[thirdparty/binutils-gdb.git] / bfd / elf-properties.c

/* ELF program property support.
   Copyright (C) 2017-2021 Free Software Foundation, Inc.

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

/* GNU program property draft is at:

   https://github.com/hjl-tools/linux-abi/wiki/property-draft.pdf
 */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "elf-bfd.h"

/* Get a property, allocate a new one if needed.  */

elf_property *
_bfd_elf_get_property (bfd *abfd, unsigned int type, unsigned int datasz)
{
  elf_property_list *p, **lastp;

  if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
    {
      /* Never should happen.  */
      abort ();
    }

  /* Keep the property list in order of type.  */
  lastp = &elf_properties (abfd);
  for (p = *lastp; p; p = p->next)
    {
      /* Reuse the existing entry.  */
      if (type == p->property.pr_type)
        {
          if (datasz > p->property.pr_datasz)
            {
              /* This can happen when mixing 32-bit and 64-bit objects.  */
              p->property.pr_datasz = datasz;
            }
          return &p->property;
        }
      else if (type < p->property.pr_type)
        break;
      lastp = &p->next;
    }
  p = (elf_property_list *) bfd_alloc (abfd, sizeof (*p));
  if (p == NULL)
    {
      _bfd_error_handler (_("%pB: out of memory in _bfd_elf_get_property"),
                          abfd);
      _exit (EXIT_FAILURE);
    }
  memset (p, 0, sizeof (*p));
  p->property.pr_type = type;
  p->property.pr_datasz = datasz;
  p->next = *lastp;
  *lastp = p;
  return &p->property;
}

/* Parse GNU properties.  */

bool
_bfd_elf_parse_gnu_properties (bfd *abfd, Elf_Internal_Note *note)
{
  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
  unsigned int align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
  bfd_byte *ptr = (bfd_byte *) note->descdata;
  bfd_byte *ptr_end = ptr + note->descsz;

  if (note->descsz < 8 || (note->descsz % align_size) != 0)
    {
    bad_size:
      _bfd_error_handler
        (_("warning: %pB: corrupt GNU_PROPERTY_TYPE (%ld) size: %#lx"),
         abfd, note->type, note->descsz);
      return false;
    }

  while (ptr != ptr_end)
    {
      unsigned int type;
      unsigned int datasz;
      elf_property *prop;

      if ((size_t) (ptr_end - ptr) < 8)
        goto bad_size;

      type = bfd_h_get_32 (abfd, ptr);
      datasz = bfd_h_get_32 (abfd, ptr + 4);
      ptr += 8;

      if (datasz > (size_t) (ptr_end - ptr))
        {
          _bfd_error_handler
            (_("warning: %pB: corrupt GNU_PROPERTY_TYPE (%ld) type (0x%x) datasz: 0x%x"),
             abfd, note->type, type, datasz);
          /* Clear all properties.  */
          elf_properties (abfd) = NULL;
          return false;
        }

      if (type >= GNU_PROPERTY_LOPROC)
        {
          if (bed->elf_machine_code == EM_NONE)
            {
              /* Ignore processor-specific properties with generic ELF
                 target vector.  They should be handled by the matching
                 ELF target vector.  */
              goto next;
            }
          else if (type < GNU_PROPERTY_LOUSER
                   && bed->parse_gnu_properties)
            {
              enum elf_property_kind kind
                = bed->parse_gnu_properties (abfd, type, ptr, datasz);
              if (kind == property_corrupt)
                {
                  /* Clear all properties.  */
                  elf_properties (abfd) = NULL;
                  return false;
                }
              else if (kind != property_ignored)
                goto next;
            }
        }
      else
        {
          switch (type)
            {
            case GNU_PROPERTY_STACK_SIZE:
              if (datasz != align_size)
                {
                  _bfd_error_handler
                    (_("warning: %pB: corrupt stack size: 0x%x"),
                     abfd, datasz);
                  /* Clear all properties.  */
                  elf_properties (abfd) = NULL;
                  return false;
                }
              prop = _bfd_elf_get_property (abfd, type, datasz);
              if (datasz == 8)
                prop->u.number = bfd_h_get_64 (abfd, ptr);
              else
                prop->u.number = bfd_h_get_32 (abfd, ptr);
              prop->pr_kind = property_number;
              goto next;

