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, 38 insertions, 0 deletions

diff --git a/drivers/pinctrl/realtek/Kconfig b/drivers/pinctrl/realtek/Kconfig
new file mode 100644
index 000000000..a156c4ef5
--- /dev/null
+++ b/drivers/pinctrl/realtek/Kconfig
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+config PINCTRL_RTD
+	tristate "Realtek DHC core pin controller driver"
+	depends on ARCH_REALTEK || (COMPILE_TEST && OF)
+	default ARCH_REALTEK
+	select PINMUX
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+
+config PINCTRL_RTD1619B
+	tristate "Realtek DHC 1619B pin controller driver"
+	depends on PINCTRL_RTD
+	default ARCH_REALTEK
+
+config PINCTRL_RTD1319D
+	tristate "Realtek DHC 1319D pin controller driver"
+	depends on PINCTRL_RTD
+	default ARCH_REALTEK
+
+config PINCTRL_RTD1315E
+	tristate "Realtek DHC 1315E pin controller driver"
+	depends on PINCTRL_RTD
+	default ARCH_REALTEK
+
+config PINCTRL_RTD1625
+	tristate "Realtek DHC 1625 pin controller driver"
+	depends on PINCTRL_RTD
+	default ARCH_REALTEK
+	help
+	  This driver enables support for the pin controller on the Realtek
+	  RTD1625 SoCs.
+
+	  It implements pin multiplexing for function selection and GPIO enabling.
+	  It also utilizes the generic pin configuration interface to manage
+	  electrical properties for both individual pins and pin groups.
+
+	  Say Y here to enable the pinctrl driver for RTD1625 SoCs
\ No newline at end of file