elf32-i386.c

基于4个mips核的noc设计

  struct bfd_link_info *info = (struct bfd_link_info *) inf;

  /* If a symbol has been forced local or we have found a regular
     definition for the symbolic link case, then we won't be needing
     any relocs.  */
  if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
      && ((h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0
	  || info->symbolic))
    {
      for (s = h->pcrel_relocs_copied; s != NULL; s = s->next)
	s->section->_raw_size -= s->count * sizeof (Elf32_External_Rel);
    }

  return true;
}

/* Relocate an i386 ELF section.  */

static boolean
elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
			   contents, relocs, local_syms, local_sections)
     bfd *output_bfd;
     struct bfd_link_info *info;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     Elf_Internal_Rela *relocs;
     Elf_Internal_Sym *local_syms;
     asection **local_sections;
{
  bfd *dynobj;
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  bfd_vma *local_got_offsets;
  asection *sgot;
  asection *splt;
  asection *sreloc;
  Elf_Internal_Rela *rel;
  Elf_Internal_Rela *relend;

  dynobj = elf_hash_table (info)->dynobj;
  symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (input_bfd);
  local_got_offsets = elf_local_got_offsets (input_bfd);

  sreloc = NULL;
  splt = NULL;
  sgot = NULL;
  if (dynobj != NULL)
    {
      splt = bfd_get_section_by_name (dynobj, ".plt");
      sgot = bfd_get_section_by_name (dynobj, ".got");
    }

  rel = relocs;
  relend = relocs + input_section->reloc_count;
  for (; rel < relend; rel++)
    {
      int r_type;
      reloc_howto_type *howto;
      unsigned long r_symndx;
      struct elf_link_hash_entry *h;
      Elf_Internal_Sym *sym;
      asection *sec;
      bfd_vma relocation;
      bfd_reloc_status_type r;
      unsigned int indx;

      r_type = ELF32_R_TYPE (rel->r_info);
      if (r_type == (int) R_386_GNU_VTINHERIT
	  || r_type == (int) R_386_GNU_VTENTRY)
	continue;

      if ((indx = (unsigned) r_type) >= R_386_standard
	  && ((indx = (unsigned) r_type - R_386_ext_offset) - R_386_standard
	      >= R_386_ext - R_386_standard))
	{
	  bfd_set_error (bfd_error_bad_value);
	  return false;
	}
      howto = elf_howto_table + indx;

      r_symndx = ELF32_R_SYM (rel->r_info);

      if (info->relocateable)
	{
	  /* This is a relocateable link.  We don't have to change
	     anything, unless the reloc is against a section symbol,
	     in which case we have to adjust according to where the
	     section symbol winds up in the output section.  */
	  if (r_symndx < symtab_hdr->sh_info)
	    {
	      sym = local_syms + r_symndx;
	      if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
		{
		  bfd_vma val;

		  sec = local_sections[r_symndx];
		  val = bfd_get_32 (input_bfd, contents + rel->r_offset);
		  val += sec->output_offset + sym->st_value;
		  bfd_put_32 (input_bfd, val, contents + rel->r_offset);
		}
	    }

