bfd/elf-properties.c

   1 /* ELF program property support.
   2    Copyright (C) 2017-2021 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., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 /* GNU program property draft is at:
  22
  23    https://github.com/hjl-tools/linux-abi/wiki/property-draft.pdf
  24  */
  25
  26 #include "sysdep.h"
  27 #include "bfd.h"
  28 #include "libbfd.h"
  29 #include "elf-bfd.h"
  30
  31 /* Get a property, allocate a new one if needed.  */
  32
  33 elf_property *
  34 _bfd_elf_get_property (bfd *abfd, unsigned int type, unsigned int datasz)
  35 {
  36   elf_property_list *p, **lastp;
  37
  38   if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
  39     {
  40       /* Never should happen.  */
  41       abort ();
  42     }
  43
  44   /* Keep the property list in order of type.  */
  45   lastp = &elf_properties (abfd);
  46   for (p = *lastp; p; p = p->next)
  47     {
  48       /* Reuse the existing entry.  */
  49       if (type == p->property.pr_type)
  50         {
  51           if (datasz > p->property.pr_datasz)
  52             {
  53               /* This can happen when mixing 32-bit and 64-bit objects.  */
  54               p->property.pr_datasz = datasz;
  55             }
  56           return &p->property;
  57         }
  58       else if (type < p->property.pr_type)
  59         break;
  60       lastp = &p->next;
  61     }
  62   p = (elf_property_list *) bfd_alloc (abfd, sizeof (*p));
  63   if (p == NULL)
  64     {
  65       _bfd_error_handler (_("%pB: out of memory in _bfd_elf_get_property"),
  66                           abfd);
  67       _exit (EXIT_FAILURE);
  68     }
  69   memset (p, 0, sizeof (*p));
  70   p->property.pr_type = type;
  71   p->property.pr_datasz = datasz;
  72   p->next = *lastp;
  73   *lastp = p;
  74   return &p->property;
  75 }
  76
  77 /* Parse GNU properties.  */
  78
  79 bool
  80 _bfd_elf_parse_gnu_properties (bfd *abfd, Elf_Internal_Note *note)
  81 {
  82   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
  83   unsigned int align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
  84   bfd_byte *ptr = (bfd_byte *) note->descdata;
  85   bfd_byte *ptr_end = ptr + note->descsz;
  86
  87   if (note->descsz < 8 || (note->descsz % align_size) != 0)
  88     {
  89     bad_size:
  90       _bfd_error_handler
  91         (_("warning: %pB: corrupt GNU_PROPERTY_TYPE (%ld) size: %#lx"),
  92          abfd, note->type, note->descsz);
  93       return false;
  94     }
  95
  96   while (ptr != ptr_end)
  97     {
  98       unsigned int type;
  99       unsigned int datasz;
 100       elf_property *prop;
 101
 102       if ((size_t) (ptr_end - ptr) < 8)
 103         goto bad_size;
 104
 105       type = bfd_h_get_32 (abfd, ptr);
 106       datasz = bfd_h_get_32 (abfd, ptr + 4);
 107       ptr += 8;
 108
 109       if (datasz > (size_t) (ptr_end - ptr))
 110         {
 111           _bfd_error_handler
 112             (_("warning: %pB: corrupt GNU_PROPERTY_TYPE (%ld) type (0x%x) datasz: 0x%x"),
 113              abfd, note->type, type, datasz);
 114           /* Clear all properties.  */
 115           elf_properties (abfd) = NULL;
 116           return false;
 117         }
 118
 119       if (type >= GNU_PROPERTY_LOPROC)
 120         {
 121           if (bed->elf_machine_code == EM_NONE)
 122             {
 123               /* Ignore processor-specific properties with generic ELF
 124                  target vector.  They should be handled by the matching
 125                  ELF target vector.  */
 126               goto next;
 127             }
 128           else if (type < GNU_PROPERTY_LOUSER
