Commit | Line | Data |
---|---|---|
65765700 | 1 | /* .eh_frame section optimization. |
c68836a9 | 2 | Copyright 2001, 2002 Free Software Foundation, Inc. |
65765700 JJ |
3 | Written by Jakub Jelinek <jakub@redhat.com>. |
4 | ||
5 | This file is part of BFD, the Binary File Descriptor library. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "bfd.h" | |
22 | #include "sysdep.h" | |
23 | #include "libbfd.h" | |
24 | #include "elf-bfd.h" | |
25 | #include "elf/dwarf2.h" | |
26 | ||
27 | #define EH_FRAME_HDR_SIZE 8 | |
28 | ||
29 | struct cie_header | |
30 | { | |
31 | unsigned int length; | |
32 | unsigned int id; | |
33 | }; | |
34 | ||
35 | struct cie | |
36 | { | |
37 | struct cie_header hdr; | |
38 | unsigned char version; | |
39 | unsigned char augmentation[20]; | |
40 | unsigned int code_align; | |
41 | int data_align; | |
42 | unsigned int ra_column; | |
43 | unsigned int augmentation_size; | |
44 | struct elf_link_hash_entry *personality; | |
45 | unsigned char per_encoding; | |
46 | unsigned char lsda_encoding; | |
47 | unsigned char fde_encoding; | |
48 | unsigned char initial_insn_length; | |
49 | unsigned char make_relative; | |
9e2a4898 | 50 | unsigned char make_lsda_relative; |
65765700 JJ |
51 | unsigned char initial_instructions[50]; |
52 | }; | |
53 | ||
54 | struct eh_cie_fde | |
55 | { | |
56 | unsigned int offset; | |
57 | unsigned int size; | |
58 | asection *sec; | |
59 | unsigned int new_offset; | |
60 | unsigned char fde_encoding; | |
9e2a4898 JJ |
61 | unsigned char lsda_encoding; |
62 | unsigned char lsda_offset; | |
65765700 JJ |
63 | unsigned char cie : 1; |
64 | unsigned char removed : 1; | |
65 | unsigned char make_relative : 1; | |
9e2a4898 | 66 | unsigned char make_lsda_relative : 1; |
09ae86c2 | 67 | unsigned char per_encoding_relative : 1; |
65765700 JJ |
68 | }; |
69 | ||
70 | struct eh_frame_sec_info | |
71 | { | |
72 | unsigned int count; | |
73 | unsigned int alloced; | |
74 | struct eh_cie_fde entry[1]; | |
75 | }; | |
76 | ||
77 | struct eh_frame_array_ent | |
78 | { | |
79 | bfd_vma initial_loc; | |
80 | bfd_vma fde; | |
81 | }; | |
82 | ||
83 | struct eh_frame_hdr_info | |
84 | { | |
85 | struct cie last_cie; | |
86 | asection *last_cie_sec; | |
87 | unsigned int last_cie_offset; | |
88 | unsigned int fde_count, array_count; | |
89 | struct eh_frame_array_ent *array; | |
90 | /* TRUE if .eh_frame_hdr should contain the sorted search table. | |
91 | We build it if we successfully read all .eh_frame input sections | |
92 | and recognize them. */ | |
93 | boolean table; | |
68f69152 | 94 | boolean strip; |
65765700 JJ |
95 | }; |
96 | ||
97 | static bfd_vma read_unsigned_leb128 | |
98 | PARAMS ((bfd *, char *, unsigned int *)); | |
99 | static bfd_signed_vma read_signed_leb128 | |
100 | PARAMS ((bfd *, char *, unsigned int *)); | |
101 | static int get_DW_EH_PE_width | |
102 | PARAMS ((int, int)); | |
9e2a4898 JJ |
103 | static bfd_vma read_value |
104 | PARAMS ((bfd *, bfd_byte *, int)); | |
105 | static void write_value | |
106 | PARAMS ((bfd *, bfd_byte *, bfd_vma, int)); | |
65765700 JJ |
107 | static int cie_compare |
108 | PARAMS ((struct cie *, struct cie *)); | |
109 | static int vma_compare | |
110 | PARAMS ((const PTR a, const PTR b)); | |
111 | ||
112 | /* Helper function for reading uleb128 encoded data. */ | |
113 | ||
114 | static bfd_vma | |
115 | read_unsigned_leb128 (abfd, buf, bytes_read_ptr) | |
116 | bfd *abfd ATTRIBUTE_UNUSED; | |
117 | char *buf; | |
118 | unsigned int *bytes_read_ptr; | |
119 | { | |
120 | bfd_vma result; | |
121 | unsigned int num_read; | |
122 | int shift; | |
123 | unsigned char byte; | |
124 | ||
125 | result = 0; | |
126 | shift = 0; | |
127 | num_read = 0; | |
128 | do | |
129 | { | |
130 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
131 | buf ++; | |
132 | num_read ++; | |
133 | result |= (((bfd_vma) byte & 0x7f) << shift); | |
134 | shift += 7; | |
135 | } | |
136 | while (byte & 0x80); | |
137 | * bytes_read_ptr = num_read; | |
138 | return result; | |
139 | } | |
140 | ||
141 | /* Helper function for reading sleb128 encoded data. */ | |
142 | ||
143 | static bfd_signed_vma | |
144 | read_signed_leb128 (abfd, buf, bytes_read_ptr) | |
145 | bfd *abfd ATTRIBUTE_UNUSED; | |
146 | char *buf; | |
147 | unsigned int * bytes_read_ptr; | |
148 | { | |
149 | bfd_vma result; | |
150 | int shift; | |
151 | int num_read; | |
152 | unsigned char byte; | |
153 | ||
154 | result = 0; | |
155 | shift = 0; | |
156 | num_read = 0; | |
157 | do | |
158 | { | |
159 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
160 | buf ++; | |
161 | num_read ++; | |
162 | result |= (((bfd_vma) byte & 0x7f) << shift); | |
163 | shift += 7; | |
164 | } | |
165 | while (byte & 0x80); | |
166 | if (byte & 0x40) | |
167 | result |= (((bfd_vma) -1) << (shift - 7)) << 7; | |
168 | * bytes_read_ptr = num_read; | |
169 | return result; | |
170 | } | |
171 | ||
172 | #define read_uleb128(VAR, BUF) \ | |
173 | do \ | |
174 | { \ | |
175 | (VAR) = read_unsigned_leb128 (abfd, buf, &leb128_tmp); \ | |
176 | (BUF) += leb128_tmp; \ | |
177 | } \ | |
178 | while (0) | |
179 | ||
180 | #define read_sleb128(VAR, BUF) \ | |
181 | do \ | |
182 | { \ | |
183 | (VAR) = read_signed_leb128 (abfd, buf, &leb128_tmp); \ | |
184 | (BUF) += leb128_tmp; \ | |
185 | } \ | |
186 | while (0) | |
187 | ||
188 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
