Re: SPU overlay update

[Alan Modra <amodra at bigpond dot net dot au>]

My 2008-01-28 changes to elf32-spu.c introduced a bug that could cause
a ld segfault in spu_elf_relocate_section when elf_local_got_ents was
accessed.  Simply testing for a NULL would be sufficient to cure the
bug, but I think it's better to protect the access by using the same
logic as that used when setting up elf_local_got_ents.  Doing so also
cures another bug that could be tickled by data that happened to look
like a branch.

	* elf32-spu.c (spu_elf_relocate_section): Test identical conditions
	to those in process_stubs for overlay symbols.

Index: bfd/elf32-spu.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-spu.c,v
retrieving revision 1.31
diff -c -p -r1.31 elf32-spu.c
*** bfd/elf32-spu.c	3 Mar 2008 10:03:40 -0000	1.31
--- bfd/elf32-spu.c	11 Mar 2008 09:29:20 -0000
*************** spu_elf_relocate_section (bfd *output_bf
*** 2708,2714 ****
        bfd_reloc_status_type r;
        bfd_boolean unresolved_reloc;
        bfd_boolean warned;
-       bfd_boolean branch;
  
        r_symndx = ELF32_R_SYM (rel->r_info);
        r_type = ELF32_R_TYPE (rel->r_info);
--- 2708,2713 ----
*************** spu_elf_relocate_section (bfd *output_bf
*** 2769,2801 ****
        /* If this symbol is in an overlay area, we may need to relocate
  	 to the overlay stub.  */
        addend = rel->r_addend;
-       branch = (is_branch (contents + rel->r_offset)
- 		|| is_hint (contents + rel->r_offset));
        if (htab->stub_sec != NULL
! 	  && needs_ovl_stub (sym_name, sec, input_section, htab, branch)
  	  && (h == NULL
  	      || (h != htab->ovly_load && h != htab->ovly_return)))
  	{
! 	  unsigned int ovl = 0;
! 	  struct got_entry *g, **head;
  
! 	  if (branch)
! 	    ovl = (spu_elf_section_data (input_section->output_section)
! 		   ->u.o.ovl_index);
  
  	  if (h != NULL)
! 	    head = &h->got.glist;
  	  else
! 	    head = elf_local_got_ents (input_bfd) + r_symndx;
  
! 	  for (g = *head; g != NULL; g = g->next)
! 	    if (g->addend == addend && (g->ovl == ovl || g->ovl == 0))
! 	      break;
! 	  if (g == NULL)
! 	    abort ();
  
! 	  relocation = g->stub_addr;
! 	  addend = 0;
  	}
  
        r = _bfd_final_link_relocate (howto,
--- 2768,2818 ----
        /* If this symbol is in an overlay area, we may need to relocate
  	 to the overlay stub.  */
        addend = rel->r_addend;
        if (htab->stub_sec != NULL
! 	  && sec != NULL
! 	  && sec->output_section != NULL
! 	  && sec->output_section->owner == output_bfd
  	  && (h == NULL
  	      || (h != htab->ovly_load && h != htab->ovly_return)))
  	{
! 	  bfd_boolean branch;
! 	  unsigned int sym_type;
  
! 	  branch = FALSE;
! 	  if (r_type == R_SPU_REL16
! 	      || r_type == R_SPU_ADDR16)
! 	    branch = (is_branch (contents + rel->r_offset)
! 		      || is_hint (contents + rel->r_offset));
  
  	  if (h != NULL)
! 	    sym_type = h->type;
  	  else
! 	    sym_type = ELF_ST_TYPE (sym->st_info);
  
! 	  if ((sym_type == STT_FUNC || branch)
! 	      && needs_ovl_stub (sym_name, sec, input_section, htab, branch))
! 	    {
! 	      unsigned int ovl = 0;
! 	      struct got_entry *g, **head;
  
! 	      if (branch)
! 		ovl = (spu_elf_section_data (input_section->output_section)
! 		       ->u.o.ovl_index);
! 
! 	      if (h != NULL)
! 		head = &h->got.glist;
! 	      else
! 		head = elf_local_got_ents (input_bfd) + r_symndx;
! 
! 	      for (g = *head; g != NULL; g = g->next)
! 		if (g->addend == addend && (g->ovl == ovl || g->ovl == 0))
! 		  break;
! 	      if (g == NULL)
! 		abort ();
! 
! 	      relocation = g->stub_addr;
! 	      addend = 0;
! 	    }
  	}
  
        r = _bfd_final_link_relocate (howto,

-- 
Alan Modra
Australia Development Lab, IBM