> From: "Theo de Raadt" <deraadt@openbsd.org>
> Date: Sun, 15 Jun 2025 10:16:57 -0600
> 
> Philip Guenther <guenther@gmail.com> wrote:
> 
> > Okay, then I think the original diff is correct, though maybe we add
> > the assertwaitok() to fpu_kernel_enter() so we remain confident of
> > that.
> 
> If an assert triggers at this point, in drm code, it is unlikely that
> a user will see it.  I expect it will deadlock the kernel hard in a
> very invisible fashion...

Well, assertwaitok() does a few checks.  The first one is:

    splassert(IPL_NONE);

This is the check we want to make sure that we're not called from
interrupt context.  By default, this just prints a warning message,
which shouldn't cause a deadlock.

There are other checks that may trigger a panic and therefore may
appear to the user as a deadlock.  So I think it is better to just add
an splassert(IPL_NONE) into fpu_kernel_enter().