189 | ||
190 | static | |
191 | int get_DW_EH_PE_width (encoding, ptr_size) | |
192 | int encoding, ptr_size; | |
193 | { | |
194 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
195 | was added to bfd. */ | |
196 | if ((encoding & 0x60) == 0x60) | |
197 | return 0; | |
198 | ||
199 | switch (encoding & 7) | |
200 | { | |
201 | case DW_EH_PE_udata2: return 2; | |
202 | case DW_EH_PE_udata4: return 4; | |
203 | case DW_EH_PE_udata8: return 8; | |
204 | case DW_EH_PE_absptr: return ptr_size; | |
205 | default: | |
206 | break; | |
207 | } | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
9e2a4898 JJ |
212 | /* Read a width sized value from memory. */ |
213 | ||
214 | static bfd_vma | |
215 | read_value (abfd, buf, width) | |
216 | bfd *abfd; | |
217 | bfd_byte *buf; | |
218 | int width; | |
219 | { | |
220 | bfd_vma value; | |
221 | ||
222 | switch (width) | |
223 | { | |
224 | case 2: value = bfd_get_16 (abfd, buf); break; | |
225 | case 4: value = bfd_get_32 (abfd, buf); break; | |
226 | case 8: value = bfd_get_64 (abfd, buf); break; | |
227 | default: BFD_FAIL (); return 0; | |
228 | } | |
229 | ||
230 | return value; | |
231 | } | |
232 | ||
233 | /* Store a width sized value to memory. */ | |
234 | ||
235 | static void | |
236 | write_value (abfd, buf, value, width) | |
237 | bfd *abfd; | |
238 | bfd_byte *buf; | |
239 | bfd_vma value; | |
240 | int width; | |
241 | { | |
242 | switch (width) | |
243 | { | |
244 | case 2: bfd_put_16 (abfd, value, buf); break; | |
245 | case 4: bfd_put_32 (abfd, value, buf); break; | |
246 | case 8: bfd_put_64 (abfd, value, buf); break; | |
247 | default: BFD_FAIL (); | |
248 | } | |
249 | } | |
250 | ||
65765700 JJ |
251 | /* Return zero if C1 and C2 CIEs can be merged. */ |
252 | ||
253 | static | |
254 | int cie_compare (c1, c2) | |
255 | struct cie *c1, *c2; | |
256 | { | |
257 | if (c1->hdr.length == c2->hdr.length | |
258 | && c1->version == c2->version | |
259 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
260 | && strcmp (c1->augmentation, "eh") != 0 | |
261 | && c1->code_align == c2->code_align | |
262 | && c1->data_align == c2->data_align | |
263 | && c1->ra_column == c2->ra_column | |
264 | && c1->augmentation_size == c2->augmentation_size | |
265 | && c1->personality == c2->personality | |
266 | && c1->per_encoding == c2->per_encoding | |
267 | && c1->lsda_encoding == c2->lsda_encoding | |
268 | && c1->fde_encoding == c2->fde_encoding | |
269 | && (c1->initial_insn_length | |
270 | == c2->initial_insn_length) | |
271 | && memcmp (c1->initial_instructions, | |
272 | c2->initial_instructions, | |
273 | c1->initial_insn_length) == 0) | |
274 | return 0; | |
275 | ||
276 | return 1; | |
277 | } | |
278 | ||
279 | /* This function is called for each input file before the .eh_frame | |
280 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
281 | functions. The function returns true iff any entries have been | |
282 | deleted. */ | |
283 | ||
284 | boolean | |
285 | _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, | |
286 | reloc_symbol_deleted_p, cookie) | |
287 | bfd *abfd; | |
288 | struct bfd_link_info *info; | |
289 | asection *sec, *ehdrsec; | |
290 | boolean (*reloc_symbol_deleted_p) (bfd_vma, PTR); | |
291 | struct elf_reloc_cookie *cookie; | |
292 | { | |
293 | bfd_byte *ehbuf = NULL, *buf; | |
294 | bfd_byte *last_cie, *last_fde; | |
295 | struct cie_header hdr; | |
296 | struct cie cie; | |
297 | struct eh_frame_hdr_info *hdr_info; | |
68f69152 | 298 | struct eh_frame_sec_info *sec_info = NULL; |
65765700 | 299 | unsigned int leb128_tmp; |
9e2a4898 JJ |
300 | unsigned int cie_usage_count, last_cie_ndx, i, offset; |
301 | unsigned int make_relative, make_lsda_relative; | |
65765700 JJ |
302 | Elf_Internal_Rela *rel; |
303 | bfd_size_type new_size; | |
304 | unsigned int ptr_size; | |
305 | ||
306 | if (sec->_raw_size == 0) | |
307 | { | |
308 | /* This file does not contain .eh_frame information. */ | |
309 | return false; | |
310 | } | |
311 | ||
312 | if ((sec->output_section != NULL | |
313 | && bfd_is_abs_section (sec->output_section))) | |
314 | { | |
315 | /* At least one of the sections is being discarded from the | |
316 | link, so we should just ignore them. */ | |
317 | return false; | |
318 | } | |
319 | ||
68f69152 JJ |
320 | BFD_ASSERT (elf_section_data (ehdrsec)->sec_info_type |
321 | == ELF_INFO_TYPE_EH_FRAME_HDR); | |
322 | hdr_info = (struct eh_frame_hdr_info *) | |
323 | elf_section_data (ehdrsec)->sec_info; | |
324 | ||
65765700 JJ |
325 | /* Read the frame unwind information from abfd. */ |
326 | ||
327 | ehbuf = (bfd_byte *) bfd_malloc (sec->_raw_size); | |
68f69152 JJ |
328 | if (ehbuf == NULL) |
329 | goto free_no_table; | |
330 | ||
331 | if (! bfd_get_section_contents (abfd, sec, ehbuf, (bfd_vma) 0, | |
332 | sec->_raw_size)) | |
333 | goto free_no_table; | |
65765700 JJ |
334 | |
335 | if (sec->_raw_size >= 4 | |
336 | && bfd_get_32 (abfd, ehbuf) == 0 | |
337 | && cookie->rel == cookie->relend) | |
338 | { | |
339 | /* Empty .eh_frame section. */ | |
340 | free (ehbuf); | |
341 | return false; | |
342 | } | |
343 | ||
65765700 JJ |
344 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
345 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
346 | if (sec->_raw_size != (unsigned int) sec->_raw_size) | |
68f69152 | 347 | goto free_no_table; |
