Commit | Line | Data |
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65765700 | 1 | /* .eh_frame section optimization. |
64be1553 AM |
2 | Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
3 | Free Software Foundation, Inc. | |
65765700 JJ |
4 | Written by Jakub Jelinek <jakub@redhat.com>. |
5 | ||
5ed6aba4 | 6 | This file is part of BFD, the Binary File Descriptor library. |
65765700 | 7 | |
5ed6aba4 NC |
8 | This program is free software; you can redistribute it and/or modify |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
65765700 | 12 | |
5ed6aba4 NC |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
65765700 | 17 | |
5ed6aba4 NC |
18 | You should have received a copy of the GNU General Public License |
19 | along with this program; if not, write to the Free Software | |
3e110533 | 20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
65765700 | 21 | |
65765700 | 22 | #include "sysdep.h" |
3db64b00 | 23 | #include "bfd.h" |
65765700 JJ |
24 | #include "libbfd.h" |
25 | #include "elf-bfd.h" | |
26 | #include "elf/dwarf2.h" | |
27 | ||
28 | #define EH_FRAME_HDR_SIZE 8 | |
29 | ||
bce613b9 JJ |
30 | struct cie |
31 | { | |
32 | unsigned int length; | |
33 | unsigned int hash; | |
34 | unsigned char version; | |
35 | char augmentation[20]; | |
36 | bfd_vma code_align; | |
37 | bfd_signed_vma data_align; | |
38 | bfd_vma ra_column; | |
39 | bfd_vma augmentation_size; | |
40 | struct elf_link_hash_entry *personality; | |
41 | asection *output_sec; | |
42 | struct eh_cie_fde *cie_inf; | |
43 | unsigned char per_encoding; | |
44 | unsigned char lsda_encoding; | |
45 | unsigned char fde_encoding; | |
46 | unsigned char initial_insn_length; | |
47 | unsigned char make_relative; | |
48 | unsigned char make_lsda_relative; | |
49 | unsigned char initial_instructions[50]; | |
50 | }; | |
51 | ||
52 | ||
53 | ||
2c42be65 RS |
54 | /* If *ITER hasn't reached END yet, read the next byte into *RESULT and |
55 | move onto the next byte. Return true on success. */ | |
56 | ||
57 | static inline bfd_boolean | |
58 | read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result) | |
59 | { | |
60 | if (*iter >= end) | |
61 | return FALSE; | |
62 | *result = *((*iter)++); | |
63 | return TRUE; | |
64 | } | |
65 | ||
66 | /* Move *ITER over LENGTH bytes, or up to END, whichever is closer. | |
67 | Return true it was possible to move LENGTH bytes. */ | |
68 | ||
69 | static inline bfd_boolean | |
70 | skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length) | |
71 | { | |
72 | if ((bfd_size_type) (end - *iter) < length) | |
73 | { | |
74 | *iter = end; | |
75 | return FALSE; | |
76 | } | |
77 | *iter += length; | |
78 | return TRUE; | |
79 | } | |
80 | ||
81 | /* Move *ITER over an leb128, stopping at END. Return true if the end | |
82 | of the leb128 was found. */ | |
83 | ||
84 | static bfd_boolean | |
85 | skip_leb128 (bfd_byte **iter, bfd_byte *end) | |
86 | { | |
87 | unsigned char byte; | |
88 | do | |
89 | if (!read_byte (iter, end, &byte)) | |
90 | return FALSE; | |
91 | while (byte & 0x80); | |
92 | return TRUE; | |
93 | } | |
94 | ||
95 | /* Like skip_leb128, but treat the leb128 as an unsigned value and | |
96 | store it in *VALUE. */ | |
97 | ||
98 | static bfd_boolean | |
99 | read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value) | |
100 | { | |
101 | bfd_byte *start, *p; | |
102 | ||
103 | start = *iter; | |
104 | if (!skip_leb128 (iter, end)) | |
105 | return FALSE; | |
106 | ||
107 | p = *iter; | |
108 | *value = *--p; | |
109 | while (p > start) | |
110 | *value = (*value << 7) | (*--p & 0x7f); | |
