PPC relocs in shared libraries

[Geoff Keating]

> Date: Wed, 25 Sep 2002 18:02:09 -0400
> From: Daniel Jacobowitz <drow@mvista.com>

> H. J.'s binutils releases have had this patch to elf32-ppc.c applied for
> some time now:
> 
> 2001-10-07  Jakub Jelinek  <jakub@redhat.com>
> 
>         * elf32-ppc.c (ppc_elf_check_relocs): Don't output relocations
>         for debugging sections.
>         (ppc_elf_relocate_section): Likewise.
> 
> diff -ur binutils-2.13.90.0.4/binutils-2.13.90.0.4/bfd/elf32-ppc.c branch-src/bfd/elf32-ppc.c
> --- binutils-2.13.90.0.4/binutils-2.13.90.0.4/bfd/elf32-ppc.c   2002-08-14 13:35:11.000000000 -0400
> +++ branch-src/bfd/elf32-ppc.c  2002-09-25 17:39:20.000000000 -0400
> @@ -2420,7 +2420,7 @@
>           /* fall through */
>  
>         default:
> -         if (info->shared && (sec->flags & SEC_ALLOC) != 0)
> +         if (info->shared)
>             {
>  #ifdef DEBUG
>               fprintf (stderr, "ppc_elf_check_relocs need to create relocation for %s\n",
> @@ -3178,8 +3178,7 @@
>         case (int) R_PPC_ADDR14:
>         case (int) R_PPC_UADDR32:
>         case (int) R_PPC_UADDR16:
> -         if (info->shared && r_symndx != 0
> -             && (input_section->flags & SEC_ALLOC) != 0)
> +         if (info->shared && r_symndx != 0)
>             {
>               Elf_Internal_Rela outrel;
>               int skip;
> 
> 
> Geoff rejected the patch, saying it was the debugger's job to handle these
> relocations.  I'm not sure if that's right - I don't see the point in having
> to handle them for shared libraries - but GDB needs the code to do so in
> order to debug unlinked modules.  So, as far as that goes, we're all
> together.  But in readelf we have this bit (around line 7990):
> 
>           for (rp = rela; rp < rela + nrelas; ++rp)
>             { 
>               if (rp->r_offset
>                   != (bfd_vma) ((unsigned char *) &external->cu_abbrev_offset
>                                 - section_begin))
>                 continue;
> 
>               if (is_32bit_elf)
>                 { 
>                   sym = symtab + ELF32_R_SYM (rp->r_info);
> 
>                   if (ELF32_ST_TYPE (sym->st_info) != STT_SECTION)
>                     { 
>                       warn (_("Skipping unexpected symbol type %u\n"),
>                             ELF32_ST_TYPE (sym->st_info));
>                       continue;
>                     }
> 
> Well, in a shared library these have all been resolved to *ABS* relocs, and
> the warning triggers.  Should the warning be corrected, or the relocations
> removed?

The warning should be corrected.  I think this code will do the right
thing if the warning is suppressed for this case.

-- 
- Geoffrey Keating <geoffk@geoffk.org>