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

/* ELF program property support.
   Copyright (C) 2017 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 (_("%B: 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.  */

bfd_boolean
_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: %B: corrupt GNU_PROPERTY_TYPE (%ld) size: %#lx"),
	 abfd, note->type, note->descsz);
      return FALSE;
    }

  while (1)
    {
      unsigned int type = bfd_h_get_32 (abfd, ptr);
      unsigned int datasz = bfd_h_get_32 (abfd, ptr + 4);
      elf_property *prop;

      ptr += 8;

      if ((ptr + datasz) > ptr_end)
	{
	  _bfd_error_handler
	    (_("warning: %B: 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: %B: 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: %B: 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);
	      prop->pr_kind = property_number;
	      goto next;

	    default:
	      break;
	    }
	}

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

next:
      ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
      if (ptr == ptr_end)
	break;

      if (ptr > (ptr_end - 8))
	goto bad_size;
    }

  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 bfd_boolean
elf_merge_gnu_properties (bfd *abfd, 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;

  if (bed->merge_gnu_properties != NULL
      && pr_type >= GNU_PROPERTY_LOPROC
      && pr_type < GNU_PROPERTY_LOUSER)
    return bed->merge_gnu_properties (abfd, 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:
      /* Never should happen.  */
      abort ();
    }

  return FALSE;
}

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

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

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

  return NULL;
}

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

static void
elf_merge_gnu_property_list (bfd *abfd, elf_property_list **listp)
{
  elf_property_list *p, **lastp;
  elf_property *pr;

  /* Merge each GNU property in ABFD with the one on *LISTP.  */
  lastp = &elf_properties (abfd);
  for (p = *lastp; p; p = p->next)
    {
      pr = elf_find_and_remove_property (listp, p->property.pr_type);
      /* Pass NULL to elf_merge_gnu_properties for the property which
	 isn't on *LISTP.  */
      elf_merge_gnu_properties (abfd, &p->property, pr);
      if (p->property.pr_kind == property_remove)
	{
	  /* Remove this property.  */
	  *lastp = p->next;
	  continue;
	}
      lastp = &p->next;
    }

  /* Merge the remaining properties on *LISTP with ABFD.  */
  for (p = *listp; p != NULL; p = p->next)
    if (elf_merge_gnu_properties (abfd, NULL, &p->property))
      {
	pr = _bfd_elf_get_property (abfd, 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;
      }
}

/* Set up GNU properties.  */

void
_bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
{
  bfd *abfd, *first_pbfd = NULL;
  elf_property_list *list;
  asection *sec;
  bfd_boolean 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
	&& bfd_count_sections (abfd) != 0
	&& elf_properties (abfd) != NULL)
      {
	has_properties = TRUE;

	/* Ignore GNU properties from ELF objects with different machine
	   code or class.  */
	if ((elf_machine_code
	     == get_elf_backend_data (abfd)->elf_machine_code)
	    && (elfclass
		== get_elf_backend_data (abfd)->s->elfclass))
	  {
	    /* 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;

  /* Merge .note.gnu.property sections.  */
  for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
    if (abfd != first_pbfd && bfd_count_sections (abfd) != 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 (first_pbfd, listp);

	if (list != NULL)
	  {
	    /* Discard .note.gnu.property section in the rest inputs.  */
	    sec = bfd_get_section_by_name (abfd,
					   NOTE_GNU_PROPERTY_SECTION_NAME);
	    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)
    {
      unsigned int size;
      unsigned int descsz;
      bfd_byte *contents;
      Elf_External_Note *e_note;
      unsigned int align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;

      sec = bfd_get_section_by_name (first_pbfd,
				     NOTE_GNU_PROPERTY_SECTION_NAME);

      /* 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;
	}

      /* Compute the section size.  */
      descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
      descsz = (descsz + 3) & -(unsigned int) 4;
      size = descsz;
      for (list = elf_properties (first_pbfd);
	   list != NULL;
	   list = list->next)
	{
	  /* There are 4 byte type + 4 byte datasz for each property.  */
	  size += 4 + 4 + list->property.pr_datasz;
	  /* Align each property.  */
	  size = (size + (align_size - 1)) & ~(align_size - 1);
	}

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

      e_note = (Elf_External_Note *) contents;
      bfd_h_put_32 (first_pbfd, sizeof "GNU", &e_note->namesz);
      bfd_h_put_32 (first_pbfd, size - descsz, &e_note->descsz);
      bfd_h_put_32 (first_pbfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
      memcpy (e_note->name, "GNU", sizeof "GNU");

      size = descsz;
      for (list = elf_properties (first_pbfd);
	   list != NULL;
	   list = list->next)
	{
	  /* There are 4 byte type + 4 byte datasz for each property.  */
	  bfd_h_put_32 (first_pbfd, list->property.pr_type,
			contents + size);
	  bfd_h_put_32 (first_pbfd, list->property.pr_datasz,
			contents + size + 4);
	  size += 4 + 4;

