elf64-sparc.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 2,055 行 · 第 1/5 页

     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message ATTRIBUTE_UNUSED;
{
  bfd_vma relocation;
  bfd_vma insn;
  bfd_reloc_status_type status;

  status = init_insn_reloc (abfd, reloc_entry, symbol, data,
			    input_section, output_bfd, &relocation, &insn);
  if (status != bfd_reloc_other)
    return status;

  insn = (insn & ~0x1fff) | 0x1c00 | (relocation & 0x3ff);
  bfd_put_32 (abfd, insn, (bfd_byte *) data + reloc_entry->address);

  return bfd_reloc_ok;
}

/* PLT/GOT stuff */

/* Both the headers and the entries are icache aligned.  */
#define PLT_ENTRY_SIZE		32
#define PLT_HEADER_SIZE		(4 * PLT_ENTRY_SIZE)
#define LARGE_PLT_THRESHOLD	32768
#define GOT_RESERVED_ENTRIES	1

#define ELF_DYNAMIC_INTERPRETER "/usr/lib/sparcv9/ld.so.1"

/* Fill in the .plt section.  */

static void
sparc64_elf_build_plt (output_bfd, contents, nentries)
     bfd *output_bfd;
     unsigned char *contents;
     int nentries;
{
  const unsigned int nop = 0x01000000;
  int i, j;

  /* The first four entries are reserved, and are initially undefined.
     We fill them with `illtrap 0' to force ld.so to do something.  */

  for (i = 0; i < PLT_HEADER_SIZE/4; ++i)
    bfd_put_32 (output_bfd, 0, contents+i*4);

  /* The first 32768 entries are close enough to plt1 to get there via
     a straight branch.  */

  for (i = 4; i < LARGE_PLT_THRESHOLD && i < nentries; ++i)
    {
      unsigned char *entry = contents + i * PLT_ENTRY_SIZE;
      unsigned int sethi, ba;

      /* sethi (. - plt0), %g1 */
      sethi = 0x03000000 | (i * PLT_ENTRY_SIZE);

      /* ba,a,pt %xcc, plt1 */
      ba = 0x30680000 | (((contents+PLT_ENTRY_SIZE) - (entry+4)) / 4 & 0x7ffff);

      bfd_put_32 (output_bfd, sethi, entry);
      bfd_put_32 (output_bfd, ba, entry+4);
      bfd_put_32 (output_bfd, nop, entry+8);
      bfd_put_32 (output_bfd, nop, entry+12);
      bfd_put_32 (output_bfd, nop, entry+16);
      bfd_put_32 (output_bfd, nop, entry+20);
      bfd_put_32 (output_bfd, nop, entry+24);
      bfd_put_32 (output_bfd, nop, entry+28);
    }

  /* Now the tricky bit.  Entries 32768 and higher are grouped in blocks of
     160: 160 entries and 160 pointers.  This is to separate code from data,
     which is much friendlier on the cache.  */

  for (; i < nentries; i += 160)
    {
      int block = (i + 160 <= nentries ? 160 : nentries - i);
      for (j = 0; j < block; ++j)
	{
	  unsigned char *entry, *ptr;
	  unsigned int ldx;

	  entry = contents + i*PLT_ENTRY_SIZE + j*4*6;
	  ptr = contents + i*PLT_ENTRY_SIZE + block*4*6 + j*8;

	  /* ldx [%o7 + ptr - entry+4], %g1 */
	  ldx = 0xc25be000 | ((ptr - entry+4) & 0x1fff);

	  bfd_put_32 (output_bfd, 0x8a10000f, entry);    /* mov %o7,%g5 */
	  bfd_put_32 (output_bfd, 0x40000002, entry+4);  /* call .+8 */
	  bfd_put_32 (output_bfd, nop, entry+8);         /* nop */
	  bfd_put_32 (output_bfd, ldx, entry+12);        /* ldx [%o7+P],%g1 */
	  bfd_put_32 (output_bfd, 0x83c3c001, entry+16); /* jmpl %o7+%g1,%g1 */
	  bfd_put_32 (output_bfd, 0x9e100005, entry+20); /* mov %g5,%o7 */

	  bfd_put_64 (output_bfd, contents - (entry+4), ptr);
	}
    }
}

/* Return the offset of a particular plt entry within the .plt section.  */

static bfd_vma
sparc64_elf_plt_entry_offset (index)
     int index;
{
  int block, ofs;

  if (index < LARGE_PLT_THRESHOLD)
    return index * PLT_ENTRY_SIZE;

