1 /* ELF program property support.
2 Copyright (C) 2017-2022 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 bool
_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 if ((type >= GNU_PROPERTY_UINT32_AND_LO
182 && type <= GNU_PROPERTY_UINT32_AND_HI)
183 || (type >= GNU_PROPERTY_UINT32_OR_LO
184 && type <= GNU_PROPERTY_UINT32_OR_HI))
185 {
186 if (datasz != 4)
187 {
188 _bfd_error_handler
189 (_("error: %pB: <corrupt property (0x%x) size: 0x%x>"),
190 abfd, type, datasz);
191 /* Clear all properties. */
192 elf_properties (abfd) = NULL;
193 return false;
194 }
195 prop = _bfd_elf_get_property (abfd, type, datasz);
196 prop->u.number |= bfd_h_get_32 (abfd, ptr);
197 prop->pr_kind = property_number;
198 if (type == GNU_PROPERTY_1_NEEDED
199 && ((prop->u.number
200 & GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS)
201 != 0))
202 {
203 elf_has_indirect_extern_access (abfd) = true;
204 /* GNU_PROPERTY_NO_COPY_ON_PROTECTED is implied. */
205 elf_has_no_copy_on_protected (abfd) = true;
206 }
207 goto next;
208 }
209 break;
210 }
211 }
212
213 _bfd_error_handler
214 (_("warning: %pB: unsupported GNU_PROPERTY_TYPE (%ld) type: 0x%x"),
215 abfd, note->type, type);
216
217 next:
218 ptr += (datasz + (align_size - 1)) & ~ (align_size - 1);
219 }
220
221 return true;
222 }
223
224 /* Merge GNU property BPROP with APROP. If APROP isn't NULL, return TRUE
225 if APROP is updated. Otherwise, return TRUE if BPROP should be merged
226 with ABFD. */
227
228 static bool
elf_merge_gnu_properties(struct bfd_link_info * info,bfd * abfd,bfd * bbfd,elf_property * aprop,elf_property * bprop)229 elf_merge_gnu_properties (struct bfd_link_info *info, bfd *abfd, bfd *bbfd,
230 elf_property *aprop, elf_property *bprop)
231 {
232 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
233 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
234 unsigned int number;
235 bool updated;
236
237 if (bed->merge_gnu_properties != NULL
238 && pr_type >= GNU_PROPERTY_LOPROC
239 && pr_type < GNU_PROPERTY_LOUSER)
240 return bed->merge_gnu_properties (info, abfd, bbfd, aprop, bprop);
241
242 switch (pr_type)
243 {
244 case GNU_PROPERTY_STACK_SIZE:
245 if (aprop != NULL && bprop != NULL)
246 {
247 if (bprop->u.number > aprop->u.number)
248 {
249 aprop->u.number = bprop->u.number;
250 return true;
251 }
252 break;
253 }
254 /* FALLTHROUGH */
255
256 case GNU_PROPERTY_NO_COPY_ON_PROTECTED:
257 /* Return TRUE if APROP is NULL to indicate that BPROP should
258 be added to ABFD. */
259 return aprop == NULL;
260
261 default:
262 updated = false;
263 if (pr_type >= GNU_PROPERTY_UINT32_OR_LO
264 && pr_type <= GNU_PROPERTY_UINT32_OR_HI)
265 {
266 if (aprop != NULL && bprop != NULL)
267 {
268 number = aprop->u.number;
269 aprop->u.number = number | bprop->u.number;
270 /* Remove the property if all bits are empty. */
271 if (aprop->u.number == 0)
272 {
273 aprop->pr_kind = property_remove;
274 updated = true;
275 }
276 else
277 updated = number != (unsigned int) aprop->u.number;
278 }
279 else
280 {
281 /* Only one of APROP and BPROP can be NULL. */
282 if (aprop != NULL)
283 {
284 if (aprop->u.number == 0)
285 {
286 /* Remove APROP if all bits are empty. */
287 aprop->pr_kind = property_remove;
288 updated = true;
289 }
290 }
291 else
292 {
293 /* Return TRUE if APROP is NULL and all bits of BPROP
294 aren't empty to indicate that BPROP should be added
295 to ABFD. */
296 updated = bprop->u.number != 0;
297 }
298 }
299 return updated;
300 }
301 else if (pr_type >= GNU_PROPERTY_UINT32_AND_LO
302 && pr_type <= GNU_PROPERTY_UINT32_AND_HI)
303 {
304 /* Only one of APROP and BPROP can be NULL:
305 1. APROP & BPROP when both APROP and BPROP aren't NULL.
