bfd/arc-got.h

   1 /* ARC-specific support for 32-bit ELF
   2    Copyright (C) 1994-2018 Free Software Foundation, Inc.
   3    Contributed by Cupertino Miranda (cmiranda@synopsys.com).
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22 #ifndef ARC_GOT_H
  23 #define ARC_GOT_H
  24
  25 #define TCB_SIZE (8)
  26
  27 #define align_power(addr, align)        \
  28   (((addr) + ((bfd_vma) 1 << (align)) - 1) & (-((bfd_vma) 1 << (align))))
  29
  30 enum tls_type_e
  31 {
  32   GOT_UNKNOWN = 0,
  33   GOT_NORMAL,
  34   GOT_TLS_GD,
  35   GOT_TLS_IE,
  36   GOT_TLS_LE
  37 };
  38
  39 enum tls_got_entries
  40 {
  41   TLS_GOT_NONE = 0,
  42   TLS_GOT_MOD,
  43   TLS_GOT_OFF,
  44   TLS_GOT_MOD_AND_OFF
  45 };
  46
  47 struct got_entry
  48 {
  49   struct got_entry *next;
  50   enum tls_type_e type;
  51   bfd_vma offset;
  52   bfd_boolean processed;
  53   bfd_boolean created_dyn_relocation;
  54   enum tls_got_entries existing_entries;
  55 };
  56
  57 static struct got_entry **
  58 arc_get_local_got_ents (bfd * abfd)
  59 {
  60   static struct got_entry **local_got_ents = NULL;
  61
  62   if (local_got_ents == NULL)
  63     {
  64       size_t       size;
  65       Elf_Internal_Shdr *symtab_hdr = &((elf_tdata (abfd))->symtab_hdr);
  66
  67       size = symtab_hdr->sh_info * sizeof (bfd_vma);
  68       local_got_ents = (struct got_entry **)
  69         bfd_alloc (abfd, sizeof (struct got_entry *) * size);
  70       if (local_got_ents == NULL)
  71         return FALSE;
  72
  73       memset (local_got_ents, 0, sizeof (struct got_entry *) * size);
  74       elf_local_got_ents (abfd) = local_got_ents;
  75     }
  76
  77   return local_got_ents;
  78 }
  79
  80 static struct got_entry *
  81 got_entry_for_type (struct got_entry **list,
  82                     enum tls_type_e type)
  83 {
  84   struct got_entry **p = list;
  85
  86   while (*p != NULL)
  87     {
  88       if ((*p)->type == type)
  89         return *p;
  90       p = &((*p)->next);
  91     }
  92   return NULL;
  93 }
  94
  95 static void
  96 new_got_entry_to_list (struct got_entry **list,
  97                        enum tls_type_e type,
  98                        bfd_vma offset,
  99                        enum tls_got_entries existing_entries)
 100 {
 101   /* Find list end.  Avoid having multiple entries of the same
 102      type.  */
 103   struct got_entry **p = list;
 104   struct got_entry *entry;
 105
 106   while (*p != NULL)
 107     {
 108       if ((*p)->type == type)
 109         return;
 110       p = &((*p)->next);
 111     }
 112
 113   entry = (struct got_entry *) xmalloc (sizeof (struct got_entry));
 114
 115   entry->type = type;
 116   entry->offset = offset;
 117   entry->next = NULL;
 118   entry->processed = FALSE;
 119   entry->created_dyn_relocation = FALSE;
 120   entry->existing_entries = existing_entries;
 121
 122   ARC_DEBUG ("New GOT got entry added to list: "
 123              "type: %d, offset: %ld, existing_entries: %d\n",
 124              type, (long) offset, existing_entries);
 125
 126   /* Add the entry to the end of the list.  */
 127   *p = entry;
 128 }
 129
 130 static enum tls_type_e
 131 tls_type_for_reloc (reloc_howto_type *howto)
 132 {
 133   enum tls_type_e ret = GOT_UNKNOWN;
 134
 135   if (is_reloc_for_GOT (howto))
 136     return GOT_NORMAL;
 137
 138   switch (howto->type)
 139     {
 140     case R_ARC_TLS_GD_GOT:
 141       ret = GOT_TLS_GD;
 142       break;
 143     case R_ARC_TLS_IE_GOT:
 144       ret = GOT_TLS_IE;
 145       break;
 146     case R_ARC_TLS_LE_32:
 147       ret = GOT_TLS_LE;
 148       break;
 149     default:
 150       ret = GOT_UNKNOWN;
 151       break;
 152     }
 153
 154   return ret;
 155 };
 156
 157 static struct got_entry **
 158 get_got_entry_list_for_symbol (bfd *abfd,
 159                                unsigned long r_symndx,
 160                                struct elf_link_hash_entry *h)
 161 {
 162   struct elf_arc_link_hash_entry *h1 =
 163     ((struct elf_arc_link_hash_entry *) h);
 164   if (h1 != NULL)
 165     {
 166       return &h1->got_ents;
 167     }
 168   else
 169     {
 170       struct got_entry **local_got_ents
 171         = arc_get_local_got_ents (abfd);
 172       return &local_got_ents[r_symndx];
 173     }
 174 }
 175
 176
 177 static enum tls_type_e
 178 arc_got_entry_type_for_reloc (reloc_howto_type *howto)
 179 {
 180   enum tls_type_e type = GOT_UNKNOWN;
 181
 182   if (is_reloc_for_GOT (howto))
 183     return  GOT_NORMAL;
 184
 185   if (is_reloc_for_TLS (howto))
 186     {
 187       switch (howto->type)
 188         {
 189           case R_ARC_TLS_GD_GOT:
 190             type = GOT_TLS_GD;