  /* See above for details.  */

  block = (index - LARGE_PLT_THRESHOLD) / 160;
  ofs = (index - LARGE_PLT_THRESHOLD) % 160;

  return ((bfd_vma) (LARGE_PLT_THRESHOLD + block*160) * PLT_ENTRY_SIZE
	  + ofs * 6*4);
}

static bfd_vma
sparc64_elf_plt_ptr_offset (index, max)
     int index, max;
{
  int block, ofs, last;

  BFD_ASSERT(index >= LARGE_PLT_THRESHOLD);

  /* See above for details.  */

  block = (((index - LARGE_PLT_THRESHOLD) / 160) * 160)
	  + LARGE_PLT_THRESHOLD;
  ofs = index - block;
  if (block + 160 > max)
    last = (max - LARGE_PLT_THRESHOLD) % 160;
  else
    last = 160;

  return (block * PLT_ENTRY_SIZE
	  + last * 6*4
	  + ofs * 8);
}

/* Look through the relocs for a section during the first phase, and
   allocate space in the global offset table or procedure linkage
   table.  */

static boolean
sparc64_elf_check_relocs (abfd, info, sec, relocs)
     bfd *abfd;
     struct bfd_link_info *info;
     asection *sec;
     const Elf_Internal_Rela *relocs;
{
  bfd *dynobj;
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  bfd_vma *local_got_offsets;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;
  asection *sgot;
  asection *srelgot;
  asection *sreloc;

  if (info->relocateable || !(sec->flags & SEC_ALLOC))
    return true;

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

  sgot = NULL;
  srelgot = NULL;
  sreloc = NULL;

  rel_end = relocs + NUM_SHDR_ENTRIES (& elf_section_data (sec)->rel_hdr);
  for (rel = relocs; rel < rel_end; rel++)
    {
      unsigned long r_symndx;
      struct elf_link_hash_entry *h;

      r_symndx = ELF64_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
	h = NULL;
      else
	h = sym_hashes[r_symndx - symtab_hdr->sh_info];

      switch (ELF64_R_TYPE_ID (rel->r_info))
	{
	case R_SPARC_GOT10:
	case R_SPARC_GOT13:
	case R_SPARC_GOT22:
	  /* This symbol requires a global offset table entry.  */

	  if (dynobj == NULL)
	    {
	      /* Create the .got section.  */
	      elf_hash_table (info)->dynobj = dynobj = abfd;
	      if (! _bfd_elf_create_got_section (dynobj, info))
		return false;
	    }

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

	  if (srelgot == NULL && (h != NULL || info->shared))
	    {
	      srelgot = bfd_get_section_by_name (dynobj, ".rela.got");
	      if (srelgot == NULL)
		{
		  srelgot = bfd_make_section (dynobj, ".rela.got");
		  if (srelgot == NULL
		      || ! bfd_set_section_flags (dynobj, srelgot,
						  (SEC_ALLOC
						   | SEC_LOAD
						   | SEC_HAS_CONTENTS
						   | SEC_IN_MEMORY
						   | SEC_LINKER_CREATED
						   | SEC_READONLY))
		      || ! bfd_set_section_alignment (dynobj, srelgot, 3))
		    return false;
		}
	    }

	  if (h != NULL)
	    {
	      if (h->got.offset != (bfd_vma) -1)
		{
		  /* We have already allocated space in the .got.  */
		  break;
		}
	      h->got.offset = sgot->_raw_size;

	      /* Make sure this symbol is output as a dynamic symbol.  */
	      if (h->dynindx == -1)
		{
		  if (! bfd_elf64_link_record_dynamic_symbol (info, h))
		    return false;
		}

	      srelgot->_raw_size += sizeof (Elf64_External_Rela);
	    }
	  else
	    {
	      /* This is a global offset table entry for a local
                 symbol.  */
	      if (local_got_offsets == NULL)
		{
		  size_t size;
		  register unsigned int i;

		  size = symtab_hdr->sh_info * sizeof (bfd_vma);
		  local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size);
		  if (local_got_offsets == NULL)
		    return false;
		  elf_local_got_offsets (abfd) = local_got_offsets;
		  for (i = 0; i < symtab_hdr->sh_info; i++)
		    local_got_offsets[i] = (bfd_vma) -1;
		}
	      if (local_got_offsets[r_symndx] != (bfd_vma) -1)
		{
		  /* We have already allocated space in the .got.  */
		  break;
		}
	      local_got_offsets[r_symndx] = sgot->_raw_size;

	      if (info->shared)
		{
		  /* If we are generating a shared object, we need to
                     output a R_SPARC_RELATIVE reloc so that the
                     dynamic linker can adjust this GOT entry.  */
		  srelgot->_raw_size += sizeof (Elf64_External_Rela);
		}
	    }

	  sgot->_raw_size += 8;

