bfd/elf32-mt.c

   1 /* Morpho Technologies MT specific support for 32-bit ELF
   2    Copyright (C) 2001-2017 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           3,                      /* size (0 = byte, 1 = short, 2 = long) */
  52           0,                      /* 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   if (r_type >= (unsigned int) R_MT_max)
 240     {
 241       /* xgettext:c-format */
 242       _bfd_error_handler (_("%B: invalid MT reloc number: %d"), abfd, r_type);
 243       r_type = 0;
 244     }
 245   cache_ptr->howto = & mt_elf_howto_table [r_type];
 246 }
 247
 248 /* Perform a single relocation.  By default we use the standard BFD
 249    routines.  */
 250
 251 static bfd_reloc_status_type
 252 mt_final_link_relocate
 253     (reloc_howto_type *  howto,
 254      bfd *               input_bfd,
 255      asection *          input_section,
 256      bfd_byte *          contents,
 257      Elf_Internal_Rela * rel,
 258      bfd_vma             relocation)
 259 {
 260   return _bfd_final_link_relocate (howto, input_bfd, input_section,
 261                                    contents, rel->r_offset,
 262                                    relocation, rel->r_addend);
 263 }
 264
 265 /* Relocate a MT ELF section.
 266    There is some attempt to make this function usable for many architectures,
 267    both USE_REL and USE_RELA ['twould be nice if such a critter existed],
 268    if only to serve as a learning tool.
 269
 270    The RELOCATE_SECTION function is called by the new ELF backend linker
 271    to handle the relocations for a section.
 272
 273    The relocs are always passed as Rela structures; if the section
 274    actually uses Rel structures, the r_addend field will always be
 275    zero.
 276
 277    This function is responsible for adjusting the section contents as
 278    necessary, and (if using Rela relocs and generating a relocatable
 279    output file) adjusting the reloc addend as necessary.
 280
 281    This function does not have to worry about setting the reloc
 282    address or the reloc symbol index.
 283
 284    LOCAL_SYMS is a pointer to the swapped in local symbols.
 285
 286    LOCAL_SECTIONS is an array giving the section in the input file
 287    corresponding to the st_shndx field of each local symbol.
 288
 289    The global hash table entry for the global symbols can be found
 290    via elf_sym_hashes (input_bfd).
 291
 292    When generating relocatable output, this function must handle
 293    STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
 294    going to be the section symbol corresponding to the output
 295    section, which means that the addend must be adjusted
 296    accordingly.  */
 297
 298 static bfd_boolean
 299 mt_elf_relocate_section
 300     (bfd *                   output_bfd ATTRIBUTE_UNUSED,
 301      struct bfd_link_info *  info,
 302      bfd *                   input_bfd,
 303      asection *              input_section,
 304      bfd_byte *              contents,
 305      Elf_Internal_Rela *     relocs,
 306      Elf_Internal_Sym *      local_syms,
 307      asection **             local_sections)
 308 {
 309   Elf_Internal_Shdr *           symtab_hdr;
 310   struct elf_link_hash_entry ** sym_hashes;
 311   Elf_Internal_Rela *           rel;
 312   Elf_Internal_Rela *           relend;
 313
 314   symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
 315   sym_hashes = elf_sym_hashes (input_bfd);
 316   relend     = relocs + input_section->reloc_count;
 317
 318   for (rel = relocs; rel < relend; rel ++)
 319     {
 320       reloc_howto_type *           howto;
 321       unsigned long                r_symndx;
 322       Elf_Internal_Sym *           sym;
 323       asection *                   sec;
 324       struct elf_link_hash_entry * h;
 325       bfd_vma                      relocation;
 326       bfd_reloc_status_type        r;
 327       const char *                 name = NULL;
 328       int                          r_type;
 329
 330       r_type = ELF32_R_TYPE (rel->r_info);
 331
 332       r_symndx = ELF32_R_SYM (rel->r_info);
 333
 334       howto  = mt_elf_howto_table + ELF32_R_TYPE (rel->r_info);
 335       h      = NULL;
 336       sym    = NULL;
 337       sec    = NULL;
 338
 339       if (r_symndx < symtab_hdr->sh_info)
 340         {
 341           sym = local_syms + r_symndx;
 342           sec = local_sections [r_symndx];
 343           relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
 344
 345           name = bfd_elf_string_from_elf_section
 346             (input_bfd, symtab_hdr->sh_link, sym->st_name);
 347           name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
 348         }
 349       else
 350         {
 351           bfd_boolean unresolved_reloc;
 352           bfd_boolean warned, ignored;
 353
 354           RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
 355                                    r_symndx, symtab_hdr, sym_hashes,
 356                                    h, sec, relocation,
