bfd/arc-got.h

   1 /* ARC-specific support for 32-bit ELF
   2    Copyright (C) 1994-2019 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 /* Return the local got list, if not defined, create an empty one.  */
  58
  59 static struct got_entry **
  60 arc_get_local_got_ents (bfd * abfd)
  61 {
  62   if (elf_local_got_ents (abfd) == NULL)
  63     {
  64       bfd_size_type amt = (elf_tdata (abfd)->symtab_hdr.sh_info
  65                            * sizeof (*elf_local_got_ents (abfd)));
  66       elf_local_got_ents (abfd) = bfd_zmalloc (amt);
  67       if (elf_local_got_ents (abfd) == NULL)
  68         {
  69           _bfd_error_handler (_("%pB: cannot allocate memory for local "
  70                                 "GOT entries"), abfd);
  71           bfd_set_error (bfd_error_bad_value);
  72           return NULL;
  73         }
  74     }
  75
  76   return elf_local_got_ents (abfd);
  77 }
  78
  79 static struct got_entry *
  80 got_entry_for_type (struct got_entry **list,
  81                     enum tls_type_e type)
  82 {
  83   struct got_entry **p = list;
  84
  85   while (*p != NULL)
  86     {
  87       if ((*p)->type == type)
  88         return *p;
  89       p = &((*p)->next);
  90     }
  91   return NULL;
  92 }
  93
  94 static void
  95 new_got_entry_to_list (struct got_entry **list,
  96                        enum tls_type_e type,
  97                        bfd_vma offset,
  98                        enum tls_got_entries existing_entries)
  99 {
 100   /* Find list end.  Avoid having multiple entries of the same
 101      type.  */
 102   struct got_entry **p = list;
 103   struct got_entry *entry;
 104
 105   while (*p != NULL)
 106     {
 107       if ((*p)->type == type)
 108         return;
 109       p = &((*p)->next);
 110     }
 111
 112   entry = (struct got_entry *) xmalloc (sizeof (struct got_entry));
 113
 114   entry->type = type;
 115   entry->offset = offset;
 116   entry->next = NULL;
 117   entry->processed = FALSE;
 118   entry->created_dyn_relocation = FALSE;
 119   entry->existing_entries = existing_entries;
 120
 121   ARC_DEBUG ("New GOT got entry added to list: "
 122              "type: %d, offset: %ld, existing_entries: %d\n",
 123              type, (long) offset, existing_entries);
 124
 125   /* Add the entry to the end of the list.  */
 126   *p = entry;
 127 }
 128
 129 static enum tls_type_e
 130 tls_type_for_reloc (reloc_howto_type *howto)
 131 {
 132   enum tls_type_e ret = GOT_UNKNOWN;
 133
 134   if (is_reloc_for_GOT (howto))
 135     return GOT_NORMAL;
 136
 137   switch (howto->type)
 138     {
 139     case R_ARC_TLS_GD_GOT:
 140       ret = GOT_TLS_GD;
 141       break;
 142     case R_ARC_TLS_IE_GOT:
 143       ret = GOT_TLS_IE;
 144       break;
 145     case R_ARC_TLS_LE_32:
 146       ret = GOT_TLS_LE;
 147       break;
 148     default:
 149       ret = GOT_UNKNOWN;
 150       break;
 151     }
 152
 153   return ret;
 154 };
 155
 156 static struct got_entry **
 157 get_got_entry_list_for_symbol (bfd *abfd,
 158                                unsigned long r_symndx,
 159                                struct elf_link_hash_entry *h)
 160 {
 161   struct elf_arc_link_hash_entry *h1 =
 162     ((struct elf_arc_link_hash_entry *) h);
 163   if (h1 != NULL)
 164     {
 165       return &h1->got_ents;
 166     }
 167   else
 168     {
 169       return arc_get_local_got_ents (abfd) + r_symndx;
 170     }
 171 }
 172
 173
 174 static enum tls_type_e
 175 arc_got_entry_type_for_reloc (reloc_howto_type *howto)
 176 {
 177   enum tls_type_e type = GOT_UNKNOWN;
 178
 179   if (is_reloc_for_GOT (howto))
 180     return  GOT_NORMAL;
 181
 182   if (is_reloc_for_TLS (howto))
 183     {
 184       switch (howto->type)
 185         {
 186           case R_ARC_TLS_GD_GOT:
 187             type = GOT_TLS_GD;
 188             break;
 189           case R_ARC_TLS_IE_GOT:
 190             type = GOT_TLS_IE;
 191             break;
 192           default:
 193             break;
 194         }
 195     }
 196   return type;
 197 }
 198
 199 #define ADD_SYMBOL_REF_SEC_AND_RELOC(SECNAME, COND_FOR_RELOC, H)        \
 200   htab->s##SECNAME->size;                                               \
 201   {                                                                     \
