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, 33 insertions, 0 deletions

diff --git a/drivers/pinctrl/intel/Kconfig.tng b/drivers/pinctrl/intel/Kconfig.tng
new file mode 100644
index 000000000..6f88a64d2
--- /dev/null
+++ b/drivers/pinctrl/intel/Kconfig.tng
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Intel Tangier and compatible pin control drivers
+
+if X86_INTEL_MID || COMPILE_TEST
+
+config PINCTRL_TANGIER
+	tristate
+	select PINMUX
+	select PINCONF
+	select GENERIC_PINCONF
+	help
+	  This is a library driver for Intel Tangier pin controller and to
+	  be selected and used by respective compatible platform drivers.
+
+	  If built as a module its name will be pinctrl-tangier.
+
+config PINCTRL_MERRIFIELD
+	tristate "Intel Merrifield pinctrl driver"
+	select PINCTRL_TANGIER
+	help
+	  Intel Merrifield Family-Level Interface Shim (FLIS) driver provides
+	  an interface that allows configuring of SoC pins and using them as
+	  GPIOs.
+
+config PINCTRL_MOOREFIELD
+	tristate "Intel Moorefield pinctrl driver"
+	select PINCTRL_TANGIER
+	help
+	  Intel Moorefield Family-Level Interface Shim (FLIS) driver provides
+	  an interface that allows configuring of SoC pins and using them as
+	  GPIOs.
+
+endif