ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 92 insertions, 0 deletions

diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig
new file mode 100644
index 000000000..e6049a75b
--- /dev/null
+++ b/drivers/w1/masters/Kconfig
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# 1-wire bus master configuration
+#
+
+menu "1-wire Bus Masters"
+
+config W1_MASTER_AMD_AXI
+	tristate "AMD AXI 1-wire bus host"
+	help
+	  Say Y here is you want to support the AMD AXI 1-wire IP core.
+	  This driver makes use of the programmable logic IP to perform
+	  correctly timed 1 wire transactions without relying on GPIO timing
+	  through the kernel.
+
+	  This driver can also be built as a module.  If so, the module will be
+	  called amd_w1_axi.
+
+config W1_MASTER_MATROX
+	tristate "Matrox G400 transport layer for 1-wire"
+	depends on PCI
+	help
+	  Say Y here if you want to communicate with your 1-wire devices
+	  using Matrox's G400 GPIO pins.
+
+	  This support is also available as a module.  If so, the module
+	  will be called matrox_w1.
+
+config W1_MASTER_DS2490
+	tristate "DS2490 USB <-> W1 transport layer for 1-wire"
+  	depends on USB
+  	help
+	  Say Y here if you want to have a driver for DS2490 based USB <-> W1 bridges,
+	  for example DS9490*.
+
+  	  This support is also available as a module.  If so, the module
+	  will be called ds2490.
+
+config W1_MASTER_DS2482
+	tristate "Maxim DS2482 I2C to 1-Wire bridge"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Maxim DS2482
+	  I2C to 1-Wire bridge.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ds2482.
+
+config W1_MASTER_MXC
+	tristate "Freescale MXC 1-wire busmaster"
+	depends on ARCH_MXC || COMPILE_TEST
+	help
+	  Say Y here to enable MXC 1-wire host
+
+config W1_MASTER_GPIO
+	tristate "GPIO 1-wire busmaster"
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  Say Y here if you want to communicate with your 1-wire devices using
+	  GPIO pins. This driver uses the GPIO API to control the wire.
+
+	  This support is also available as a module.  If so, the module
+	  will be called w1-gpio.
+
+config HDQ_MASTER_OMAP
+	tristate "OMAP HDQ driver"
+	depends on ARCH_OMAP || COMPILE_TEST
+	help
+	  Say Y here if you want support for the 1-wire or HDQ Interface
+	  on an OMAP processor.
+
+config W1_MASTER_SGI
+	tristate "SGI ASIC driver"
+	help
+	  Say Y here if you want support for your 1-wire devices using
+	  SGI ASIC 1-Wire interface
+
+	  This support is also available as a module.  If so, the module
+	  will be called sgi_w1.
+
+config W1_MASTER_UART
+	tristate "UART 1-wire driver"
+	depends on SERIAL_DEV_BUS
+	help
+	  Say Y here if you want to communicate with your 1-wire devices using
+	  UART interface.
+
+	  This support is also available as a module.  If so, the module
+	  will be called w1-uart.
+
+endmenu
+