65765700 JJ |
348 | |
349 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
350 | == ELFCLASS64) ? 8 : 4; | |
351 | buf = ehbuf; | |
352 | last_cie = NULL; | |
353 | last_cie_ndx = 0; | |
354 | memset (&cie, 0, sizeof (cie)); | |
355 | cie_usage_count = 0; | |
356 | new_size = sec->_raw_size; | |
357 | make_relative = hdr_info->last_cie.make_relative; | |
9e2a4898 | 358 | make_lsda_relative = hdr_info->last_cie.make_lsda_relative; |
65765700 JJ |
359 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
360 | + 99 * sizeof (struct eh_cie_fde)); | |
361 | if (sec_info == NULL) | |
362 | goto free_no_table; | |
363 | sec_info->alloced = 100; | |
364 | ||
365 | #define ENSURE_NO_RELOCS(buf) \ | |
366 | if (cookie->rel < cookie->relend \ | |
367 | && (cookie->rel->r_offset \ | |
368 | < (bfd_size_type) ((buf) - ehbuf))) \ | |
369 | goto free_no_table | |
370 | ||
371 | #define SKIP_RELOCS(buf) \ | |
372 | while (cookie->rel < cookie->relend \ | |
373 | && (cookie->rel->r_offset \ | |
374 | < (bfd_size_type) ((buf) - ehbuf))) \ | |
375 | cookie->rel++ | |
376 | ||
377 | #define GET_RELOC(buf) \ | |
378 | ((cookie->rel < cookie->relend \ | |
379 | && (cookie->rel->r_offset \ | |
380 | == (bfd_size_type) ((buf) - ehbuf))) \ | |
381 | ? cookie->rel : NULL) | |
382 | ||
383 | for (;;) | |
384 | { | |
385 | unsigned char *aug; | |
386 | ||
387 | if (sec_info->count == sec_info->alloced) | |
388 | { | |
389 | sec_info = bfd_realloc (sec_info, | |
390 | sizeof (struct eh_frame_sec_info) | |
391 | + (sec_info->alloced + 99) | |
392 | * sizeof (struct eh_cie_fde)); | |
393 | if (sec_info == NULL) | |
394 | goto free_no_table; | |
395 | ||
396 | memset (&sec_info->entry[sec_info->alloced], 0, | |
397 | 100 * sizeof (struct eh_cie_fde)); | |
398 | sec_info->alloced += 100; | |
399 | } | |
400 | ||
401 | last_fde = buf; | |
402 | /* If we are at the end of the section, we still need to decide | |
403 | on whether to output or discard last encountered CIE (if any). */ | |
404 | if ((bfd_size_type) (buf - ehbuf) == sec->_raw_size) | |
405 | hdr.id = (unsigned int) -1; | |
406 | else | |
407 | { | |
408 | if ((bfd_size_type) (buf + 4 - ehbuf) > sec->_raw_size) | |
409 | /* No space for CIE/FDE header length. */ | |
410 | goto free_no_table; | |
411 | ||
412 | hdr.length = bfd_get_32 (abfd, buf); | |
413 | if (hdr.length == 0xffffffff) | |
414 | /* 64-bit .eh_frame is not supported. */ | |
415 | goto free_no_table; | |
416 | buf += 4; | |
417 | if ((buf - ehbuf) + hdr.length > sec->_raw_size) | |
418 | /* CIE/FDE not contained fully in this .eh_frame input section. */ | |
419 | goto free_no_table; | |
420 | ||
421 | sec_info->entry[sec_info->count].offset = last_fde - ehbuf; | |
422 | sec_info->entry[sec_info->count].size = 4 + hdr.length; | |
423 | ||
424 | if (hdr.length == 0) | |
425 | { | |
426 | /* CIE with length 0 must be only the last in the section. */ | |
427 | if ((bfd_size_type) (buf - ehbuf) < sec->_raw_size) | |
428 | goto free_no_table; | |
429 | ENSURE_NO_RELOCS (buf); | |
430 | sec_info->count++; | |
431 | /* Now just finish last encountered CIE processing and break | |
432 | the loop. */ | |
433 | hdr.id = (unsigned int) -1; | |
434 | } | |
435 | else | |
436 | { | |
437 | hdr.id = bfd_get_32 (abfd, buf); | |
438 | buf += 4; | |
439 | if (hdr.id == (unsigned int) -1) | |
440 | goto free_no_table; | |
441 | } | |
442 | } | |
443 | ||
444 | if (hdr.id == 0 || hdr.id == (unsigned int) -1) | |
445 | { | |
446 | unsigned int initial_insn_length; | |
447 | ||
448 | /* CIE */ | |
449 | if (last_cie != NULL) | |
450 | { | |
451 | /* Now check if this CIE is identical to last CIE, in which case | |
452 | we can remove it, provided we adjust all FDEs. | |
453 | Also, it can be removed if we have removed all FDEs using | |
454 | that. */ | |
455 | if (cie_compare (&cie, &hdr_info->last_cie) == 0 | |
456 | || cie_usage_count == 0) | |
457 | { | |
458 | new_size -= cie.hdr.length + 4; | |
459 | sec_info->entry[last_cie_ndx].removed = 1; | |
460 | sec_info->entry[last_cie_ndx].sec = hdr_info->last_cie_sec; | |
461 | sec_info->entry[last_cie_ndx].new_offset | |
462 | = hdr_info->last_cie_offset; | |
463 | } | |
464 | else | |
465 | { | |
466 | hdr_info->last_cie = cie; | |
467 | hdr_info->last_cie_sec = sec; | |
468 | hdr_info->last_cie_offset = last_cie - ehbuf; | |
469 | sec_info->entry[last_cie_ndx].make_relative | |
470 | = cie.make_relative; | |
9e2a4898 JJ |
471 | sec_info->entry[last_cie_ndx].make_lsda_relative |
472 | = cie.make_lsda_relative; | |
09ae86c2 JJ |
473 | sec_info->entry[last_cie_ndx].per_encoding_relative |
474 | = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
65765700 JJ |
475 | } |
476 | } | |
477 | ||
478 | if (hdr.id == (unsigned int) -1) | |
479 | break; | |
480 | ||
481 | last_cie_ndx = sec_info->count; | |
482 | sec_info->entry[sec_info->count].cie = 1; | |
483 | ||
484 | cie_usage_count = 0; | |
485 | memset (&cie, 0, sizeof (cie)); | |
486 | cie.hdr = hdr; | |
487 | cie.version = *buf++; | |
488 | ||
489 | /* Cannot handle unknown versions. */ | |
490 | if (cie.version != 1) | |
491 | goto free_no_table; | |
492 | if (strlen (buf) > sizeof (cie.augmentation) - 1) | |
493 | goto free_no_table; | |
494 | ||
495 | strcpy (cie.augmentation, buf); | |
496 | buf = strchr (buf, '\0') + 1; | |
497 | ENSURE_NO_RELOCS (buf); | |
498 | if (buf[0] == 'e' && buf[1] == 'h') | |