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

		case 0:
		  break;

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

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

	    default:
	      /* Never should happen.  */
	      abort ();
	    }
	  size += list->property.pr_datasz;

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

      /* Cache the section contents for elf_link_input_bfd.  */
      elf_section_data (sec)->this_hdr.contents = contents;
    }
}
Commit	Line	Data
46bed679 L	1	/* ELF program property support.
	2	Copyright (C) 2017 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 (_("%B: 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
e4097f5e	91	(_("warning: %B: corrupt GNU_PROPERTY_TYPE (%ld) size: %#lx"),
46bed679 L	92	abfd, note->type, note->descsz);
	93	return FALSE;
	94	}
	95
	96	while (1)
	97	{
	98	unsigned int type = bfd_h_get_32 (abfd, ptr);
	99	unsigned int datasz = bfd_h_get_32 (abfd, ptr + 4);
	100	elf_property *prop;
	101
	102	ptr += 8;
	103
	104	if ((ptr + datasz) > ptr_end)
	105	{
	106	_bfd_error_handler
e4097f5e	107	(_("warning: %B: corrupt GNU_PROPERTY_TYPE (%ld) type (0x%x) datasz: 0x%x"),
46bed679 L	108	abfd, note->type, type, datasz);
	109	/* Clear all properties. */
	110	elf_properties (abfd) = NULL;
	111	return FALSE;
	112	}
	113
	114	if (type >= GNU_PROPERTY_LOPROC)
	115	{
537616aa L	116	if (bed->elf_machine_code == EM_NONE)
	117	{
	118	/* Ignore processor-specific properties with generic ELF
	119	target vector. They should be handled by the matching
	120	ELF target vector. */
	121	goto next;
	122	}
	123	else if (type < GNU_PROPERTY_LOUSER
	124	&& bed->parse_gnu_properties)
46bed679 L	125	{
	126	enum elf_property_kind kind
	127	= bed->parse_gnu_properties (abfd, type, ptr, datasz);
	128	if (kind == property_corrupt)
	129	{
	130	/* Clear all properties. */
	131	elf_properties (abfd) = NULL;
	132	return FALSE;
	133	}
	134	else if (kind != property_ignored)
	135	goto next;
	136	}
	137	}
	138	else
	139	{
	140	switch (type)
	141	{
	142	case GNU_PROPERTY_STACK_SIZE:
	143	if (datasz != align_size)
	144	{
	145	_bfd_error_handler
e4097f5e	146	(_("warning: %B: corrupt stack size: 0x%x"),
46bed679 L	147	abfd, datasz);
	148	/* Clear all properties. */
	149	elf_properties (abfd) = NULL;
	150	return FALSE;
	151	}
	152	prop = _bfd_elf_get_property (abfd, type, datasz);
	153	if (datasz == 8)
	154	prop->u.number = bfd_h_get_64 (abfd, ptr);
	155	else
	156	prop->u.number = bfd_h_get_32 (abfd, ptr);
	157	prop->pr_kind = property_number;
	158	goto next;
	159
	160	case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
	161	if (datasz != 0)
	162	{
	163	_bfd_error_handler
e4097f5e	164	(_("warning: %B: corrupt no copy on protected size: 0x%x"),
46bed679 L	165	abfd, datasz);
	166	/* Clear all properties. */
	167	elf_properties (abfd) = NULL;
	168	return FALSE;
	169	}
	170	prop = _bfd_elf_get_property (abfd, type, datasz);
	171	prop->pr_kind = property_number;
	172	goto next;
	173
	174	default:
	175	break;
	176	}
	177	}
	178
	179	_bfd_error_handler
e4097f5e	180	(_("warning: %B: unsupported GNU_PROPERTY_TYPE (%ld) type: 0x%x"),
46bed679 L	181	abfd, note->type, type);
	182
	183	next:
	184	ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
	185	if (ptr == ptr_end)
	186	break;
	187
	188	if (ptr > (ptr_end - 8))
	189	goto bad_size;
	190	}
	191
	192	return TRUE;
	193	}
	194
	195	/* Merge GNU property BPROP with APROP. If APROP isn't NULL, return TRUE
	196	if APROP is updated. Otherwise, return TRUE if BPROP should be merged
	197	with ABFD. */
	198
	199	static bfd_boolean
	200	elf_merge_gnu_properties (bfd abfd, elf_property aprop,
	201	elf_property *bprop)
	202	{
	203	const struct elf_backend_data *bed = get_elf_backend_data (abfd);
	204	unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
	205
	206	if (bed->merge_gnu_properties != NULL
	207	&& pr_type >= GNU_PROPERTY_LOPROC
	208	&& pr_type < GNU_PROPERTY_LOUSER)
