Re: [patch] Nios II build_id fix

[Alan Modra <amodra at gmail dot com>]

On Sat, Apr 05, 2014 at 09:16:10PM -0600, Sandra Loosemore wrote:
> On 04/04/2014 07:31 PM, Alan Modra wrote:
> >On Fri, Apr 04, 2014 at 10:52:22AM -0700, Cesar Philippidis wrote:
> >>@@ -2016,6 +2016,10 @@ nios2_elf32_build_stubs (struct bfd_link
> >>      {
> >>        bfd_size_type size;
> >>
> >>+      /* Ignore non-stub sections.  */
> >>+      if (!strstr (stub_sec->name, STUB_SUFFIX))
> >>+	continue;
> >
> >Um, how do you manage to get non-stub sections in the stub bfd?  Hmm,
> >via dynobj being set to the stub bfd, I expect.  If so, you could
> >probably test (stub_sec->flags & SEC_LINKER_CREATED) == 0 instead.
> 
> I had the same question when looking at this code.  I think this
> also suffers from the same bug (PR 13049) mentioned in the comment
> on STUB_SUFFIX in elf32-arm.c.
> 
> Hmmmm.  I see that stub sections are being created without
> SEC_LINKER_CREATED (ld/emultempl/nios2elf.em), while dynamic
> sections created in dynobj do have that flag by default (from
> ELF_DYNAMIC_SEC_FLAGS).  Other sections that end up in dynobj maybe
> do, maybe don't

What other sections?  I don't think there will be any.  You'll either
have stub sections or dynobj sections.  The latter all have
SEC_LINKER_CREATED, the former doesn't.

I handle exactly the same situation in elf64-ppc.c, where dynobj is
forced to be the stub bfd, without resorting to testing for
STUB_SUFFIX in the name.

Note that elf32-arm.c only needs to test for the stub name because the
ARM backend does create other sections (glue, veneer) in the stub bfd
besides stub sections.  nios2 doesn't, as far as I can see.

-- 
Alan Modra
Australia Development Lab, IBM