Re: RFC: Unwind info for PLT

[Jakub Jelinek <jakub@redhat.com>]

On Fri, Jun 10, 2011 at 08:15:37AM -0700, Richard Henderson wrote:
> On 06/10/2011 12:45 AM, Jakub Jelinek wrote:
> > Anyway, I think hardcoding this in the linker would be problematic,
> > we couldn't tweak it, so providing some special hidden symbols around
> > the .plt section and let glibc crtfiles provide it sounds like the best
> > option to me.
> 
> Would it be problematic beyond the fact that it's easier to write the
> directives in assembler than it is within bfd?

Yeah, easier to write and easier to change.  Anyway, if you prefer to do
it in ld, I can try to do it there.  Just a question, should it be done
unconditionally, or guarded with some ld cmdline option (either existing one, like
abuse --eh-frame-hdr for it, or a new one)?

On other targets like SPARC or PowerPC -mbss-plt it is the dynamic linker
which updates or completely writes .plt section though, should in that
case the dynamic linker provide the unwind info instead?

> As for the actual unwind info, I agree that using pointer arithmetic
> is the better expression over decoding the insns.  Increasing the
> alignment is probably a good idea, also for the actual decoding of
> the insns on the real hardware.

Ok.

	Jakub