	  continue;
	}

      /* This is a final link.  */
      h = NULL;
      sym = NULL;
      sec = NULL;
      if (r_symndx < symtab_hdr->sh_info)
	{
	  sym = local_syms + r_symndx;
	  sec = local_sections[r_symndx];
	  relocation = (sec->output_section->vma
			+ sec->output_offset
			+ sym->st_value);
	}
      else
	{
	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
	  while (h->root.type == bfd_link_hash_indirect
		 || h->root.type == bfd_link_hash_warning)
	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
	  if (h->root.type == bfd_link_hash_defined
	      || h->root.type == bfd_link_hash_defweak)
	    {
	      sec = h->root.u.def.section;
	      if (r_type == R_386_GOTPC
		  || (r_type == R_386_PLT32
		      && splt != NULL
		      && h->plt.offset != (bfd_vma) -1)
		  || (r_type == R_386_GOT32
		      && elf_hash_table (info)->dynamic_sections_created
		      && (! info->shared
			  || (! info->symbolic && h->dynindx != -1)
			  || (h->elf_link_hash_flags
			      & ELF_LINK_HASH_DEF_REGULAR) == 0))
		  || (info->shared
		      && ((! info->symbolic && h->dynindx != -1)
			  || (h->elf_link_hash_flags
			      & ELF_LINK_HASH_DEF_REGULAR) == 0)
		      && (r_type == R_386_32
			  || r_type == R_386_PC32)
		      && ((input_section->flags & SEC_ALLOC) != 0
			  /* DWARF will emit R_386_32 relocations in its
			     sections against symbols defined externally
			     in shared libraries.  We can't do anything
			     with them here.  */
			  || ((input_section->flags & SEC_DEBUGGING) != 0
			      && (h->elf_link_hash_flags
				  & ELF_LINK_HASH_DEF_DYNAMIC) != 0))))
		{
		  /* In these cases, we don't need the relocation
                     value.  We check specially because in some
                     obscure cases sec->output_section will be NULL.  */
		  relocation = 0;
		}
	      else if (sec->output_section == NULL)
		{
		  (*_bfd_error_handler)
		    (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"),
		     bfd_get_filename (input_bfd), h->root.root.string,
		     bfd_get_section_name (input_bfd, input_section));
		  relocation = 0;
		}
	      else
		relocation = (h->root.u.def.value
			      + sec->output_section->vma
			      + sec->output_offset);
	    }
	  else if (h->root.type == bfd_link_hash_undefweak)
	    relocation = 0;
	  else if (info->shared && !info->symbolic
		   && !info->no_undefined
		   && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
	    relocation = 0;
	  else
	    {
	      if (! ((*info->callbacks->undefined_symbol)
		     (info, h->root.root.string, input_bfd,
		      input_section, rel->r_offset,
		      (!info->shared || info->no_undefined
		       || ELF_ST_VISIBILITY (h->other)))))
		return false;
	      relocation = 0;
	    }
	}

      switch (r_type)
	{
	case R_386_GOT32:
	  /* Relocation is to the entry for this symbol in the global
	     offset table.  */
	  BFD_ASSERT (sgot != NULL);

	  if (h != NULL)
	    {
	      bfd_vma off;

	      off = h->got.offset;
	      BFD_ASSERT (off != (bfd_vma) -1);

	      if (! elf_hash_table (info)->dynamic_sections_created
		  || (info->shared
		      && (info->symbolic || h->dynindx == -1)
		      && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
		{
		  /* This is actually a static link, or it is a
		     -Bsymbolic link and the symbol is defined
		     locally, or the symbol was forced to be local
		     because of a version file.  We must initialize
		     this entry in the global offset table.  Since the
		     offset must always be a multiple of 4, we use the
		     least significant bit to record whether we have
		     initialized it already.

		     When doing a dynamic link, we create a .rel.got
		     relocation entry to initialize the value.  This
		     is done in the finish_dynamic_symbol routine.  */
		  if ((off & 1) != 0)
		    off &= ~1;
		  else
		    {
		      bfd_put_32 (output_bfd, relocation,
				  sgot->contents + off);
		      h->got.offset |= 1;
		    }
		}

	      relocation = sgot->output_offset + off;
	    }
	  else
	    {
	      bfd_vma off;

	      BFD_ASSERT (local_got_offsets != NULL
			  && local_got_offsets[r_symndx] != (bfd_vma) -1);

	      off = local_got_offsets[r_symndx];

	      /* The offset must always be a multiple of 4.  We use
                 the least significant bit to record whether we have
                 already generated the necessary reloc.  */
	      if ((off & 1) != 0)
		off &= ~1;
	      else
		{
		  bfd_put_32 (output_bfd, relocation, sgot->contents + off);

		  if (info->shared)
		    {
		      asection *srelgot;
		      Elf_Internal_Rel outrel;

		      srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
		      BFD_ASSERT (srelgot != NULL);

		      outrel.r_offset = (sgot->output_section->vma
					 + sgot->output_offset
					 + off);
		      outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
		      bfd_elf32_swap_reloc_out (output_bfd, &outrel,
						(((Elf32_External_Rel *)
						  srelgot->contents)
						 + srelgot->reloc_count));
		      ++srelgot->reloc_count;
		    }

		  local_got_offsets[r_symndx] |= 1;
		}

	      relocation = sgot->output_offset + off;
	    }

	  break;

	case R_386_GOTOFF:
	  /* Relocation is relative to the start of the global offset
	     table.  */

	  if (sgot == NULL)
	    {
	      sgot = bfd_get_section_by_name (dynobj, ".got");
	      BFD_ASSERT (sgot != NULL);
	    }

