Re: [PATCH 7/9] arm64/build: Warn on orphan section placement

From: Kees Cook
Date: Tue Mar 17 2020 - 19:01:23 EST


On Tue, Mar 17, 2020 at 09:56:14PM +0000, Will Deacon wrote:
> On Thu, Feb 27, 2020 at 04:22:42PM -0800, Kees Cook wrote:
> > We don't want to depend on the linker's orphan section placement
> > heuristics as these can vary between linkers, and may change between
> > versions. All sections need to be explicitly named in the linker
> > script.
> >
> > Explicitly include debug sections when they're present. Add .eh_frame*
> > to discard as it seems that these are still generated even though
> > -fno-asynchronous-unwind-tables is being specified. Add .plt and
> > .data.rel.ro to discards as they are not actually used. Add .got.plt
> > to the image as it does appear to be mapped near .data. Finally enable
> > orphan section warnings.
>
> Hmm, I don't understand what .got.plt is doing here. Please can you
> elaborate?

I didn't track it down, but it seems to have been present (and merged
into the kernel .data) for a while now. I can try to track this down if
you want?

--
Kees Cook