 191             break;
 192           case R_ARC_TLS_IE_GOT:
 193             type = GOT_TLS_IE;
 194             break;
 195           default:
 196             break;
 197         }
 198     }
 199   return type;
 200 }
 201
 202 #define ADD_SYMBOL_REF_SEC_AND_RELOC(SECNAME, COND_FOR_RELOC, H)        \
 203   htab->s##SECNAME->size;                                               \
 204   {                                                                     \
 205     if (COND_FOR_RELOC)                                                 \
 206       {                                                                 \
 207         htab->srel##SECNAME->size += sizeof (Elf32_External_Rela);      \
 208           ARC_DEBUG ("arc_info: Added reloc space in "                  \
 209                      #SECNAME " section at " __FILE__                   \
 210                      ":%d for symbol %s\n",                             \
 211                      __LINE__, name_for_global_symbol (H));             \
 212       }                                                                 \
 213     if (H)                                                              \
 214       if (h->dynindx == -1 && !h->forced_local)                         \
 215         if (! bfd_elf_link_record_dynamic_symbol (info, H))             \
 216           return FALSE;                                                 \
 217      htab->s##SECNAME->size += 4;                                       \
 218    }                                                                    \
 219
 220 static bfd_boolean
 221 arc_fill_got_info_for_reloc (enum tls_type_e type,
 222                              struct got_entry **list,
 223                              struct bfd_link_info *  info,
 224                              struct elf_link_hash_entry *h)
 225 {
 226   struct elf_link_hash_table *htab = elf_hash_table (info);
 227
 228   if (got_entry_for_type (list, type) != NULL)
 229     return TRUE;
 230
 231   switch (type)
 232     {
 233       case GOT_NORMAL:
 234         {
 235           bfd_vma offset
 236             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, bfd_link_pic (info)
 237                                                  || h != NULL, h);
 238           new_got_entry_to_list (list, type, offset, TLS_GOT_NONE);
 239         }
 240         break;
 241
 242
 243       case GOT_TLS_GD:
 244         {
 245           bfd_vma offset
 246             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 247           bfd_vma ATTRIBUTE_UNUSED notneeded
 248             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 249           new_got_entry_to_list (list, type, offset, TLS_GOT_MOD_AND_OFF);
 250         }
 251         break;
 252       case GOT_TLS_IE:
 253       case GOT_TLS_LE:
 254         {
 255           bfd_vma offset
 256             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 257           new_got_entry_to_list (list, type, offset, TLS_GOT_OFF);
 258         }
 259         break;
 260
 261       default:
 262         return FALSE;
 263         break;
 264     }
 265   return TRUE;
 266 }
 267
 268
 269 static bfd_vma
 270 relocate_fix_got_relocs_for_got_info (struct got_entry **          list_p,
 271                                       enum tls_type_e              type,
 272                                       struct bfd_link_info *       info,
 273                                       bfd *                        output_bfd,
 274                                       unsigned long                r_symndx,
 275                                       Elf_Internal_Sym *           local_syms,
 276                                       asection **                  local_sections,
 277                                       struct elf_link_hash_entry * h,
 278                                       struct arc_relocation_data * reloc_data)
 279 {
 280   struct elf_link_hash_table *htab = elf_hash_table (info);
 281   struct got_entry *entry = NULL;
 282
 283   if (list_p == NULL || type == GOT_UNKNOWN || type == GOT_TLS_LE)
 284     return 0;
 285
 286   entry = got_entry_for_type (list_p, type);
 287   BFD_ASSERT (entry);
 288
 289   if (h == NULL
 290       || (! elf_hash_table (info)->dynamic_sections_created
 291           || (bfd_link_pic (info)
 292               && SYMBOL_REFERENCES_LOCAL (info, h))))
 293     {
 294       const char ATTRIBUTE_UNUSED *symbol_name;
 295       static const char local_name[] = "(local)";
 296       asection *tls_sec = NULL;
 297       bfd_vma sym_value = 0;
 298
 299       if (h != NULL)
 300         {
 301           // TODO: This should not be here.
