bfd/elf32-mt.c

   1 /* Morpho Technologies MT specific support for 32-bit ELF
   2    Copyright (C) 2001-2014 Free Software Foundation, Inc.
   3
   4    This file is part of BFD, the Binary File Descriptor library.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  19    MA 02111-1307, USA.  */
  20
  21 #include "sysdep.h"
  22 #include "bfd.h"
  23 #include "libbfd.h"
  24 #include "elf-bfd.h"
  25 #include "elf/mt.h"
  26
  27 /* Prototypes.  */
  28 static reloc_howto_type * mt_reloc_type_lookup
  29   (bfd *, bfd_reloc_code_real_type);
  30
  31 static void mt_info_to_howto_rela
  32   (bfd *, arelent *, Elf_Internal_Rela *);
  33
  34 static bfd_reloc_status_type mt_elf_relocate_hi16
  35   (bfd *, Elf_Internal_Rela *, bfd_byte *, bfd_vma);
  36
  37 static bfd_reloc_status_type mt_final_link_relocate
  38   (reloc_howto_type *, bfd *, asection *, bfd_byte *,
  39    Elf_Internal_Rela *, bfd_vma);
  40
  41 static bfd_boolean mt_elf_relocate_section
  42   (bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
  43    Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
  44
  45 /* Relocation tables.  */
  46 static reloc_howto_type mt_elf_howto_table [] =
  47 {
  48   /* This reloc does nothing.  */
  49   HOWTO (R_MT_NONE,           /* type */
  50           0,                      /* rightshift */
  51           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  52           32,                     /* bitsize */
  53           FALSE,                  /* pc_relative */
  54           0,                      /* bitpos */
  55           complain_overflow_dont, /* complain_on_overflow */
  56           bfd_elf_generic_reloc,  /* special_function */
  57           "R_MT_NONE",          /* name */
  58           FALSE,                  /* partial_inplace */
  59           0 ,                     /* src_mask */
  60           0,                      /* dst_mask */
  61           FALSE),                 /* pcrel_offset */
  62
  63   /* A 16 bit absolute relocation.  */
  64   HOWTO (R_MT_16,             /* type */
  65           0,                      /* rightshift */
  66           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  67           16,                     /* bitsize */
  68           FALSE,                  /* pc_relative */
  69           0,                      /* bitpos */
  70           complain_overflow_dont, /* complain_on_overflow */
  71           bfd_elf_generic_reloc,  /* special_function */
  72           "R_MT_16",            /* name */
  73           FALSE,                  /* partial_inplace */
  74           0 ,                     /* src_mask */
  75           0xffff,                 /* dst_mask */
  76           FALSE),                 /* pcrel_offset */
  77
  78   /* A 32 bit absolute relocation.  */
  79   HOWTO (R_MT_32,             /* type */
  80           0,                      /* rightshift */
  81           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  82           32,                     /* bitsize */
  83           FALSE,                  /* pc_relative */
  84           0,                      /* bitpos */
  85           complain_overflow_dont, /* complain_on_overflow */
  86           bfd_elf_generic_reloc,  /* special_function */
  87           "R_MT_32",            /* name */
  88           FALSE,                  /* partial_inplace */
  89           0 ,                     /* src_mask */
  90           0xffffffff,             /* dst_mask */
  91           FALSE),                 /* pcrel_offset */
  92
  93   /* A 32 bit pc-relative relocation.  */
  94   HOWTO (R_MT_32_PCREL,       /* type */
  95           0,                      /* rightshift */
  96           2,                      /* size (0 = byte, 1 = short, 2 = long) */
  97           32,                     /* bitsize */
  98           TRUE,                   /* pc_relative */
  99           0,                      /* bitpos */
 100           complain_overflow_dont, /* complain_on_overflow */
 101           bfd_elf_generic_reloc,  /* special_function */
 102           "R_MT_32_PCREL",    /* name */
 103           FALSE,                  /* partial_inplace */
 104           0 ,                     /* src_mask */
 105           0xffffffff,             /* dst_mask */
 106           TRUE),                  /* pcrel_offset */
 107
 108   /* A 16 bit pc-relative relocation.  */
 109   HOWTO (R_MT_PC16,           /* type */
