[Question] ifunc odering in ELF

[Juchan Kim]

Hi Florian,

OK. That's what I also expected. 
Thanks for the reply.

Cheers,
Juchan

On Mon, 2019-09-16 at 22:43 -0400, Florian Weimer wrote:
> * Juchan Kim:
> 
> > 
> > We have two ifuncs foo1 and foo2 in our library
> > 
> > foo1 has foo1_resolver() 
> > foo2 has foo2_resolver()
> > 
> > 
> > foo1_resolver() {
> > 	...
> > }
> > 
> > foo2_resolver() {
> > 	foo1()
> > 	...
> > }
> IFUNC resolvers must not depend on run-time relocations.  If you
> follow
> that rule, this cannot happen.
> 
> binutils ld sorts IFUNC relocations last, which helps, but to cover
> more
> cases (but not all of them), run-time reordering of relocations is
> needed.  We have some patches for that, but my impression is that the
> glibc project does not want them.  Instead, we're probably going to
> remove all IFUNC resolvers with relocation dependencies from glibc,
> and
> tell others to do so as well.
> 
> Thanks,
> Florian