Merge tag 'core-debugobjects-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core debugobjects update from Thomas Gleixner:
 "A single update to debugobjects:

  Prevent a race vs statically initialized objects. Such objects are
  usually not initialized via an init() function. They are special cased
  and detected on first use under the assumption that they are already
  correctly initialized via the static initializer.

  This works correctly unless there are two concurrent debug object
  operations on such an object.

  The first one detects that the object is not yet tracked and tries to
  establish a tracking object after dropping the debug objects hash
  bucket lock. The concurrent operation does the same. The one which
  wins the race ends up modifying the state of the object which makes
  the other one fail resulting in a bogus debug objects warning.

  Prevent this by making the detection of a static object and the
  allocation of a tracking object atomic under the hash bucket lock. So
  the first one to acquire the hash bucket lock will succeed and the
  second one will observe the correct tracking state.

  This race existed forever but was only exposed when the timer wheel
  code added a debug_object_assert_init() call outside of the timer base
  locked region. This replaced the previous warning about
  timer::function being NULL which had to be removed when the
  timer_shutdown() mechanics were added"

* tag 'core-debugobjects-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobject: Prevent init race with static objects

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