 110           0,                      /* rightshift */
 111           2,                      /* size (0 = byte, 1 = short, 2 = long) */
 112           16,                     /* bitsize */
 113           TRUE,                   /* pc_relative */
 114           0,                      /* bitpos */
 115           complain_overflow_signed, /* complain_on_overflow */
 116           bfd_elf_generic_reloc,  /* special_function */
 117           "R_MT_PC16",          /* name */
 118           FALSE,                  /* partial_inplace */
 119           0,                      /* src_mask */
 120           0xffff,                 /* dst_mask */
 121           TRUE),                  /* pcrel_offset */
 122
 123   /* high 16 bits of symbol value.  */
 124   HOWTO (R_MT_HI16,          /* type */
 125          0,                     /* rightshift */
 126          2,                     /* size (0 = byte, 1 = short, 2 = long) */
 127          16,                    /* bitsize */
 128          FALSE,                 /* pc_relative */
 129          0,                     /* bitpos */
 130          complain_overflow_dont, /* complain_on_overflow */
 131          bfd_elf_generic_reloc, /* special_function */
 132          "R_MT_HI16",        /* name */
 133          FALSE,                  /* partial_inplace */
 134          0xffff0000,            /* src_mask */
 135          0xffff0000,            /* dst_mask */
 136          FALSE),                /* pcrel_offset */
 137
 138   /* Low 16 bits of symbol value.  */
 139   HOWTO (R_MT_LO16,          /* type */
 140          0,                     /* rightshift */
 141          2,                     /* size (0 = byte, 1 = short, 2 = long) */
 142          16,                    /* bitsize */
 143          FALSE,                 /* pc_relative */
 144          0,                     /* bitpos */
 145          complain_overflow_dont, /* complain_on_overflow */
 146          bfd_elf_generic_reloc, /* special_function */
 147          "R_MT_LO16",        /* name */
 148          FALSE,                  /* partial_inplace */
 149          0xffff,                /* src_mask */
 150          0xffff,                /* dst_mask */
 151          FALSE),                /* pcrel_offset */
 152 };
 153
 154 /* Map BFD reloc types to MT ELF reloc types.  */
 155
 156 static reloc_howto_type *
 157 mt_reloc_type_lookup
 158     (bfd *                    abfd ATTRIBUTE_UNUSED,
 159      bfd_reloc_code_real_type code)
 160 {
 161   /* Note that the mt_elf_howto_table is indxed by the R_
 162      constants.  Thus, the order that the howto records appear in the
 163      table *must* match the order of the relocation types defined in
 164      include/elf/mt.h.  */
 165
 166   switch (code)
 167     {
 168     case BFD_RELOC_NONE:
 169       return &mt_elf_howto_table[ (int) R_MT_NONE];
 170     case BFD_RELOC_16:
 171       return &mt_elf_howto_table[ (int) R_MT_16];
 172     case BFD_RELOC_32:
 173       return &mt_elf_howto_table[ (int) R_MT_32];
 174     case BFD_RELOC_32_PCREL:
 175       return &mt_elf_howto_table[ (int) R_MT_32_PCREL];
 176     case BFD_RELOC_16_PCREL:
 177       return &mt_elf_howto_table[ (int) R_MT_PC16];
 178     case BFD_RELOC_HI16:
 179       return &mt_elf_howto_table[ (int) R_MT_HI16];
 180     case BFD_RELOC_LO16:
 181       return &mt_elf_howto_table[ (int) R_MT_LO16];
 182
 183     default:
 184       /* Pacify gcc -Wall.  */
 185       return NULL;
 186     }
 187   return NULL;
 188 }
 189
 190 static reloc_howto_type *
 191 mt_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 192                       const char *r_name)
 193 {
 194   unsigned int i;
 195
 196   for (i = 0;
 197        i < sizeof (mt_elf_howto_table) / sizeof (mt_elf_howto_table[0]);
 198        i++)
 199     if (mt_elf_howto_table[i].name != NULL
 200         && strcasecmp (mt_elf_howto_table[i].name, r_name) == 0)
 201       return &mt_elf_howto_table[i];
 202
 203   return NULL;
 204 }
 205
 206 bfd_reloc_status_type
 207 mt_elf_relocate_hi16
 208     (bfd *               input_bfd,
 209      Elf_Internal_Rela * relhi,
 210      bfd_byte *          contents,
 211      bfd_vma             value)
 212 {
 213   bfd_vma insn;
 214
 215   insn = bfd_get_32 (input_bfd, contents + relhi->r_offset);
 216
 217   value += relhi->r_addend;
 218   value >>= 16;
 219   insn = ((insn & ~0xFFFF) | value);
