RFC: Add DT_GNU_DEBUG

[H.J. Lu]

On Sun, Aug 1, 2021 at 10:22 PM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu:
>
> > On Wed, Jul 28, 2021 at 1:04 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >> > Do you want to drive this, or should I ? It looks like you know the people
> >> > involved better than I do.
> >> >
> >>
> >> https://groups.google.com/g/generic-abi/c/1ngxmSwrafc
> >>
> >
> > I don't think the gABI community is interested in a new debug dynamic
> > tag.  I propose DT_GNU_DEBUG:
> >
> > #define DT_GNU_DEBUG   0x6ffffff8
> >
> > for the address of a pointer which will be filled by the dynamic
> > linker.  Linker should
> > add the DT_GNU_DEBUG entry to executable's dynamic section.
> >
> > BTW, we have a choice.  DT_GNU_DEBUG can be readonly or readonly after
> > relocation, like DT_DEBUG.
>
> What about adding DT_DEBUG_SIZE, specifying the size of the data pointed
> to by DT_DEBUG?

It works if we don't need to support static executables.

> Perhaps the gABI folks are interested in that, too?  I think it's worth
> a try.  If the answer is “no”, we can still add DT_GNU_DEBUG_SIZE to the
> GNU ABI.

I did.  I didn't get any feedback.

-- 
H.J.