 129                    && bed->parse_gnu_properties)
 130             {
 131               enum elf_property_kind kind
 132                 = bed->parse_gnu_properties (abfd, type, ptr, datasz);
 133               if (kind == property_corrupt)
 134                 {
 135                   /* Clear all properties.  */
 136                   elf_properties (abfd) = NULL;
 137                   return false;
 138                 }
 139               else if (kind != property_ignored)
 140                 goto next;
 141             }
 142         }
 143       else
 144         {
 145           switch (type)
 146             {
 147             case GNU_PROPERTY_STACK_SIZE:
 148               if (datasz != align_size)
 149                 {
 150                   _bfd_error_handler
 151                     (_("warning: %pB: corrupt stack size: 0x%x"),
 152                      abfd, datasz);
 153                   /* Clear all properties.  */
 154                   elf_properties (abfd) = NULL;
 155                   return false;
 156                 }
 157               prop = _bfd_elf_get_property (abfd, type, datasz);
 158               if (datasz == 8)
 159                 prop->u.number = bfd_h_get_64 (abfd, ptr);
 160               else
 161                 prop->u.number = bfd_h_get_32 (abfd, ptr);
 162               prop->pr_kind = property_number;
 163               goto next;
 164
 165             case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
 166               if (datasz != 0)
 167                 {
 168                   _bfd_error_handler
 169                     (_("warning: %pB: corrupt no copy on protected size: 0x%x"),
 170                      abfd, datasz);
 171                   /* Clear all properties.  */
 172                   elf_properties (abfd) = NULL;
 173                   return false;
 174                 }
 175               prop = _bfd_elf_get_property (abfd, type, datasz);
 176               elf_has_no_copy_on_protected (abfd) = true;
 177               prop->pr_kind = property_number;
 178               goto next;
 179
 180             default:
 181               if ((type >= GNU_PROPERTY_UINT32_AND_LO
 182                    && type <= GNU_PROPERTY_UINT32_AND_HI)
 183                   || (type >= GNU_PROPERTY_UINT32_OR_LO
 184                       && type <= GNU_PROPERTY_UINT32_OR_HI))
 185                 {
 186                   if (datasz != 4)
 187                     {
 188                       _bfd_error_handler
 189                         (_("error: %pB: <corrupt property (0x%x) size: 0x%x>"),
 190                          abfd, type, datasz);
 191                       /* Clear all properties.  */
 192                       elf_properties (abfd) = NULL;
 193                       return false;
 194                     }
 195                   prop = _bfd_elf_get_property (abfd, type, datasz);
 196                   prop->u.number |= bfd_h_get_32 (abfd, ptr);
 197                   prop->pr_kind = property_number;
 198                   if ((abfd->flags & DYNAMIC) == 0
 199                       && type == GNU_PROPERTY_1_NEEDED
 200                       && ((prop->u.number
 201                            & GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS)
 202                           != 0))
 203                     {
 204                       /* NB: Skip the shared library since it may not be
 205                          the same at run-time.  */
 206                       elf_has_indirect_extern_access (abfd) = true;
 207                       /* GNU_PROPERTY_NO_COPY_ON_PROTECTED is implied.  */
 208                       elf_has_no_copy_on_protected (abfd) = true;
 209                     }
