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, 35 insertions, 0 deletions

diff --git a/sound/mips/Kconfig b/sound/mips/Kconfig
new file mode 100644
index 000000000..c484b1e42
--- /dev/null
+++ b/sound/mips/Kconfig
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# ALSA MIPS drivers
+
+menuconfig SND_MIPS
+	bool "MIPS sound devices"
+	depends on MIPS
+	default y
+	help
+	  Support for sound devices of MIPS architectures.
+
+if SND_MIPS
+
+config SND_SGI_O2
+	tristate "SGI O2 Audio"
+	depends on SGI_IP32
+	select SND_PCM
+	help
+	  Sound support for the SGI O2 Workstation.
+
+config SND_SGI_HAL2
+	tristate "SGI HAL2 Audio"
+	depends on SGI_HAS_HAL2
+	select SND_PCM
+	help
+	  Sound support for the SGI Indy and Indigo2 Workstation.
+
+config SND_N64
+	bool "N64 Audio"
+	depends on MACH_NINTENDO64 && SND=y
+	select SND_PCM
+	help
+	  Sound support for the N64.
+
+endif	# SND_MIPS
+