 220
 221   bfd_put_32 (input_bfd, insn, contents + relhi->r_offset);
 222   return bfd_reloc_ok;
 223 }
 224 \f
 225 /* XXX: The following code is the result of a cut&paste.  This unfortunate
 226    practice is very widespread in the various target back-end files.  */
 227
 228 /* Set the howto pointer for a MT ELF reloc.  */
 229
 230 static void
 231 mt_info_to_howto_rela
 232     (bfd *               abfd ATTRIBUTE_UNUSED,
 233      arelent *           cache_ptr,
 234      Elf_Internal_Rela * dst)
 235 {
 236   unsigned int r_type;
 237
 238   r_type = ELF32_R_TYPE (dst->r_info);
 239   cache_ptr->howto = & mt_elf_howto_table [r_type];
 240 }
 241
 242 /* Perform a single relocation.  By default we use the standard BFD
 243    routines.  */
 244
 245 static bfd_reloc_status_type
 246 mt_final_link_relocate
 247     (reloc_howto_type *  howto,
 248      bfd *               input_bfd,
 249      asection *          input_section,
 250      bfd_byte *          contents,
 251      Elf_Internal_Rela * rel,
 252      bfd_vma             relocation)
 253 {
 254   return _bfd_final_link_relocate (howto, input_bfd, input_section,
 255                                    contents, rel->r_offset,
 256                                    relocation, rel->r_addend);
 257 }
 258
 259 /* Relocate a MT ELF section.
 260    There is some attempt to make this function usable for many architectures,
 261    both USE_REL and USE_RELA ['twould be nice if such a critter existed],
 262    if only to serve as a learning tool.
 263
 264    The RELOCATE_SECTION function is called by the new ELF backend linker
 265    to handle the relocations for a section.
 266
 267    The relocs are always passed as Rela structures; if the section
 268    actually uses Rel structures, the r_addend field will always be
 269    zero.
 270
 271    This function is responsible for adjusting the section contents as
 272    necessary, and (if using Rela relocs and generating a relocatable
 273    output file) adjusting the reloc addend as necessary.
 274
 275    This function does not have to worry about setting the reloc
 276    address or the reloc symbol index.
 277
 278    LOCAL_SYMS is a pointer to the swapped in local symbols.
 279
 280    LOCAL_SECTIONS is an array giving the section in the input file
 281    corresponding to the st_shndx field of each local symbol.
 282
 283    The global hash table entry for the global symbols can be found
 284    via elf_sym_hashes (input_bfd).
 285
 286    When generating relocatable output, this function must handle
 287    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
 288    going to be the section symbol corresponding to the output
 289    section, which means that the addend must be adjusted
 290    accordingly.  */
 291
 292 static bfd_boolean
 293 mt_elf_relocate_section
 294     (bfd *                   output_bfd ATTRIBUTE_UNUSED,
 295      struct bfd_link_info *  info,
 296      bfd *                   input_bfd,
 297      asection *              input_section,
 298      bfd_byte *              contents,
 299      Elf_Internal_Rela *     relocs,
 300      Elf_Internal_Sym *      local_syms,
 301      asection **             local_sections)
 302 {
 303   Elf_Internal_Shdr *           symtab_hdr;
 304   struct elf_link_hash_entry ** sym_hashes;
 305   Elf_Internal_Rela *           rel;
 306   Elf_Internal_Rela *           relend;
 307
 308   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
 309   sym_hashes = elf_sym_hashes (input_bfd);
 310   relend     = relocs + input_section->reloc_count;
 311
 312   for (rel = relocs; rel < relend; rel ++)
 313     {
 314       reloc_howto_type *           howto;
 315       unsigned long                r_symndx;
 316       Elf_Internal_Sym *           sym;
 317       asection *                   sec;
 318       struct elf_link_hash_entry * h;
 319       bfd_vma                      relocation;
 320       bfd_reloc_status_type        r;
 321       const char *                 name = NULL;
 322       int                          r_type;
 323
 324       r_type = ELF32_R_TYPE (rel->r_info);
 325
 326       r_symndx = ELF32_R_SYM (rel->r_info);
 327
 328       howto  = mt_elf_howto_table + ELF32_R_TYPE (rel->r_info);
 329       h      = NULL;
 330       sym    = NULL;
 331       sec    = NULL;
 332
 333       if (r_symndx < symtab_hdr->sh_info)
 334         {
 335           sym = local_syms + r_symndx;
