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, 50 insertions, 0 deletions

diff --git a/drivers/pci/pwrctrl/Kconfig b/drivers/pci/pwrctrl/Kconfig
new file mode 100644
index 000000000..9eec767cd
--- /dev/null
+++ b/drivers/pci/pwrctrl/Kconfig
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config HAVE_PWRCTRL
+	bool
+
+config PCI_PWRCTRL
+	tristate
+
+config PCI_PWRCTRL_PWRSEQ
+	tristate
+	select POWER_SEQUENCING
+	select PCI_PWRCTRL
+
+config PCI_PWRCTRL_GENERIC
+	tristate "Generic PCI Power Control driver for PCI slots and endpoints"
+	select POWER_SEQUENCING
+	select PCI_PWRCTRL
+	help
+	  Say Y here to enable the generic PCI Power Control driver to control
+	  the power state of PCI slots and endpoints.
+
+	  This is a generic driver that controls the power state of different
+	  PCI slots and endpoints. The voltage regulators powering the rails
+	  of the PCI slots or endpoints are expected to be defined in the
+	  devicetree node of the PCI bridge or endpoint.
+
+config PCI_PWRCTRL_TC9563
+	tristate "PCI Power Control driver for TC9563 PCIe switch"
+	select PCI_PWRCTRL
+	default m if ARCH_QCOM
+	depends on I2C
+	help
+	  Say Y here to enable the PCI Power Control driver of TC9563 PCIe
+	  switch.
+
+	  This driver enables power and configures the TC9563 PCIe switch
+	  through i2c. TC9563 is a PCIe switch which has one upstream and three
+	  downstream ports. To one of the downstream ports integrated ethernet
+	  MAC is connected as endpoint device. Other two downstream ports are
+	  supposed to connect to external device.
+
+# deprecated
+config HAVE_PWRCTL
+	bool
+	select HAVE_PWRCTRL
+
+# deprecated
+config PCI_PWRCTL_PWRSEQ
+	tristate
+	select PCI_PWRCTRL_PWRSEQ