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>

2 files changed, 184 insertions, 0 deletions

diff --git a/Documentation/gpu/imagination/index.rst b/Documentation/gpu/imagination/index.rst
new file mode 100644
index 000000000..0c1e247ce
--- /dev/null
+++ b/Documentation/gpu/imagination/index.rst
@@ -0,0 +1,13 @@
+=======================================
+drm/imagination PowerVR Graphics Driver
+=======================================
+
+.. kernel-doc:: drivers/gpu/drm/imagination/pvr_drv.c
+   :doc: PowerVR (Series 6 and later) and IMG Graphics Driver
+
+Contents
+========
+.. toctree::
+   :maxdepth: 2
+
+   uapi
diff --git a/Documentation/gpu/imagination/uapi.rst b/Documentation/gpu/imagination/uapi.rst
new file mode 100644
index 000000000..7502413d0
--- /dev/null
+++ b/Documentation/gpu/imagination/uapi.rst
@@ -0,0 +1,171 @@
+====
+UAPI
+====
+The sources associated with this section can be found in ``pvr_drm.h``.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR UAPI
+
+OBJECT ARRAYS
+=============
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_obj_array
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: DRM_PVR_OBJ_ARRAY
+
+IOCTLS
+======
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL interface
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: PVR_IOCTL
+
+DEV_QUERY
+---------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL DEV_QUERY interface
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_dev_query
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_dev_query_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_dev_query_gpu_info
+                 drm_pvr_dev_query_runtime_info
+                 drm_pvr_dev_query_hwrt_info
+                 drm_pvr_dev_query_quirks
+                 drm_pvr_dev_query_enhancements
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_heap_id
+                 drm_pvr_heap
+                 drm_pvr_dev_query_heap_info
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_static_data_area_usage
+                 drm_pvr_static_data_area
+                 drm_pvr_dev_query_static_data_areas
+
+CREATE_BO
+---------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL CREATE_BO interface
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_create_bo_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for CREATE_BO
+
+GET_BO_MMAP_OFFSET
+------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL GET_BO_MMAP_OFFSET interface
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_get_bo_mmap_offset_args
+
+CREATE_VM_CONTEXT and DESTROY_VM_CONTEXT
+----------------------------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL CREATE_VM_CONTEXT and DESTROY_VM_CONTEXT interfaces
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_create_vm_context_args
+                 drm_pvr_ioctl_destroy_vm_context_args
+
+VM_MAP and VM_UNMAP
+-------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL VM_MAP and VM_UNMAP interfaces
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_vm_map_args
+                 drm_pvr_ioctl_vm_unmap_args
+
+CREATE_CONTEXT and DESTROY_CONTEXT
+----------------------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL CREATE_CONTEXT and DESTROY_CONTEXT interfaces
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_create_context_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ctx_priority
+                 drm_pvr_ctx_type
+                 drm_pvr_static_render_context_state
+                 drm_pvr_static_render_context_state_format
+                 drm_pvr_reset_framework
+                 drm_pvr_reset_framework_format
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_destroy_context_args
+
+CREATE_FREE_LIST and DESTROY_FREE_LIST
+--------------------------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL CREATE_FREE_LIST and DESTROY_FREE_LIST interfaces
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_create_free_list_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_destroy_free_list_args
+
+CREATE_HWRT_DATASET and DESTROY_HWRT_DATASET
+--------------------------------------------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL CREATE_HWRT_DATASET and DESTROY_HWRT_DATASET interfaces
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_create_hwrt_dataset_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_create_hwrt_geom_data_args
+                 drm_pvr_create_hwrt_rt_data_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_destroy_hwrt_dataset_args
+
+SUBMIT_JOBS
+-----------
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: PowerVR IOCTL SUBMIT_JOBS interface
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for the drm_pvr_sync_op object.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_ioctl_submit_jobs_args
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for SUBMIT_JOB ioctl geometry command.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for SUBMIT_JOB ioctl fragment command.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for SUBMIT_JOB ioctl compute command.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :doc: Flags for SUBMIT_JOB ioctl transfer command.
+
+.. kernel-doc:: include/uapi/drm/pvr_drm.h
+   :identifiers: drm_pvr_sync_op
+                 drm_pvr_job_type
+                 drm_pvr_hwrt_data_ref
+                 drm_pvr_job
+
+Internal notes
+==============
+.. kernel-doc:: drivers/gpu/drm/imagination/pvr_device.h
+   :doc: IOCTL validation helpers
+
+.. kernel-doc:: drivers/gpu/drm/imagination/pvr_device.h
+   :identifiers: PVR_STATIC_ASSERT_64BIT_ALIGNED PVR_IOCTL_UNION_PADDING_CHECK
+                 pvr_ioctl_union_padding_check