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, 53 insertions, 0 deletions

diff --git a/sound/ppc/Kconfig b/sound/ppc/Kconfig
new file mode 100644
index 000000000..8789cb503
--- /dev/null
+++ b/sound/ppc/Kconfig
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# ALSA PowerMac drivers
+
+menuconfig SND_PPC
+	bool "PowerPC sound devices"
+	depends on PPC
+	default y
+	help
+	  Support for sound devices specific to PowerPC architectures.
+
+if SND_PPC
+
+config SND_POWERMAC
+	tristate "PowerMac (AWACS, DACA, Burgundy, Tumbler, Keywest)"
+	depends on I2C && INPUT && PPC_PMAC
+	select SND_PCM
+	select SND_VMASTER
+	help
+	  Say Y here to include support for the integrated sound device.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-powermac.
+
+config SND_POWERMAC_AUTO_DRC
+	bool "Toggle DRC automatically at headphone/line plug-in"
+	depends on SND_POWERMAC
+	default y
+	help
+	  Say Y here to enable the automatic toggle of DRC (dynamic
+	  range compression) on Tumbler/Snapper.
+	  If this feature is enabled, DRC is turned off when the
+	  headphone/line jack is plugged, and turned on when unplugged.
+
+	  Note that you can turn on/off DRC manually even without this
+	  option.
+
+config SND_PS3
+	tristate "PS3 Audio support"
+	depends on PS3_PS3AV
+	select SND_PCM
+	default m
+	help
+	  Say Y here to include support for audio on the PS3
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd_ps3.
+
+config SND_PS3_DEFAULT_START_DELAY
+	int "Startup delay time in ms"
+	depends on SND_PS3
+	default "2000"
+
+endif	# SND_PPC