Re: [PATCH v2 1/2] arm/build: Warn on orphan section placement

[Kees Cook]

On Tue, Jun 23, 2020 at 05:03:46PM -0700, Nick Desaulniers wrote:
> On Mon, Jun 22, 2020 at 1:49 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > [...]
> > @@ -37,6 +38,13 @@
> >                 *(.idmap.text)                                          \
> >                 __idmap_text_end = .;                                   \
> >
> > +#define ARM_COMMON_DISCARD                                             \
> > +               *(.ARM.attributes)                                      \
> 
> I could have sworn that someone (Eli?) once told me that this section
> (.ARM.attributes) is used for disambiguating which ARM version or
> which optional extensions were used when compiling, and that without
> this section, one would not be able to disassemble 32b ARM precisely.
> If that's the case, we might not want to discard it?

Perhaps we want to treat it like .comment and include it in the ELF?

> > +#define ARM_STUBS_TEXT                                                 \
> > +               *(.gnu.warning)                                         \
> > +               *(.glue_7t)                                             \
> > +               *(.glue_7)                                              \
> 
> This changes the order of .glue_7t relative to .glue_7.  Maybe that
> doesn't matter.

Good point. I'll swap it just for consistency.

Thanks!

-- 
Kees Cook