From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/char/Kconfig | 374 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 374 insertions(+) create mode 100644 drivers/char/Kconfig (limited to 'drivers/char/Kconfig') diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig new file mode 100644 index 000000000..9865227af --- /dev/null +++ b/drivers/char/Kconfig @@ -0,0 +1,374 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Character device configuration +# + +menu "Character devices" + +source "drivers/tty/Kconfig" + +config TTY_PRINTK + tristate "TTY driver to output user messages via printk" + depends on EXPERT && TTY + default n + help + If you say Y here, the support for writing user messages (i.e. + console messages) via printk is available. + + The feature is useful to inline user messages with kernel + messages. + In order to use this feature, you should output user messages + to /dev/ttyprintk or redirect console to this TTY, or boot + the kernel with console=ttyprintk. + + If unsure, say N. + +config TTY_PRINTK_LEVEL + depends on TTY_PRINTK + int "ttyprintk log level (1-7)" + range 1 7 + default "6" + help + Printk log level to use for ttyprintk messages. + +config PRINTER + tristate "Parallel printer support" + depends on PARPORT + depends on HAS_IOPORT || PARPORT_NOT_PC + help + If you intend to attach a printer to the parallel port of your Linux + box (as opposed to using a serial printer; if the connector at the + printer has 9 or 25 holes ["female"], then it's serial), say Y. + Also read the Printing-HOWTO, available from + . + + It is possible to share one parallel port among several devices + (e.g. printer and ZIP drive) and it is safe to compile the + corresponding drivers into the kernel. + + To compile this driver as a module, choose M here and read + . The module will be called lp. + + If you have several parallel ports, you can specify which ports to + use with the "lp" kernel command line option. (Try "man bootparam" + or see the documentation of your boot loader (lilo or loadlin) about + how to pass options to the kernel at boot time.) The syntax of the + "lp" command line option can be found in . + + If you have more than 8 printers, you need to increase the LP_NO + macro in lp.c and the PARPORT_MAX macro in parport.h. + +config LP_CONSOLE + bool "Support for console on line printer" + depends on PRINTER + help + If you want kernel messages to be printed out as they occur, you + can have a console on the printer. This option adds support for + doing that; to actually get it to happen you need to pass the + option "console=lp0" to the kernel at boot time. + + If the printer is out of paper (or off, or unplugged, or too + busy..) the kernel will stall until the printer is ready again. + By defining CONSOLE_LP_STRICT to 0 (at your own risk) you + can make the kernel continue when this happens, + but it'll lose the kernel messages. + + If unsure, say N. + +config PPDEV + tristate "Support for user-space parallel port device drivers" + depends on PARPORT + help + Saying Y to this adds support for /dev/parport device nodes. This + is needed for programs that want portable access to the parallel + port, for instance deviceid (which displays Plug-and-Play device + IDs). + + This is the parallel port equivalent of SCSI generic support (sg). + It is safe to say N to this -- it is not needed for normal printing + or parallel port CD-ROM/disk support. + + To compile this driver as a module, choose M here: the + module will be called ppdev. + + If unsure, say N. + +config VIRTIO_CONSOLE + tristate "Virtio console" + depends on TTY + select HVC_DRIVER + select VIRTIO + help + Virtio console for use with hypervisors. + + Also serves as a general-purpose serial device for data + transfer between the guest and host. Character devices at + /dev/vportNpn will be created when corresponding ports are + found, where N is the device number and n is the port number + within that device. If specified by the host, a sysfs + attribute called 'name' will be populated with a name for + the port which can be used by udev scripts to create a + symlink to the device. + +config IBM_BSR + tristate "IBM POWER Barrier Synchronization Register support" + depends on PPC_PSERIES + help + This devices exposes a hardware mechanism for fast synchronization + of threads across a large system which avoids