306 2. If APROP is NULL, remove x86 feature.
307 3. Otherwise, do nothing.
308 */
309 if (aprop != NULL && bprop != NULL)
310 {
311 number = aprop->u.number;
312 aprop->u.number = number & bprop->u.number;
313 updated = number != (unsigned int) aprop->u.number;
314 /* Remove the property if all feature bits are cleared. */
315 if (aprop->u.number == 0)
316 aprop->pr_kind = property_remove;
317 }
318 else
319 {
320 /* There should be no AND properties since some input
321 doesn't have them. */
322 if (aprop != NULL)
323 {
324 aprop->pr_kind = property_remove;
325 updated = true;
326 }
327 }
328 return updated;
329 }
330
331 /* Never should happen. */
332 abort ();
333 }
334
335 return false;
336 }
337
338 /* Return the property of TYPE on *LISTP and remove it from *LISTP if RM is
339 true. Return NULL if not found. */
340
341 static elf_property *
elf_find_and_remove_property(elf_property_list ** listp,unsigned int type,bool rm)342 elf_find_and_remove_property (elf_property_list **listp,
343 unsigned int type, bool rm)
344 {
345 elf_property_list *list;
346
347 for (list = *listp; list; list = list->next)
348 {
349 if (type == list->property.pr_type)
350 {
351 /* Remove this property. */
352 if (rm)
353 *listp = list->next;
354 return &list->property;
355 }
356 else if (type < list->property.pr_type)
357 break;
358 listp = &list->next;
359 }
360
361 return NULL;
362 }
363
364 /* Merge GNU property list *LISTP in ABFD with FIRST_PBFD. */
365
366 static void
elf_merge_gnu_property_list(struct bfd_link_info * info,bfd * first_pbfd,bfd * abfd,elf_property_list ** listp)367 elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
368 bfd *abfd, elf_property_list **listp)
369 {
370 elf_property_list *p, **lastp;
371 elf_property *pr;
372 bool number_p;
373 bfd_vma number = 0;
374
375 /* Merge each GNU property in FIRST_PBFD with the one on *LISTP. */
376 lastp = &elf_properties (first_pbfd);
377 for (p = *lastp; p; p = p->next)
378 if (p->property.pr_kind != property_remove)
379 {
380 if (p->property.pr_kind == property_number)
381 {
382 number_p = true;
383 number = p->property.u.number;
384 }
385 else
386 number_p = false;
387 pr = elf_find_and_remove_property (listp, p->property.pr_type,
388 true);
389 /* Pass NULL to elf_merge_gnu_properties for the property which
390 isn't on *LISTP. */
391 elf_merge_gnu_properties (info, first_pbfd, abfd, &p->property, pr);
392 if (p->property.pr_kind == property_remove)
393 {
394 if (info->has_map_file)
395 {
396 if (number_p)
397 {
398 if (pr != NULL)
399 info->callbacks->minfo
400 (_("Removed property %W to merge %pB (0x%v) "
401 "and %pB (0x%v)\n"),
402 (bfd_vma) p->property.pr_type, first_pbfd,
403 number, abfd, pr->u.number);
404 else
405 info->callbacks->minfo
406 (_("Removed property %W to merge %pB (0x%v) "
407 "and %pB (not found)\n"),
408 (bfd_vma) p->property.pr_type, first_pbfd,
409 number, abfd);
410 }
411 else
412 {
413 if (pr != NULL)
414 info->callbacks->minfo
415 (_("Removed property %W to merge %pB and %pB\n"),
416 (bfd_vma) p->property.pr_type, first_pbfd, abfd);
417 else
418 info->callbacks->minfo
419 (_("Removed property %W to merge %pB and %pB "
420 "(not found)\n"),
421 (bfd_vma) p->property.pr_type, first_pbfd, abfd);
422 }
423 }
424
425 /* Remove this property. */
426 *lastp = p->next;
427 continue;
428 }
429 else if (number_p)
430 {
431 if (pr != NULL)
432 {
433 if (p->property.u.number != number
434 || p->property.u.number != pr->u.number)
435 info->callbacks->minfo