 210                   goto next;
 211                 }
 212               break;
 213             }
 214         }
 215
 216       _bfd_error_handler
 217         (_("warning: %pB: unsupported GNU_PROPERTY_TYPE (%ld) type: 0x%x"),
 218          abfd, note->type, type);
 219
 220     next:
 221       ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
 222     }
 223
 224   return true;
 225 }
 226
 227 /* Merge GNU property BPROP with APROP.  If APROP isn't NULL, return TRUE
 228    if APROP is updated.  Otherwise, return TRUE if BPROP should be merged
 229    with ABFD.  */
 230
 231 static bool
 232 elf_merge_gnu_properties (struct bfd_link_info *info, bfd *abfd, bfd *bbfd,
 233                           elf_property *aprop, elf_property *bprop)
 234 {
 235   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
 236   unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
 237   unsigned int number;
 238   bool updated;
 239
 240   if (bed->merge_gnu_properties != NULL
 241       && pr_type >= GNU_PROPERTY_LOPROC
 242       && pr_type < GNU_PROPERTY_LOUSER)
 243     return bed->merge_gnu_properties (info, abfd, bbfd, aprop, bprop);
 244
 245   switch (pr_type)
 246     {
 247     case GNU_PROPERTY_STACK_SIZE:
 248       if (aprop != NULL && bprop != NULL)
 249         {
 250           if (bprop->u.number > aprop->u.number)
 251             {
 252               aprop->u.number = bprop->u.number;
 253               return true;
 254             }
 255           break;
 256         }
 257       /* FALLTHROUGH */
 258
 259     case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
 260       /* Return TRUE if APROP is NULL to indicate that BPROP should
 261          be added to ABFD.  */
 262       return aprop == NULL;
 263
 264     default:
 265       updated = false;
 266       if (pr_type >= GNU_PROPERTY_UINT32_OR_LO
 267           && pr_type <= GNU_PROPERTY_UINT32_OR_HI)
 268         {
 269           if (aprop != NULL && bprop != NULL)
 270             {
 271               number = aprop->u.number;
 272               aprop->u.number = number | bprop->u.number;
 273               /* Remove the property if all bits are empty.  */
 274               if (aprop->u.number == 0)
 275                 {
 276                   aprop->pr_kind = property_remove;
 277                   updated = true;
 278                 }
 279               else
 280                 updated = number != (unsigned int) aprop->u.number;
 281             }
 282           else
 283             {
 284               /* Only one of APROP and BPROP can be NULL.  */
 285               if (aprop != NULL)
 286                 {
 287                   if (aprop->u.number == 0)
 288                     {
 289                       /* Remove APROP if all bits are empty.  */
 290                       aprop->pr_kind = property_remove;
 291                       updated = true;
 292                     }
 293                 }
 294               else
 295                 {
 296                   /* Return TRUE if APROP is NULL and all bits of BPROP
 297                      aren't empty to indicate that BPROP should be added
 298                      to ABFD.  */
 299                   updated = bprop->u.number != 0;
 300                 }
 301             }
 302           return updated;
 303         }
 304       else if (pr_type >= GNU_PROPERTY_UINT32_AND_LO
 305                && pr_type <= GNU_PROPERTY_UINT32_AND_HI)
 306         {
 307           /* Only one of APROP and BPROP can be NULL:
 308              1. APROP & BPROP when both APROP and BPROP aren't NULL.
 309              2. If APROP is NULL, remove x86 feature.
 310              3. Otherwise, do nothing.
