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, 91 insertions, 0 deletions

diff --git a/drivers/rapidio/Kconfig b/drivers/rapidio/Kconfig
new file mode 100644
index 000000000..f1d742ac8
--- /dev/null
+++ b/drivers/rapidio/Kconfig
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RapidIO configuration
+#
+
+config HAVE_RAPIDIO
+	bool
+
+menuconfig RAPIDIO
+	tristate "RapidIO support"
+	depends on HAVE_RAPIDIO || PCI
+	help
+	  If you say Y here, the kernel will include drivers and
+	  infrastructure code to support RapidIO interconnect devices.
+
+source "drivers/rapidio/devices/Kconfig"
+
+config RAPIDIO_DISC_TIMEOUT
+	int "Discovery timeout duration (seconds)"
+	depends on RAPIDIO
+	default "30"
+	help
+	  Amount of time a discovery node waits for a host to complete
+	  enumeration before giving up.
+
+config RAPIDIO_ENABLE_RX_TX_PORTS
+	bool "Enable RapidIO Input/Output Ports"
+	depends on RAPIDIO
+	help
+	  The RapidIO specification describes a Output port transmit
+	  enable and a Input port receive enable. The recommended state
+	  for Input ports and Output ports should be disabled. When
+	  this switch is set the RapidIO subsystem will enable all
+	  ports for Input/Output direction to allow other traffic
+	  than Maintenance transfers.
+
+config RAPIDIO_DMA_ENGINE
+	bool "DMA Engine support for RapidIO"
+	depends on RAPIDIO
+	depends on DMADEVICES
+	select DMA_ENGINE
+	help
+	  Say Y here if you want to use DMA Engine frameork for RapidIO data
+	  transfers to/from target RIO devices. RapidIO uses NREAD and
+	  NWRITE (NWRITE_R, SWRITE) requests to transfer data between local
+	  memory and memory on remote target device. You need a DMA controller
+	  capable to perform data transfers to/from RapidIO.
+
+	  If you are unsure about this, say Y here.
+
+config RAPIDIO_DEBUG
+	bool "RapidIO subsystem debug messages"
+	depends on RAPIDIO
+	help
+	  Say Y here if you want the RapidIO subsystem to produce a bunch of
+	  debug messages to the system log. Select this if you are having a
+	  problem with the RapidIO subsystem and want to see more of what is
+	  going on.
+
+	  If you are unsure about this, say N here.
+
+config RAPIDIO_ENUM_BASIC
+	tristate "Basic Enumeration method"
+	depends on RAPIDIO
+	help
+	  This option includes basic RapidIO fabric enumeration and discovery
+	  mechanism similar to one described in RapidIO specification Annex 1.
+
+config RAPIDIO_CHMAN
+	tristate "RapidIO Channelized Messaging driver"
+	depends on RAPIDIO
+	help
+	  This option includes RapidIO channelized messaging driver which
+	  provides socket-like interface to allow sharing of single RapidIO
+	  messaging mailbox between multiple user-space applications.
+	  See "Documentation/driver-api/rapidio/rio_cm.rst" for driver description.
+
+config RAPIDIO_MPORT_CDEV
+	tristate "RapidIO /dev mport device driver"
+	depends on RAPIDIO
+	help
+	  This option includes generic RapidIO mport device driver which
+	  allows to user space applications to perform RapidIO-specific
+	  operations through selected RapidIO mport.
+
+menu "RapidIO Switch drivers"
+	depends on RAPIDIO
+
+source "drivers/rapidio/switches/Kconfig"
+
+endmenu