	209	return bed->merge_gnu_properties (abfd, aprop, bprop);
	210
	211	switch (pr_type)
	212	{
	213	case GNU_PROPERTY_STACK_SIZE:
	214	if (aprop != NULL && bprop != NULL)
	215	{
	216	if (bprop->u.number > aprop->u.number)
	217	{
	218	aprop->u.number = bprop->u.number;
	219	return TRUE;
	220	}
	221	break;
	222	}
	223	/* FALLTHROUGH */
	224
	225	case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
	226	/* Return TRUE if APROP is NULL to indicate that BPROP should
	227	be added to ABFD. */
	228	return aprop == NULL;
	229
	230	default:
	231	/* Never should happen. */
	232	abort ();
	233	}
	234
	235	return FALSE;
	236	}
	237
	238	/* Return the property of TYPE on LISTP and remove it from LISTP.
	239	Return NULL if not found. */
	240
	241	static elf_property *
	242	elf_find_and_remove_property (elf_property_list **listp,
	243	unsigned int type)
	244	{
245	elf_property_list *list;
246
247	for (list = *listp; list; list = list->next)
248	{
249	if (type == list->property.pr_type)
250	{
251	/* Remove this property. */
252	*listp = list->next;
253	return &list->property;
254	}
255	else if (type < list->property.pr_type)
256	break;
257	listp = &list->next;
258	}
259
260	return NULL;
261	}
262
263	/* Merge GNU property list LISTP with ABFD. /
264
265	static void
266	elf_merge_gnu_property_list (bfd abfd, elf_property_list *listp)
267	{
268	elf_property_list p, *lastp;
269	elf_property *pr;
270
271	/* Merge each GNU property in ABFD with the one on LISTP. /
272	lastp = &elf_properties (abfd);
273	for (p = *lastp; p; p = p->next)
274	{
275	pr = elf_find_and_remove_property (listp, p->property.pr_type);
276	/* Pass NULL to elf_merge_gnu_properties for the property which
277	isn't on LISTP. /
278	elf_merge_gnu_properties (abfd, &p->property, pr);
279	if (p->property.pr_kind == property_remove)
280	{
281	/* Remove this property. */
282	*lastp = p->next;
283	continue;
284	}
285	lastp = &p->next;
286	}
287
288	/* Merge the remaining properties on LISTP with ABFD. /
289	for (p = *listp; p != NULL; p = p->next)
290	if (elf_merge_gnu_properties (abfd, NULL, &p->property))
291	{
292	pr = _bfd_elf_get_property (abfd, p->property.pr_type,
293	p->property.pr_datasz);
294	/* It must be a new property. */
295	if (pr->pr_kind != property_unknown)
296	abort ();
297	/* Add a new property. */
298	*pr = p->property;
299	}
300	}
301
302	/* Set up GNU properties. */
303
304	void
305	_bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
306	{
307	bfd abfd, first_pbfd = NULL;
308	elf_property_list *list;
309	asection *sec;
310	bfd_boolean has_properties = FALSE;
311	const struct elf_backend_data *bed
312	= get_elf_backend_data (info->output_bfd);
313	unsigned int elfclass = bed->s->elfclass;
314	int elf_machine_code = bed->elf_machine_code;
315
316	/* Find the first relocatable ELF input with GNU properties. */
317	for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
318	if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
319	&& bfd_count_sections (abfd) != 0
320	&& elf_properties (abfd) != NULL)
321	{
322	has_properties = TRUE;
323
324	/* Ignore GNU properties from ELF objects with different machine
325	code or class. */
326	if ((elf_machine_code
327	== get_elf_backend_data (abfd)->elf_machine_code)
328	&& (elfclass
329	== get_elf_backend_data (abfd)->s->elfclass))
330	{
331	/* Keep .note.gnu.property section in FIRST_PBFD. */
332	first_pbfd = abfd;
333	break;
334	}
335	}
336
337	/* Do nothing if there is no .note.gnu.property section. */
338	if (!has_properties)
339	return;
340
341	/* Merge .note.gnu.property sections. */
342	for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
343	if (abfd != first_pbfd && bfd_count_sections (abfd) != 0)
344	{
345	elf_property_list *null_ptr = NULL;
346	elf_property_list **listp = &null_ptr;
347
348	/* Merge .note.gnu.property section in relocatable ELF input. */
349	if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
350	{
351	list = elf_properties (abfd);
352