499 | { | |
500 | /* GCC < 3.0 .eh_frame CIE */ | |
501 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
502 | is private to each CIE, so we don't need it for anything. | |
503 | Just skip it. */ | |
504 | buf += ptr_size; | |
505 | SKIP_RELOCS (buf); | |
506 | } | |
507 | read_uleb128 (cie.code_align, buf); | |
508 | read_sleb128 (cie.data_align, buf); | |
509 | read_uleb128 (cie.ra_column, buf); | |
510 | ENSURE_NO_RELOCS (buf); | |
511 | cie.lsda_encoding = DW_EH_PE_omit; | |
512 | cie.fde_encoding = DW_EH_PE_omit; | |
513 | cie.per_encoding = DW_EH_PE_omit; | |
514 | aug = cie.augmentation; | |
515 | if (aug[0] != 'e' || aug[1] != 'h') | |
516 | { | |
517 | if (*aug == 'z') | |
518 | { | |
519 | aug++; | |
520 | read_uleb128 (cie.augmentation_size, buf); | |
521 | ENSURE_NO_RELOCS (buf); | |
522 | } | |
523 | ||
524 | while (*aug != '\0') | |
525 | switch (*aug++) | |
526 | { | |
527 | case 'L': | |
528 | cie.lsda_encoding = *buf++; | |
529 | ENSURE_NO_RELOCS (buf); | |
530 | if (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size) == 0) | |
531 | goto free_no_table; | |
532 | break; | |
533 | case 'R': | |
534 | cie.fde_encoding = *buf++; | |
535 | ENSURE_NO_RELOCS (buf); | |
536 | if (get_DW_EH_PE_width (cie.fde_encoding, ptr_size) == 0) | |
537 | goto free_no_table; | |
538 | break; | |
539 | case 'P': | |
540 | { | |
541 | int per_width; | |
542 | ||
543 | cie.per_encoding = *buf++; | |
544 | per_width = get_DW_EH_PE_width (cie.per_encoding, | |
545 | ptr_size); | |
546 | if (per_width == 0) | |
547 | goto free_no_table; | |
548 | if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned) | |
549 | buf = (ehbuf | |
550 | + ((buf - ehbuf + per_width - 1) | |
551 | & ~((bfd_size_type) per_width - 1))); | |
552 | ENSURE_NO_RELOCS (buf); | |
553 | rel = GET_RELOC (buf); | |
554 | /* Ensure we have a reloc here, against | |
555 | a global symbol. */ | |
556 | if (rel != NULL) | |
557 | { | |
558 | unsigned long r_symndx; | |
559 | ||
560 | #ifdef BFD64 | |
561 | if (ptr_size == 8) | |
562 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
563 | else | |
564 | #endif | |
565 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
566 | if (r_symndx >= cookie->locsymcount) | |
567 | { | |
568 | struct elf_link_hash_entry *h; | |
569 | ||
570 | r_symndx -= cookie->extsymoff; | |
571 | h = cookie->sym_hashes[r_symndx]; | |
572 | ||
573 | while (h->root.type == bfd_link_hash_indirect | |
574 | || h->root.type == bfd_link_hash_warning) | |
575 | h = (struct elf_link_hash_entry *) | |
576 | h->root.u.i.link; | |
577 | ||
578 | cie.personality = h; | |
579 | } | |
580 | cookie->rel++; | |
581 | } | |
582 | buf += per_width; | |
583 | } | |
584 | break; | |
585 | default: | |
586 | /* Unrecognized augmentation. Better bail out. */ | |
587 | goto free_no_table; | |
588 | } | |
589 | } | |
590 | ||
591 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a JJ |
592 | as possible. */ |
593 | if (info->shared | |
65765700 JJ |
594 | && (cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) |
595 | cie.make_relative = 1; | |
596 | ||
0bb2d96a | 597 | if (info->shared |
9e2a4898 JJ |
598 | && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
599 | cie.make_lsda_relative = 1; | |
600 | ||
65765700 JJ |
601 | /* If FDE encoding was not specified, it defaults to |
602 | DW_EH_absptr. */ | |
603 | if (cie.fde_encoding == DW_EH_PE_omit) | |
604 | cie.fde_encoding = DW_EH_PE_absptr; | |
605 | ||
606 | initial_insn_length = cie.hdr.length - (buf - last_fde - 4); | |
607 | if (initial_insn_length <= 50) | |
608 | { | |
609 | cie.initial_insn_length = initial_insn_length; | |
610 | memcpy (cie.initial_instructions, buf, initial_insn_length); | |
611 | } | |
612 | buf += initial_insn_length; | |
613 | ENSURE_NO_RELOCS (buf); | |
614 | last_cie = last_fde; | |
615 | } | |
616 | else | |
617 | { | |
618 | /* Ensure this FDE uses the last CIE encountered. */ | |
619 | if (last_cie == NULL | |
620 | || hdr.id != (unsigned int) (buf - 4 - last_cie)) | |
621 | goto free_no_table; | |
622 | ||
623 | ENSURE_NO_RELOCS (buf); | |
624 | rel = GET_RELOC (buf); | |
625 | if (rel == NULL) | |
626 | /* This should not happen. */ | |
627 | goto free_no_table; | |
628 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) | |
629 | { | |
630 | cookie->rel = rel; | |
631 | /* This is a FDE against discarded section, it should | |
632 | be deleted. */ | |
633 | new_size -= hdr.length + 4; | |
634 | sec_info->entry[sec_info->count].removed = 1; | |
635 | } | |
636 | else | |
637 | { | |
0bb2d96a | 638 | if (info->shared |
af40ce3c JJ |
639 | && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr |
640 | && cie.make_relative == 0) | |
641 | || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a JJ |
642 | { |
643 | /* If shared library uses absolute pointers | |
644 | which we cannot turn into PC relative, | |
645 | don't create the binary search table, | |
646 | since it is affected by runtime relocations. */ | |
647 | hdr_info->table = false; | |
648 | } | |
65765700 JJ |
649 | cie_usage_count++; |
650 | hdr_info->fde_count++; | |
651 | } | |
652 | cookie->rel = rel; | |
9e2a4898 JJ |
653 | if (cie.lsda_encoding != DW_EH_PE_omit) |
654 | { | |
655 | unsigned int dummy; | |
656 | ||
657 | aug = buf; | |
658 | buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
