-1/+1
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>
2025-03-11printk: Rename console_stop to console_suspendMarcos Paulo de Souza1-2/+2
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>
2025-03-04s390: Convert MACHINE_IS_[LPAR|VM|KVM], etc, machine_is_[lpar|vm|kvm]()Heiko Carstens1-3/+4
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>
generated by cgit v1.2.3 (git 2.39.0) at 2025-05-04 20:17:21 +0300