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, 31 insertions, 0 deletions

diff --git a/drivers/leds/blink/Kconfig b/drivers/leds/blink/Kconfig
new file mode 100644
index 000000000..bdcb7377c
--- /dev/null
+++ b/drivers/leds/blink/Kconfig
@@ -0,0 +1,31 @@
+config LEDS_BCM63138
+	tristate "LED Support for Broadcom BCM63138 SoC"
+	depends on LEDS_CLASS
+	depends on ARCH_BCMBCA || ARCH_BCM_5301X || BCM63XX || COMPILE_TEST
+	depends on HAS_IOMEM
+	depends on OF
+	default ARCH_BCMBCA
+	help
+	  This option enables support for LED controller that is part of
+	  BCM63138 SoC. The same hardware block is known to be also used
+	  in BCM4908, BCM6848, BCM6858, BCM63148, BCM63381 and BCM68360.
+
+	  If compiled as module it will be called leds-bcm63138.
+
+config LEDS_LGM
+       tristate "LED support for LGM SoC series"
+       depends on X86 || COMPILE_TEST
+       depends on GPIOLIB && LEDS_CLASS && MFD_SYSCON && OF
+       help
+         This option enables support for LEDs connected to GPIO lines on
+         Lightning Mountain (LGM) SoC. Lightning Mountain is a AnyWAN
+         gateway-on-a-chip SoC to be shipped on mid and high end home
+         gateways and routers.
+
+         These LEDs are driven by a Serial Shift Output (SSO) controller.
+         The driver supports hardware blinking and the LEDs can be configured
+         to be triggered by software/CPU or by hardware.
+
+         Say 'Y' here if you are working on LGM SoC based platform. Otherwise,
+         say 'N'. To compile this driver as a module, choose M here: the module
+         will be called leds-lgm-sso.