659 | if (cie.augmentation[0] == 'z') | |
660 | read_uleb128 (dummy, buf); | |
661 | /* If some new augmentation data is added before LSDA | |
662 | in FDE augmentation area, this need to be adjusted. */ | |
663 | sec_info->entry[sec_info->count].lsda_offset = (buf - aug); | |
664 | } | |
65765700 JJ |
665 | buf = last_fde + 4 + hdr.length; |
666 | SKIP_RELOCS (buf); | |
667 | } | |
668 | ||
669 | sec_info->entry[sec_info->count].fde_encoding = cie.fde_encoding; | |
9e2a4898 | 670 | sec_info->entry[sec_info->count].lsda_encoding = cie.lsda_encoding; |
65765700 JJ |
671 | sec_info->count++; |
672 | } | |
673 | ||
674 | elf_section_data (sec)->sec_info = sec_info; | |
675 | elf_section_data (sec)->sec_info_type = ELF_INFO_TYPE_EH_FRAME; | |
676 | ||
677 | /* Ok, now we can assign new offsets. */ | |
678 | offset = 0; | |
679 | last_cie_ndx = 0; | |
680 | for (i = 0; i < sec_info->count; i++) | |
681 | { | |
682 | if (! sec_info->entry[i].removed) | |
683 | { | |
684 | sec_info->entry[i].new_offset = offset; | |
685 | offset += sec_info->entry[i].size; | |
686 | if (sec_info->entry[i].cie) | |
687 | { | |
688 | last_cie_ndx = i; | |
689 | make_relative = sec_info->entry[i].make_relative; | |
9e2a4898 | 690 | make_lsda_relative = sec_info->entry[i].make_lsda_relative; |
65765700 JJ |
691 | } |
692 | else | |
9e2a4898 JJ |
693 | { |
694 | sec_info->entry[i].make_relative = make_relative; | |
695 | sec_info->entry[i].make_lsda_relative = make_lsda_relative; | |
09ae86c2 | 696 | sec_info->entry[i].per_encoding_relative = 0; |
9e2a4898 | 697 | } |
65765700 JJ |
698 | } |
699 | else if (sec_info->entry[i].cie && sec_info->entry[i].sec == sec) | |
700 | { | |
701 | /* Need to adjust new_offset too. */ | |
702 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
703 | == sec_info->entry[i].new_offset); | |
704 | sec_info->entry[i].new_offset | |
705 | = sec_info->entry[last_cie_ndx].new_offset; | |
706 | } | |
707 | } | |
708 | if (hdr_info->last_cie_sec == sec) | |
709 | { | |
710 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
711 | == hdr_info->last_cie_offset); | |
712 | hdr_info->last_cie_offset = sec_info->entry[last_cie_ndx].new_offset; | |
713 | } | |
714 | ||
a5eb27e6 JJ |
715 | /* FIXME: Currently it is not possible to shrink sections to zero size at |
716 | this point, so build a fake minimal CIE. */ | |
717 | if (new_size == 0) | |
718 | new_size = 16; | |
719 | ||
65765700 | 720 | /* Shrink the sec as needed. */ |
65765700 JJ |
721 | sec->_cooked_size = new_size; |
722 | if (sec->_cooked_size == 0) | |
723 | sec->flags |= SEC_EXCLUDE; | |
724 | ||
68f69152 | 725 | free (ehbuf); |
65765700 JJ |
726 | return new_size != sec->_raw_size; |
727 | ||
728 | free_no_table: | |
68f69152 JJ |
729 | if (ehbuf) |
730 | free (ehbuf); | |
65765700 JJ |
731 | if (sec_info) |
732 | free (sec_info); | |
733 | hdr_info->table = false; | |
734 | hdr_info->last_cie.hdr.length = 0; | |
735 | return false; | |
736 | } | |
737 | ||
738 | /* This function is called for .eh_frame_hdr section after | |
739 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
740 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
741 | ||
742 | boolean | |
743 | _bfd_elf_discard_section_eh_frame_hdr (abfd, info, sec) | |
744 | bfd *abfd; | |
745 | struct bfd_link_info *info; | |
746 | asection *sec; | |
747 | { | |
748 | struct eh_frame_hdr_info *hdr_info; | |
749 | unsigned int ptr_size; | |
750 | ||
751 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
752 | == ELFCLASS64) ? 8 : 4; | |
753 | ||
754 | if ((elf_section_data (sec)->sec_info_type | |
755 | != ELF_INFO_TYPE_EH_FRAME_HDR) | |
756 | || ! info->eh_frame_hdr) | |
757 | { | |
758 | _bfd_strip_section_from_output (info, sec); | |
759 | return false; | |
760 | } | |
761 | ||
762 | hdr_info = (struct eh_frame_hdr_info *) | |
763 | elf_section_data (sec)->sec_info; | |
68f69152 JJ |
764 | if (hdr_info->strip) |
765 | return false; | |
65765700 JJ |
766 | sec->_cooked_size = EH_FRAME_HDR_SIZE; |
767 | if (hdr_info->table) | |
768 | sec->_cooked_size += 4 + hdr_info->fde_count * 8; | |
769 | ||
770 | /* Request program headers to be recalculated. */ | |
771 | elf_tdata (abfd)->program_header_size = 0; | |
772 | elf_tdata (abfd)->eh_frame_hdr = true; | |
773 | return true; | |
774 | } | |
775 | ||
68f69152 JJ |
776 | /* This function is called from size_dynamic_sections. |
777 | It needs to decide whether .eh_frame_hdr should be output or not, | |
778 | because later on it is too late for calling _bfd_strip_section_from_output, | |
779 | since dynamic symbol table has been sized. */ | |
780 | ||
781 | boolean | |
782 | _bfd_elf_maybe_strip_eh_frame_hdr (info) | |
783 | struct bfd_link_info *info; | |
784 | { | |
785 | asection *sec, *o; | |
786 | bfd *abfd; | |
787 | struct eh_frame_hdr_info *hdr_info; | |
788 | ||
789 | sec = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".eh_frame_hdr"); | |
2d653fc7 | 790 | if (sec == NULL || bfd_is_abs_section (sec->output_section)) |
68f69152 JJ |
791 | return true; |
792 | ||
793 | hdr_info | |
794 | = bfd_zmalloc (sizeof (struct eh_frame_hdr_info)); | |
795 | if (hdr_info == NULL) | |
796 | return false; | |
797 | ||
798 | elf_section_data (sec)->sec_info = hdr_info; | |
799 | elf_section_data (sec)->sec_info_type = ELF_INFO_TYPE_EH_FRAME_HDR; | |
800 | ||
801 | abfd = NULL; | |
802 | if (info->eh_frame_hdr) | |
