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, 27 insertions, 0 deletions

diff --git a/drivers/accel/ivpu/Kconfig b/drivers/accel/ivpu/Kconfig
new file mode 100644
index 000000000..9e055b5ce
--- /dev/null
+++ b/drivers/accel/ivpu/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config DRM_ACCEL_IVPU
+	tristate "Intel NPU (Neural Processing Unit)"
+	depends on DRM_ACCEL
+	depends on X86_64 && !UML
+	depends on PCI && PCI_MSI
+	select FW_LOADER
+	select DRM_GEM_SHMEM_HELPER
+	select GENERIC_ALLOCATOR
+	select WANT_DEV_COREDUMP
+	help
+	  Choose this option if you have a system with an 14th generation
+	  Intel CPU (Meteor Lake) or newer. Intel NPU (formerly called Intel VPU)
+	  is a CPU-integrated inference accelerator for Computer Vision
+	  and Deep Learning applications.
+
+	  If "M" is selected, the module will be called intel_vpu.
+
+config DRM_ACCEL_IVPU_DEBUG
+	bool "Intel NPU debug mode"
+	depends on DRM_ACCEL_IVPU
+	help
+	  Choose this option to enable additional
+	  debug features for the Intel NPU driver:
+	  - Always print debug messages regardless of dyndbg config,
+	  - Enable unsafe module params.