436 (_("Updated property %W (0x%v) to merge %pB (0x%v) "
437 "and %pB (0x%v)\n"),
438 (bfd_vma) p->property.pr_type, p->property.u.number,
439 first_pbfd, number, abfd, pr->u.number);
440 }
441 else
442 {
443 if (p->property.u.number != number)
444 info->callbacks->minfo
445 (_("Updated property %W (%v) to merge %pB (0x%v) "
446 "and %pB (not found)\n"),
447 (bfd_vma) p->property.pr_type, p->property.u.number,
448 first_pbfd, number, abfd);
449 }
450 }
451 lastp = &p->next;
452 }
453
454 /* Merge the remaining properties on *LISTP with FIRST_PBFD. */
455 for (p = *listp; p != NULL; p = p->next)
456 {
457 if (p->property.pr_kind == property_number)
458 {
459 number_p = true;
460 number = p->property.u.number;
461 }
462 else
463 number_p = false;
464
465 if (elf_merge_gnu_properties (info, first_pbfd, abfd, NULL, &p->property))
466 {
467 if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
468 elf_has_no_copy_on_protected (first_pbfd) = true;
469
470 pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
471 p->property.pr_datasz);
472 /* It must be a new property. */
473 if (pr->pr_kind != property_unknown)
474 abort ();
475 /* Add a new property. */
476 *pr = p->property;
477 }
478 else
479 {
480 pr = elf_find_and_remove_property (&elf_properties (first_pbfd),
481 p->property.pr_type,
482 false);
483 if (pr == NULL)
484 {
485 if (number_p)
486 info->callbacks->minfo
487 (_("Removed property %W to merge %pB (not found) and "
488 "%pB (0x%v)\n"),
489 (bfd_vma) p->property.pr_type, first_pbfd, abfd,
490 number);
491 else
492 info->callbacks->minfo
493 (_("Removed property %W to merge %pB and %pB\n"),
494 (bfd_vma) p->property.pr_type, first_pbfd, abfd);
495 }
496 else if (pr->pr_kind != property_remove)
497 abort ();
498 }
499 }
500 }
501
502 /* Get GNU property section size. */
503
504 static bfd_size_type
elf_get_gnu_property_section_size(elf_property_list * list,unsigned int align_size)505 elf_get_gnu_property_section_size (elf_property_list *list,
506 unsigned int align_size)
507 {
508 bfd_size_type size;
509 unsigned int descsz;
510
511 /* Compute the output section size. */
512 descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
513 descsz = (descsz + 3) & -(unsigned int) 4;
514 size = descsz;
515 for (; list != NULL; list = list->next)
516 {
517 unsigned int datasz;
518 /* Check if this property should be skipped. */
519 if (list->property.pr_kind == property_remove)
520 continue;
521 /* There are 4 byte type + 4 byte datasz for each property. */
522 if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
523 datasz = align_size;
524 else
525 datasz = list->property.pr_datasz;
526 size += 4 + 4 + datasz;
527 /* Align each property. */
528 size = (size + (align_size - 1)) & ~(align_size - 1);
529 }
530
531 return size;
532 }
533
534 /* Write GNU properties. */
535
536 static void
elf_write_gnu_properties(struct bfd_link_info * info,bfd * abfd,bfd_byte * contents,elf_property_list * list,unsigned int size,unsigned int align_size)537 elf_write_gnu_properties (struct bfd_link_info *info,
538 bfd *abfd, bfd_byte *contents,
539 elf_property_list *list, unsigned int size,
540 unsigned int align_size)
541 {
542 unsigned int descsz;
543 unsigned int datasz;
544 Elf_External_Note *e_note;
545
546 e_note = (Elf_External_Note *) contents;
547 descsz = offsetof (Elf_External_Note, name[sizeof "GNU"]);
548 descsz = (descsz + 3) & -(unsigned int) 4;
549 bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
