bfd/elf-properties.c

   1 /* ELF program property support.
   2    Copyright (C) 2017-2020 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 bfd_boolean
  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               break;
 182             }
 183         }
 184
 185       _bfd_error_handler
 186         (_("warning: %pB: unsupported GNU_PROPERTY_TYPE (%ld) type: 0x%x"),
 187          abfd, note->type, type);
 188
 189     next:
 190       ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
 191     }
 192
 193   return TRUE;
 194 }
 195
 196 /* Merge GNU property BPROP with APROP.  If APROP isn't NULL, return TRUE
 197    if APROP is updated.  Otherwise, return TRUE if BPROP should be merged
 198    with ABFD.  */
 199
 200 static bfd_boolean
 201 elf_merge_gnu_properties (struct bfd_link_info *info, bfd *abfd, bfd *bbfd,
 202                           elf_property *aprop, elf_property *bprop)
 203 {
 204   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
 205   unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
 206
 207   if (bed->merge_gnu_properties != NULL
 208       && pr_type >= GNU_PROPERTY_LOPROC
 209       && pr_type < GNU_PROPERTY_LOUSER)
 210     return bed->merge_gnu_properties (info, abfd, bbfd, aprop, bprop);
 211
 212   switch (pr_type)
 213     {
 214     case GNU_PROPERTY_STACK_SIZE:
 215       if (aprop != NULL && bprop != NULL)
 216         {
 217           if (bprop->u.number > aprop->u.number)
 218             {
 219               aprop->u.number = bprop->u.number;
 220               return TRUE;
 221             }
 222           break;
 223         }
 224       /* FALLTHROUGH */
 225
 226     case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
 227       /* Return TRUE if APROP is NULL to indicate that BPROP should
 228          be added to ABFD.  */
 229       return aprop == NULL;
 230
 231     default:
 232       /* Never should happen.  */
 233       abort ();
 234     }
 235
 236   return FALSE;
 237 }
 238
 239 /* Return the property of TYPE on *LISTP and remove it from *LISTP if RM is
 240    true.  Return NULL if not found.  */
 241
 242 static elf_property *
 243 elf_find_and_remove_property (elf_property_list **listp,
 244                               unsigned int type, bfd_boolean rm)
 245 {
 246   elf_property_list *list;
 247
 248   for (list = *listp; list; list = list->next)
 249     {
 250       if (type == list->property.pr_type)
 251         {
 252           /* Remove this property.  */
 253           if (rm)
 254             *listp = list->next;
 255           return &list->property;
 256         }
 257       else if (type < list->property.pr_type)
 258         break;
 259       listp = &list->next;
 260     }
 261
 262   return NULL;
 263 }
 264
 265 /* Merge GNU property list *LISTP in ABFD with FIRST_PBFD.  */
 266
 267 static void
 268 elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
 269                              bfd *abfd, elf_property_list **listp)
 270 {
 271   elf_property_list *p, **lastp;
 272   elf_property *pr;
 273   bfd_boolean number_p;
 274   bfd_vma number = 0;
 275
 276   /* Merge each GNU property in FIRST_PBFD with the one on *LISTP.  */
 277   lastp = &elf_properties (first_pbfd);
 278   for (p = *lastp; p; p = p->next)
 279     if (p->property.pr_kind != property_remove)
 280       {
 281         if (p->property.pr_kind == property_number)
 282           {
 283             number_p = TRUE;
 284             number = p->property.u.number;
 285           }
 286         else
 287           number_p = FALSE;
 288         pr = elf_find_and_remove_property (listp, p->property.pr_type,
 289                                            TRUE);
 290         /* Pass NULL to elf_merge_gnu_properties for the property which
 291            isn't on *LISTP.  */
 292         elf_merge_gnu_properties (info, first_pbfd, abfd, &p->property, pr);
 293         if (p->property.pr_kind == property_remove)
 294           {
 295             if (info->has_map_file)
 296               {
 297                 if (number_p)
 298                   {
 299                     if (pr != NULL)
 300                       info->callbacks->minfo
 301                         (_("Removed property %W to merge %pB (0x%v) "
 302                            "and %pB (0x%v)\n"),
 303                          (bfd_vma) p->property.pr_type, first_pbfd,
 304                          number, abfd, pr->u.number);
 305                     else
 306                       info->callbacks->minfo
 307                         (_("Removed property %W to merge %pB (0x%v) "
 308                            "and %pB (not found)\n"),
 309                          (bfd_vma) p->property.pr_type, first_pbfd,
 310                          number, abfd);
 311                   }
 312                 else
 313                   {
 314                     if (pr != NULL)
 315                       info->callbacks->minfo
 316                         (_("Removed property %W to merge %pB and %pB\n"),
