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Re: [GOLD] ifunc tests
On Wed, Mar 06, 2013 at 06:15:04AM -0800, Ian Lance Taylor wrote:
> On Wed, Mar 6, 2013 at 3:45 AM, Alan Modra <email@example.com> wrote:
> > ifuncmain1pie and ifuncmain6pie fail on powerpc, because the ifunc
> > resolver function runs *before* all GOT relocations have been applied.
> > (The tests all pass on powerpc64 with a recent gcc due to
> > -mcmodel=medium avoiding the GOT/TOC. They fail with any other
> > -mcmodel.)
> I don't understand why the ifunc relocations can't be run after all
> the other relocations are applied. That is how it works on x86. Gold
> uses a separate reloc section for the IRELATIVE relocs and puts it
> after the other reloc sections. The dynamic linker then processes the
> relocs in order.
Yes, we do the same on powerpc (*), but it only works for relocs in a
single binary, not when the ifunc relocation in a shared library uses
a resolver function in another shared library or the main app. In
that case GOT relocs may not have been applied. Exactly this
situation occurs in ifuncmain6pie/ifuncmod6.so.
*) I do have a reloc ordering problem in ifuncmod1.so that I intend to
fix. A foo() dynamic reloc there is before one setting up the GOT
entry for global:
00010c58 00000901 R_PPC_ADDR32 foo() foo + 0
00010c44 00000f01 R_PPC_ADDR32 00010c7c global + 0
Australia Development Lab, IBM