From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/mux/Kconfig | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 drivers/mux/Kconfig (limited to 'drivers/mux/Kconfig') diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig new file mode 100644 index 000000000..6d17dfa25 --- /dev/null +++ b/drivers/mux/Kconfig @@ -0,0 +1,75 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Multiplexer devices +# + +config MULTIPLEXER + bool + +config MUX_CORE + bool "Generic Multiplexer Support" + select MULTIPLEXER + help + This framework is designed to abstract multiplexer handling for + devices via various GPIO-, MMIO/Regmap or specific multiplexer + controller chips. + + If unsure, say no. + +if MULTIPLEXER + +menu "Multiplexer drivers" + +config MUX_ADG792A + tristate "Analog Devices ADG792A/ADG792G Multiplexers" + depends on I2C + help + ADG792A and ADG792G Wide Bandwidth Triple 4:1 Multiplexers + + The driver supports both operating the three multiplexers in + parallel and operating them independently. + + To compile the driver as a module, choose M here: the module will + be called mux-adg792a. + +config MUX_ADGS1408 + tristate "Analog Devices ADGS1408/ADGS1409 Multiplexers" + depends on SPI + help + ADGS1408 8:1 multiplexer and ADGS1409 double 4:1 multiplexer + switches. + + To compile the driver as a module, choose M here: the module will + be called mux-adgs1408. + +config MUX_GPIO + tristate "GPIO-controlled Multiplexer" + depends on GPIOLIB || COMPILE_TEST + help + GPIO-controlled Multiplexer controller. + + The driver builds a single multiplexer controller using a number + of gpio pins. For N pins, there will be 2^N possible multiplexer + states. The GPIO pins can be connected (by the hardware) to several + multiplexers, which in that case will be operated in parallel. + + To compile the driver as a module, choose M here: the module will + be called mux-gpio. + +config MUX_MMIO + tristate "MMIO/Regmap register bitfield-controlled Multiplexer" + depends on OF + select REGMAP_MMIO + help + MMIO/Regmap register bitfield-controlled Multiplexer controller. + + The driver builds multiplexer controllers for bitfields in either + a syscon register or a driver regmap register. For N bit wide + bitfields, there will be 2^N possible multiplexer states. + + To compile the driver as a module, choose M here: the module will + be called mux-mmio. + +endmenu + +endif # MULTIPLEXER -- cgit v1.3.1