            case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
              if (datasz != 0)
                {
                  _bfd_error_handler
                    (_("warning: %pB: corrupt no copy on protected size: 0x%x"),
                     abfd, datasz);
                  /* Clear all properties.  */
                  elf_properties (abfd) = NULL;
                  return false;
                }
              prop = _bfd_elf_get_property (abfd, type, datasz);
              elf_has_no_copy_on_protected (abfd) = true;
              prop->pr_kind = property_number;
              goto next;

            default:
              if ((type >= GNU_PROPERTY_UINT32_AND_LO
                   && type <= GNU_PROPERTY_UINT32_AND_HI)
                  || (type >= GNU_PROPERTY_UINT32_OR_LO
                      && type <= GNU_PROPERTY_UINT32_OR_HI))
                {
                  if (datasz != 4)
                    {
                      _bfd_error_handler
                        (_("error: %pB: <corrupt property (0x%x) size: 0x%x>"),
                         abfd, type, datasz);
                      /* Clear all properties.  */
                      elf_properties (abfd) = NULL;
                      return false;
                    }
                  prop = _bfd_elf_get_property (abfd, type, datasz);
                  prop->u.number |= bfd_h_get_32 (abfd, ptr);
                  prop->pr_kind = property_number;
                  goto next;
                }
              break;
            }
        }

      _bfd_error_handler
        (_("warning: %pB: unsupported GNU_PROPERTY_TYPE (%ld) type: 0x%x"),
         abfd, note->type, type);

    next:
      ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
    }

  return true;
}

/* Merge GNU property BPROP with APROP.  If APROP isn't NULL, return TRUE
   if APROP is updated.  Otherwise, return TRUE if BPROP should be merged
   with ABFD.  */

static bool
elf_merge_gnu_properties (struct bfd_link_info *info, bfd *abfd, bfd *bbfd,
                          elf_property *aprop, elf_property *bprop)
{
  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
  unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
  unsigned int number;
  bool updated;

  if (bed->merge_gnu_properties != NULL
      && pr_type >= GNU_PROPERTY_LOPROC
      && pr_type < GNU_PROPERTY_LOUSER)
    return bed->merge_gnu_properties (info, abfd, bbfd, aprop, bprop);

  switch (pr_type)
    {
    case GNU_PROPERTY_STACK_SIZE:
      if (aprop != NULL && bprop != NULL)
        {
          if (bprop->u.number > aprop->u.number)
            {
              aprop->u.number = bprop->u.number;
              return true;
            }
          break;
        }
      /* FALLTHROUGH */

    case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
      /* Return TRUE if APROP is NULL to indicate that BPROP should
         be added to ABFD.  */
      return aprop == NULL;