803 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
804 | { | |
805 | /* Count only sections which have at least a single CIE or FDE. | |
806 | There cannot be any CIE or FDE <= 8 bytes. */ | |
807 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
2d653fc7 | 808 | if (o && o->_raw_size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
809 | break; |
810 | } | |
811 | ||
812 | if (abfd == NULL) | |
813 | { | |
814 | _bfd_strip_section_from_output (info, sec); | |
815 | hdr_info->strip = true; | |
816 | } | |
817 | else | |
818 | hdr_info->table = true; | |
819 | return true; | |
820 | } | |
821 | ||
65765700 JJ |
822 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
823 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
824 | or -1 if the address refers to a CIE/FDE which has been removed | |
825 | or to offset with dynamic relocation which is no longer needed. */ | |
826 | ||
827 | bfd_vma | |
828 | _bfd_elf_eh_frame_section_offset (output_bfd, sec, offset) | |
829 | bfd *output_bfd ATTRIBUTE_UNUSED; | |
830 | asection *sec; | |
831 | bfd_vma offset; | |
832 | { | |
833 | struct eh_frame_sec_info *sec_info; | |
834 | unsigned int lo, hi, mid; | |
835 | ||
836 | if (elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
837 | return offset; | |
838 | sec_info = (struct eh_frame_sec_info *) | |
839 | elf_section_data (sec)->sec_info; | |
840 | ||
841 | if (offset >= sec->_raw_size) | |
842 | return offset - (sec->_cooked_size - sec->_raw_size); | |
843 | ||
844 | lo = 0; | |
845 | hi = sec_info->count; | |
846 | mid = 0; | |
847 | while (lo < hi) | |
848 | { | |
849 | mid = (lo + hi) / 2; | |
850 | if (offset < sec_info->entry[mid].offset) | |
851 | hi = mid; | |
852 | else if (offset | |
853 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
854 | lo = mid + 1; | |
855 | else | |
856 | break; | |
857 | } | |
858 | ||
859 | BFD_ASSERT (lo < hi); | |
860 | ||
861 | /* FDE or CIE was removed. */ | |
862 | if (sec_info->entry[mid].removed) | |
863 | return (bfd_vma) -1; | |
864 | ||
865 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
866 | relocation against FDE's initial_location field. */ | |
867 | if (sec_info->entry[mid].make_relative | |
868 | && ! sec_info->entry[mid].cie | |
869 | && offset == sec_info->entry[mid].offset + 8) | |
0bb2d96a | 870 | return (bfd_vma) -2; |
65765700 | 871 | |
9e2a4898 JJ |
872 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
873 | for run-time relocation against LSDA field. */ | |
874 | if (sec_info->entry[mid].make_lsda_relative | |
875 | && ! sec_info->entry[mid].cie | |
876 | && (offset | |
877 | == (sec_info->entry[mid].offset + 8 | |
878 | + sec_info->entry[mid].lsda_offset))) | |
0bb2d96a | 879 | return (bfd_vma) -2; |
9e2a4898 | 880 | |
c68836a9 AM |
881 | return (offset + sec_info->entry[mid].new_offset |
882 | - sec_info->entry[mid].offset); | |
65765700 JJ |
883 | } |
884 | ||
885 | /* Write out .eh_frame section. This is called with the relocated | |
886 | contents. */ | |
887 | ||
888 | boolean | |
889 | _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) | |
890 | bfd *abfd; | |
891 | asection *sec, *ehdrsec; | |
892 | bfd_byte *contents; | |
893 | { | |
894 | struct eh_frame_sec_info *sec_info; | |
895 | struct eh_frame_hdr_info *hdr_info; | |
896 | unsigned int i; | |
897 | bfd_byte *p, *buf; | |
898 | unsigned int leb128_tmp; | |
899 | unsigned int cie_offset = 0; | |
900 | unsigned int ptr_size; | |
901 | ||
902 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
903 | == ELFCLASS64) ? 8 : 4; | |
904 | ||
905 | if (elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
906 | return bfd_set_section_contents (abfd, sec->output_section, | |
907 | contents, | |
908 | (file_ptr) sec->output_offset, | |
909 | sec->_raw_size); | |
910 | sec_info = (struct eh_frame_sec_info *) | |
911 | elf_section_data (sec)->sec_info; | |
912 | hdr_info = NULL; | |
913 | if (ehdrsec | |
914 | && (elf_section_data (ehdrsec)->sec_info_type | |
915 | == ELF_INFO_TYPE_EH_FRAME_HDR)) | |
916 | { | |
917 | hdr_info = (struct eh_frame_hdr_info *) | |
918 | elf_section_data (ehdrsec)->sec_info; | |
919 | if (hdr_info->table && hdr_info->array == NULL) | |
920 | hdr_info->array | |
921 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
922 | if (hdr_info->array == NULL) | |
923 | hdr_info = NULL; | |
924 | } | |
925 | ||
926 | p = contents; | |
927 | for (i = 0; i < sec_info->count; ++i) | |
928 | { | |
929 | if (sec_info->entry[i].removed) | |
930 | { | |
931 | if (sec_info->entry[i].cie) | |
932 | { | |
a3aa38ee JJ |
933 | /* If CIE is removed due to no remaining FDEs referencing it |
934 | and there were no CIEs kept before it, sec_info->entry[i].sec | |
935 | will be zero. */ | |
936 | if (sec_info->entry[i].sec == NULL) | |
937 | cie_offset = 0; | |
938 | else | |
939 | { | |
940 | cie_offset = sec_info->entry[i].new_offset; | |
941 | cie_offset += (sec_info->entry[i].sec->output_section->vma | |
942 | + sec_info->entry[i].sec->output_offset | |
943 | - sec->output_section->vma | |
944 | - sec->output_offset); | |
945 | } | |
65765700 JJ |
946 | } |
947 | continue; | |
948 | } | |
a3aa38ee | 949 | |
65765700 JJ |
950 | if (sec_info->entry[i].cie) |
951 | { | |
952 | /* CIE */ | |
953 | cie_offset = sec_info->entry[i].new_offset; | |
9e2a4898 | 954 | if (sec_info->entry[i].make_relative |
09ae86c2 JJ |
