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, 58 insertions, 0 deletions

diff --git a/drivers/pmdomain/mediatek/Kconfig b/drivers/pmdomain/mediatek/Kconfig
new file mode 100644
index 000000000..8923e6516
--- /dev/null
+++ b/drivers/pmdomain/mediatek/Kconfig
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "MediaTek PM Domains"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+
+config MTK_SCPSYS
+	bool "MediaTek SCPSYS Support"
+	default ARCH_MEDIATEK
+	depends on OF
+	select REGMAP
+	select MTK_INFRACFG
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  Say yes here to add support for the MediaTek SCPSYS power domain
+	  driver.
+
+config MTK_SCPSYS_PM_DOMAINS
+	bool "MediaTek SCPSYS generic power domain"
+	default ARCH_MEDIATEK
+	depends on PM
+	select PM_GENERIC_DOMAINS
+	select REGMAP
+	help
+	  Say y here to enable power domain support.
+	  In order to meet high performance and low power requirements, the System
+	  Control Processor System (SCPSYS) has several power management related
+	  tasks in the system.
+
+config MTK_MFG_PM_DOMAIN
+	bool "MediaTek MFlexGraphics power domain"
+	default ARCH_MEDIATEK
+	depends on PM
+	depends on OF
+	depends on COMMON_CLK
+	select MAILBOX
+	select PM_GENERIC_DOMAINS
+	imply MTK_GPUEB_MBOX
+	help
+	  Say y or m here to enable the power domains driver for MediaTek
+	  MFlexGraphics. This driver allows for power and frequency control of
+	  GPUs on MediaTek SoCs such as the MT8196 or MT6991.
+
+	  This driver is required for the Mali GPU to work at all on MT8196 and
+	  MT6991.
+
+config AIROHA_CPU_PM_DOMAIN
+	tristate "Airoha CPU power domain"
+	default ARCH_AIROHA
+	depends on HAVE_ARM_SMCCC
+	depends on PM
+	select PM_GENERIC_DOMAINS
+	help
+	  Say y here to enable CPU power domain support for Airoha SoC.
+
+	  CPU frequency and power is controlled by ATF with SMC command to
+	  set performance states.
+
+endmenu