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, 73 insertions, 0 deletions

diff --git a/drivers/net/fddi/Kconfig b/drivers/net/fddi/Kconfig
new file mode 100644
index 000000000..846bf41c2
--- /dev/null
+++ b/drivers/net/fddi/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# FDDI network device configuration
+#
+
+config FDDI
+	tristate "FDDI driver support"
+	depends on PCI || EISA || TC
+	help
+	  Fiber Distributed Data Interface is a high speed local area network
+	  design; essentially a replacement for high speed Ethernet. FDDI can
+	  run over copper or fiber. If you are connected to such a network and
+	  want a driver for the FDDI card in your computer, say Y here (and
+	  then also Y to the driver for your FDDI card, below). Most people
+	  will say N.
+
+if FDDI
+
+config DEFZA
+	tristate "DEC FDDIcontroller 700/700-C (DEFZA-xx) support"
+	depends on FDDI && TC
+	help
+	  This is support for the DEC FDDIcontroller 700 (DEFZA-AA, fiber)
+	  and 700-C (DEFZA-CA, copper) TURBOchannel network cards which
+	  can connect you to a local FDDI network.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called defza.  If unsure, say N.
+
+config DEFXX
+	tristate "Digital DEFTA/DEFEA/DEFPA adapter support"
+	depends on FDDI && (PCI || EISA || TC)
+	help
+	  This is support for the DIGITAL series of TURBOchannel (DEFTA),
+	  EISA (DEFEA) and PCI (DEFPA) controllers which can connect you
+	  to a local FDDI network.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called defxx.  If unsure, say N.
+
+config SKFP
+	tristate "SysKonnect FDDI PCI support"
+	depends on FDDI && PCI
+	select BITREVERSE
+	help
+	  Say Y here if you have a SysKonnect FDDI PCI adapter.
+	  The following adapters are supported by this driver:
+	  - SK-5521 (SK-NET FDDI-UP)
+	  - SK-5522 (SK-NET FDDI-UP DAS)
+	  - SK-5541 (SK-NET FDDI-FP)
+	  - SK-5543 (SK-NET FDDI-LP)
+	  - SK-5544 (SK-NET FDDI-LP DAS)
+	  - SK-5821 (SK-NET FDDI-UP64)
+	  - SK-5822 (SK-NET FDDI-UP64 DAS)
+	  - SK-5841 (SK-NET FDDI-FP64)
+	  - SK-5843 (SK-NET FDDI-LP64)
+	  - SK-5844 (SK-NET FDDI-LP64 DAS)
+	  - Netelligent 100 FDDI DAS Fibre SC
+	  - Netelligent 100 FDDI SAS Fibre SC
+	  - Netelligent 100 FDDI DAS UTP
+	  - Netelligent 100 FDDI SAS UTP
+	  - Netelligent 100 FDDI SAS Fibre MIC
+
+	  Read <file:Documentation/networking/device_drivers/fddi/skfp.rst>
+	  for information about the driver.
+
+	  Questions concerning this driver can be addressed to:
+	  <linux@syskonnect.de>
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called skfp.  This is recommended.
+
+endif # FDDI