 202     if (COND_FOR_RELOC)                                                 \
 203       {                                                                 \
 204         htab->srel##SECNAME->size += sizeof (Elf32_External_Rela);      \
 205           ARC_DEBUG ("arc_info: Added reloc space in "                  \
 206                      #SECNAME " section at " __FILE__                   \
 207                      ":%d for symbol %s\n",                             \
 208                      __LINE__, name_for_global_symbol (H));             \
 209       }                                                                 \
 210     if (H)                                                              \
 211       if (H->dynindx == -1 && !H->forced_local)                         \
 212         if (! bfd_elf_link_record_dynamic_symbol (info, H))             \
 213           return FALSE;                                                 \
 214      htab->s##SECNAME->size += 4;                                       \
 215    }                                                                    \
 216
 217 static bfd_boolean
 218 arc_fill_got_info_for_reloc (enum tls_type_e type,
 219                              struct got_entry **list,
 220                              struct bfd_link_info *  info,
 221                              struct elf_link_hash_entry *h)
 222 {
 223   struct elf_link_hash_table *htab = elf_hash_table (info);
 224
 225   if (got_entry_for_type (list, type) != NULL)
 226     return TRUE;
 227
 228   switch (type)
 229     {
 230       case GOT_NORMAL:
 231         {
 232           bfd_vma offset
 233             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, bfd_link_pic (info)
 234                                                  || h != NULL, h);
 235           new_got_entry_to_list (list, type, offset, TLS_GOT_NONE);
 236         }
 237         break;
 238
 239
 240       case GOT_TLS_GD:
 241         {
 242           bfd_vma offset
 243             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 244           bfd_vma ATTRIBUTE_UNUSED notneeded
 245             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 246           new_got_entry_to_list (list, type, offset, TLS_GOT_MOD_AND_OFF);
 247         }
 248         break;
 249       case GOT_TLS_IE:
 250       case GOT_TLS_LE:
 251         {
 252           bfd_vma offset
 253             = ADD_SYMBOL_REF_SEC_AND_RELOC (got, TRUE, h);
 254           new_got_entry_to_list (list, type, offset, TLS_GOT_OFF);
 255         }
 256         break;
 257
 258       default:
 259         return FALSE;
 260         break;
 261     }
 262   return TRUE;
 263 }
 264
 265
 266 static bfd_vma
 267 relocate_fix_got_relocs_for_got_info (struct got_entry **          list_p,
 268                                       enum tls_type_e              type,
 269                                       struct bfd_link_info *       info,
 270                                       bfd *                        output_bfd,
 271                                       unsigned long                r_symndx,
 272                                       Elf_Internal_Sym *           local_syms,
 273                                       asection **                  local_sections,
 274                                       struct elf_link_hash_entry * h,
 275                                       struct arc_relocation_data * reloc_data)
 276 {
 277   struct elf_link_hash_table *htab = elf_hash_table (info);
 278   struct got_entry *entry = NULL;
 279
 280   if (list_p == NULL || type == GOT_UNKNOWN || type == GOT_TLS_LE)
 281     return 0;
 282
 283   entry = got_entry_for_type (list_p, type);
 284   BFD_ASSERT (entry);
 285
 286   if (h == NULL
 287       || h->forced_local == TRUE
 288       || (! elf_hash_table (info)->dynamic_sections_created
 289           || (bfd_link_pic (info)
 290               && SYMBOL_REFERENCES_LOCAL (info, h))))
 291     {
 292       const char ATTRIBUTE_UNUSED *symbol_name;
 293       static const char local_name[] = "(local)";
 294       asection *tls_sec = NULL;
 295       bfd_vma sym_value = 0;
 296
 297       if (h != NULL)
 298         {
 299           // TODO: This should not be here.
