Re: [PATCH for-4.22?] x86/EFI: arrange for non-discardable .reloc in xen.efi

["Roger Pau Monné" <roger.pau@citrix.com>]

On Wed, Jun 17, 2026 at 12:37:38PM +0200, Jan Beulich wrote:
> On 17.06.2026 12:29, Roger Pau Monné wrote:
> > On Tue, Jun 16, 2026 at 06:17:54PM +0200, Jan Beulich wrote:
> >> Loaders respecting IMAGE_SCN_MEM_DISCARDABLE would not load such sections,
> >> yet we need to access it ourselves when switching out of "physical mode".
> >> Leverage behavior new to GNU ld 2.46: Any contribution to .reloc which
> >> doesn't have the discardable flag set (which cannot even be expressed in
> >> ELF) will yield the output section also non-discardable.
> >>
> >> Since for intermediate binaries we don't care about section attributes,
> >> link in the new object only on the final linking pass.
> > 
> > I'm not sure I follow.  Xen already does generate a custom .reloc
> > section without the IMAGE_SCN_MEM_DISCARDABLE attribute when using
> > the mkreloc utility, and hence the .reloc section should never be
> > marked as discardable?
> 
> mkreloc is used only when we recognize the linker to be incapable of
> producing (correct) base relocations. As a modern linker is required for
> the desired IMAGE_SCN_MEM_DISCARDABLE handling for .reloc, mkreloc
> wouldn't normally be used there. Hence no .reloc section with the wanted
> property.

I see, MKRELOC becomes ":" then, I didn't catch that.

Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.