    default:
      updated = false;
      if (pr_type >= GNU_PROPERTY_UINT32_OR_LO
          && pr_type <= GNU_PROPERTY_UINT32_OR_HI)
        {
          if (aprop != NULL && bprop != NULL)
            {
              number = aprop->u.number;
              aprop->u.number = number | bprop->u.number;
              /* Remove the property if all bits are empty.  */
              if (aprop->u.number == 0)
                {
                  aprop->pr_kind = property_remove;
                  updated = true;
                }
              else
                updated = number != (unsigned int) aprop->u.number;
            }
          else
            {
              /* Only one of APROP and BPROP can be NULL.  */
              if (aprop != NULL)
                {
                  if (aprop->u.number == 0)
                    {
                      /* Remove APROP if all bits are empty.  */
                      aprop->pr_kind = property_remove;
                      updated = true;
                    }
                }
              else
                {
                  /* Return TRUE if APROP is NULL and all bits of BPROP
                     aren't empty to indicate that BPROP should be added
                     to ABFD.  */
                  updated = bprop->u.number != 0;
                }
            }
          return updated;
        }
      else if (pr_type >= GNU_PROPERTY_UINT32_AND_LO
               && pr_type <= GNU_PROPERTY_UINT32_AND_HI)
        {
          /* Only one of APROP and BPROP can be NULL:
             1. APROP & BPROP when both APROP and BPROP aren't NULL.
             2. If APROP is NULL, remove x86 feature.
             3. Otherwise, do nothing.
             */
          if (aprop != NULL && bprop != NULL)
            {
              number = aprop->u.number;
              aprop->u.number = number & bprop->u.number;
              updated = number != (unsigned int) aprop->u.number;
              /* Remove the property if all feature bits are cleared.  */
              if (aprop->u.number == 0)
                aprop->pr_kind = property_remove;
            }
          else
            {
              /* There should be no AND properties since some input
                 doesn't have them.   */
              if (aprop != NULL)
                {
                  aprop->pr_kind = property_remove;
                  updated = true;
                }
            }
          return updated;
        }

      /* Never should happen.  */
      abort ();
    }

  return false;
}

/* Return the property of TYPE on *LISTP and remove it from *LISTP if RM is
   true.  Return NULL if not found.  */

static elf_property *
elf_find_and_remove_property (elf_property_list **listp,
                              unsigned int type, bool rm)
{
  elf_property_list *list;

  for (list = *listp; list; list = list->next)
    {
      if (type == list->property.pr_type)
        {
          /* Remove this property.  */
          if (rm)
            *listp = list->next;
          return &list->property;
        }
      else if (type < list->property.pr_type)
        break;
      listp = &list->next;
    }

  return NULL;
}

/* Merge GNU property list *LISTP in ABFD with FIRST_PBFD.  */

static void
elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
                             bfd *abfd, elf_property_list **listp)
{
  elf_property_list *p, **lastp;
  elf_property *pr;
  bool number_p;
  bfd_vma number = 0;

  /* Merge each GNU property in FIRST_PBFD with the one on *LISTP.  */
  lastp = &elf_properties (first_pbfd);
  for (p = *lastp; p; p = p->next)
    if (p->property.pr_kind != property_remove)
      {
        if (p->property.pr_kind == property_number)
          {
            number_p = true;
            number = p->property.u.number;
          }
        else
          number_p = false;
        pr = elf_find_and_remove_property (listp, p->property.pr_type,
                                           true);
        /* Pass NULL to elf_merge_gnu_properties for the property which
           isn't on *LISTP.  */
        elf_merge_gnu_properties (info, first_pbfd, abfd, &p->property, pr);
        if (p->property.pr_kind == property_remove)
          {
            if (info->has_map_file)
              {
                if (number_p)
                  {
                    if (pr != NULL)
                      info->callbacks->minfo
                        (_("Removed property %W to merge %pB (0x%v) "
                           "and %pB (0x%v)\n"),
                         (bfd_vma) p->property.pr_type, first_pbfd,
                         number, abfd, pr->u.number);
                    else
                      info->callbacks->minfo
                        (_("Removed property %W to merge %pB (0x%v) "
                           "and %pB (not found)\n"),
                         (bfd_vma) p->property.pr_type, first_pbfd,
                         number, abfd);
                  }
                else
                  {
                    if (pr != NULL)
                      info->callbacks->minfo
                        (_("Removed property %W to merge %pB and %pB\n"),
                         (bfd_vma) p->property.pr_type, first_pbfd, abfd);
                    else
                      info->callbacks->minfo
                        (_("Removed property %W to merge %pB and %pB "
                           "(not found)\n"),
                         (bfd_vma) p->property.pr_type, first_pbfd, abfd);
                  }
              }

