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, 112 insertions, 0 deletions

diff --git a/sound/Kconfig b/sound/Kconfig
new file mode 100644
index 000000000..8b4020539
--- /dev/null
+++ b/sound/Kconfig
@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig SOUND
+	tristate "Sound card support"
+	depends on HAS_IOMEM || INDIRECT_IOMEM
+	help
+	  If you have a sound card in your computer, i.e. if it can say more
+	  than an occasional beep, say Y.
+
+if SOUND
+
+config SOUND_OSS_CORE
+	bool
+	default n
+
+config SOUND_OSS_CORE_PRECLAIM
+	bool "Preclaim OSS device numbers"
+	depends on SOUND_OSS_CORE
+	default y
+	help
+	  With this option enabled, the kernel will claim all OSS device
+	  numbers if any OSS support (native or emulation) is enabled
+	  whether the respective module is loaded or not and try to load the
+	  appropriate module using sound-slot/service-* and char-major-*
+	  module aliases when one of the device numbers is opened.  With
+	  this option disabled, kernel will only claim actually in-use
+	  device numbers and opening a missing device will generate only the
+	  standard char-major-* aliases.
+
+	  The only visible difference is use of additional module aliases
+	  and whether OSS sound devices appear multiple times in
+	  /proc/devices.  sound-slot/service-* module aliases are scheduled
+	  to be removed (ie. PRECLAIM won't be available) and this option is
+	  to make the transition easier.  This option can be overridden
+	  during boot using the kernel parameter soundcore.preclaim_oss.
+
+	  Disabling this allows alternative OSS implementations.
+
+	  If unsure, say Y.
+
+source "sound/oss/dmasound/Kconfig"
+
+menuconfig SND
+	tristate "Advanced Linux Sound Architecture"
+	help
+	  Say 'Y' or 'M' to enable ALSA (Advanced Linux Sound Architecture),
+	  the new base sound system.
+
+	  For more information, see <http://www.alsa-project.org/>
+
+if SND
+
+source "sound/core/Kconfig"
+
+source "sound/drivers/Kconfig"
+
+source "sound/isa/Kconfig"
+
+source "sound/pci/Kconfig"
+
+source "sound/hda/Kconfig"
+
+source "sound/ppc/Kconfig"
+
+source "sound/ac97/Kconfig"
+
+source "sound/aoa/Kconfig"
+
+source "sound/arm/Kconfig"
+
+source "sound/atmel/Kconfig"
+
+source "sound/spi/Kconfig"
+
+source "sound/mips/Kconfig"
+
+source "sound/sh/Kconfig"
+
+# the following will depend on the order of config.
+# here assuming USB is defined before ALSA
+source "sound/usb/Kconfig"
+
+source "sound/firewire/Kconfig"
+
+# the following will depend on the order of config.
+# here assuming PCMCIA is defined before ALSA
+source "sound/pcmcia/Kconfig"
+
+source "sound/sparc/Kconfig"
+
+source "sound/parisc/Kconfig"
+
+source "sound/soc/Kconfig"
+
+source "sound/x86/Kconfig"
+
+source "sound/synth/Kconfig"
+
+source "sound/xen/Kconfig"
+
+source "sound/virtio/Kconfig"
+
+endif # SND
+
+endif # SOUND
+
+config AC97_BUS
+	tristate
+	help
+	  This is used to avoid config and link hard dependencies between the
+	  sound subsystem and other function drivers completely unrelated to
+	  sound although they're sharing the AC97 bus. Concerned drivers
+	  should "select" this.