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, 46 insertions, 0 deletions

diff --git a/drivers/acpi/dptf/Kconfig b/drivers/acpi/dptf/Kconfig
new file mode 100644
index 000000000..4b3fdc03e
--- /dev/null
+++ b/drivers/acpi/dptf/Kconfig
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menuconfig ACPI_DPTF
+	bool "Intel DPTF (Dynamic Platform and Thermal Framework) Support"
+	depends on X86
+	help
+	  Intel Dynamic Platform and Thermal Framework (DPTF) is a platform
+	  level hardware/software solution for power and thermal management.
+
+	  As a container for multiple power/thermal technologies, DPTF provides
+	  a coordinated approach for different policies to effect the hardware
+	  state of a system.
+
+if ACPI_DPTF
+
+config DPTF_POWER
+	tristate "Platform Power DPTF Participant"
+	default m
+	help
+	  This driver adds support for Dynamic Platform and Thermal Framework
+	  (DPTF) Platform Power Participant device (INT3407) support.
+	  This participant is responsible for exposing platform telemetry:
+		max_platform_power
+		platform_power_source
+		adapter_rating
+		battery_steady_power
+		charger_type
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called dptf_power.
+
+config DPTF_PCH_FIVR
+	tristate "PCH FIVR DPTF Participant"
+	default m
+	help
+	  This driver adds support for Dynamic Platform and Thermal Framework
+	  (DPTF) PCH FIVR Participant device support. This driver allows to
+	  switch the PCH FIVR (Fully Integrated Voltage Regulator) frequency.
+	  This participant is responsible for exposing:
+		freq_mhz_low_clock
+		freq_mhz_high_clock
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called dptf_pch_fivr.
+
+endif