Re: Stale entries left in GOT & PLT while discarding sections

["Rajat Jain" <rajat dot noida dot india at gmail dot com>]

On 4/7/06, Alan Modra <amodra@bigpond.net.au> wrote:
> On Fri, Apr 07, 2006 at 07:09:55PM +0530, Rajat Jain wrote:
> > 1) As per my understanding the reason that the (stale) entries for the
> > removed sections / symbols are left in the GOT / PLT is because "ld"
> > creates the GOT and PLT at an early stage and later when reading the
> > linker script discards the sections as requested. It however does not
> > see (and does not care) that due to the removal of certain sections,
> > the entries in GOT and PLT have become inconsistent. Is my
> > understanding correct?
>
> Yes.
>
> > 2) Is there any solution to the problem I am facing here? I mean is
> > there a way to remove the entries from the GOT and PLT as well?
>
> I think the basic machinery to do this is already in the linker
> --gc-sections support.  If I was trying to do this, I would
>
> o Break out the gc_sweep_hook calls in elflink.c:elf_gc_sweep into
>  another function.  ie. Set SEC_EXCLUDE in elf_gc_sweep, but don't call
>  the hook to decrement plt/got reloc counts.  The new function should
>  call gc_sweep_hook on all SEC_EXCLUDE sections that have been
>  processed by check_relocs.
> o Arrange to call the new function immediately after
>  ldlang.c:lang_process calls lang_place_orphans.
>

Hi Alan,

Thanks for the clue. I now have a new direction to look at :)

Thanks again,

Rajat