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, 95 insertions, 0 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
new file mode 100644
index 000000000..a7144d275
--- /dev/null
+++ b/drivers/video/Kconfig
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Video configuration
+#
+
+menu "Graphics support"
+
+config APERTURE_HELPERS
+	bool
+	help
+	  Support tracking and hand-over of aperture ownership. Required
+	  by graphics drivers for firmware-provided framebuffers.
+
+config SCREEN_INFO
+	bool
+	default n
+
+config STI_CORE
+	bool
+	depends on PARISC
+	help
+	  STI refers to the HP "Standard Text Interface" which is a set of
+	  BIOS routines contained in a ROM chip in HP PA-RISC based machines.
+
+config VIDEO
+	bool
+	default n
+
+source "drivers/auxdisplay/Kconfig"
+
+if HAS_IOMEM
+
+config HAVE_FB_ATMEL
+	bool
+
+source "drivers/char/agp/Kconfig"
+
+source "drivers/gpu/vga/Kconfig"
+
+source "drivers/gpu/Kconfig"
+source "drivers/gpu/host1x/Kconfig"
+source "drivers/gpu/ipu-v3/Kconfig"
+source "drivers/gpu/nova-core/Kconfig"
+
+source "drivers/gpu/drm/Kconfig"
+
+menu "Frame buffer Devices"
+source "drivers/video/fbdev/Kconfig"
+endmenu
+
+source "drivers/video/backlight/Kconfig"
+
+config VGASTATE
+       tristate
+       default n
+
+config VIDEOMODE_HELPERS
+	bool
+
+config HDMI
+	bool
+
+endif # HAS_IOMEM
+
+config FIRMWARE_EDID
+	bool "Enable firmware EDID"
+	depends on EFI_GENERIC_STUB || X86
+	help
+	  This enables access to the EDID transferred from the firmware.
+	  On EFI systems, the EDID comes from the same device as the
+	  primary GOP. On x86 with BIOS, it comes from the VESA BIOS.
+	  DRM display drivers will be able to export the information
+	  to userspace.
+
+	  Also enable this if DDC/I2C transfers do not work for your driver
+	  and if you are using nvidiafb, i810fb or savagefb.
+
+	  In general, choosing Y for this option is safe.  If you
+	  experience extremely long delays while booting before you get
+	  something on your display, try setting this to N.  Matrox cards in
+	  combination with certain motherboards and monitors are known to
+	  suffer from this problem.
+
+if VT
+	source "drivers/video/console/Kconfig"
+endif
+
+if FB_CORE || SGI_NEWPORT_CONSOLE
+	source "drivers/video/logo/Kconfig"
+
+endif
+
+source "drivers/gpu/trace/Kconfig"
+
+endmenu