#if 0
	  /* Doesn't work for 64-bit -fPIC, since sethi/or builds
	     unsigned numbers.  If we permit ourselves to modify
	     code so we get sethi/xor, this could work.
	     Question: do we consider conditionally re-enabling
             this for -fpic, once we know about object code models?  */
	  /* If the .got section is more than 0x1000 bytes, we add
	     0x1000 to the value of _GLOBAL_OFFSET_TABLE_, so that 13
	     bit relocations have a greater chance of working.  */
	  if (sgot->_raw_size >= 0x1000
	      && elf_hash_table (info)->hgot->root.u.def.value == 0)
	    elf_hash_table (info)->hgot->root.u.def.value = 0x1000;
#endif

	  break;

	case R_SPARC_WPLT30:
	case R_SPARC_PLT32:
	case R_SPARC_HIPLT22:
	case R_SPARC_LOPLT10:
	case R_SPARC_PCPLT32:
	case R_SPARC_PCPLT22:
	case R_SPARC_PCPLT10:
	case R_SPARC_PLT64:
	  /* This symbol requires a procedure linkage table entry.  We
             actually build the entry in adjust_dynamic_symbol,
             because this might be a case of linking PIC code without
             linking in any dynamic objects, in which case we don't
             need to generate a procedure linkage table after all.  */

	  if (h == NULL)
	    {
	      /* It does not make sense to have a procedure linkage
                 table entry for a local symbol.  */
	      bfd_set_error (bfd_error_bad_value);
	      return false;
	    }

	  /* Make sure this symbol is output as a dynamic symbol.  */
	  if (h->dynindx == -1)
	    {
	      if (! bfd_elf64_link_record_dynamic_symbol (info, h))
		return false;
	    }

	  h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT;
	  break;

	case R_SPARC_PC10:
	case R_SPARC_PC22:
	case R_SPARC_PC_HH22:
	case R_SPARC_PC_HM10:
	case R_SPARC_PC_LM22:
	  if (h != NULL
	      && strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
	    break;
	  /* Fall through.  */
	case R_SPARC_DISP8:
	case R_SPARC_DISP16:
	case R_SPARC_DISP32:
	case R_SPARC_DISP64:
	case R_SPARC_WDISP30:
	case R_SPARC_WDISP22:
	case R_SPARC_WDISP19:
	case R_SPARC_WDISP16:
	  if (h == NULL)
	    break;
	  /* Fall through.  */
	case R_SPARC_8:
	case R_SPARC_16:
	case R_SPARC_32:
	case R_SPARC_HI22:
	case R_SPARC_22:
	case R_SPARC_13:
	case R_SPARC_LO10:
	case R_SPARC_UA32:
	case R_SPARC_10:
	case R_SPARC_11:
	case R_SPARC_64:
	case R_SPARC_OLO10:
	case R_SPARC_HH22:
	case R_SPARC_HM10:
	case R_SPARC_LM22:
	case R_SPARC_7:
	case R_SPARC_5:
	case R_SPARC_6:
	case R_SPARC_HIX22:
	case R_SPARC_LOX10:
	case R_SPARC_H44:
	case R_SPARC_M44:
	case R_SPARC_L44:
	case R_SPARC_UA64:
	case R_SPARC_UA16:
	  /* When creating a shared object, we must copy these relocs
	     into the output file.  We create a reloc section in
	     dynobj and make room for the reloc.

	     But don't do this for debugging sections -- this shows up
	     with DWARF2 -- first because they are not loaded, and
	     second because DWARF sez the debug info is not to be
	     biased by the load address.  */
	  if (info->shared && (sec->flags & SEC_ALLOC))
	    {
	      if (sreloc == NULL)
		{
		  const char *name;

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

		  BFD_ASSERT (strncmp (name, ".rela", 5) == 0
			      && strcmp (bfd_get_section_name (abfd, sec),
					 name + 5) == 0);

		  sreloc = bfd_get_section_by_name (dynobj, name);
		  if (sreloc == NULL)
		    {
		      flagword flags;

		      sreloc = bfd_make_section (dynobj, name);
		      flags = (SEC_HAS_CONTENTS | SEC_READONLY
			       | SEC_IN_MEMORY | SEC_LINKER_CREATED);
		      if ((sec->flags & SEC_ALLOC) != 0)
			flags |= SEC_ALLOC | SEC_LOAD;
		      if (sreloc == NULL