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, 42 insertions, 0 deletions

diff --git a/drivers/pmdomain/bcm/Kconfig b/drivers/pmdomain/bcm/Kconfig
new file mode 100644
index 000000000..b28c9f6d2
--- /dev/null
+++ b/drivers/pmdomain/bcm/Kconfig
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Broadcom PM Domains"
+
+config BCM2835_POWER
+	bool "BCM2835 power domain driver"
+	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+	default y if ARCH_BCM2835
+	select PM_GENERIC_DOMAINS if PM
+	select RESET_CONTROLLER
+	help
+	  This enables support for the BCM2835 power domains and reset
+	  controller.  Any usage of power domains by the Raspberry Pi
+	  firmware means that Linux usage of the same power domain
+	  must be accessed using the RASPBERRYPI_POWER driver
+
+config RASPBERRYPI_POWER
+	bool "Raspberry Pi power domain driver"
+	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+	depends on RASPBERRYPI_FIRMWARE=y
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the RPi power domains which can be enabled
+	  or disabled via the RPi firmware.
+
+config BCM_PMB
+	bool "Broadcom PMB (Power Management Bus) driver"
+	depends on ARCH_BCMBCA || (COMPILE_TEST && OF)
+	default ARCH_BCMBCA
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the Broadcom's PMB (Power Management Bus) that
+	  is used for disabling and enabling SoC devices.
+
+config BCM63XX_POWER
+	bool "BCM63xx power domain driver"
+	depends on BMIPS_GENERIC || (COMPILE_TEST && OF)
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the BCM63xx power domains controller on
+	  BCM6318, BCM6328, BCM6362 and BCM63268 SoCs.
+
+endmenu