user/sven/linux.git/include/linux/printk.h, branch v6.11.3

Merge tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2024-07-25T20:18:41Z

Pull printk updates from Petr Mladek: - trivial printk changes The bigger "real" printk work is still being discussed. * tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: vsprintf: add missing MODULE_DESCRIPTION() macro printk: Rename console_replay_all() and update context

printk: Add match_devname_and_update_preferred_console()

2024-07-04T13:41:44Z

Let's add match_devname_and_update_preferred_console() for driver subsystems to call during init when the console is ready, and it's character device name is known. For now, we use it only for the serial layer to allow console=DEVNAME:0.0 style hardware based addressing for consoles. The earlier attempt on doing this caused a regression with the kernel command line console order as it added calling __add_preferred_console() again later on during init. A better approach was suggested by Petr where we add the deferred console to the console_cmdline[] and update it later on when the console is ready. Suggested-by: Petr Mladek Co-developed-by: Petr Mladek Signed-off-by: Tony Lindgren Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240703100615.118762-2-tony.lindgren@linux.intel.com Signed-off-by: Greg Kroah-Hartman

Revert "printk: Save console options for add_preferred_console_match()"

2024-06-25T05:58:10Z

This reverts commit f03e8c1060f86c23eb49bafee99d9fcbd1c1bd77. Let's roll back all of the serial core and printk console changes that went into 6.10-rc1 as there still are problems with them that need to be sorted out. Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1 Reported-by: Petr Mladek Reported-by: Tony Lindgren Cc: Jiri Slaby Cc: John Ogness Cc: Sergey Senozhatsky Cc: Andy Shevchenko Cc: Ilpo Järvinen Signed-off-by: Greg Kroah-Hartman

printk: Rename console_replay_all() and update context

2024-06-03T15:17:29Z

Rename console_replay_all() to console_try_replay_all() to make clear that the implementation is best effort. Also, the function should not be called in NMI context as it takes locks, so update the comment in code. Fixes: 693f75b91a91 ("printk: Add function to replay kernel log on consoles") Fixes: 1b743485e27f ("tty/sysrq: Replay kernel log messages on consoles via sysrq") Suggested-by: Petr Mladek Signed-off-by: Shimoyashiki Taichi Signed-off-by: Sreenath Vijayan Link: https://lore.kernel.org/r/Zlguq/wU21Z8MqI4@sreenath.vijayan@sony.com Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek

Merge tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2024-05-22T18:53:02Z

Pull tty / serial updates from Greg KH: "Here is the big set of tty/serial driver changes for 6.10-rc1. Included in here are: - Usual good set of api cleanups and evolution by Jiri Slaby to make the serial interfaces move out of the 1990's by using kfifos instead of hand-rolling their own logic. - 8250_exar driver updates - max3100 driver updates - sc16is7xx driver updates - exar driver updates - sh-sci driver updates - tty ldisc api addition to help refuse bindings - other smaller serial driver updates All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits) serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev() serial: imx: Raise TX trigger level to 8 serial: 8250_pnp: Simplify "line" related code serial: sh-sci: simplify locking when re-issuing RXDMA fails serial: sh-sci: let timeout timer only run when DMA is scheduled serial: sh-sci: describe locking requirements for invalidating RXDMA serial: sh-sci: protect invalidating RXDMA on shutdown tty: add the option to have a tty reject a new ldisc serial: core: Call device_set_awake_path() for console port dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema tty: serial: uartps: Add support for uartps controller reset arm64: zynqmp: Add resets property for UART nodes dt-bindings: serial: cdns,uart: Add optional reset property serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS() serial: 8250_exar: Keep the includes sorted serial: 8250_exar: Make type of bit the same in exar_ee_*_bit() serial: 8250_exar: Use BIT() in exar_ee_read() serial: 8250_exar: Switch to use dev_err_probe() serial: 8250_exar: Return directly from switch-cases serial: 8250_exar: Decrease indentation level ...