 300           reloc_data->sym_value = h->root.u.def.value;
 301           reloc_data->sym_section = h->root.u.def.section;
 302
 303           sym_value = h->root.u.def.value
 304             + h->root.u.def.section->output_section->vma
 305             + h->root.u.def.section->output_offset;
 306
 307           tls_sec = elf_hash_table (info)->tls_sec;
 308
 309           symbol_name = h->root.root.string;
 310         }
 311       else
 312         {
 313           Elf_Internal_Sym *sym = local_syms + r_symndx;
 314           asection *sec = local_sections[r_symndx];
 315
 316           sym_value = sym->st_value
 317             + sec->output_section->vma
 318             + sec->output_offset;
 319
 320           tls_sec = elf_hash_table (info)->tls_sec;
 321
 322           symbol_name = local_name;
 323         }
 324
 325
 326       if (entry && !entry->processed)
 327         {
 328           switch (entry->type)
 329             {
 330             case GOT_TLS_GD:
 331               {
 332                 BFD_ASSERT (tls_sec && tls_sec->output_section);
 333                 bfd_vma sec_vma = tls_sec->output_section->vma;
 334
 335                 if (h == NULL || h->forced_local
 336                    || !elf_hash_table (info)->dynamic_sections_created)
 337                   {
 338                     bfd_put_32 (output_bfd,
 339                             sym_value - sec_vma
 340                             + (elf_hash_table (info)->dynamic_sections_created
 341                                ? 0
 342                                : (align_power (0,
 343                                                tls_sec->alignment_power))),
 344                             htab->sgot->contents + entry->offset
 345                             + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 346                                ? 4 : 0));
 347
 348                     ARC_DEBUG ("arc_info: FIXED -> %s value = %#lx "
 349                           "@ %lx, for symbol %s\n",
 350                           (entry->type == GOT_TLS_GD ? "GOT_TLS_GD" :
 351                            "GOT_TLS_IE"),
 352                           (long) (sym_value - sec_vma),
 353                           (long) (htab->sgot->output_section->vma
 354                              + htab->sgot->output_offset
 355                              + entry->offset
 356                              + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 357                                 ? 4 : 0)),
 358                           symbol_name);
 359                   }
 360               }
 361               break;
 362
 363             case GOT_TLS_IE:
 364               {
 365                 BFD_ASSERT (tls_sec && tls_sec->output_section);
 366                 bfd_vma ATTRIBUTE_UNUSED sec_vma
 367                   = tls_sec->output_section->vma;
 368
 369                 bfd_put_32 (output_bfd,
 370                             sym_value - sec_vma
 371                             + (elf_hash_table (info)->dynamic_sections_created
 372                                ? 0
 373                                : (align_power (TCB_SIZE,
 374                                                tls_sec->alignment_power))),
 375                             htab->sgot->contents + entry->offset
 376                             + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 377                                ? 4 : 0));
 378
 379                 ARC_DEBUG ("arc_info: FIXED -> %s value = %#lx "
 380                            "@ %p, for symbol %s\n",
 381                            (entry->type == GOT_TLS_GD ? "GOT_TLS_GD" :
 382                             "GOT_TLS_IE"),
 383                            (long) (sym_value - sec_vma),
 384                            (long) (htab->sgot->output_section->vma
 385                               + htab->sgot->output_offset
 386                               + entry->offset
 387                               + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
 388                                  ? 4 : 0)),
 389                            symbol_name);
 390               }
 391               break;
 392
 393             case GOT_NORMAL:
 394               {
 395                 bfd_vma sec_vma
 396                   = reloc_data->sym_section->output_section->vma
 397                   + reloc_data->sym_section->output_offset;
 398
 399                 if (h != NULL
 400                     && h->root.type == bfd_link_hash_undefweak)
 401                   ARC_DEBUG ("arc_info: PATCHED: NOT_PATCHED "
 402                              "@ %#08lx for sym %s in got offset %#lx "
 403                              "(is undefweak)\n",
 404                              (long) (htab->sgot->output_section->vma
 405                                      + htab->sgot->output_offset
 406                                      + entry->offset),
 407                              symbol_name,
 408                              (long) entry->offset);
 409                 else
 410                   {
 411                     bfd_put_32 (output_bfd,
 412                                 reloc_data->sym_value + sec_vma,
 413                                 htab->sgot->contents + entry->offset);
 414                     ARC_DEBUG ("arc_info: PATCHED: %#08lx "
 415                                "@ %#08lx for sym %s in got offset %#lx\n",
 416                                (long) (reloc_data->sym_value + sec_vma),
 417                                (long) (htab->sgot->output_section->vma
 418                                        + htab->sgot->output_offset + entry->offset),
 419                                symbol_name,
 420                                (long) entry->offset);
 421                   }
 422               }
 423               break;
 424             default:
 425               BFD_ASSERT (0);
 426               break;
 427             }
 428           entry->processed = TRUE;
 429         }
 430     }
 431
 432   return entry->offset;
 433 }
 434
 435 static void
 436 create_got_dynrelocs_for_single_entry (struct got_entry *list,
 437                                        bfd *output_bfd,
 438                                        struct bfd_link_info *  info,
 439                                        struct elf_link_hash_entry *h)
 440 {
 441   if (list == NULL)
 442     return;
 443
 444   bfd_vma got_offset = list->offset;
 445
 446   if (list->type == GOT_NORMAL
 447       && !list->created_dyn_relocation)
 448     {
 449       if (bfd_link_pic (info)
 450           && h != NULL
 451               && (info->symbolic || h->dynindx == -1)
 452               && h->def_regular)
 453         {
 454           ADD_RELA (output_bfd, got, got_offset, 0, R_ARC_RELATIVE, 0);
 455         }
 456       /* Do not fully understand the side effects of this condition.