            /* Remove this property.  */
            *lastp = p->next;
            continue;
          }
        else if (number_p)
          {
            if (pr != NULL)
              {
                if (p->property.u.number != number
                    || p->property.u.number != pr->u.number)
                  info->callbacks->minfo
                    (_("Updated property %W (0x%v) to merge %pB (0x%v) "
                       "and %pB (0x%v)\n"),
                     (bfd_vma) p->property.pr_type, p->property.u.number,
                     first_pbfd, number, abfd, pr->u.number);
              }
            else
              {
                if (p->property.u.number != number)
                  info->callbacks->minfo
                    (_("Updated property %W (%v) to merge %pB (0x%v) "
                       "and %pB (not found)\n"),
                     (bfd_vma) p->property.pr_type, p->property.u.number,
                     first_pbfd, number, abfd);
              }
          }
        lastp = &p->next;
      }

  /* Merge the remaining properties on *LISTP with FIRST_PBFD.  */
  for (p = *listp; p != NULL; p = p->next)
    {
      if (p->property.pr_kind == property_number)
        {
          number_p = true;
          number = p->property.u.number;
        }
      else
        number_p = false;

      if (elf_merge_gnu_properties (info, first_pbfd, abfd, NULL, &p->property))
        {
          if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
            elf_has_no_copy_on_protected (first_pbfd) = true;

          pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
                                      p->property.pr_datasz);
          /* It must be a new property.  */
          if (pr->pr_kind != property_unknown)
            abort ();
          /* Add a new property.  */
          *pr = p->property;
        }
      else
        {
          pr = elf_find_and_remove_property (&elf_properties (first_pbfd),
                                             p->property.pr_type,
                                             false);
          if (pr == NULL)
            {
              if (number_p)
                info->callbacks->minfo
                  (_("Removed property %W to merge %pB (not found) and "
                     "%pB (0x%v)\n"),
                   (bfd_vma) p->property.pr_type, first_pbfd, abfd,
                   number);
              else
                info->callbacks->minfo
                  (_("Removed property %W to merge %pB and %pB\n"),
                   (bfd_vma) p->property.pr_type, first_pbfd, abfd);
            }
          else if (pr->pr_kind != property_remove)
            abort ();
        }
    }
}

/* Get GNU property section size.  */

static bfd_size_type
elf_get_gnu_property_section_size (elf_property_list *list,
                                   unsigned int align_size)
{
  bfd_size_type size;
  unsigned int descsz;

  /* Compute the output section size.  */
  descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
  descsz = (descsz + 3) & -(unsigned int) 4;
  size = descsz;
  for (; list != NULL; list = list->next)
    {
      unsigned int datasz;
      /* Check if this property should be skipped.  */
      if (list->property.pr_kind == property_remove)
        continue;
      /* There are 4 byte type + 4 byte datasz for each property.  */
      if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
        datasz = align_size;
      else
        datasz = list->property.pr_datasz;
      size += 4 + 4 + datasz;
      /* Align each property.  */
      size = (size + (align_size - 1)) & ~(align_size - 1);
    }

  return size;
}

/* Write GNU properties.  */

static void
elf_write_gnu_properties (bfd *abfd, bfd_byte *contents,
                          elf_property_list *list, unsigned int size,
                          unsigned int align_size)
{
  unsigned int descsz;
  unsigned int datasz;
  Elf_External_Note *e_note;

  e_note = (Elf_External_Note *) contents;
  descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
  descsz = (descsz + 3) & -(unsigned int) 4;
  bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
  bfd_h_put_32 (abfd, size - descsz, &e_note->descsz);
  bfd_h_put_32 (abfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
  memcpy (e_note->name, "GNU", sizeof "GNU");

  size = descsz;
  for (; list != NULL; list = list->next)
    {
      /* Check if this property should be skipped.  */
      if (list->property.pr_kind == property_remove)
        continue;
      /* There are 4 byte type + 4 byte datasz for each property.  */
      if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
        datasz = align_size;
      else
        datasz = list->property.pr_datasz;
      bfd_h_put_32 (abfd, list->property.pr_type, contents + size);
      bfd_h_put_32 (abfd, datasz, contents + size + 4);
      size += 4 + 4;