955 | || sec_info->entry[i].make_lsda_relative |
956 | || sec_info->entry[i].per_encoding_relative) | |
65765700 JJ |
957 | { |
958 | unsigned char *aug; | |
9e2a4898 | 959 | unsigned int action; |
65765700 JJ |
960 | unsigned int dummy, per_width, per_encoding; |
961 | ||
9e2a4898 | 962 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 963 | DW_EH_PE_* value. */ |
9e2a4898 | 964 | action = (sec_info->entry[i].make_relative ? 1 : 0) |
09ae86c2 JJ |
965 | | (sec_info->entry[i].make_lsda_relative ? 2 : 0) |
966 | | (sec_info->entry[i].per_encoding_relative ? 4 : 0); | |
65765700 JJ |
967 | buf = contents + sec_info->entry[i].offset; |
968 | /* Skip length, id and version. */ | |
969 | buf += 9; | |
970 | aug = buf; | |
971 | buf = strchr (buf, '\0') + 1; | |
972 | read_uleb128 (dummy, buf); | |
973 | read_sleb128 (dummy, buf); | |
974 | read_uleb128 (dummy, buf); | |
975 | if (*aug == 'z') | |
976 | { | |
977 | read_uleb128 (dummy, buf); | |
978 | aug++; | |
979 | } | |
980 | ||
9e2a4898 | 981 | while (action) |
65765700 JJ |
982 | switch (*aug++) |
983 | { | |
984 | case 'L': | |
9e2a4898 JJ |
985 | if (action & 2) |
986 | { | |
987 | BFD_ASSERT (*buf == sec_info->entry[i].lsda_encoding); | |
988 | *buf |= DW_EH_PE_pcrel; | |
989 | action &= ~2; | |
990 | } | |
65765700 JJ |
991 | buf++; |
992 | break; | |
993 | case 'P': | |
994 | per_encoding = *buf++; | |
995 | per_width = get_DW_EH_PE_width (per_encoding, | |
996 | ptr_size); | |
997 | BFD_ASSERT (per_width != 0); | |
09ae86c2 JJ |
998 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
999 | == sec_info->entry[i].per_encoding_relative); | |
65765700 JJ |
1000 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
1001 | buf = (contents | |
1002 | + ((buf - contents + per_width - 1) | |
1003 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
1004 | if (action & 4) |
1005 | { | |
1006 | bfd_vma value; | |
1007 | ||
1008 | value = read_value (abfd, buf, per_width); | |
1009 | value += (sec_info->entry[i].offset | |
1010 | - sec_info->entry[i].new_offset); | |
1011 | write_value (abfd, buf, value, per_width); | |
1012 | action &= ~4; | |
1013 | } | |
65765700 JJ |
1014 | buf += per_width; |
1015 | break; | |
9e2a4898 JJ |
1016 | case 'R': |
1017 | if (action & 1) | |
1018 | { | |
1019 | BFD_ASSERT (*buf == sec_info->entry[i].fde_encoding); | |
1020 | *buf |= DW_EH_PE_pcrel; | |
1021 | action &= ~1; | |
1022 | } | |
1023 | buf++; | |
1024 | break; | |
65765700 JJ |
1025 | default: |
1026 | BFD_FAIL (); | |
1027 | } | |
65765700 JJ |
1028 | } |
1029 | } | |
af40ce3c | 1030 | else if (sec_info->entry[i].size > 4) |
65765700 JJ |
1031 | { |
1032 | /* FDE */ | |
1033 | bfd_vma value = 0, address; | |
9e2a4898 | 1034 | unsigned int width; |
65765700 JJ |
1035 | |
1036 | buf = contents + sec_info->entry[i].offset; | |
1037 | /* Skip length. */ | |
1038 | buf += 4; | |
1039 | bfd_put_32 (abfd, | |
1040 | sec_info->entry[i].new_offset + 4 - cie_offset, buf); | |
1041 | buf += 4; | |
9e2a4898 JJ |
1042 | width = get_DW_EH_PE_width (sec_info->entry[i].fde_encoding, |
1043 | ptr_size); | |
1044 | address = value = read_value (abfd, buf, width); | |
1045 | if (value) | |
65765700 | 1046 | { |
9e2a4898 JJ |
1047 | switch (sec_info->entry[i].fde_encoding & 0xf0) |
1048 | { | |
1049 | case DW_EH_PE_indirect: | |
1050 | case DW_EH_PE_textrel: | |
1051 | BFD_ASSERT (hdr_info == NULL); | |
1052 | break; | |
1053 | case DW_EH_PE_datarel: | |
1054 | { | |
1055 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1056 | ||
1057 | BFD_ASSERT (got != NULL); | |
1058 | address += got->vma; | |
1059 | } | |
1060 | break; | |
1061 | case DW_EH_PE_pcrel: | |
1062 | value += (sec_info->entry[i].offset | |
1063 | - sec_info->entry[i].new_offset); | |
1064 | address += (sec->output_section->vma + sec->output_offset | |
1065 | + sec_info->entry[i].offset + 8); | |
1066 | break; | |
1067 | } | |
1068 | if (sec_info->entry[i].make_relative) | |
1069 | value -= (sec->output_section->vma + sec->output_offset | |
65765700 | 1070 | + sec_info->entry[i].new_offset + 8); |
9e2a4898 | 1071 | write_value (abfd, buf, value, width); |
65765700 JJ |
1072 | } |
1073 | ||
1074 | if (hdr_info) | |
1075 | { | |
1076 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1077 | hdr_info->array[hdr_info->array_count++].fde | |
1078 | = (sec->output_section->vma + sec->output_offset | |
1079 | + sec_info->entry[i].new_offset); | |
1080 | } | |
9e2a4898 JJ |
1081 | |
1082 | if ((sec_info->entry[i].lsda_encoding & 0xf0) == DW_EH_PE_pcrel | |
1083 | || sec_info->entry[i].make_lsda_relative) | |
1084 | { | |
1085 | buf += sec_info->entry[i].lsda_offset; | |
1086 | width = get_DW_EH_PE_width (sec_info->entry[i].lsda_encoding, | |
1087 | ptr_size); | |
1088 | value = read_value (abfd, buf, width); | |
1089 | if (value) | |
1090 | { | |
1091 | if ((sec_info->entry[i].lsda_encoding & 0xf0) | |
1092 | == DW_EH_PE_pcrel) | |
1093 | value += (sec_info->entry[i].offset | |
1094 | - sec_info->entry[i].new_offset); | |
1095 | else if (sec_info->entry[i].make_lsda_relative) | |
1096 | value -= (sec->output_section->vma + sec->output_offset | |
1097 | + sec_info->entry[i].new_offset + 8 | |
1098 | + sec_info->entry[i].lsda_offset); | |
1099 | write_value (abfd, buf, value, width); | |
1100 | } | |
1101 | } | |
65765700 | 1102 | } |
af40ce3c JJ |
1103 | else |
