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, 32 insertions, 0 deletions

diff --git a/drivers/clk/versatile/Kconfig b/drivers/clk/versatile/Kconfig
new file mode 100644
index 000000000..403f16495
--- /dev/null
+++ b/drivers/clk/versatile/Kconfig
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Clock driver for ARM Reference designs"
+	depends on HAS_IOMEM
+	depends on ARM || ARM64 || COMPILE_TEST
+
+config CLK_ICST
+	bool "Clock driver for ARM Reference designs ICST"
+	select REGMAP_MMIO
+	help
+	  Supports clocking on ARM Reference designs:
+	  - Integrator/AP and Integrator/CP
+	  - RealView PB1176, EB, PB11MP and PBX
+
+config CLK_SP810
+	bool "Clock driver for ARM SP810 System Controller"
+	default y if (ARCH_VEXPRESS && ARM)
+	help
+	  Supports clock muxing (REFCLK/TIMCLK to TIMERCLKEN0-3) capabilities
+	  of the ARM SP810 System Controller cell.
+
+config CLK_VEXPRESS_OSC
+	tristate "Clock driver for Versatile Express OSC clock generators"
+	depends on VEXPRESS_CONFIG
+	select REGMAP_MMIO
+	default y if ARCH_VEXPRESS
+	help
+	  Simple regmap-based driver driving clock generators on Versatile
+	  Express platforms hidden behind its configuration infrastructure,
+	  commonly known as OSCs.
+
+endmenu