 317                          (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 318                     else
 319                       info->callbacks->minfo
 320                         (_("Removed property %W to merge %pB and %pB "
 321                            "(not found)\n"),
 322                          (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 323                   }
 324               }
 325
 326             /* Remove this property.  */
 327             *lastp = p->next;
 328             continue;
 329           }
 330         else if (number_p)
 331           {
 332             if (pr != NULL)
 333               {
 334                 if (p->property.u.number != number
 335                     || p->property.u.number != pr->u.number)
 336                   info->callbacks->minfo
 337                     (_("Updated property %W (0x%v) to merge %pB (0x%v) "
 338                        "and %pB (0x%v)\n"),
 339                      (bfd_vma) p->property.pr_type, p->property.u.number,
 340                      first_pbfd, number, abfd, pr->u.number);
 341               }
 342             else
 343               {
 344                 if (p->property.u.number != number)
 345                   info->callbacks->minfo
 346                     (_("Updated property %W (%v) to merge %pB (0x%v) "
 347                        "and %pB (not found)\n"),
 348                      (bfd_vma) p->property.pr_type, p->property.u.number,
 349                      first_pbfd, number, abfd);
 350               }
 351           }
 352         lastp = &p->next;
 353       }
 354
 355   /* Merge the remaining properties on *LISTP with FIRST_PBFD.  */
 356   for (p = *listp; p != NULL; p = p->next)
 357     {
 358       if (p->property.pr_kind == property_number)
 359         {
 360           number_p = TRUE;
 361           number = p->property.u.number;
 362         }
 363       else
 364         number_p = FALSE;
 365
 366       if (elf_merge_gnu_properties (info, first_pbfd, abfd, NULL, &p->property))
 367         {
 368           if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
 369             elf_has_no_copy_on_protected (first_pbfd) = TRUE;
 370
 371           pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
 372                                       p->property.pr_datasz);
 373           /* It must be a new property.  */
 374           if (pr->pr_kind != property_unknown)
 375             abort ();
 376           /* Add a new property.  */
 377           *pr = p->property;
 378         }
 379       else
 380         {
 381           pr = elf_find_and_remove_property (&elf_properties (first_pbfd),
 382                                              p->property.pr_type,
 383                                              FALSE);
 384           if (pr == NULL)
 385             {
 386               if (number_p)
 387                 info->callbacks->minfo
 388                   (_("Removed property %W to merge %pB (not found) and "
 389                      "%pB (0x%v)\n"),
 390                    (bfd_vma) p->property.pr_type, first_pbfd, abfd,
 391                    number);
 392               else
 393                 info->callbacks->minfo
 394                   (_("Removed property %W to merge %pB and %pB\n"),
 395                    (bfd_vma) p->property.pr_type, first_pbfd, abfd);
 396             }
 397           else if (pr->pr_kind != property_remove)
 398             abort ();
 399         }
 400     }
 401 }
 402
 403 /* Get GNU property section size.  */
 404
 405 static bfd_size_type
 406 elf_get_gnu_property_section_size (elf_property_list *list,
 407                                    unsigned int align_size)
 408 {
 409   bfd_size_type size;
 410   unsigned int descsz;
 411
 412   /* Compute the output section size.  */
 413   descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
 414   descsz = (descsz + 3) & -(unsigned int) 4;
 415   size = descsz;
 416   for (; list != NULL; list = list->next)
 417     {
 418       unsigned int datasz;
 419       /* Check if this property should be skipped.  */
 420       if (list->property.pr_kind == property_remove)
 421         continue;
 422       /* There are 4 byte type + 4 byte datasz for each property.  */
 423       if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
 424         datasz = align_size;
 425       else
 426         datasz = list->property.pr_datasz;
 427       size += 4 + 4 + datasz;
 428       /* Align each property.  */
 429       size = (size + (align_size - 1)) & ~(align_size - 1);
 430     }
 431
 432   return size;
 433 }
 434
 435 /* Write GNU properties.  */
 436
 437 static void
 438 elf_write_gnu_properties (bfd *abfd, bfd_byte *contents,
 439                           elf_property_list *list, unsigned int size,
 440                           unsigned int align_size)
 441 {
 442   unsigned int descsz;
 443   unsigned int datasz;
 444   Elf_External_Note *e_note;
 445
 446   e_note = (Elf_External_Note *) contents;
 447   descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
