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 *
_bfd_elf_get_property(bfd * abfd,unsigned int type,unsigned int datasz)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
_bfd_elf_parse_gnu_properties(bfd * abfd,Elf_Internal_Note * note)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
elf_merge_gnu_properties(struct bfd_link_info * info,bfd * abfd,bfd * bbfd,elf_property * aprop,elf_property * bprop)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 *
elf_find_and_remove_property(elf_property_list ** listp,unsigned int type,bfd_boolean rm)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
elf_merge_gnu_property_list(struct bfd_link_info * info,bfd * first_pbfd,bfd * abfd,elf_property_list ** listp)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
elf_get_gnu_property_section_size(elf_property_list * list,unsigned int align_size)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
elf_write_gnu_properties(bfd * abfd,bfd_byte * contents,elf_property_list * list,unsigned int size,unsigned int align_size)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 *
_bfd_elf_link_setup_gnu_properties(struct bfd_link_info * info)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
_bfd_elf_convert_gnu_property_size(bfd * ibfd,bfd * obfd)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
_bfd_elf_convert_gnu_properties(bfd * ibfd,asection * isec,bfd * obfd,bfd_byte ** ptr,bfd_size_type * ptr_size)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 }
721