550 bfd_h_put_32 (abfd, size - descsz, &e_note->descsz);
551 bfd_h_put_32 (abfd, NT_GNU_PROPERTY_TYPE_0, &e_note->type);
552 memcpy (e_note->name, "GNU", sizeof "GNU");
553
554 size = descsz;
555 for (; list != NULL; list = list->next)
556 {
557 /* Check if this property should be skipped. */
558 if (list->property.pr_kind == property_remove)
559 continue;
560 /* There are 4 byte type + 4 byte datasz for each property. */
561 if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
562 datasz = align_size;
563 else
564 datasz = list->property.pr_datasz;
565 bfd_h_put_32 (abfd, list->property.pr_type, contents + size);
566 bfd_h_put_32 (abfd, datasz, contents + size + 4);
567 size += 4 + 4;
568
569 /* Write out property value. */
570 switch (list->property.pr_kind)
571 {
572 case property_number:
573 switch (datasz)
574 {
575 default:
576 /* Never should happen. */
577 abort ();
578
579 case 0:
580 break;
581
582 case 4:
583 /* Save the pointer to GNU_PROPERTY_1_NEEDED so that it
584 can be updated later if needed. */
585 if (info != NULL
586 && list->property.pr_type == GNU_PROPERTY_1_NEEDED)
587 info->needed_1_p = contents + size;
588 bfd_h_put_32 (abfd, list->property.u.number,
589 contents + size);
590 break;
591
592 case 8:
593 bfd_h_put_64 (abfd, list->property.u.number,
594 contents + size);
595 break;
596 }
597 break;
598
599 default:
600 /* Never should happen. */
601 abort ();
602 }
603 size += datasz;
604
605 /* Align each property. */
606 size = (size + (align_size - 1)) & ~ (align_size - 1);
607 }
608 }
609
610 /* Set up GNU properties. Return the first relocatable ELF input with
611 GNU properties if found. Otherwise, return NULL. */
612
613 bfd *
_bfd_elf_link_setup_gnu_properties(struct bfd_link_info * info)614 _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
615 {
616 bfd *abfd, *first_pbfd = NULL, *elf_bfd = NULL;
617 elf_property_list *list;
618 asection *sec;
619 bool has_properties = false;
620 const struct elf_backend_data *bed
621 = get_elf_backend_data (info->output_bfd);
622 unsigned int elfclass = bed->s->elfclass;
623 int elf_machine_code = bed->elf_machine_code;
624 elf_property *p;
625
626 /* Find the first relocatable ELF input with GNU properties. */
627 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
628 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
629 && (abfd->flags & DYNAMIC) == 0
630 && (elf_machine_code
631 == get_elf_backend_data (abfd)->elf_machine_code)
632 && (elfclass == get_elf_backend_data (abfd)->s->elfclass))
633 {
634 /* Ignore GNU properties from ELF objects with different machine
635 code or class. Also skip objects without a GNU_PROPERTY note
636 section. */
637 elf_bfd = abfd;
638
639 if (elf_properties (abfd) != NULL)
640 {
641 has_properties = true;
642
643 if (bfd_get_section_by_name (abfd,
644 NOTE_GNU_PROPERTY_SECTION_NAME)
645 != NULL)
646 {
647 /* Keep .note.gnu.property section in FIRST_PBFD. */
648 first_pbfd = abfd;
649 break;
650 }
651 }
652 }
653
654 if (info->indirect_extern_access > 0 && elf_bfd != NULL)
655 {
656 /* Support -z indirect-extern-access. */
657 if (first_pbfd == NULL)
658 {
659 sec = bfd_make_section_with_flags (elf_bfd,
660 NOTE_GNU_PROPERTY_SECTION_NAME,
661 (SEC_ALLOC
662 | SEC_LOAD
663 | SEC_IN_MEMORY
664 | SEC_READONLY
665 | SEC_HAS_CONTENTS
666 | SEC_DATA));
667 if (sec == NULL)
668 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n"));
669
670 if (!bfd_set_section_alignment (sec,
671 elfclass == ELFCLASS64 ? 3 : 2))