 302           reloc_data->sym_value = h->root.u.def.value;
 303           reloc_data->sym_section = h->root.u.def.section;
 304
 305           sym_value = h->root.u.def.value
 306             + h->root.u.def.section->output_section->vma
 307             + h->root.u.def.section->output_offset;
 308
 309           tls_sec = elf_hash_table (info)->tls_sec;
 310
 311           symbol_name = h->root.root.string;
 312         }
 313       else
 314         {
 315           Elf_Internal_Sym *sym = local_syms + r_symndx;
 316           asection *sec = local_sections[r_symndx];
 317
 318           sym_value = sym->st_value
 319             + sec->output_section->vma
 320             + sec->output_offset;
 321
 322           tls_sec = elf_hash_table (info)->tls_sec;
 323
 324           symbol_name = local_name;
 325         }
 326
 327
 328       if (entry && !entry->processed)
 329         {
 330           switch (entry->type)
 331             {
 332             case GOT_TLS_GD:
 333               {
 334                 BFD_ASSERT (tls_sec && tls_sec->output_section);
 335                 bfd_vma sec_vma = tls_sec->output_section->vma;
 336
 337                 bfd_put_32 (output_bfd,
 338                             sym_value - sec_vma,
 339                             htab->sgot->contents + entry->offset
 340                             + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 341                                ? 4 : 0));
 342
 343                 ARC_DEBUG ("arc_info: FIXED -> %s value = %#lx "
 344                            "@ %lx, for symbol %s\n",
 345                            (entry->type == GOT_TLS_GD ? "GOT_TLS_GD" :
 346                             "GOT_TLS_IE"),
 347                            (long) (sym_value - sec_vma),
 348                            (long) (htab->sgot->output_section->vma
 349                               + htab->sgot->output_offset->vma
 350                               + entry->offset
 351                               + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 352                                  ? 4 : 0)),
 353                            symbol_name);
 354               }
 355               break;
 356
 357             case GOT_TLS_IE:
 358               {
 359                 BFD_ASSERT (tls_sec && tls_sec->output_section);
 360                 bfd_vma ATTRIBUTE_UNUSED sec_vma
 361                   = tls_sec->output_section->vma;
 362
 363                 bfd_put_32 (output_bfd,
 364                             sym_value - sec_vma
 365                             + (elf_hash_table (info)->dynamic_sections_created
 366                                ? 0
 367                                : (align_power (TCB_SIZE,
 368                                                tls_sec->alignment_power))),
 369                             htab->sgot->contents + entry->offset
 370                             + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 371                                ? 4 : 0));
 372
 373                 ARC_DEBUG ("arc_info: FIXED -> %s value = %#lx "
 374                            "@ %p, for symbol %s\n",
 375                            (entry->type == GOT_TLS_GD ? "GOT_TLS_GD" :
 376                             "GOT_TLS_IE"),
 377                            (long) (sym_value - sec_vma),
 378                            (long) (htab->sgot->output_section->vma
 379                               + htab->sgot->output_offset->vma
 380                               + entry->offset
 381                               + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 382                                  ? 4 : 0)),
 383                            symbol_name);
 384               }
 385               break;
 386
 387             case GOT_NORMAL:
 388               {
 389                 bfd_vma sec_vma
 390                   = reloc_data->sym_section->output_section->vma
 391                   + reloc_data->sym_section->output_offset;
 392
 393                 if (h != NULL
 394                     && h->root.type == bfd_link_hash_undefweak)
 395                   ARC_DEBUG ("arc_info: PATCHED: NOT_PATCHED "
 396                              "@ %#08lx for sym %s in got offset %#lx "
 397                              "(is undefweak)\n",
 398                              (long) (htab->sgot->output_section->vma
 399                                      + htab->sgot->output_offset
 400                                      + entry->offset),
 401                              symbol_name,
 402                              (long) entry->offset);
 403                 else
 404                   {
 405                     bfd_put_32 (output_bfd,
 406                                 reloc_data->sym_value + sec_vma,
 407                                 htab->sgot->contents + entry->offset);
 408                     ARC_DEBUG ("arc_info: PATCHED: %#08lx "
 409                                "@ %#08lx for sym %s in got offset %#lx\n",
 410                                (long) (reloc_data->sym_value + sec_vma),
 411                                (long) (htab->sgot->output_section->vma
 412                                        + htab->sgot->output_offset + entry->offset),
 413                                symbol_name,
 414                                (long) entry->offset);
 415                   }
 416               }
 417               break;
 418             default:
 419               BFD_ASSERT (0);
 420               break;
 421             }
 422           entry->processed = TRUE;
 423         }
 424     }
 425
 426   return entry->offset;
 427 }
 428
 429 static void
 430 create_got_dynrelocs_for_single_entry (struct got_entry *list,
 431                                        bfd *output_bfd,
 432                                        struct bfd_link_info *  info,
 433                                        struct elf_link_hash_entry *h)
 434 {
 435   if (list == NULL)
 436     return;
 437
 438   bfd_vma got_offset = list->offset;
 439
 440   if (list->type == GOT_NORMAL
 441       && !list->created_dyn_relocation)
 442     {
 443       if (bfd_link_pic (info)
 444           && h != NULL
 445               && (info->symbolic || h->dynindx == -1)
 446               && h->def_regular)
 447         {
 448           ADD_RELA (output_bfd, got, got_offset, 0, R_ARC_RELATIVE, 0);
 449         }
 450       /* Do not fully understand the side effects of this condition.