 336           sec = local_sections [r_symndx];
 337           relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
 338
 339           name = bfd_elf_string_from_elf_section
 340             (input_bfd, symtab_hdr->sh_link, sym->st_name);
 341           name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
 342         }
 343       else
 344         {
 345           bfd_boolean unresolved_reloc;
 346           bfd_boolean warned, ignored;
 347
 348           RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
 349                                    r_symndx, symtab_hdr, sym_hashes,
 350                                    h, sec, relocation,
 351                                    unresolved_reloc, warned, ignored);
 352
 353           name = h->root.root.string;
 354         }
 355
 356       if (sec != NULL && discarded_section (sec))
 357         RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
 358                                          rel, 1, relend, howto, 0, contents);
 359
 360       if (info->relocatable)
 361         continue;
 362
 363       /* Finally, the sole MT-specific part.  */
 364       switch (r_type)
 365         {
 366         case R_MT_HI16:
 367           r = mt_elf_relocate_hi16 (input_bfd, rel, contents, relocation);
 368           break;
 369         default:
 370           r = mt_final_link_relocate (howto, input_bfd, input_section,
 371                                           contents, rel, relocation);
 372           break;
 373         }
 374
 375
 376       if (r != bfd_reloc_ok)
 377         {
 378           const char * msg = (const char *) NULL;
 379
 380           switch (r)
 381             {
 382             case bfd_reloc_overflow:
 383               r = info->callbacks->reloc_overflow
 384                 (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
 385                  input_bfd, input_section, rel->r_offset);
 386               break;
 387
 388             case bfd_reloc_undefined:
 389               r = info->callbacks->undefined_symbol
 390                 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
 391               break;
 392
 393             case bfd_reloc_outofrange:
 394               msg = _("internal error: out of range error");
 395               break;
 396
 397             case bfd_reloc_dangerous:
 398               msg = _("internal error: dangerous relocation");
 399               break;
 400
 401             default:
 402               msg = _("internal error: unknown error");
 403               break;
 404             }
 405
 406           if (msg)
 407             r = info->callbacks->warning
 408               (info, msg, name, input_bfd, input_section, rel->r_offset);
 409
 410           if (! r)
 411             return FALSE;
 412         }
 413     }
 414
 415   return TRUE;
 416 }
 417
 418 /* Look through the relocs for a section during the first phase.
 419    Since we don't do .gots or .plts, we just need to consider the
 420    virtual table relocs for gc.  */
 421
 422 static bfd_boolean
 423 mt_elf_check_relocs
 424     (bfd *                     abfd,
 425      struct bfd_link_info *    info,
 426      asection *                sec,
 427      const Elf_Internal_Rela * relocs)
 428 {
 429   Elf_Internal_Shdr *           symtab_hdr;
 430   struct elf_link_hash_entry ** sym_hashes;
 431   const Elf_Internal_Rela *     rel;
 432   const Elf_Internal_Rela *     rel_end;
 433
 434   if (info->relocatable)
 435     return TRUE;
 436
 437   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
 438   sym_hashes = elf_sym_hashes (abfd);
 439
 440   rel_end = relocs + sec->reloc_count;
 441   for (rel = relocs; rel < rel_end; rel++)
 442     {
 443       struct elf_link_hash_entry *h;
 444       unsigned long r_symndx;
 445
 446       r_symndx = ELF32_R_SYM (rel->r_info);
 447       if (r_symndx < symtab_hdr->sh_info)
 448         h = NULL;
 449       else
 450         {
 451           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
 452           while (h->root.type == bfd_link_hash_indirect
 453                  || h->root.type == bfd_link_hash_warning)
 454             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 455
 456           /* PR15323, ref flags aren't set for references in the same
 457              object.  */
 458           h->root.non_ir_ref = 1;
 459         }
 460     }
 461