672 info->callbacks->einfo (_("%F%pA: failed to align section\n"),
673 sec);
674
675 elf_section_type (sec) = SHT_NOTE;
676 first_pbfd = elf_bfd;
677 has_properties = true;
678 }
679
680 p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_1_NEEDED, 4);
681 if (p->pr_kind == property_unknown)
682 {
683 /* Create GNU_PROPERTY_1_NEEDED. */
684 p->u.number
685 = GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
686 p->pr_kind = property_number;
687 }
688 else
689 p->u.number
690 |= GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
691 }
692
693 /* Do nothing if there is no .note.gnu.property section. */
694 if (!has_properties)
695 return NULL;
696
697 /* Merge .note.gnu.property sections. */
698 info->callbacks->minfo (_("\n"));
699 info->callbacks->minfo (_("Merging program properties\n"));
700 info->callbacks->minfo (_("\n"));
701
702 for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
703 if (abfd != first_pbfd
704 && (abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED)) == 0)
705 {
706 elf_property_list *null_ptr = NULL;
707 elf_property_list **listp = &null_ptr;
708
709 /* Merge .note.gnu.property section in relocatable ELF input. */
710 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
711 {
712 list = elf_properties (abfd);
713
714 /* Ignore GNU properties from ELF objects with different
715 machine code. */
716 if (list != NULL
717 && (elf_machine_code
718 == get_elf_backend_data (abfd)->elf_machine_code))
719 listp = &elf_properties (abfd);
720 }
721 else
722 list = NULL;
723
724 /* Merge properties with FIRST_PBFD. FIRST_PBFD can be NULL
725 when all properties are from ELF objects with different
726 machine code or class. */
727 if (first_pbfd != NULL)
728 elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);
729
730 if (list != NULL)
731 {
732 /* Discard the .note.gnu.property section in this bfd. */
733 sec = bfd_get_section_by_name (abfd,
734 NOTE_GNU_PROPERTY_SECTION_NAME);
735 if (sec != NULL)
736 sec->output_section = bfd_abs_section_ptr;
737 }
738 }
739
740 /* Rewrite .note.gnu.property section so that GNU properties are
741 always sorted by type even if input GNU properties aren't sorted. */
742 if (first_pbfd != NULL)
743 {
744 bfd_size_type size;
745 bfd_byte *contents;
746 unsigned int align_size = elfclass == ELFCLASS64 ? 8 : 4;
747
748 sec = bfd_get_section_by_name (first_pbfd,
749 NOTE_GNU_PROPERTY_SECTION_NAME);
750 BFD_ASSERT (sec != NULL);
751
752 /* Update stack size in .note.gnu.property with -z stack-size=N
753 if N > 0. */
754 if (info->stacksize > 0)
755 {
756 bfd_vma stacksize = info->stacksize;
757
758 p = _bfd_elf_get_property (first_pbfd, GNU_PROPERTY_STACK_SIZE,
759 align_size);
760 if (p->pr_kind == property_unknown)
761 {
762 /* Create GNU_PROPERTY_STACK_SIZE. */
763 p->u.number = stacksize;
764 p->pr_kind = property_number;
765 }
766 else if (stacksize > p->u.number)
767 p->u.number = stacksize;
768 }
769 else if (elf_properties (first_pbfd) == NULL)
770 {
771 /* Discard .note.gnu.property section if all properties have
772 been removed. */
773 sec->output_section = bfd_abs_section_ptr;
774 return NULL;
775 }
776
777 /* Fix up GNU properties. */
778 if (bed->fixup_gnu_properties)
779 bed->fixup_gnu_properties (info, &elf_properties (first_pbfd));
780
781 if (elf_properties (first_pbfd) == NULL)
782 {
783 /* Discard .note.gnu.property section if all properties have
784 been removed. */
785 sec->output_section = bfd_abs_section_ptr;
786 return NULL;