 311              */
 312           if (aprop != NULL && bprop != NULL)
 313             {
 314               number = aprop->u.number;
 315               aprop->u.number = number & bprop->u.number;
 316               updated = number != (unsigned int) aprop->u.number;
 317               /* Remove the property if all feature bits are cleared.  */
 318               if (aprop->u.number == 0)
 319                 aprop->pr_kind = property_remove;
 320             }
 321           else
 322             {
 323               /* There should be no AND properties since some input
 324                  doesn't have them.   */
 325               if (aprop != NULL)
 326                 {
 327                   aprop->pr_kind = property_remove;
 328                   updated = true;
 329                 }
 330             }
 331           return updated;
 332         }
 333
 334       /* Never should happen.  */
 335       abort ();
 336     }
 337
 338   return false;
 339 }
 340
 341 /* Return the property of TYPE on *LISTP and remove it from *LISTP if RM is
 342    true.  Return NULL if not found.  */
 343
 344 static elf_property *
 345 elf_find_and_remove_property (elf_property_list **listp,
 346                               unsigned int type, bool rm)
 347 {
 348   elf_property_list *list;
 349
 350   for (list = *listp; list; list = list->next)
 351     {
 352       if (type == list->property.pr_type)
 353         {
 354           /* Remove this property.  */
 355           if (rm)
 356             *listp = list->next;
 357           return &list->property;
 358         }
 359       else if (type < list->property.pr_type)
 360         break;
 361       listp = &list->next;
 362     }
 363
 364   return NULL;
 365 }
 366
 367 /* Merge GNU property list *LISTP in ABFD with FIRST_PBFD.  */
 368
 369 static void
 370 elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
 371                              bfd *abfd, elf_property_list **listp)
 372 {
 373   elf_property_list *p, **lastp;
 374   elf_property *pr;
 375   bool number_p;
 376   bfd_vma number = 0;
 377
 378   /* Merge each GNU property in FIRST_PBFD with the one on *LISTP.  */
 379   lastp = &elf_properties (first_pbfd);
 380   for (p = *lastp; p; p = p->next)
 381     if (p->property.pr_kind != property_remove)
 382       {
 383         if (p->property.pr_kind == property_number)
 384           {
 385             number_p = true;
 386             number = p->property.u.number;
 387           }
 388         else
 389           number_p = false;
 390         pr = elf_find_and_remove_property (listp, p->property.pr_type,
 391                                            true);
 392         /* Pass NULL to elf_merge_gnu_properties for the property which
 393            isn't on *LISTP.  */
 394         elf_merge_gnu_properties (info, first_pbfd, abfd, &p->property, pr);
 395         if (p->property.pr_kind == property_remove)
 396           {
 397             if (info->has_map_file)
 398               {
 399                 if (number_p)
 400                   {
 401                     if (pr != NULL)
 402                       info->callbacks->minfo
 403                         (_("Removed property %W to merge %pB (0x%v) "
 404                            "and %pB (0x%v)\n"),
 405                          (bfd_vma) p->property.pr_type, first_pbfd,
 406                          number, abfd, pr->u.number);
 407                     else
 408                       info->callbacks->minfo
 409                         (_("Removed property %W to merge %pB (0x%v) "
 410                            "and %pB (not found)\n"),
 411                          (bfd_vma) p->property.pr_type, first_pbfd,
 412                          number, abfd);
 413                   }
 414                 else
 415                   {
 416                     if (pr != NULL)
 417                       info->callbacks->minfo
 418                         (_("Removed property %W to merge %pB and %pB\n"),
 419                          (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 420                     else
 421                       info->callbacks->minfo
 422                         (_("Removed property %W to merge %pB and %pB "
 423                            "(not found)\n"),
 424                          (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 425                   }
 426               }
 427
 428             /* Remove this property.  */
 429             *lastp = p->next;
 430             continue;
 431           }
 432         else if (number_p)