 448   descsz = (descsz + 3) & -(unsigned int) 4;
 449   bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
 450   bfd_h_put_32 (abfd, size - descsz, &e_note->descsz);
 451   bfd_h_put_32 (abfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
 452   memcpy (e_note->name, "GNU", sizeof "GNU");
 453
 454   size = descsz;
 455   for (; list != NULL; list = list->next)
 456     {
 457       /* Check if this property should be skipped.  */
 458       if (list->property.pr_kind == property_remove)
 459         continue;
 460       /* There are 4 byte type + 4 byte datasz for each property.  */
 461       if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
 462         datasz = align_size;
 463       else
 464         datasz = list->property.pr_datasz;
 465       bfd_h_put_32 (abfd, list->property.pr_type, contents + size);
 466       bfd_h_put_32 (abfd, datasz, contents + size + 4);
 467       size += 4 + 4;
 468
 469       /* Write out property value.  */
 470       switch (list->property.pr_kind)
 471         {
 472         case property_number:
 473           switch (datasz)
 474             {
 475             default:
 476               /* Never should happen.  */
 477               abort ();
 478
 479             case 0:
 480               break;
 481
 482             case 4:
 483               bfd_h_put_32 (abfd, list->property.u.number,
 484                             contents + size);
 485               break;
 486
 487             case 8:
 488               bfd_h_put_64 (abfd, list->property.u.number,
 489                             contents + size);
 490               break;
 491             }
 492           break;
 493
 494         default:
 495           /* Never should happen.  */
 496           abort ();
 497         }
 498       size += datasz;
 499
 500       /* Align each property.  */
 501       size = (size + (align_size - 1)) & ~ (align_size - 1);
 502     }
 503 }
 504
 505 /* Set up GNU properties.  Return the first relocatable ELF input with
 506    GNU properties if found.  Otherwise, return NULL.  */
 507
 508 bfd *
 509 _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
 510 {
 511   bfd *abfd, *first_pbfd = NULL;
 512   elf_property_list *list;
 513   asection *sec;
 514   bfd_boolean has_properties = FALSE;
 515   const struct elf_backend_data *bed
 516     = get_elf_backend_data (info->output_bfd);
 517   unsigned int elfclass = bed->s->elfclass;
 518   int elf_machine_code = bed->elf_machine_code;
 519
 520   /* Find the first relocatable ELF input with GNU properties.  */
 521   for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
 522     if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
 523         && (abfd->flags & DYNAMIC) == 0
 524         && elf_properties (abfd) != NULL)
 525       {
 526         has_properties = TRUE;
 527
 528         /* Ignore GNU properties from ELF objects with different machine
 529            code or class.  Also skip objects without a GNU_PROPERTY note
 530            section.  */
 531         if ((elf_machine_code
 532              == get_elf_backend_data (abfd)->elf_machine_code)
 533             && (elfclass
 534                 == get_elf_backend_data (abfd)->s->elfclass)
 535             && bfd_get_section_by_name (abfd,
 536                                         NOTE_GNU_PROPERTY_SECTION_NAME) != NULL
 537             )
 538           {
 539             /* Keep .note.gnu.property section in FIRST_PBFD.  */
 540             first_pbfd = abfd;
 541             break;
 542           }
 543       }
 544
 545   /* Do nothing if there is no .note.gnu.property section.  */
 546   if (!has_properties)
 547     return NULL;
 548
 549   /* Merge .note.gnu.property sections.  */
 550   info->callbacks->minfo (_("\n"));
 551   info->callbacks->minfo (_("Merging program properties\n"));
 552   info->callbacks->minfo (_("\n"));
 553
 554   for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
 555     if (abfd != first_pbfd
 556         && (abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED)) == 0)
 557       {
 558         elf_property_list *null_ptr = NULL;
 559         elf_property_list **listp = &null_ptr;
 560
 561         /* Merge .note.gnu.property section in relocatable ELF input.  */
 562         if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
 563           {
 564             list = elf_properties (abfd);
 565
 566             /* Ignore GNU properties from ELF objects with different
 567                machine code.  */
 568             if (list != NULL
 569                 && (elf_machine_code
 570                     == get_elf_backend_data (abfd)->elf_machine_code))
 571               listp = &elf_properties (abfd);
 572           }
 573         else
 574           list = NULL;
 575
 576         /* Merge properties with FIRST_PBFD.  FIRST_PBFD can be NULL
 577            when all properties are from ELF objects with different
 578            machine code or class.  */
 579         if (first_pbfd != NULL)
 580           elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);
 581