 462   return TRUE;
 463 }
 464
 465 /* Return the MACH for an e_flags value.  */
 466
 467 static int
 468 elf32_mt_machine (bfd *abfd)
 469 {
 470   switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
 471     {
 472     case EF_MT_CPU_MRISC:       return bfd_mach_ms1;
 473     case EF_MT_CPU_MRISC2:      return bfd_mach_mrisc2;
 474     case EF_MT_CPU_MS2:         return bfd_mach_ms2;
 475     }
 476
 477   return bfd_mach_ms1;
 478 }
 479
 480 static bfd_boolean
 481 mt_elf_object_p (bfd * abfd)
 482 {
 483   bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
 484
 485   return TRUE;
 486 }
 487
 488 /* Function to set the ELF flag bits.  */
 489
 490 static bfd_boolean
 491 mt_elf_set_private_flags (bfd *    abfd,
 492                            flagword flags)
 493 {
 494   elf_elfheader (abfd)->e_flags = flags;
 495   elf_flags_init (abfd) = TRUE;
 496   return TRUE;
 497 }
 498
 499 /* Merge backend specific data from an object file to the output
 500    object file when linking.  */
 501
 502 static bfd_boolean
 503 mt_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
 504 {
 505   flagword     old_flags, new_flags;
 506   bfd_boolean  ok = TRUE;
 507
 508   /* Check if we have the same endianness.  */
 509   if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)
 510     return FALSE;
 511
 512   /* If they're not both mt, then merging is meaningless, so just
 513      don't do it.  */
 514   if (strcmp (ibfd->arch_info->arch_name, "mt") != 0)
 515     return TRUE;
 516   if (strcmp (obfd->arch_info->arch_name, "mt") != 0)
 517     return TRUE;
 518
 519   new_flags = elf_elfheader (ibfd)->e_flags;
 520   old_flags = elf_elfheader (obfd)->e_flags;
 521
 522 #ifdef DEBUG
 523   _bfd_error_handler ("%B: old_flags = 0x%.8lx, new_flags = 0x%.8lx, init = %s",
 524                       ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
 525 #endif
 526
 527   if (!elf_flags_init (obfd))
 528     {
 529       old_flags = new_flags;
 530       elf_flags_init (obfd) = TRUE;
 531     }
 532   else if ((new_flags & EF_MT_CPU_MASK) != (old_flags & EF_MT_CPU_MASK))
 533     {
 534       /* CPU has changed.  This is invalid, because MRISC, MRISC2 and
 535          MS2 are not subsets of each other.   */
 536       ok = FALSE;
 537     }
 538
 539   if (ok)
 540     {
 541       obfd->arch_info = ibfd->arch_info;
 542       elf_elfheader (obfd)->e_flags = old_flags;
 543     }
 544
 545   return ok;
 546 }
 547
 548 static bfd_boolean
 549 mt_elf_print_private_bfd_data (bfd * abfd, void * ptr)
 550 {
 551   FILE *   file = (FILE *) ptr;
 552   flagword flags;
 553
 554   BFD_ASSERT (abfd != NULL && ptr != NULL);
 555
 556   /* Print normal ELF private data.  */
 557   _bfd_elf_print_private_bfd_data (abfd, ptr);
 558
 559   flags = elf_elfheader (abfd)->e_flags;
 560   fprintf (file, _("private flags = 0x%lx:"), (unsigned long) flags);
 561
 562   switch (flags & EF_MT_CPU_MASK)
 563     {
 564     default:
 565     case EF_MT_CPU_MRISC:   fprintf (file, " ms1-16-002");      break;
 566     case EF_MT_CPU_MRISC2:  fprintf (file, " ms1-16-003");      break;
 567     case EF_MT_CPU_MS2:     fprintf (file, " ms2");     break;
 568     }
 569
 570   fputc ('\n', file);
 571
 572   return TRUE;
 573 }
 574
 575 \f
 576 #define TARGET_BIG_SYM   bfd_elf32_mt_vec
 577 #define TARGET_BIG_NAME  "elf32-mt"
 578
 579 #define ELF_ARCH         bfd_arch_mt
 580 #define ELF_MACHINE_CODE EM_MT
 581 #define ELF_MAXPAGESIZE  1 /* No pages on the MT.  */
 582
 583 #define elf_info_to_howto_rel                   NULL
 584 #define elf_info_to_howto                       mt_info_to_howto_rela
 585
 586 #define elf_backend_relocate_section            mt_elf_relocate_section
 587
 588 #define bfd_elf32_bfd_reloc_type_lookup         mt_reloc_type_lookup
 589 #define bfd_elf32_bfd_reloc_name_lookup   mt_reloc_name_lookup
 590
 591 #define elf_backend_check_relocs                mt_elf_check_relocs
 592 #define elf_backend_object_p                    mt_elf_object_p
 593 #define elf_backend_rela_normal                 1
 594
 595 #define elf_backend_can_gc_sections             1
 596
 597 #define bfd_elf32_bfd_set_private_flags         mt_elf_set_private_flags
 598 #define bfd_elf32_bfd_merge_private_bfd_data    mt_elf_merge_private_bfd_data
 599 #define bfd_elf32_bfd_print_private_bfd_data    mt_elf_print_private_bfd_data
 600
 601 #include "elf32-target.h"