 433           {
 434             if (pr != NULL)
 435               {
 436                 if (p->property.u.number != number
 437                     || p->property.u.number != pr->u.number)
 438                   info->callbacks->minfo
 439                     (_("Updated property %W (0x%v) to merge %pB (0x%v) "
 440                        "and %pB (0x%v)\n"),
 441                      (bfd_vma) p->property.pr_type, p->property.u.number,
 442                      first_pbfd, number, abfd, pr->u.number);
 443               }
 444             else
 445               {
 446                 if (p->property.u.number != number)
 447                   info->callbacks->minfo
 448                     (_("Updated property %W (%v) to merge %pB (0x%v) "
 449                        "and %pB (not found)\n"),
 450                      (bfd_vma) p->property.pr_type, p->property.u.number,
 451                      first_pbfd, number, abfd);
 452               }
 453           }
 454         lastp = &p->next;
 455       }
 456
 457   /* Merge the remaining properties on *LISTP with FIRST_PBFD.  */
 458   for (p = *listp; p != NULL; p = p->next)
 459     {
 460       if (p->property.pr_kind == property_number)
 461         {
 462           number_p = true;
 463           number = p->property.u.number;
 464         }
 465       else
 466         number_p = false;
 467
 468       if (elf_merge_gnu_properties (info, first_pbfd, abfd, NULL, &p->property))
 469         {
 470           if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
 471             elf_has_no_copy_on_protected (first_pbfd) = true;
 472
 473           pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
 474                                       p->property.pr_datasz);
 475           /* It must be a new property.  */
 476           if (pr->pr_kind != property_unknown)
 477             abort ();
 478           /* Add a new property.  */
 479           *pr = p->property;
 480         }
 481       else
 482         {
 483           pr = elf_find_and_remove_property (&elf_properties (first_pbfd),
 484                                              p->property.pr_type,
 485                                              false);
 486           if (pr == NULL)
 487             {
 488               if (number_p)
 489                 info->callbacks->minfo
 490                   (_("Removed property %W to merge %pB (not found) and "
 491                      "%pB (0x%v)\n"),
 492                    (bfd_vma) p->property.pr_type, first_pbfd, abfd,
 493                    number);
 494               else
 495                 info->callbacks->minfo
 496                   (_("Removed property %W to merge %pB and %pB\n"),
 497                    (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 498             }
 499           else if (pr->pr_kind != property_remove)
 500             abort ();
 501         }
 502     }
 503 }
 504
 505 /* Get GNU property section size.  */
 506
 507 static bfd_size_type
 508 elf_get_gnu_property_section_size (elf_property_list *list,
 509                                    unsigned int align_size)
 510 {
 511   bfd_size_type size;
 512   unsigned int descsz;
 513
 514   /* Compute the output section size.  */
 515   descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
 516   descsz = (descsz + 3) & -(unsigned int) 4;
 517   size = descsz;
 518   for (; list != NULL; list = list->next)
 519     {
 520       unsigned int datasz;
 521       /* Check if this property should be skipped.  */
 522       if (list->property.pr_kind == property_remove)
 523         continue;
 524       /* There are 4 byte type + 4 byte datasz for each property.  */
 525       if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
 526         datasz = align_size;
 527       else
 528         datasz = list->property.pr_datasz;
 529       size += 4 + 4 + datasz;
 530       /* Align each property.  */
 531       size = (size + (align_size - 1)) & ~(align_size - 1);
 532     }
 533
 534   return size;
 535 }
 536
 537 /* Write GNU properties.  */
 538
 539 static void
 540 elf_write_gnu_properties (struct bfd_link_info *info,
 541                           bfd *abfd, bfd_byte *contents,
 542                           elf_property_list *list, unsigned int size,
 543                           unsigned int align_size)
 544 {
 545   unsigned int descsz;
 546   unsigned int datasz;
 547   Elf_External_Note *e_note;
 548
 549   e_note = (Elf_External_Note *) contents;
 550   descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