787 }
788
789 /* Compute the section size. */
790 list = elf_properties (first_pbfd);
791 size = elf_get_gnu_property_section_size (list, align_size);
792
793 /* Update .note.gnu.property section now. */
794 sec->size = size;
795 contents = (bfd_byte *) bfd_zalloc (first_pbfd, size);
796
797 if (info->indirect_extern_access <= 0)
798 {
799 /* Get GNU_PROPERTY_1_NEEDED properties. */
800 p = elf_find_and_remove_property (&elf_properties (first_pbfd),
801 GNU_PROPERTY_1_NEEDED, false);
802 if (p != NULL)
803 {
804 if (info->indirect_extern_access < 0)
805 {
806 /* Set indirect_extern_access to 1 to indicate that
807 it is turned on by input properties. */
808 if ((p->u.number
809 & GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS)
810 != 0)
811 info->indirect_extern_access = 1;
812 }
813 else
814 /* Turn off indirect external access. */
815 p->u.number
816 &= ~GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS;
817 }
818 }
819
820 elf_write_gnu_properties (info, first_pbfd, contents, list, size,
821 align_size);
822
823 /* Cache the section contents for elf_link_input_bfd. */
824 elf_section_data (sec)->this_hdr.contents = contents;
825
826 /* If GNU_PROPERTY_NO_COPY_ON_PROTECTED is set, protected data
827 symbol is defined in the shared object. */
828 if (elf_has_no_copy_on_protected (first_pbfd))
829 info->extern_protected_data = false;
830
831 if (info->indirect_extern_access > 0)
832 {
833 /* For indirect external access, don't generate copy
834 relocations. NB: Set to nocopyreloc to 2 to indicate
835 that it is implied by indirect_extern_access. */
836 info->nocopyreloc = 2;
837 info->extern_protected_data = false;
838 }
839 }
840
841 return first_pbfd;
842 }
843
844 /* Convert GNU property size. */
845
846 bfd_size_type
_bfd_elf_convert_gnu_property_size(bfd * ibfd,bfd * obfd)847 _bfd_elf_convert_gnu_property_size (bfd *ibfd, bfd *obfd)
848 {
849 unsigned int align_size;
850 const struct elf_backend_data *bed;
851 elf_property_list *list = elf_properties (ibfd);
852
853 bed = get_elf_backend_data (obfd);
854 align_size = bed->s->elfclass == ELFCLASS64 ? 8 : 4;
855
856 /* Get the output .note.gnu.property section size. */
857 return elf_get_gnu_property_section_size (list, align_size);
858 }
859
860 /* Convert GNU properties. */
861
862 bool
_bfd_elf_convert_gnu_properties(bfd * ibfd,asection * isec,bfd * obfd,bfd_byte ** ptr,bfd_size_type * ptr_size)863 _bfd_elf_convert_gnu_properties (bfd *ibfd, asection *isec,
864 bfd *obfd, bfd_byte **ptr,
865 bfd_size_type *ptr_size)
866 {
867 unsigned int size;
868 bfd_byte *contents;
869 unsigned int align_shift;
870 const struct elf_backend_data *bed;
871 elf_property_list *list = elf_properties (ibfd);
872
873 bed = get_elf_backend_data (obfd);
874 align_shift = bed->s->elfclass == ELFCLASS64 ? 3 : 2;
875
876 /* Get the output .note.gnu.property section size. */
877 size = bfd_section_size (isec->output_section);
878
879 /* Update the output .note.gnu.property section alignment. */
880 bfd_set_section_alignment (isec->output_section, align_shift);
881
882 if (size > bfd_section_size (isec))
883 {
884 contents = (bfd_byte *) bfd_malloc (size);
885 if (contents == NULL)
886 return false;
887 free (*ptr);
888 *ptr = contents;
889 }
890 else
891 contents = *ptr;
892
893 *ptr_size = size;
894
895 /* Generate the output .note.gnu.property section. */
896 elf_write_gnu_properties (NULL, ibfd, contents, list, size,
897 1 << align_shift);
898
899 return true;
900 }
901