Re: R_SPARC_13

[Richard Mortimer]

On 18/01/2011 06:50, David Miller wrote:
> From: David Miller<davem@xxxxxxxxxxxxx>
> Date: Mon, 17 Jan 2011 16:37:09 -0800 (PST)
>
> > So we do end up seeing the R_SPARC_LO10 + R_SPARC_13 sequences in the
> > final module object.
> >
> > Therefore, we really should handle R_SPARC_13 in the sparc module loader.
>
> Ok, I now feel like I'm hallucinating.
>
> davem@sunset:~/src/GIT/linux-2.6-stable$ uname -a
> Linux sunset 2.6.37 #1 SMP Wed Jan 12 20:14:59 PST 2011 sparc64 GNU/Linux
> davem@sunset:~/src/GIT/linux-2.6-stable$ objdump --reloc /lib/modules/2.6.37/kernel/net/ipv6/ipv6.ko | grep R_SPARC_13
> 0000000000000c7c R_SPARC_13        *ABS*+0x0000000000000004
> 0000000000001ae4 R_SPARC_13        *ABS*+0x0000000000000018
> 0000000000001b0c R_SPARC_13        *ABS*+0x0000000000000008
>   ...
> davem@sunset:~/src/GIT/linux-2.6-stable$ lsmod | grep ipv6
> ipv6                  240422  12
> davem@sunset:~/src/GIT/linux-2.6-stable$
>
> I must be missing something obvious.

I think objdump may be distorting the truth a little. I found the 
following in binutils gas/config/tc-sparc.c tc-gen_reloc(). I wonder if 
it is displaying rewritten records rather than displaying the raw 
contents. I haven't traced it through the code but the fact that it is 
obviously working for you means that something like this is going on.

  /* We expand R_SPARC_OLO10 to R_SPARC_LO10 and R_SPARC_13
     on the same location.  */
  if (code == BFD_RELOC_SPARC_OLO10)
    {
      relocs[1] = reloc = (arelent *) xmalloc (sizeof (arelent));
      relocs[2] = NULL;

      reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
      *reloc->sym_ptr_ptr
        = symbol_get_bfdsym (section_symbol (absolute_section));
      reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
      reloc->howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_SPARC13);
      reloc->addend = fixp->tc_fix_data;
    }

I will try your alignment patch without any R_SPARC_13 related changes 
and see how that goes.

Regards

Richard
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