 551   descsz = (descsz + 3) & -(unsigned int) 4;
 552   bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
 553   bfd_h_put_32 (abfd, size - descsz, &e_note->descsz);
 554   bfd_h_put_32 (abfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
 555   memcpy (e_note->name, "GNU", sizeof "GNU");
 556
 557   size = descsz;
 558   for (; list != NULL; list = list->next)
 559     {
 560       /* Check if this property should be skipped.  */
 561       if (list->property.pr_kind == property_remove)
 562         continue;
 563       /* There are 4 byte type + 4 byte datasz for each property.  */
 564       if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
 565         datasz = align_size;
 566       else
 567         datasz = list->property.pr_datasz;
 568       bfd_h_put_32 (abfd, list->property.pr_type, contents + size);
 569       bfd_h_put_32 (abfd, datasz, contents + size + 4);
 570       size += 4 + 4;
 571
 572       /* Write out property value.  */
 573       switch (list->property.pr_kind)
 574         {
 575         case property_number:
 576           switch (datasz)
 577             {
 578             default:
 579               /* Never should happen.  */
 580               abort ();
 581
 582             case 0:
 583               break;
 584
 585             case 4:
 586               /* Save the pointer to GNU_PROPERTY_1_NEEDED so that it
 587                  can be updated later if needed.  */
 588               if (info != NULL
 589                   && list->property.pr_type == GNU_PROPERTY_1_NEEDED)
 590                 info->needed_1_p = contents + size;
 591               bfd_h_put_32 (abfd, list->property.u.number,
 592                             contents + size);
 593               break;
 594
 595             case 8:
 596               bfd_h_put_64 (abfd, list->property.u.number,
 597                             contents + size);
 598               break;
 599             }
 600           break;
 601
 602         default:
 603           /* Never should happen.  */
 604           abort ();
 605         }
 606       size += datasz;
 607
 608       /* Align each property.  */
 609       size = (size + (align_size - 1)) & ~ (align_size - 1);
 610     }
 611 }
 612
 613 /* Set up GNU properties.  Return the first relocatable ELF input with
 614    GNU properties if found.  Otherwise, return NULL.  */
 615
 616 bfd *
 617 _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
 618 {
 619   bfd *abfd, *first_pbfd = NULL, *elf_bfd = NULL;
 620   elf_property_list *list;
 621   asection *sec;
 622   bool has_properties = false;
 623   const struct elf_backend_data *bed
 624     = get_elf_backend_data (info->output_bfd);
 625   unsigned int elfclass = bed->s->elfclass;
 626   int elf_machine_code = bed->elf_machine_code;
 627   elf_property *p;
 628
 629   /* Find the first relocatable ELF input with GNU properties.  */
 630   for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
 631     if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
 632         && (abfd->flags & DYNAMIC) == 0
 633         && (elf_machine_code
 634             == get_elf_backend_data (abfd)->elf_machine_code)
 635         && (elfclass == get_elf_backend_data (abfd)->s->elfclass))
 636       {
 637         /* Ignore GNU properties from ELF objects with different machine
 638            code or class.  Also skip objects without a GNU_PROPERTY note
 639            section.  */
 640         elf_bfd = abfd;
 641
 642         if (elf_properties (abfd) != NULL)
 643           {
 644             has_properties = true;
 645
 646             if (bfd_get_section_by_name (abfd,
 647                                          NOTE_GNU_PROPERTY_SECTION_NAME)
 648                 != NULL)
 649               {
 650                 /* Keep .note.gnu.property section in FIRST_PBFD.  */
 651                 first_pbfd = abfd;
 652                 break;
 653               }
 654           }
 655       }
 656
 657   if (info->indirect_extern_access > 0 && elf_bfd != NULL)
 658     {
 659       /* Support -z indirect-extern-access.  */
 660       if (first_pbfd == NULL)
 661         {
 662           sec = bfd_make_section_with_flags (elf_bfd,
 663                                              NOTE_GNU_PROPERTY_SECTION_NAME,
 664                                              (SEC_ALLOC
 665                                               | SEC_LOAD
 666                                               | SEC_IN_MEMORY
 667                                               | SEC_READONLY