111 | ||
112 | return TRUE; | |
113 | } | |
114 | ||
115 | /* Like read_uleb128, but for signed values. */ | |
116 | ||
117 | static bfd_boolean | |
118 | read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value) | |
119 | { | |
120 | bfd_byte *start, *p; | |
121 | ||
122 | start = *iter; | |
123 | if (!skip_leb128 (iter, end)) | |
124 | return FALSE; | |
125 | ||
126 | p = *iter; | |
127 | *value = ((*--p & 0x7f) ^ 0x40) - 0x40; | |
128 | while (p > start) | |
129 | *value = (*value << 7) | (*--p & 0x7f); | |
130 | ||
131 | return TRUE; | |
132 | } | |
65765700 JJ |
133 | |
134 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
135 | ||
136 | static | |
c39a58e6 | 137 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
65765700 JJ |
138 | { |
139 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
140 | was added to bfd. */ | |
141 | if ((encoding & 0x60) == 0x60) | |
142 | return 0; | |
143 | ||
144 | switch (encoding & 7) | |
145 | { | |
146 | case DW_EH_PE_udata2: return 2; | |
147 | case DW_EH_PE_udata4: return 4; | |
148 | case DW_EH_PE_udata8: return 8; | |
149 | case DW_EH_PE_absptr: return ptr_size; | |
150 | default: | |
151 | break; | |
152 | } | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
84f97cb6 AS |
157 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
158 | ||
9e2a4898 JJ |
159 | /* Read a width sized value from memory. */ |
160 | ||
161 | static bfd_vma | |
c39a58e6 | 162 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
9e2a4898 JJ |
163 | { |
164 | bfd_vma value; | |
165 | ||
166 | switch (width) | |
167 | { | |
84f97cb6 AS |
168 | case 2: |
169 | if (is_signed) | |
170 | value = bfd_get_signed_16 (abfd, buf); | |
171 | else | |
172 | value = bfd_get_16 (abfd, buf); | |
173 | break; | |
174 | case 4: | |
175 | if (is_signed) | |
176 | value = bfd_get_signed_32 (abfd, buf); | |
177 | else | |
178 | value = bfd_get_32 (abfd, buf); | |
179 | break; | |
180 | case 8: | |
181 | if (is_signed) | |
182 | value = bfd_get_signed_64 (abfd, buf); | |
183 | else | |
184 | value = bfd_get_64 (abfd, buf); | |
185 | break; | |
186 | default: | |
187 | BFD_FAIL (); | |
188 | return 0; | |
9e2a4898 JJ |
189 | } |
190 | ||
191 | return value; | |
192 | } | |
b34976b6 | 193 | |
9e2a4898 JJ |
194 | /* Store a width sized value to memory. */ |
195 | ||
196 | static void | |
c39a58e6 | 197 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
9e2a4898 JJ |
198 | { |
199 | switch (width) | |
200 | { | |
201 | case 2: bfd_put_16 (abfd, value, buf); break; | |
202 | case 4: bfd_put_32 (abfd, value, buf); break; | |
203 | case 8: bfd_put_64 (abfd, value, buf); break; | |
204 | default: BFD_FAIL (); | |
205 | } | |
206 | } | |
207 | ||
bce613b9 | 208 | /* Return one if C1 and C2 CIEs can be merged. */ |
65765700 | 209 | |
bce613b9 JJ |
210 | static int |
211 | cie_eq (const void *e1, const void *e2) | |
65765700 | 212 | { |
bce613b9 JJ |
213 | const struct cie *c1 = e1; |
214 | const struct cie *c2 = e2; | |
215 | ||
216 | if (c1->hash == c2->hash | |
217 | && c1->length == c2->length | |
65765700 JJ |
218 | && c1->version == c2->version |
219 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
220 | && strcmp (c1->augmentation, "eh") != 0 | |
221 | && c1->code_align == c2->code_align | |
222 | && c1->data_align == c2->data_align | |
223 | && c1->ra_column == c2->ra_column | |
224 | && c1->augmentation_size == c2->augmentation_size | |
225 | && c1->personality == c2->personality | |
bce613b9 | 226 | && c1->output_sec == c2->output_sec |
65765700 JJ |