      /* Write out property value.  */
      switch (list->property.pr_kind)
        {
        case property_number:
          switch (datasz)
            {
            default:
              /* Never should happen.  */
              abort ();

            case 0:
              break;

            case 4:
              bfd_h_put_32 (abfd, list->property.u.number,
                            contents + size);
              break;

            case 8:
              bfd_h_put_64 (abfd, list->property.u.number,
                            contents + size);
              break;
            }
          break;

        default:
          /* Never should happen.  */
          abort ();
        }
      size += datasz;

      /* Align each property.  */
      size = (size + (align_size - 1)) & ~ (align_size - 1);
    }
}

/* Set up GNU properties.  Return the first relocatable ELF input with
   GNU properties if found.  Otherwise, return NULL.  */

bfd *
_bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
{
  bfd *abfd, *first_pbfd = NULL;
  elf_property_list *list;
  asection *sec;
  bool has_properties = false;
  const struct elf_backend_data *bed
    = get_elf_backend_data (info->output_bfd);
  unsigned int elfclass = bed->s->elfclass;
  int elf_machine_code = bed->elf_machine_code;

  /* Find the first relocatable ELF input with GNU properties.  */
  for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
    if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
        && (abfd->flags & DYNAMIC) == 0
        && elf_properties (abfd) != NULL)
      {
        has_properties = true;

        /* Ignore GNU properties from ELF objects with different machine
           code or class.  Also skip objects without a GNU_PROPERTY note
           section.  */
        if ((elf_machine_code
             == get_elf_backend_data (abfd)->elf_machine_code)
            && (elfclass
                == get_elf_backend_data (abfd)->s->elfclass)
            && bfd_get_section_by_name (abfd,
                                        NOTE_GNU_PROPERTY_SECTION_NAME) != NULL
            )
          {
            /* Keep .note.gnu.property section in FIRST_PBFD.  */
            first_pbfd = abfd;
            break;
          }
      }

  /* Do nothing if there is no .note.gnu.property section.  */
  if (!has_properties)
    return NULL;

  /* Merge .note.gnu.property sections.  */
  info->callbacks->minfo (_("\n"));
  info->callbacks->minfo (_("Merging program properties\n"));
  info->callbacks->minfo (_("\n"));

  for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
    if (abfd != first_pbfd
        && (abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED)) == 0)
      {
        elf_property_list *null_ptr = NULL;
        elf_property_list **listp = &null_ptr;

        /* Merge .note.gnu.property section in relocatable ELF input.  */
        if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
          {
            list = elf_properties (abfd);

            /* Ignore GNU properties from ELF objects with different
               machine code.  */
            if (list != NULL
                && (elf_machine_code
                    == get_elf_backend_data (abfd)->elf_machine_code))
              listp = &elf_properties (abfd);
          }
        else
          list = NULL;

        /* Merge properties with FIRST_PBFD.  FIRST_PBFD can be NULL
           when all properties are from ELF objects with different
           machine code or class.  */
        if (first_pbfd != NULL)
          elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);

        if (list != NULL)
          {
            /* Discard the .note.gnu.property section in this bfd.  */
            sec = bfd_get_section_by_name (abfd,
                                           NOTE_GNU_PROPERTY_SECTION_NAME);
            if (sec != NULL)
              sec->output_section = bfd_abs_section_ptr;
          }
      }