 668                                               | SEC_HAS_CONTENTS
 669                                               | SEC_DATA));
 670           if (sec == NULL)
 671             info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
 672
 673           if (!bfd_set_section_alignment (sec,
 674                                           elfclass == ELFCLASS64 ? 3 : 2))
 675             info->callbacks->einfo (_("%F%pA: failed to align section\n"),
 676                                     sec);
 677
 678           elf_section_type (sec) = SHT_NOTE;
 679           first_pbfd = elf_bfd;
 680           has_properties = true;
 681         }
 682
 683       p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_1_NEEDED, 4);
 684       if (p->pr_kind == property_unknown)
 685         {
 686           /* Create GNU_PROPERTY_1_NEEDED.  */
 687           p->u.number
 688             = GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
 689           p->pr_kind = property_number;
 690         }
 691       else
 692         p->u.number
 693           |= GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
 694     }
 695
 696   /* Do nothing if there is no .note.gnu.property section.  */
 697   if (!has_properties)
 698     return NULL;
 699
 700   /* Merge .note.gnu.property sections.  */
 701   info->callbacks->minfo (_("\n"));
 702   info->callbacks->minfo (_("Merging program properties\n"));
 703   info->callbacks->minfo (_("\n"));
 704
 705   for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
 706     if (abfd != first_pbfd
 707         && (abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED)) == 0)
 708       {
 709         elf_property_list *null_ptr = NULL;
 710         elf_property_list **listp = &null_ptr;
 711
 712         /* Merge .note.gnu.property section in relocatable ELF input.  */
 713         if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
 714           {
 715             list = elf_properties (abfd);
 716
 717             /* Ignore GNU properties from ELF objects with different
 718                machine code.  */
 719             if (list != NULL
 720                 && (elf_machine_code
 721                     == get_elf_backend_data (abfd)->elf_machine_code))
 722               listp = &elf_properties (abfd);
 723           }
 724         else
 725           list = NULL;
 726
 727         /* Merge properties with FIRST_PBFD.  FIRST_PBFD can be NULL
 728            when all properties are from ELF objects with different
 729            machine code or class.  */
 730         if (first_pbfd != NULL)
 731           elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);
 732
 733         if (list != NULL)
 734           {
 735             /* Discard the .note.gnu.property section in this bfd.  */
 736             sec = bfd_get_section_by_name (abfd,
 737                                            NOTE_GNU_PROPERTY_SECTION_NAME);
 738             if (sec != NULL)
 739               sec->output_section = bfd_abs_section_ptr;
 740           }
 741       }
 742
 743   /* Rewrite .note.gnu.property section so that GNU properties are
 744      always sorted by type even if input GNU properties aren't sorted.  */
 745   if (first_pbfd != NULL)
 746     {
 747       bfd_size_type size;
 748       bfd_byte *contents;
 749       unsigned int align_size = elfclass == ELFCLASS64 ? 8 : 4;
 750
 751       sec = bfd_get_section_by_name (first_pbfd,
 752                                      NOTE_GNU_PROPERTY_SECTION_NAME);
 753       BFD_ASSERT (sec != NULL);
 754
 755       /* Update stack size in .note.gnu.property with -z stack-size=N
 756          if N > 0.  */
 757       if (info->stacksize > 0)
 758         {
 759           bfd_vma stacksize = info->stacksize;
 760
 761           p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_STACK_SIZE,
 762                                      align_size);
 763           if (p->pr_kind == property_unknown)
 764             {
 765               /* Create GNU_PROPERTY_STACK_SIZE.  */
 766               p->u.number = stacksize;
 767               p->pr_kind = property_number;
 768             }
 769           else if (stacksize > p->u.number)
 770             p->u.number = stacksize;
 771         }
 772       else if (elf_properties (first_pbfd) == NULL)
 773         {
 774           /* Discard .note.gnu.property section if all properties have
 775              been removed.  */
 776           sec->output_section = bfd_abs_section_ptr;
 777           return NULL;
 778         }
 779
 780       /* Fix up GNU properties.  */