227 | && c1->per_encoding == c2->per_encoding |
228 | && c1->lsda_encoding == c2->lsda_encoding | |
229 | && c1->fde_encoding == c2->fde_encoding | |
c39a58e6 | 230 | && c1->initial_insn_length == c2->initial_insn_length |
65765700 JJ |
231 | && memcmp (c1->initial_instructions, |
232 | c2->initial_instructions, | |
233 | c1->initial_insn_length) == 0) | |
bce613b9 | 234 | return 1; |
65765700 | 235 | |
bce613b9 JJ |
236 | return 0; |
237 | } | |
238 | ||
239 | static hashval_t | |
240 | cie_hash (const void *e) | |
241 | { | |
242 | const struct cie *c = e; | |
243 | return c->hash; | |
244 | } | |
245 | ||
246 | static hashval_t | |
247 | cie_compute_hash (struct cie *c) | |
248 | { | |
249 | hashval_t h = 0; | |
250 | h = iterative_hash_object (c->length, h); | |
251 | h = iterative_hash_object (c->version, h); | |
252 | h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h); | |
253 | h = iterative_hash_object (c->code_align, h); | |
254 | h = iterative_hash_object (c->data_align, h); | |
255 | h = iterative_hash_object (c->ra_column, h); | |
256 | h = iterative_hash_object (c->augmentation_size, h); | |
257 | h = iterative_hash_object (c->personality, h); | |
258 | h = iterative_hash_object (c->output_sec, h); | |
259 | h = iterative_hash_object (c->per_encoding, h); | |
260 | h = iterative_hash_object (c->lsda_encoding, h); | |
261 | h = iterative_hash_object (c->fde_encoding, h); | |
262 | h = iterative_hash_object (c->initial_insn_length, h); | |
263 | h = iterative_hash (c->initial_instructions, c->initial_insn_length, h); | |
264 | c->hash = h; | |
265 | return h; | |
65765700 JJ |
266 | } |
267 | ||
353057a5 RS |
268 | /* Return the number of extra bytes that we'll be inserting into |
269 | ENTRY's augmentation string. */ | |
270 | ||
271 | static INLINE unsigned int | |
272 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) | |
273 | { | |
274 | unsigned int size = 0; | |
275 | if (entry->cie) | |
276 | { | |
277 | if (entry->add_augmentation_size) | |
278 | size++; | |
279 | if (entry->add_fde_encoding) | |
280 | size++; | |
281 | } | |
282 | return size; | |
283 | } | |
284 | ||
285 | /* Likewise ENTRY's augmentation data. */ | |
286 | ||
287 | static INLINE unsigned int | |
288 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) | |
289 | { | |
290 | unsigned int size = 0; | |
291 | if (entry->cie) | |
292 | { | |
293 | if (entry->add_augmentation_size) | |
294 | size++; | |
295 | if (entry->add_fde_encoding) | |
296 | size++; | |
297 | } | |
298 | else | |
299 | { | |
300 | if (entry->cie_inf->add_augmentation_size) | |
301 | size++; | |
302 | } | |
303 | return size; | |
304 | } | |
305 | ||
306 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the | |
307 | required alignment of ENTRY in bytes. */ | |
308 | ||
309 | static unsigned int | |
310 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) | |
311 | { | |
312 | if (entry->removed) | |
313 | return 0; | |
314 | if (entry->size == 4) | |
315 | return 4; | |
316 | return (entry->size | |
317 | + extra_augmentation_string_bytes (entry) | |
318 | + extra_augmentation_data_bytes (entry) | |
319 | + alignment - 1) & -alignment; | |
320 | } | |
321 | ||
dcf507a6 RS |
322 | /* Assume that the bytes between *ITER and END are CFA instructions. |
323 | Try to move *ITER past the first instruction and return true on | |
324 | success. ENCODED_PTR_WIDTH gives the width of pointer entries. */ | |
325 | ||
326 | static bfd_boolean | |
327 | skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width) | |
328 | { | |
329 | bfd_byte op; | |
330 | bfd_vma length; | |