bouncing a cacheline + between several cores on a system + +config POWERNV_OP_PANEL + tristate "IBM POWERNV Operator Panel Display support" + depends on PPC_POWERNV + default m + help + If you say Y here, a special character device node, /dev/op_panel, + will be created which exposes the operator panel display on IBM + Power Systems machines with FSPs. + + If you don't require access to the operator panel display from user + space, say N. + + If unsure, say M here to build it as a module called powernv-op-panel. + +source "drivers/char/ipmi/Kconfig" + +config DS1620 + tristate "NetWinder thermometer support" + depends on ARCH_NETWINDER + help + Say Y here to include support for the thermal management hardware + found in the NetWinder. This driver allows the user to control the + temperature set points and to read the current temperature. + + It is also possible to say M here to build it as a module (ds1620) + It is recommended to be used on a NetWinder, but it is not a + necessity. + +config NWBUTTON + tristate "NetWinder Button" + depends on ARCH_NETWINDER + help + If you say Y here and create a character device node /dev/nwbutton + with major and minor numbers 10 and 158 ("man mknod"), then every + time the orange button is pressed a number of times, the number of + times the button was pressed will be written to that device. + + This is most useful for applications, as yet unwritten, which + perform actions based on how many times the button is pressed in a + row. + + Do not hold the button down for too long, as the driver does not + alter the behaviour of the hardware reset circuitry attached to the + button; it will still execute a hard reset if the button is held + down for longer than approximately five seconds. + + To compile this driver as a module, choose M here: the + module will be called nwbutton. + + Most people will answer Y to this question and "Reboot Using Button" + below to be able to initiate a system shutdown from the button. + +config NWBUTTON_REBOOT + bool "Reboot Using Button" + depends on NWBUTTON + help + If you say Y here, then you will be able to initiate a system + shutdown and reboot by pressing the orange button a number of times. + The number of presses to initiate the shutdown is two by default, + but this can be altered by modifying the value of NUM_PRESSES_REBOOT + in nwbutton.h and recompiling the driver or, if you compile the + driver as a module, you can specify the number of presses at load + time with "insmod button reboot_count=". + +config NWFLASH + tristate "NetWinder flash support" + depends on ARCH_NETWINDER + help + If you say Y here and create a character device /dev/flash with + major 10 and minor 160 you can manipulate the flash ROM containing + the NetWinder firmware. Be careful as accidentally overwriting the + flash contents can render your computer unbootable. On no account + allow random users access to this device. :-) + + To compile this driver as a module, choose M here: the + module will be called nwflash. + + If you're not sure, say N. + +source "drivers/char/hw_random/Kconfig" + +config XILINX_HWICAP + tristate "Xilinx HWICAP Support" + depends on MICROBLAZE + help + This option enables support for Xilinx Internal Configuration + Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex + FPGA platforms to partially reconfigure the FPGA at runtime. + + If unsure, say N. + +config SONYPI + tristate "Sony Vaio Programmable I/O Control Device support" + depends on X86_32 && PCI && INPUT && HAS_IOPORT + depends on ACPI_EC || !ACPI + help + This driver enables access to the Sony Programmable I/O Control + Device which can be found in many (all ?) Sony Vaio laptops. + + If you have one of those laptops, read + , and say Y or M here. + + To compile this driver as a module, choose M here: the + module will be called sonypi. + +config SCx200_GPIO + tristate "NatSemi SCx200 GPIO Support" + depends on SCx200 + select NSC_GPIO + help + Give userspace access to the GPIO pins on the National + Semiconductor SCx200 processors. + + If compiled as a module, it will be called scx200_gpio. + +config PC8736x_GPIO + tristate "NatSemi PC8736x GPIO Support" + depends on X86_32 && !UML + default SCx200_GPIO # mostly N + select NSC_GPIO # needed for support routines + help + Give userspace access to the GPIO pins on the National + Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip + has multiple functional units, inc several managed by + hwmon/pc87360 driver. Tested with PC-87366 + + If compiled as a module, it will be called pc8736x_gpio. + +config NSC_GPIO + tristate "NatSemi Base GPIO Support" + depends on X86_32 + # selected by SCx200_GPIO and PC8736x_GPIO + # what about 2 selectors differing: m != y + help + Common support used (and needed) by scx200_gpio and + pc8736x_gpio drivers. If those drivers are built as + modules, this one will be too, named nsc_gpio + +config DEVMEM + bool "/dev/mem virtual device support" + default y + help + Say Y here if you want to support the /dev/mem device. + The /dev/mem device is used to access areas of physical + memory. + When in doubt, say "Y". + +config NVRAM + tristate "/dev/nvram support" + depends on X86 || HAVE_ARCH_NVRAM_OPS + default M68K || PPC + help + If you say Y here and create a character special file /dev/nvram + with major number 10 and minor number 144 using mknod ("man mknod"), + you get read and write access to the non-volatile memory. + + /dev/nvram may be used to view settings in NVRAM or to change them + (with some utility). It could also be used to frequently + save a few bits of very important data that may not be lost over + power-off and for which writing to disk is too insecure. Note + however that most NVRAM space in a PC belongs to the BIOS and you + should NEVER idly tamper with it. See Ralf Brown's interrupt list + for a guide to the use of CMOS bytes by your BIOS. + + This memory is conventionally called "NVRAM" on PowerPC machines, + "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes. + + To compile this driver as a module, choose M here: the + module will be called nvram. + +config DEVPORT + bool "/dev/port character device" + depends on HAS_IOPORT + default y + help + Say Y here if you want to support the /dev/port device. The /dev/port + device is similar to /dev/mem, but for I/O ports. + +config HPET + bool "HPET - High Precision Event Timer" if X86 + default n + depends on ACPI + help + If you say Y here, you will have a miscdevice named "/dev/hpet/". Each + open selects one of the timers supported by the HPET. The timers are + non-periodic and/or periodic. + +config HPET_MMAP + bool "Allow mmap of HPET" + default y + depends on HPET + help + If you say Y here, user applications will be able to mmap + the HPET registers. + +config HPET_MMAP_DEFAULT + bool "Enable HPET MMAP access by default" + default y + depends on HPET_MMAP + help + In some hardware implementations, the page containing HPET + registers may also contain other things that shouldn't be + exposed to the user. This option selects the default (if + kernel parameter hpet_mmap is not set) user access to the + registers for applications that require it. + +config HANGCHECK_TIMER + tristate "Hangcheck timer" + depends on X86 || PPC64 || S390 + help + The hangcheck-timer module detects when the system has gone + out to lunch past a certain margin. It can reboot the system + or merely print a warning. + +config UV_MMTIMER + tristate "UV_MMTIMER Memory mapped RTC for SGI UV" + depends on X86_UV + default m + help + The uv_mmtimer device allows direct userspace access to the + UV system timer. + +source "drivers/char/tpm/Kconfig" + +config TELCLOCK + tristate "Telecom clock driver for ATCA SBC" + depends on X86 + default n + help + The telecom clock device is specific to the MPCBL0010 and MPCBL0050 + ATCA computers and allows direct userspace access to the + configuration of the telecom clock configuration settings. This + device is used for hardware synchronization across the ATCA backplane + fabric. Upon loading, the driver exports a sysfs directory, + /sys/devices/faux/telco_clock, with a number of files for + controlling the behavior of this hardware. + +source "drivers/s390/char/Kconfig" + +source "drivers/char/xillybus/Kconfig" + +config ADI + tristate "SPARC Privileged ADI driver" + depends on SPARC64 + default m + help + SPARC M7 and newer processors utilize ADI (Application Data + Integrity) to version and protect memory. This driver provides + read/write access to the ADI versions for privileged processes. + This feature is also known as MCD (Memory Corruption Detection) + and SSM (Silicon Secured Memory). Intended consumers of this + driver include crash and makedumpfile. + +endmenu -- cgit v1.3.1