 781       if (bed->fixup_gnu_properties)
 782         bed->fixup_gnu_properties (info, &elf_properties (first_pbfd));
 783
 784       if (elf_properties (first_pbfd) == NULL)
 785         {
 786           /* Discard .note.gnu.property section if all properties have
 787              been removed.  */
 788           sec->output_section = bfd_abs_section_ptr;
 789           return NULL;
 790         }
 791
 792       /* Compute the section size.  */
 793       list = elf_properties (first_pbfd);
 794       size = elf_get_gnu_property_section_size (list, align_size);
 795
 796       /* Update .note.gnu.property section now.  */
 797       sec->size = size;
 798       contents = (bfd_byte *) bfd_zalloc (first_pbfd, size);
 799
 800       if (info->indirect_extern_access <= 0)
 801         {
 802           /* Get GNU_PROPERTY_1_NEEDED properties.  */
 803           p = elf_find_and_remove_property (&elf_properties (first_pbfd),
 804                                             GNU_PROPERTY_1_NEEDED, false);
 805           if (p != NULL)
 806             {
 807               if (info->indirect_extern_access < 0)
 808                 {
 809                   /* Set indirect_extern_access to 1 to indicate that
 810                      it is turned on by input properties.  */
 811                   if ((p->u.number
 812                        & GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS)
 813                       != 0)
 814                     info->indirect_extern_access = 1;
 815                 }
 816               else
 817                 /* Turn off indirect external access.  */
 818                 p->u.number
 819                   &= ~GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
 820             }
 821         }
 822
 823       elf_write_gnu_properties (info, first_pbfd, contents, list, size,
 824                                 align_size);
 825
 826       /* Cache the section contents for elf_link_input_bfd.  */
 827       elf_section_data (sec)->this_hdr.contents = contents;
 828
 829       /* If GNU_PROPERTY_NO_COPY_ON_PROTECTED is set, protected data
 830          symbol is defined in the shared object.  */
 831       if (elf_has_no_copy_on_protected (first_pbfd))
 832         info->extern_protected_data = false;
 833
 834       if (info->indirect_extern_access > 0)
 835         {
 836           /* For indirect external access, don't generate copy
 837              relocations.  NB: Set to nocopyreloc to 2 to indicate
 838              that it is implied by indirect_extern_access.  */
 839           info->nocopyreloc = 2;
 840           info->extern_protected_data = false;
 841         }
 842     }
 843
 844   return first_pbfd;
 845 }
 846
 847 /* Convert GNU property size.  */
 848
 849 bfd_size_type
 850 _bfd_elf_convert_gnu_property_size (bfd *ibfd, bfd *obfd)
 851 {
 852   unsigned int align_size;
 853   const struct elf_backend_data *bed;
 854   elf_property_list *list = elf_properties (ibfd);
 855
 856   bed = get_elf_backend_data (obfd);
 857   align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
 858
 859   /* Get the output .note.gnu.property section size.  */
 860   return elf_get_gnu_property_section_size (list, align_size);
 861 }
 862
 863 /* Convert GNU properties.  */
 864
 865 bool
 866 _bfd_elf_convert_gnu_properties (bfd *ibfd, asection *isec,
 867                                  bfd *obfd, bfd_byte **ptr,
 868                                  bfd_size_type *ptr_size)
 869 {
 870   unsigned int size;
 871   bfd_byte *contents;
 872   unsigned int align_shift;
 873   const struct elf_backend_data *bed;
 874   elf_property_list *list = elf_properties (ibfd);
 875
 876   bed = get_elf_backend_data (obfd);
 877   align_shift = bed->s->elfclass == ELFCLASS64 ? 3 : 2;
 878
 879   /* Get the output .note.gnu.property section size.  */
 880   size = bfd_section_size (isec->output_section);
 881
 882   /* Update the output .note.gnu.property section alignment.  */
 883   bfd_set_section_alignment (isec->output_section, align_shift);
 884
 885   if (size > bfd_section_size (isec))
 886     {
 887       contents = (bfd_byte *) bfd_malloc (size);
 888       if (contents == NULL)
 889         return false;
 890       free (*ptr);
 891       *ptr = contents;
 892     }
 893   else
 894     contents = *ptr;
 895
 896   *ptr_size = size;
 897
 898   /* Generate the output .note.gnu.property section.  */
 899   elf_write_gnu_properties (NULL, ibfd, contents, list, size,
 900                             1 << align_shift);
 901
 902   return true;
 903 }