Re: [PATCH 1/2] efi/runtime-wrappers: bound the wait for EFI runtime service calls

[Breno Leitao <leitao@debian.org>]

Hi Ard,

On Thu, Jun 11, 2026 at 12:57:50PM +0200, Ard Biesheuvel wrote:
> > Could we just clear the EFI_RUNTIME_SERVICES bit here right away? That
> > way, we probably won't need the second patch (unless I'm mistaken). It
> > /should/ also block the calls that are not routed via the workqueue,
> > e.g., any EFI pstore calls to the non-blocking SetVariable() variant,
> > but I just noticed that we never check EFI_RUNTIME_SERVICES on those
> > code paths, which is probably a bug. 
> >
> > And please return EFI_ABORTED rather than EFI_TIMEOUT - probably doesn't
> > matter in practice but I'd like to avoid introducing more EFI return codes
> > in the runtime context that the spec mentions only for boot services stuff.
> 
> Also, could we prevent the kthread that runs the workqueue from being scheduled
> again if we decide that the runtime services are wedged?

Sure, I can park it at for (;;) schedule()). Maybe with a helper?!

> x86 has some logic for this when a page fault occurs, and I wonder if
> there is a generic way to do something similar.

I have no clue, to be honest. If you have something specific in mind,
I'll dig in.

Thanks for the review,
--breno