Re: [linux-next:master 4972/5926] kernel/kexec_handover_debug.c:16:18: error: use of undeclared identifier 'kho_scratch_cnt'

[Pasha Tatashin <pasha.tatashin@soleen.com>]

On Tue, Nov 4, 2025 at 5:15 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Tue, 4 Nov 2025 12:50:49 -0500 Pasha Tatashin <pasha.tatashin@soleen.com> wrote:
>
> > The fix looks like this:
> > diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c
> > index de4466b47455..2a8c20c238a8 100644
> > --- a/kernel/kexec_handover.c
> > +++ b/kernel/kexec_handover.c
> > @@ -477,8 +477,8 @@ static void __init kho_mem_deserialize(const void *fdt)
> >   * area for early allocations that happen before page allocator is
> >   * initialized.
> >   */
> > -static struct kho_scratch *kho_scratch;
> > -static unsigned int kho_scratch_cnt;
> > +struct kho_scratch *kho_scratch;
> > +unsigned int kho_scratch_cnt;
>
> This patch is making changes which are already present.
>
> > --- a/kernel/kexec_handover_internal.h
> > +++ b/kernel/kexec_handover_internal.h
>
> Against files which were moved to kernel/liveupdate/!
>
> > Andrew, Mike, do you want me to resend the "[PATCH v3 0/3] KHO: kfence
> > + KHO memory corruption fix" series with the fix included?
>
> A little fix against what's presently in mm.git would be great, please.

Hi Andrew,

This is because in mm.git you have patches that move kexec_handover*
to kernel/liveupdate/ (and they fix this build problem), but
linux-next does not have these patches. The patch I sent is a fixup
for  "kho: warn and fail on metadata or preserved memory in scratch
area" patch.