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, 83 insertions, 0 deletions

diff --git a/arch/mips/bmips/Kconfig b/arch/mips/bmips/Kconfig
new file mode 100644
index 000000000..63dfc6950
--- /dev/null
+++ b/arch/mips/bmips/Kconfig
@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: GPL-2.0
+if BMIPS_GENERIC
+
+choice
+	prompt "Built-in device tree"
+	help
+	  Legacy bootloaders do not pass a DTB pointer to the kernel, so
+	  if a "wrapper" is not being used, the kernel will need to include
+	  a device tree that matches the target board.
+
+	  The builtin DTB will only be used if the firmware does not supply
+	  a valid DTB.
+
+config DT_NONE
+	bool "None"
+
+config DT_BCM93384WVG
+	bool "BCM93384WVG Zephyr CPU"
+	select BUILTIN_DTB
+
+config DT_BCM93384WVG_VIPER
+	bool "BCM93384WVG Viper CPU (EXPERIMENTAL)"
+	select BUILTIN_DTB
+
+config DT_BCM96368MVWG
+	bool "BCM96368MVWG"
+	select BUILTIN_DTB
+
+config DT_BCM9EJTAGPRB
+	bool "BCM9EJTAGPRB"
+	select BUILTIN_DTB
+
+config DT_BCM97125CBMB
+	bool "BCM97125CBMB"
+	select BUILTIN_DTB
+
+config DT_BCM97346DBSMB
+	bool "BCM97346DBSMB"
+	select BUILTIN_DTB
+
+config DT_BCM97358SVMB
+	bool "BCM97358SVMB"
+	select BUILTIN_DTB
+
+config DT_BCM97360SVMB
+	bool "BCM97360SVMB"
+	select BUILTIN_DTB
+
+config DT_BCM97362SVMB
+	bool "BCM97362SVMB"
+	select BUILTIN_DTB
+
+config DT_BCM97420C
+	bool "BCM97420C"
+	select BUILTIN_DTB
+
+config DT_BCM97425SVMB
+	bool "BCM97425SVMB"
+	select BUILTIN_DTB
+
+config DT_BCM97435SVMB
+	bool "BCM97435SVMB"
+	select BUILTIN_DTB
+
+config DT_COMTREND_VR3032U
+	bool "Comtrend VR-3032u"
+	select BUILTIN_DTB
+
+config DT_NETGEAR_CVG834G
+	bool "NETGEAR CVG834G"
+	select BUILTIN_DTB
+
+config DT_SFR_NEUFBOX4_SERCOMM
+	bool "SFR Neufbox 4 (Sercomm)"
+	select BUILTIN_DTB
+
+config DT_SFR_NEUFBOX6_SERCOMM
+	bool "SFR Neufbox 6 (Sercomm)"
+	select BUILTIN_DTB
+
+endchoice
+
+endif