353	/* Ignore GNU properties from ELF objects with different
354	machine code. */
355	if (list != NULL
356	&& (elf_machine_code
357	== get_elf_backend_data (abfd)->elf_machine_code))
358	listp = &elf_properties (abfd);
359	}
360	else
361	list = NULL;
362
363	/* Merge properties with FIRST_PBFD. FIRST_PBFD can be NULL
364	when all properties are from ELF objects with different
365	machine code or class. */
366	if (first_pbfd != NULL)
367	elf_merge_gnu_property_list (first_pbfd, listp);
368
369	if (list != NULL)
370	{
371	/* Discard .note.gnu.property section in the rest inputs. */
372	sec = bfd_get_section_by_name (abfd,
373	NOTE_GNU_PROPERTY_SECTION_NAME);
374	sec->output_section = bfd_abs_section_ptr;
375	}
376	}
377
378	/* Rewrite .note.gnu.property section so that GNU properties are
379	always sorted by type even if input GNU properties aren't sorted. */
380	if (first_pbfd != NULL)
381	{
382	unsigned int size;
383	unsigned int descsz;
384	bfd_byte *contents;
385	Elf_External_Note *e_note;
386	unsigned int align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
387
388	sec = bfd_get_section_by_name (first_pbfd,
389	NOTE_GNU_PROPERTY_SECTION_NAME);
390
391	/* Update stack size in .note.gnu.property with -z stack-size=N
392	if N > 0. */
393	if (info->stacksize > 0)
394	{
395	elf_property *p;
396	bfd_vma stacksize = info->stacksize;
397
398	p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_STACK_SIZE,
399	align_size);
400	if (p->pr_kind == property_unknown)
401	{
402	/* Create GNU_PROPERTY_STACK_SIZE. */
403	p->u.number = stacksize;
404	p->pr_kind = property_number;
405	}
406	else if (stacksize > p->u.number)
407	p->u.number = stacksize;
408	}
409	else if (elf_properties (first_pbfd) == NULL)
410	{
411	/* Discard .note.gnu.property section if all properties have
412	been removed. */
413	sec->output_section = bfd_abs_section_ptr;
414	return;
415	}
416
417	/* Compute the section size. */
418	descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
419	descsz = (descsz + 3) & -(unsigned int) 4;
420	size = descsz;
421	for (list = elf_properties (first_pbfd);
422	list != NULL;
423	list = list->next)
424	{
425	/* There are 4 byte type + 4 byte datasz for each property. */
426	size += 4 + 4 + list->property.pr_datasz;
427	/* Align each property. */
428	size = (size + (align_size - 1)) & ~(align_size - 1);
429	}
430
431	/* Update .note.gnu.property section now. */
432	sec->size = size;
433	contents = (bfd_byte *) bfd_zalloc (first_pbfd, size);
434
435	e_note = (Elf_External_Note *) contents;
436	bfd_h_put_32 (first_pbfd, sizeof "GNU", &e_note->namesz);
437	bfd_h_put_32 (first_pbfd, size - descsz, &e_note->descsz);
438	bfd_h_put_32 (first_pbfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
439	memcpy (e_note->name, "GNU", sizeof "GNU");
440
441	size = descsz;
442	for (list = elf_properties (first_pbfd);
443	list != NULL;
444	list = list->next)
445	{
446	/* There are 4 byte type + 4 byte datasz for each property. */
447	bfd_h_put_32 (first_pbfd, list->property.pr_type,
448	contents + size);
449	bfd_h_put_32 (first_pbfd, list->property.pr_datasz,
450	contents + size + 4);
451	size += 4 + 4;
452
453	/* Write out property value. */
454	switch (list->property.pr_kind)
455	{
456	case property_number:
457	switch (list->property.pr_datasz)
458	{
459	default:
460	/* Never should happen. */
461	abort ();
462
463	case 0:
464	break;
465
466	case 4:
467	bfd_h_put_32 (first_pbfd, list->property.u.number,
468	contents + size);
469	break;
470
471	case 8:
472	bfd_h_put_64 (first_pbfd, list->property.u.number,
473	contents + size);
474	break;
475	}
476	break;
477
478	default:
479	/* Never should happen. */
480	abort ();
481	}
482	size += list->property.pr_datasz;
483
484	/* Align each property. */
485	size = (size + (align_size - 1)) & ~ (align_size - 1);
486	}
487
488	/* Cache the section contents for elf_link_input_bfd. */
489	elf_section_data (sec)->this_hdr.contents = contents;
490	}
491	}