	  /* Note that sgot->output_offset is not involved in this
	     calculation.  We always want the start of .got.  If we
	     defined _GLOBAL_OFFSET_TABLE in a different way, as is
	     permitted by the ABI, we might have to change this
	     calculation.  */
	  relocation -= sgot->output_section->vma;

	  break;

	case R_386_GOTPC:
	  /* Use global offset table as symbol value.  */

	  if (sgot == NULL)
	    {
	      sgot = bfd_get_section_by_name (dynobj, ".got");
	      BFD_ASSERT (sgot != NULL);
	    }

	  relocation = sgot->output_section->vma;

	  break;

	case R_386_PLT32:
	  /* Relocation is to the entry for this symbol in the
	     procedure linkage table.  */

	  /* Resolve a PLT32 reloc against a local symbol directly,
             without using the procedure linkage table.  */
	  if (h == NULL)
	    break;

	  if (h->plt.offset == (bfd_vma) -1
	      || splt == NULL)
	    {
	      /* We didn't make a PLT entry for this symbol.  This
                 happens when statically linking PIC code, or when
                 using -Bsymbolic.  */
	      break;
	    }

	  relocation = (splt->output_section->vma
			+ splt->output_offset
			+ h->plt.offset);

	  break;

	case R_386_32:
	case R_386_PC32:
	  if (info->shared
	      && (input_section->flags & SEC_ALLOC) != 0
	      && (r_type != R_386_PC32
		  || (h != NULL
		      && h->dynindx != -1
		      && (! info->symbolic
			  || (h->elf_link_hash_flags
			      & ELF_LINK_HASH_DEF_REGULAR) == 0))))
	    {
	      Elf_Internal_Rel outrel;
	      boolean skip, relocate;

	      /* When generating a shared object, these relocations
		 are copied into the output file to be resolved at run
		 time.  */

	      if (sreloc == NULL)
		{
		  const char *name;

		  name = (bfd_elf_string_from_elf_section
			  (input_bfd,
			   elf_elfheader (input_bfd)->e_shstrndx,
			   elf_section_data (input_section)->rel_hdr.sh_name));
		  if (name == NULL)
		    return false;

		  if (strncmp (name, ".rel", 4) != 0
		      || strcmp (bfd_get_section_name (input_bfd,
						       input_section),
				 name + 4) != 0)
		    {
		      if (input_bfd->my_archive)
			(*_bfd_error_handler) (_("%s(%s): bad relocation section name `%s\'"),
					       bfd_get_filename (input_bfd->my_archive),
					       bfd_get_filename (input_bfd),
					       name);
		      else
			(*_bfd_error_handler) (_("%s: bad relocation section name `%s\'"),
					       bfd_get_filename (input_bfd),
					       name);
		      return false;
		    }

		  sreloc = bfd_get_section_by_name (dynobj, name);
		  BFD_ASSERT (sreloc != NULL);
		}

	      skip = false;

	      if (elf_section_data (input_section)->stab_info == NULL)
		outrel.r_offset = rel->r_offset;
	      else
		{
		  bfd_vma off;

		  off = (_bfd_stab_section_offset
			 (output_bfd, &elf_hash_table (info)->stab_info,
			  input_section,
			  &elf_section_data (input_section)->stab_info,
			  rel->r_offset));
		  if (off == (bfd_vma) -1)
		    skip = true;
		  outrel.r_offset = off;
		}

	      outrel.r_offset += (input_section->output_section->vma
				  + input_section->output_offset);

	      if (skip)
		{
		  memset (&outrel, 0, sizeof outrel);
		  relocate = false;
		}
	      else if (r_type == R_386_PC32)
		{
		  BFD_ASSERT (h != NULL && h->dynindx != -1);
		  relocate = false;
		  outrel.r_info = ELF32_R_INFO (h->dynindx, R_386_PC32);
		}
	      else
		{
		  /* h->dynindx may be -1 if this symbol was marked to
                     become local.  */
		  if (h == NULL
		      || ((info->symbolic || h->dynindx == -1)
			  && (h->elf_link_hash_flags
			      & ELF_LINK_HASH_DEF_REGULAR) != 0))
		    {
		      relocate = true;
		      outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
		    }
		  else
		    {
		      BFD_ASSERT (h->dynindx != -1);