printk: cleanup deprecated uses of strncpy/strcpy

2024-05-07T08:41:51Z

Cleanup some deprecated uses of strncpy() and strcpy() [1]. There doesn't seem to be any bugs with the current code but the readability of this code could benefit from a quick makeover while removing some deprecated stuff as a benefit. The most interesting replacement made in this patch involves concatenating "ttyS" with a digit-led user-supplied string. Instead of doing two distinct string copies with carefully managed offsets and lengths, let's use the more robust and self-explanatory scnprintf(). scnprintf will 1) respect the bounds of @buf, 2) null-terminate @buf, 3) do the concatenation. This allows us to drop the manual NUL-byte assignment. Also, since isdigit() is used about a dozen lines after the open-coded version we'll replace it for uniformity's sake. All the strcpy() --> strscpy() replacements are trivial as the source strings are literals and much smaller than the destination size. No behavioral change here. Use the new 2-argument version of strscpy() introduced in Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). However, to make this work fully (since the size must be known at compile time), also update the extern-qualified declaration to have the proper size information. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 [2] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [3] Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240429-strncpy-kernel-printk-printk-c-v1-1-4da7926d7b69@google.com [pmladek@suse.com: Removed obsolete brackets and added empty lines.] Signed-off-by: Petr Mladek

printk: Add function to replay kernel log on consoles

2024-04-11T12:22:52Z

Add a generic function console_replay_all() for replaying the kernel log on consoles, in any context. It would allow viewing the logs on an unresponsive terminal via sysrq. Reuse the existing code from console_flush_on_panic() for resetting the sequence numbers, by introducing a new helper function __console_rewind_all(). It is safe to be called under console_lock(). Try to acquire lock on the console subsystem without waiting. If successful, reset the sequence number to oldest available record on all consoles and call console_unlock() which will automatically flush the messages to the consoles. Suggested-by: John Ogness Suggested-by: Petr Mladek Signed-off-by: Shimoyashiki Taichi Reviewed-by: John Ogness Signed-off-by: Sreenath Vijayan Link: https://lore.kernel.org/r/90ee131c643a5033d117b556c0792de65129d4c3.1710220326.git.sreenath.vijayan@sony.com Signed-off-by: Greg Kroah-Hartman

printk: Save console options for add_preferred_console_match()

2024-04-09T13:30:13Z

Driver subsystems may need to translate the preferred console name to the character device name used. We already do some of this in console_setup() with a few hardcoded names, but that does not scale well. The console options are parsed early in console_setup(), and the consoles are added with __add_preferred_console(). At this point we don't know much about the character device names and device drivers getting probed. To allow driver subsystems to set up a preferred console, let's save the kernel command line console options. To add a preferred console from a driver subsystem with optional character device name translation, let's add a new function add_preferred_console_match(). This allows the serial core layer to support console=DEVNAME:0.0 style hardware based addressing in addition to the current console=ttyS0 style naming. And we can start moving console_setup() character device parsing to the driver subsystem specific code. We use a separate array from the console_cmdline array as the character device name and index may be unknown at the console_setup() time. And eventually there's no need to call __add_preferred_console() until the subsystem is ready to handle the console. Adding the console name in addition to the character device name, and a flag for an added console, could be added to the struct console_cmdline. And the console_cmdline array handling could be modified accordingly. But that complicates things compared saving the console options, and then adding the consoles when the subsystems handling the consoles are ready. Co-developed-by: Andy Shevchenko Signed-off-by: Tony Lindgren Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240327110021.59793-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman

printk: Let no_printk() use _printk()

2024-03-19T15:11:42Z

When printk-indexing is enabled, each printk() invocation emits a pi_entry structure, containing the format string and other information related to its location in the kernel sources. This is even true for no_printk(): while the actual code to print the message is optimized out by the compiler due to the always-false check, the pi_entry structure is still emitted. As the main purpose of no_printk() is to provide a helper to maintain printf()-style format checking when debugging is disabled, this leads to the inclusion in the index of lots of printk formats that cannot be emitted by the current kernel. Fix this by switching no_printk() from printk() to _printk(). This reduces the size of an arm64 defconfig kernel with CONFIG_PRINTK_INDEX=y by 576 KiB. Fixes: 337015573718b161 ("printk: Userspace format indexing support") Signed-off-by: Geert Uytterhoeven Reviewed-by: Andy Shevchenko Reviewed-by: Xiubo Li Reviewed-by: Chris Down Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/56cf92edccffea970e1f40a075334dd6cf5bb2a4.1709127473.git.geert+renesas@glider.be Signed-off-by: Petr Mladek

dump_stack: Do not get cpu_sync for panic CPU

2024-02-07T16:23:19Z

dump_stack() is called in panic(). If for some reason another CPU is holding the printk_cpu_sync and is unable to release it, the panic CPU will be unable to continue and print the stacktrace. Since non-panic CPUs are not allowed to store new printk messages anyway, there is no need to synchronize the stacktrace output in a panic situation. For the panic CPU, do not get the printk_cpu_sync because it is not needed and avoids a potential deadlock scenario in panic(). Link: https://lore.kernel.org/lkml/ZcIGKU8sxti38Kok@alley Signed-off-by: John Ogness Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240207134103.1357162-15-john.ogness@linutronix.de Signed-off-by: Petr Mladek