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, 118 insertions, 0 deletions

diff --git a/drivers/bcma/Kconfig b/drivers/bcma/Kconfig
new file mode 100644
index 000000000..b9558ff20
--- /dev/null
+++ b/drivers/bcma/Kconfig
@@ -0,0 +1,118 @@
+# SPDX-License-Identifier: GPL-2.0
+config BCMA_POSSIBLE
+	bool
+	depends on HAS_IOMEM && HAS_DMA
+	default y
+
+menuconfig BCMA
+	tristate "Broadcom specific AMBA"
+	depends on BCMA_POSSIBLE
+	help
+	  Bus driver for Broadcom specific Advanced Microcontroller Bus
+	  Architecture.
+
+if BCMA
+
+# Support for Block-I/O. SELECT this from the driver that needs it.
+config BCMA_BLOCKIO
+	bool
+
+config BCMA_HOST_PCI_POSSIBLE
+	bool
+	depends on PCI = y
+	default y
+
+config BCMA_HOST_PCI
+	bool "Support for BCMA on PCI-host bus"
+	depends on BCMA_HOST_PCI_POSSIBLE
+	select BCMA_DRIVER_PCI
+	default y
+
+config BCMA_HOST_SOC
+	bool "Support for BCMA in a SoC"
+	depends on HAS_IOMEM
+	help
+	  Host interface for a Broadcom AIX bus directly mapped into
+	  the memory. This only works with the Broadcom SoCs from the
+	  BCM47XX line.
+
+	  If unsure, say N
+
+config BCMA_DRIVER_PCI
+	bool "BCMA Broadcom PCI core driver"
+	depends on PCI
+	default y
+	help
+	  BCMA bus may have many versions of PCIe core. This driver
+	  supports:
+	  1) PCIe core working in clientmode
+	  2) PCIe Gen 2 clientmode core
+
+	  In general PCIe (Gen 2) clientmode core is required on PCIe
+	  hosted buses. It's responsible for initialization and basic
+	  hardware management.
+	  This driver is also prerequisite for a hostmode PCIe core
+	  support.
+
+config BCMA_DRIVER_PCI_HOSTMODE
+	bool "Driver for PCI core working in hostmode"
+	depends on MIPS && BCMA_DRIVER_PCI && PCI_DRIVERS_LEGACY && BCMA = y
+	help
+	  PCI core hostmode operation (external PCI bus).
+
+config BCMA_DRIVER_MIPS
+	bool "BCMA Broadcom MIPS core driver"
+	depends on MIPS || COMPILE_TEST
+	help
+	  Driver for the Broadcom MIPS core attached to Broadcom specific
+	  Advanced Microcontroller Bus.
+
+	  If unsure, say N
+
+config BCMA_PFLASH
+	bool
+	depends on BCMA_DRIVER_MIPS
+	default y
+
+config BCMA_SFLASH
+	bool "ChipCommon-attached serial flash support"
+	depends on BCMA_HOST_SOC
+	default y
+	help
+	  Some cheap devices have serial flash connected to the ChipCommon
+	  instead of independent SPI controller. It requires using a separated
+	  driver that implements ChipCommon specific interface communication.
+
+	  Enabling this symbol will let bcma recognize serial flash and register
+	  it as platform device.
+
+config BCMA_NFLASH
+	bool
+	depends on BCMA_DRIVER_MIPS
+	default y
+
+config BCMA_DRIVER_GMAC_CMN
+	bool "BCMA Broadcom GBIT MAC COMMON core driver"
+	help
+	  Driver for the Broadcom GBIT MAC COMMON core attached to Broadcom
+	  specific Advanced Microcontroller Bus.
+
+	  If unsure, say N
+
+config BCMA_DRIVER_GPIO
+	bool "BCMA GPIO driver"
+	depends on GPIOLIB
+	select GPIOLIB_IRQCHIP if BCMA_HOST_SOC
+	help
+	  Driver to provide access to the GPIO pins of the bcma bus.
+
+	  If unsure, say N
+
+config BCMA_DEBUG
+	bool "BCMA debugging"
+	help
+	  This turns on additional debugging messages.
+
+	  If unsure, say N
+
+endif # BCMA