 457          The relocation space might still being reserved.  Perhaps
 458          I should clear its value.  */
 459       else if (h != NULL && h->dynindx != -1)
 460         {
 461           ADD_RELA (output_bfd, got, got_offset, h->dynindx, R_ARC_GLOB_DAT, 0);
 462         }
 463       list->created_dyn_relocation = TRUE;
 464     }
 465   else if (list->existing_entries != TLS_GOT_NONE
 466            && !list->created_dyn_relocation)
 467     {
 468        /* TODO TLS: This is not called for local symbols.
 469           In order to correctly implement TLS, this should also
 470           be called for all local symbols with tls got entries.
 471           Should be moved to relocate_section in order to make it
 472           work for local symbols.  */
 473       struct elf_link_hash_table *htab = elf_hash_table (info);
 474       enum tls_got_entries e = list->existing_entries;
 475
 476       BFD_ASSERT (list->type != GOT_TLS_GD
 477                   || list->existing_entries == TLS_GOT_MOD_AND_OFF);
 478
 479       bfd_vma dynindx = (h == NULL || h->dynindx == -1) ? 0 : h->dynindx;
 480
 481       if (e == TLS_GOT_MOD_AND_OFF || e == TLS_GOT_MOD)
 482         {
 483               ADD_RELA (output_bfd, got, got_offset, dynindx,
 484                         R_ARC_TLS_DTPMOD, 0);
 485               ARC_DEBUG ("arc_info: TLS_DYNRELOC: type = %d, \
 486 GOT_OFFSET = %#lx, GOT_VMA = %#lx, INDEX = %ld, ADDEND = 0x0\n",
 487                          list->type,
 488                          (long) got_offset,
 489                          (long) (htab->sgot->output_section->vma
 490                                  + htab->sgot->output_offset + got_offset),
 491                          (long) dynindx);
 492         }
 493
 494       if (e == TLS_GOT_MOD_AND_OFF || e == TLS_GOT_OFF)
 495         {
 496           bfd_vma addend = 0;
 497           if (list->type == GOT_TLS_IE)
 498           {
 499             addend = bfd_get_32 (output_bfd,
 500                                  htab->sgot->contents + got_offset);
 501           }
 502
 503           ADD_RELA (output_bfd, got,
 504                     got_offset + (e == TLS_GOT_MOD_AND_OFF ? 4 : 0),
 505                     dynindx,
 506                     (list->type == GOT_TLS_IE ? R_ARC_TLS_TPOFF
 507                                               : R_ARC_TLS_DTPOFF),
 508                     addend);
 509
 510           ARC_DEBUG ("arc_info: TLS_DYNRELOC: type = %d, \
 511 GOT_OFFSET = %#lx, GOT_VMA = %#lx, INDEX = %ld, ADDEND = %#lx\n",
 512                      list->type,
 513                      (long) got_offset,
 514                      (long) (htab->sgot->output_section->vma
 515                              + htab->sgot->output_offset + got_offset),
 516                      (long) dynindx, (long) addend);
 517         }
 518       list->created_dyn_relocation = TRUE;
 519     }
 520 }
 521
 522 static void
 523 create_got_dynrelocs_for_got_info (struct got_entry **list_p,
 524                                    bfd *output_bfd,
 525                                    struct bfd_link_info *  info,
 526                                    struct elf_link_hash_entry *h)
 527 {
 528   if (list_p == NULL)
 529     return;
 530
 531   struct got_entry *list = *list_p;
 532   /* Traverse the list of got entries for this symbol.  */
 533   while (list)
 534     {
 535       create_got_dynrelocs_for_single_entry (list, output_bfd, info, h);
 536       list = list->next;
 537     }
 538 }
 539
 540 #undef ADD_SYMBOL_REF_SEC_AND_RELOC
 541
 542 #endif /* ARC_GOT_H */