 451          The relocation space might still being reserved.  Perhaps
 452          I should clear its value.  */
 453       else if (h != NULL && h->dynindx != -1)
 454         {
 455           ADD_RELA (output_bfd, got, got_offset, h->dynindx, R_ARC_GLOB_DAT, 0);
 456         }
 457       list->created_dyn_relocation = TRUE;
 458     }
 459   else if (list->existing_entries != TLS_GOT_NONE
 460            && !list->created_dyn_relocation)
 461     {
 462        /* TODO TLS: This is not called for local symbols.
 463           In order to correctly implement TLS, this should also
 464           be called for all local symbols with tls got entries.
 465           Should be moved to relocate_section in order to make it
 466           work for local symbols.  */
 467       struct elf_link_hash_table *htab = elf_hash_table (info);
 468       enum tls_got_entries e = list->existing_entries;
 469
 470       BFD_ASSERT (list->type != GOT_TLS_GD
 471                   || list->existing_entries == TLS_GOT_MOD_AND_OFF);
 472
 473       bfd_vma dynindx = (h == NULL || h->dynindx == -1) ? 0 : h->dynindx;
 474
 475       if (e == TLS_GOT_MOD_AND_OFF || e == TLS_GOT_MOD)
 476         {
 477               ADD_RELA (output_bfd, got, got_offset, dynindx,
 478                         R_ARC_TLS_DTPMOD, 0);
 479               ARC_DEBUG ("arc_info: TLS_DYNRELOC: type = %d, \
 480 GOT_OFFSET = %#lx, GOT_VMA = %#lx, INDEX = %ld, ADDEND = 0x0\n",
 481                          list->type,
 482                          (long) got_offset,
 483                          (long) (htab->sgot->output_section->vma
 484                                  + htab->sgot->output_offset + got_offset),
 485                          (long) dynindx);
 486         }
 487
 488       if (e == TLS_GOT_MOD_AND_OFF || e == TLS_GOT_OFF)
 489         {
 490           bfd_vma addend = 0;
 491           if (list->type == GOT_TLS_IE)
 492           {
 493             addend = bfd_get_32 (output_bfd,
 494                                  htab->sgot->contents + got_offset);
 495           }
 496
 497           ADD_RELA (output_bfd, got,
 498                     got_offset + (e == TLS_GOT_MOD_AND_OFF ? 4 : 0),
 499                     dynindx,
 500                     (list->type == GOT_TLS_IE ? R_ARC_TLS_TPOFF
 501                                               : R_ARC_TLS_DTPOFF),
 502                     addend);
 503
 504           ARC_DEBUG ("arc_info: TLS_DYNRELOC: type = %d, \
 505 GOT_OFFSET = %#lx, GOT_VMA = %#lx, INDEX = %ld, ADDEND = %#lx\n",
 506                      list->type,
 507                      (long) got_offset,
 508                      (long) (htab->sgot->output_section->vma
 509                              + htab->sgot->output_offset + got_offset),
 510                      (long) dynindx, (long) addend);
 511         }
 512       list->created_dyn_relocation = TRUE;
 513     }
 514 }
 515
 516 static void
 517 create_got_dynrelocs_for_got_info (struct got_entry **list_p,
 518                                    bfd *output_bfd,
 519                                    struct bfd_link_info *  info,
 520                                    struct elf_link_hash_entry *h)
 521 {
 522   if (list_p == NULL)
 523     return;
 524
 525   struct got_entry *list = *list_p;
 526   /* Traverse the list of got entries for this symbol.  */
 527   while (list)
 528     {
 529       create_got_dynrelocs_for_single_entry (list, output_bfd, info, h);
 530       list = list->next;
 531     }
 532 }
 533
 534 #undef ADD_SYMBOL_REF_SEC_AND_RELOC
 535
 536 #endif /* ARC_GOT_H */