 357                                    unresolved_reloc, warned, ignored);
 358
 359           name = h->root.root.string;
 360         }
 361
 362       if (sec != NULL && discarded_section (sec))
 363         RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
 364                                          rel, 1, relend, howto, 0, contents);
 365
 366       if (bfd_link_relocatable (info))
 367         continue;
 368
 369       /* Finally, the sole MT-specific part.  */
 370       switch (r_type)
 371         {
 372         case R_MT_HI16:
 373           r = mt_elf_relocate_hi16 (input_bfd, rel, contents, relocation);
 374           break;
 375         default:
 376           r = mt_final_link_relocate (howto, input_bfd, input_section,
 377                                           contents, rel, relocation);
 378           break;
 379         }
 380
 381
 382       if (r != bfd_reloc_ok)
 383         {
 384           const char * msg = (const char *) NULL;
 385
 386           switch (r)
 387             {
 388             case bfd_reloc_overflow:
 389               (*info->callbacks->reloc_overflow)
 390                 (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
 391                  input_bfd, input_section, rel->r_offset);
 392               break;
 393
 394             case bfd_reloc_undefined:
 395               (*info->callbacks->undefined_symbol)
 396                 (info, name, input_bfd, input_section, rel->r_offset, TRUE);
 397               break;
 398
 399             case bfd_reloc_outofrange:
 400               msg = _("internal error: out of range error");
 401               break;
 402
 403             case bfd_reloc_dangerous:
 404               msg = _("internal error: dangerous relocation");
 405               break;
 406
 407             default:
 408               msg = _("internal error: unknown error");
 409               break;
 410             }
 411
 412           if (msg)
 413             (*info->callbacks->warning) (info, msg, name, input_bfd,
 414                                          input_section, rel->r_offset);
 415         }
 416     }
 417
 418   return TRUE;
 419 }
 420
 421 /* Look through the relocs for a section during the first phase.
 422    Since we don't do .gots or .plts, we just need to consider the
 423    virtual table relocs for gc.  */
 424
 425 static bfd_boolean
 426 mt_elf_check_relocs
 427     (bfd *                     abfd,
 428      struct bfd_link_info *    info,
 429      asection *                sec,
 430      const Elf_Internal_Rela * relocs)
 431 {
 432   Elf_Internal_Shdr *           symtab_hdr;
 433   struct elf_link_hash_entry ** sym_hashes;
 434   const Elf_Internal_Rela *     rel;
 435   const Elf_Internal_Rela *     rel_end;
 436
 437   if (bfd_link_relocatable (info))
 438     return TRUE;
 439
 440   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
 441   sym_hashes = elf_sym_hashes (abfd);
 442
 443   rel_end = relocs + sec->reloc_count;
 444   for (rel = relocs; rel < rel_end; rel++)
 445     {
 446       struct elf_link_hash_entry *h;
 447       unsigned long r_symndx;
 448
 449       r_symndx = ELF32_R_SYM (rel->r_info);
 450       if (r_symndx < symtab_hdr->sh_info)
 451         h = NULL;
 452       else
 453         {
 454           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
 455           while (h->root.type == bfd_link_hash_indirect
 456                  || h->root.type == bfd_link_hash_warning)
 457             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 458         }
 459     }
 460
 461   return TRUE;
 462 }
 463
 464 /* Return the MACH for an e_flags value.  */
 465
 466 static int
 467 elf32_mt_machine (bfd *abfd)
 468 {
 469   switch (elf_elfheader (abfd)->e_flags & EF_MT_CPU_MASK)
 470     {
 471     case EF_MT_CPU_MRISC:       return bfd_mach_ms1;
 472     case EF_MT_CPU_MRISC2:      return bfd_mach_mrisc2;
 473     case EF_MT_CPU_MS2:         return bfd_mach_ms2;
 474     }
 475
 476   return bfd_mach_ms1;
 477 }
 478
 479 static bfd_boolean
 480 mt_elf_object_p (bfd * abfd)
 481 {
 482   bfd_default_set_arch_mach (abfd, bfd_arch_mt, elf32_mt_machine (abfd));
 483
 484   return TRUE;
 485 }
 486
 487 /* Function to set the ELF flag bits.  */
 488
 489 static bfd_boolean
 490 mt_elf_set_private_flags (bfd *    abfd,
 491                            flagword flags)
 492 {
 493   elf_elfheader (abfd)->e_flags = flags;
 494   elf_flags_init (abfd) = TRUE;
 495   return TRUE;
 496 }
 497
 498 /* Merge backend specific data from an object file to the output
 499    object file when linking.  */
 500
 501 static bfd_boolean
 502 mt_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
 503 {
 504   bfd *obfd = info->output_bfd;
 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, info))
 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%.8x, new_flags = 0x%.8x, 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   mt_elf32_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"