331 | ||
332 | if (!read_byte (iter, end, &op)) | |
333 | return FALSE; | |
334 | ||
ac685e6a | 335 | switch (op & 0xc0 ? op & 0xc0 : op) |
dcf507a6 RS |
336 | { |
337 | case DW_CFA_nop: | |
338 | case DW_CFA_advance_loc: | |
339 | case DW_CFA_restore: | |
ac685e6a JJ |
340 | case DW_CFA_remember_state: |
341 | case DW_CFA_restore_state: | |
342 | case DW_CFA_GNU_window_save: | |
dcf507a6 RS |
343 | /* No arguments. */ |
344 | return TRUE; | |
345 | ||
346 | case DW_CFA_offset: | |
347 | case DW_CFA_restore_extended: | |
348 | case DW_CFA_undefined: | |
349 | case DW_CFA_same_value: | |
350 | case DW_CFA_def_cfa_register: | |
351 | case DW_CFA_def_cfa_offset: | |
352 | case DW_CFA_def_cfa_offset_sf: | |
353 | case DW_CFA_GNU_args_size: | |
354 | /* One leb128 argument. */ | |
355 | return skip_leb128 (iter, end); | |
356 | ||
ac685e6a JJ |
357 | case DW_CFA_val_offset: |
358 | case DW_CFA_val_offset_sf: | |
dcf507a6 RS |
359 | case DW_CFA_offset_extended: |
360 | case DW_CFA_register: | |
361 | case DW_CFA_def_cfa: | |
362 | case DW_CFA_offset_extended_sf: | |
363 | case DW_CFA_GNU_negative_offset_extended: | |
364 | case DW_CFA_def_cfa_sf: | |
365 | /* Two leb128 arguments. */ | |
366 | return (skip_leb128 (iter, end) | |
367 | && skip_leb128 (iter, end)); | |
368 | ||
369 | case DW_CFA_def_cfa_expression: | |
370 | /* A variable-length argument. */ | |
371 | return (read_uleb128 (iter, end, &length) | |
372 | && skip_bytes (iter, end, length)); | |
373 | ||
374 | case DW_CFA_expression: | |
ac685e6a | 375 | case DW_CFA_val_expression: |
dcf507a6 RS |
376 | /* A leb128 followed by a variable-length argument. */ |
377 | return (skip_leb128 (iter, end) | |
378 | && read_uleb128 (iter, end, &length) | |
379 | && skip_bytes (iter, end, length)); | |
380 | ||
381 | case DW_CFA_set_loc: | |
382 | return skip_bytes (iter, end, encoded_ptr_width); | |
383 | ||
384 | case DW_CFA_advance_loc1: | |
385 | return skip_bytes (iter, end, 1); | |
386 | ||
387 | case DW_CFA_advance_loc2: | |
388 | return skip_bytes (iter, end, 2); | |
389 | ||
390 | case DW_CFA_advance_loc4: | |
391 | return skip_bytes (iter, end, 4); | |
392 | ||
393 | case DW_CFA_MIPS_advance_loc8: | |
394 | return skip_bytes (iter, end, 8); | |
395 | ||
396 | default: | |
397 | return FALSE; | |
398 | } | |
399 | } | |
400 | ||
401 | /* Try to interpret the bytes between BUF and END as CFA instructions. | |
402 | If every byte makes sense, return a pointer to the first DW_CFA_nop | |
403 | padding byte, or END if there is no padding. Return null otherwise. | |
404 | ENCODED_PTR_WIDTH is as for skip_cfa_op. */ | |
405 | ||
406 | static bfd_byte * | |
ac685e6a JJ |
407 | skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width, |
408 | unsigned int *set_loc_count) | |
dcf507a6 RS |
409 | { |
410 | bfd_byte *last; | |
411 | ||
412 | last = buf; | |
413 | while (buf < end) | |
414 | if (*buf == DW_CFA_nop) | |
415 | buf++; | |
416 | else | |
417 | { | |
ac685e6a JJ |
418 | if (*buf == DW_CFA_set_loc) |
419 | ++*set_loc_count; | |
dcf507a6 RS |
420 | if (!skip_cfa_op (&buf, end, encoded_ptr_width)) |
421 | return 0; | |
422 | last = buf; | |
423 | } | |
424 | return last; | |
425 | } | |
426 | ||
65765700 JJ |
427 | /* This function is called for each input file before the .eh_frame |
428 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
b34976b6 | 429 | functions. The function returns TRUE iff any entries have been |
65765700 JJ |
430 | deleted. */ |
431 | ||
b34976b6 | 432 | bfd_boolean |
c39a58e6 AM |
433 | _bfd_elf_discard_section_eh_frame |