 582         if (list != NULL)
 583           {
 584             /* Discard the .note.gnu.property section in this bfd.  */
 585             sec = bfd_get_section_by_name (abfd,
 586                                            NOTE_GNU_PROPERTY_SECTION_NAME);
 587             if (sec != NULL)
 588               sec->output_section = bfd_abs_section_ptr;
 589           }
 590       }
 591
 592   /* Rewrite .note.gnu.property section so that GNU properties are
 593      always sorted by type even if input GNU properties aren't sorted.  */
 594   if (first_pbfd != NULL)
 595     {
 596       bfd_size_type size;
 597       bfd_byte *contents;
 598       unsigned int align_size = elfclass == ELFCLASS64 ? 8 : 4;
 599
 600       sec = bfd_get_section_by_name (first_pbfd,
 601                                      NOTE_GNU_PROPERTY_SECTION_NAME);
 602       BFD_ASSERT (sec != NULL);
 603
 604       /* Update stack size in .note.gnu.property with -z stack-size=N
 605          if N > 0.  */
 606       if (info->stacksize > 0)
 607         {
 608           elf_property *p;
 609           bfd_vma stacksize = info->stacksize;
 610
 611           p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_STACK_SIZE,
 612                                      align_size);
 613           if (p->pr_kind == property_unknown)
 614             {
 615               /* Create GNU_PROPERTY_STACK_SIZE.  */
 616               p->u.number = stacksize;
 617               p->pr_kind = property_number;
 618             }
 619           else if (stacksize > p->u.number)
 620             p->u.number = stacksize;
 621         }
 622       else if (elf_properties (first_pbfd) == NULL)
 623         {
 624           /* Discard .note.gnu.property section if all properties have
 625              been removed.  */
 626           sec->output_section = bfd_abs_section_ptr;
 627           return NULL;
 628         }
 629
 630       /* Fix up GNU properties.  */
 631       if (bed->fixup_gnu_properties)
 632         bed->fixup_gnu_properties (info, &elf_properties (first_pbfd));
 633
 634       if (elf_properties (first_pbfd) == NULL)
 635         {
 636           /* Discard .note.gnu.property section if all properties have
 637              been removed.  */
 638           sec->output_section = bfd_abs_section_ptr;
 639           return NULL;
 640         }
 641
 642       /* Compute the section size.  */
 643       list = elf_properties (first_pbfd);
 644       size = elf_get_gnu_property_section_size (list, align_size);
 645
 646       /* Update .note.gnu.property section now.  */
 647       sec->size = size;
 648       contents = (bfd_byte *) bfd_zalloc (first_pbfd, size);
 649
 650       elf_write_gnu_properties (first_pbfd, contents, list, size,
 651                                 align_size);
 652
 653       /* Cache the section contents for elf_link_input_bfd.  */
 654       elf_section_data (sec)->this_hdr.contents = contents;
 655
 656       /* If GNU_PROPERTY_NO_COPY_ON_PROTECTED is set, protected data
 657          symbol is defined in the shared object.  */
 658       if (elf_has_no_copy_on_protected (first_pbfd))
 659         info->extern_protected_data = FALSE;
 660     }
 661
 662   return first_pbfd;
 663 }
 664
 665 /* Convert GNU property size.  */
 666
 667 bfd_size_type
 668 _bfd_elf_convert_gnu_property_size (bfd *ibfd, bfd *obfd)
 669 {
 670   unsigned int align_size;
 671   const struct elf_backend_data *bed;
 672   elf_property_list *list = elf_properties (ibfd);
 673
 674   bed = get_elf_backend_data (obfd);
 675   align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
 676
 677   /* Get the output .note.gnu.property section size.  */
 678   return elf_get_gnu_property_section_size (list, align_size);
 679 }
 680
 681 /* Convert GNU properties.  */
 682
 683 bfd_boolean
 684 _bfd_elf_convert_gnu_properties (bfd *ibfd, asection *isec,
 685                                  bfd *obfd, bfd_byte **ptr,
 686                                  bfd_size_type *ptr_size)
 687 {
 688   unsigned int size;
 689   bfd_byte *contents;
 690   unsigned int align_shift;
 691   const struct elf_backend_data *bed;
 692   elf_property_list *list = elf_properties (ibfd);
 693
 694   bed = get_elf_backend_data (obfd);
 695   align_shift = bed->s->elfclass == ELFCLASS64 ? 3 : 2;
 696
 697   /* Get the output .note.gnu.property section size.  */
 698   size = bfd_section_size (isec->output_section);
 699
 700   /* Update the output .note.gnu.property section alignment.  */
 701   bfd_set_section_alignment (isec->output_section, align_shift);
 702
 703   if (size > bfd_section_size (isec))
 704     {
 705       contents = (bfd_byte *) bfd_malloc (size);
 706       if (contents == NULL)
 707         return FALSE;
 708       free (*ptr);
 709       *ptr = contents;
 710     }
 711   else
 712     contents = *ptr;
 713
 714   *ptr_size = size;
 715
 716   /* Generate the output .note.gnu.property section.  */
 717   elf_write_gnu_properties (ibfd, contents, list, size, 1 << align_shift);
 718
 719   return TRUE;
 720 }