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, 41 insertions, 0 deletions

diff --git a/drivers/pmdomain/qcom/Kconfig b/drivers/pmdomain/qcom/Kconfig
new file mode 100644
index 000000000..4abd43a88
--- /dev/null
+++ b/drivers/pmdomain/qcom/Kconfig
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Qualcomm PM Domains"
+
+config QCOM_CPR
+	tristate "Qualcomm Core Power Reduction (CPR) support"
+	depends on (ARCH_QCOM || COMPILE_TEST) && HAS_IOMEM
+	select PM_OPP
+	select REGMAP
+	help
+	  Say Y here to enable support for the CPR hardware found on Qualcomm
+	  SoCs like QCS404.
+
+	  This driver populates CPU OPPs tables and makes adjustments to the
+	  tables based on feedback from the CPR hardware. If you want to do
+	  CPUfrequency scaling say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called qcom-cpr
+
+config QCOM_RPMHPD
+	tristate "Qualcomm RPMh Power domain driver"
+	depends on QCOM_RPMH && QCOM_COMMAND_DB
+	help
+	  QCOM RPMh Power domain driver to support power-domains with
+	  performance states. The driver communicates a performance state
+	  value to RPMh which then translates it into corresponding voltage
+	  for the voltage rail.
+
+config QCOM_RPMPD
+	tristate "Qualcomm RPM Power domain driver"
+	depends on PM && OF
+	depends on QCOM_SMD_RPM
+	select PM_GENERIC_DOMAINS
+	select PM_GENERIC_DOMAINS_OF
+	help
+	  QCOM RPM Power domain driver to support power-domains with
+	  performance states. The driver communicates a performance state
+	  value to RPM which then translates it into corresponding voltage
+	  for the voltage rail.
+
+endmenu