1104 | /* Terminating FDE must be at the end of .eh_frame section only. */ | |
1105 | BFD_ASSERT (i == sec_info->count - 1); | |
65765700 JJ |
1106 | |
1107 | BFD_ASSERT (p == contents + sec_info->entry[i].new_offset); | |
1108 | memmove (p, contents + sec_info->entry[i].offset, | |
1109 | sec_info->entry[i].size); | |
1110 | p += sec_info->entry[i].size; | |
1111 | } | |
1112 | ||
a5eb27e6 JJ |
1113 | /* FIXME: Once _bfd_elf_discard_section_eh_frame will be able to |
1114 | shrink sections to zero size, this won't be needed any more. */ | |
1115 | if (p == contents && sec->_cooked_size == 16) | |
1116 | { | |
1117 | bfd_put_32 (abfd, 12, p); /* Fake CIE length */ | |
1118 | bfd_put_32 (abfd, 0, p + 4); /* Fake CIE id */ | |
1119 | p[8] = 1; /* Fake CIE version */ | |
1120 | memset (p + 9, 0, 7); /* Fake CIE augmentation, 3xleb128 | |
1121 | and 3xDW_CFA_nop as pad */ | |
1122 | p += 16; | |
1123 | } | |
1124 | ||
65765700 JJ |
1125 | BFD_ASSERT ((bfd_size_type) (p - contents) == sec->_cooked_size); |
1126 | ||
1127 | return bfd_set_section_contents (abfd, sec->output_section, | |
1128 | contents, (file_ptr) sec->output_offset, | |
1129 | sec->_cooked_size); | |
1130 | } | |
1131 | ||
1132 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1133 | VMA of FDE initial location. */ | |
1134 | ||
1135 | static int | |
1136 | vma_compare (a, b) | |
1137 | const PTR a; | |
1138 | const PTR b; | |
1139 | { | |
1140 | struct eh_frame_array_ent *p = (struct eh_frame_array_ent *) a; | |
1141 | struct eh_frame_array_ent *q = (struct eh_frame_array_ent *) b; | |
1142 | if (p->initial_loc > q->initial_loc) | |
1143 | return 1; | |
1144 | if (p->initial_loc < q->initial_loc) | |
1145 | return -1; | |
1146 | return 0; | |
1147 | } | |
1148 | ||
1149 | /* Write out .eh_frame_hdr section. This must be called after | |
1150 | _bfd_elf_write_section_eh_frame has been called on all input | |
1151 | .eh_frame sections. | |
1152 | .eh_frame_hdr format: | |
1153 | ubyte version (currently 1) | |
1154 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1155 | .eh_frame section) | |
1156 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1157 | number (or DW_EH_PE_omit if there is no | |
1158 | binary search table computed)) | |
1159 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1160 | or DW_EH_PE_omit if not present. | |
1161 | DW_EH_PE_datarel is using address of | |
1162 | .eh_frame_hdr section start as base) | |
1163 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1164 | optionally followed by: | |
1165 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1166 | fde_count x [encoded] initial_loc, fde | |
1167 | (array of encoded pairs containing | |
1168 | FDE initial_location field and FDE address, | |
1169 | sorted by increasing initial_loc) */ | |
1170 | ||
1171 | boolean | |
1172 | _bfd_elf_write_section_eh_frame_hdr (abfd, sec) | |
1173 | bfd *abfd; | |
1174 | asection *sec; | |
1175 | { | |
1176 | struct eh_frame_hdr_info *hdr_info; | |
1177 | unsigned int ptr_size; | |
1178 | bfd_byte *contents; | |
1179 | asection *eh_frame_sec; | |
1180 | bfd_size_type size; | |
1181 | ||
1182 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
1183 | == ELFCLASS64) ? 8 : 4; | |
1184 | ||
1185 | BFD_ASSERT (elf_section_data (sec)->sec_info_type | |
1186 | == ELF_INFO_TYPE_EH_FRAME_HDR); | |
1187 | hdr_info = (struct eh_frame_hdr_info *) | |
1188 | elf_section_data (sec)->sec_info; | |
57a72197 JJ |
1189 | if (hdr_info->strip) |
1190 | return true; | |
1191 | ||
65765700 JJ |
1192 | size = EH_FRAME_HDR_SIZE; |
1193 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1194 | size += 4 + hdr_info->fde_count * 8; | |
1195 | contents = bfd_malloc (size); | |
1196 | if (contents == NULL) | |
1197 | return false; | |
1198 | ||
1199 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1200 | if (eh_frame_sec == NULL) | |
1201 | return false; | |
1202 | ||
1203 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
1204 | contents[0] = 1; /* Version */ | |
1205 | contents[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4; /* .eh_frame offset */ | |
1206 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1207 | { | |
1208 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding */ | |
1209 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* search table enc */ | |
1210 | } | |
1211 | else | |
1212 | { | |
1213 | contents[2] = DW_EH_PE_omit; | |
1214 | contents[3] = DW_EH_PE_omit; | |
1215 | } | |
1216 | bfd_put_32 (abfd, eh_frame_sec->vma - sec->output_section->vma - 4, | |
1217 | contents + 4); | |
1218 | if (contents[2] != DW_EH_PE_omit) | |
1219 | { | |
1220 | unsigned int i; | |
1221 | ||
1222 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1223 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1224 | vma_compare); | |
1225 | for (i = 0; i < hdr_info->fde_count; i++) | |
1226 | { | |
1227 | bfd_put_32 (abfd, | |
1228 | hdr_info->array[i].initial_loc | |
1229 | - sec->output_section->vma, | |
1230 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1231 | bfd_put_32 (abfd, | |
1232 | hdr_info->array[i].fde - sec->output_section->vma, | |
1233 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1234 | } | |
1235 | } | |
1236 | ||
1237 | return bfd_set_section_contents (abfd, sec->output_section, | |
1238 | contents, (file_ptr) sec->output_offset, | |
1239 | sec->_cooked_size); | |
1240 | } |