  /* Rewrite .note.gnu.property section so that GNU properties are
     always sorted by type even if input GNU properties aren't sorted.  */
  if (first_pbfd != NULL)
    {
      bfd_size_type size;
      bfd_byte *contents;
      unsigned int align_size = elfclass == ELFCLASS64 ? 8 : 4;

      sec = bfd_get_section_by_name (first_pbfd,
                                     NOTE_GNU_PROPERTY_SECTION_NAME);
      BFD_ASSERT (sec != NULL);

      /* Update stack size in .note.gnu.property with -z stack-size=N
         if N > 0.  */
      if (info->stacksize > 0)
        {
          elf_property *p;
          bfd_vma stacksize = info->stacksize;

          p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_STACK_SIZE,
                                     align_size);
          if (p->pr_kind == property_unknown)
            {
              /* Create GNU_PROPERTY_STACK_SIZE.  */
              p->u.number = stacksize;
              p->pr_kind = property_number;
            }
          else if (stacksize > p->u.number)
            p->u.number = stacksize;
        }
      else if (elf_properties (first_pbfd) == NULL)
        {
          /* Discard .note.gnu.property section if all properties have
             been removed.  */
          sec->output_section = bfd_abs_section_ptr;
          return NULL;
        }

      /* Fix up GNU properties.  */
      if (bed->fixup_gnu_properties)
        bed->fixup_gnu_properties (info, &elf_properties (first_pbfd));

      if (elf_properties (first_pbfd) == NULL)
        {
          /* Discard .note.gnu.property section if all properties have
             been removed.  */
          sec->output_section = bfd_abs_section_ptr;
          return NULL;
        }

      /* Compute the section size.  */
      list = elf_properties (first_pbfd);
      size = elf_get_gnu_property_section_size (list, align_size);

      /* Update .note.gnu.property section now.  */
      sec->size = size;
      contents = (bfd_byte *) bfd_zalloc (first_pbfd, size);

      elf_write_gnu_properties (first_pbfd, contents, list, size,
                                align_size);

      /* Cache the section contents for elf_link_input_bfd.  */
      elf_section_data (sec)->this_hdr.contents = contents;

      /* If GNU_PROPERTY_NO_COPY_ON_PROTECTED is set, protected data
         symbol is defined in the shared object.  */
      if (elf_has_no_copy_on_protected (first_pbfd))
        info->extern_protected_data = false;
    }

  return first_pbfd;
}

/* Convert GNU property size.  */

bfd_size_type
_bfd_elf_convert_gnu_property_size (bfd *ibfd, bfd *obfd)
{
  unsigned int align_size;
  const struct elf_backend_data *bed;
  elf_property_list *list = elf_properties (ibfd);

  bed = get_elf_backend_data (obfd);
  align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;

  /* Get the output .note.gnu.property section size.  */
  return elf_get_gnu_property_section_size (list, align_size);
}

/* Convert GNU properties.  */

bool
_bfd_elf_convert_gnu_properties (bfd *ibfd, asection *isec,
                                 bfd *obfd, bfd_byte **ptr,
                                 bfd_size_type *ptr_size)
{
  unsigned int size;
  bfd_byte *contents;
  unsigned int align_shift;
  const struct elf_backend_data *bed;
  elf_property_list *list = elf_properties (ibfd);

  bed = get_elf_backend_data (obfd);
  align_shift = bed->s->elfclass == ELFCLASS64 ? 3 : 2;

  /* Get the output .note.gnu.property section size.  */
  size = bfd_section_size (isec->output_section);

  /* Update the output .note.gnu.property section alignment.  */
  bfd_set_section_alignment (isec->output_section, align_shift);

  if (size > bfd_section_size (isec))
    {
      contents = (bfd_byte *) bfd_malloc (size);
      if (contents == NULL)
        return false;
      free (*ptr);
      *ptr = contents;
    }
  else
    contents = *ptr;

  *ptr_size = size;

  /* Generate the output .note.gnu.property section.  */
  elf_write_gnu_properties (ibfd, contents, list, size, 1 << align_shift);

  return true;
}