434 | (bfd *abfd, struct bfd_link_info *info, asection *sec, | |
435 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), | |
436 | struct elf_reloc_cookie *cookie) | |
65765700 | 437 | { |
acfe5567 RS |
438 | #define REQUIRE(COND) \ |
439 | do \ | |
440 | if (!(COND)) \ | |
441 | goto free_no_table; \ | |
442 | while (0) | |
443 | ||
65765700 | 444 | bfd_byte *ehbuf = NULL, *buf; |
bce613b9 JJ |
445 | bfd_byte *last_fde; |
446 | struct eh_cie_fde *ent, *this_inf; | |
447 | unsigned int hdr_length, hdr_id; | |
448 | struct extended_cie | |
449 | { | |
450 | struct cie cie; | |
451 | unsigned int offset; | |
452 | unsigned int usage_count; | |
453 | unsigned int entry; | |
454 | } *ecies = NULL, *ecie; | |
455 | unsigned int ecie_count = 0, ecie_alloced = 0; | |
456 | struct cie *cie; | |
126495ed | 457 | struct elf_link_hash_table *htab; |
65765700 | 458 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 459 | struct eh_frame_sec_info *sec_info = NULL; |
bce613b9 | 460 | unsigned int offset; |
65765700 | 461 | unsigned int ptr_size; |
bce613b9 | 462 | unsigned int entry_alloced; |
65765700 | 463 | |
eea6121a | 464 | if (sec->size == 0) |
65765700 JJ |
465 | { |
466 | /* This file does not contain .eh_frame information. */ | |
b34976b6 | 467 | return FALSE; |
65765700 JJ |
468 | } |
469 | ||
e460dd0d | 470 | if (bfd_is_abs_section (sec->output_section)) |
65765700 JJ |
471 | { |
472 | /* At least one of the sections is being discarded from the | |
3472e2e9 | 473 | link, so we should just ignore them. */ |
b34976b6 | 474 | return FALSE; |
65765700 JJ |
475 | } |
476 | ||
126495ed AM |
477 | htab = elf_hash_table (info); |
478 | hdr_info = &htab->eh_info; | |
68f69152 | 479 | |
bce613b9 JJ |
480 | if (hdr_info->cies == NULL && !info->relocatable) |
481 | hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free); | |
482 | ||
65765700 JJ |
483 | /* Read the frame unwind information from abfd. */ |
484 | ||
acfe5567 | 485 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
68f69152 | 486 | |
eea6121a | 487 | if (sec->size >= 4 |
65765700 JJ |
488 | && bfd_get_32 (abfd, ehbuf) == 0 |
489 | && cookie->rel == cookie->relend) | |
490 | { | |
491 | /* Empty .eh_frame section. */ | |
492 | free (ehbuf); | |
b34976b6 | 493 | return FALSE; |
65765700 JJ |
494 | } |
495 | ||
65765700 JJ |
496 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
497 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
acfe5567 | 498 | REQUIRE (sec->size == (unsigned int) sec->size); |
65765700 | 499 | |
8c946ed5 RS |
500 | ptr_size = (get_elf_backend_data (abfd) |
501 | ->elf_backend_eh_frame_address_size (abfd, sec)); | |
502 | REQUIRE (ptr_size != 0); | |
503 | ||
65765700 | 504 | buf = ehbuf; |
65765700 JJ |
505 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
506 | + 99 * sizeof (struct eh_cie_fde)); | |
acfe5567 | 507 | REQUIRE (sec_info); |
eea6121a | 508 | |
bce613b9 | 509 | entry_alloced = 100; |
65765700 JJ |
510 | |
511 | #define ENSURE_NO_RELOCS(buf) \ | |
acfe5567 RS |
512 | REQUIRE (!(cookie->rel < cookie->relend \ |
513 | && (cookie->rel->r_offset \ | |
514 | < (bfd_size_type) ((buf) - ehbuf)) \ | |
515 | && cookie->rel->r_info != 0)) | |
65765700 JJ |
516 | |
517 | #define SKIP_RELOCS(buf) \ | |
518 | while (cookie->rel < cookie->relend \ | |
3472e2e9 | 519 | && (cookie->rel->r_offset \ |
65765700 JJ |
520 | < (bfd_size_type) ((buf) - ehbuf))) \ |
521 | cookie->rel++ | |
522 | ||
523 | #define GET_RELOC(buf) \ | |
524 | ((cookie->rel < cookie->relend \ | |
525 | && (cookie->rel->r_offset \ | |
3472e2e9 | 526 | == (bfd_size_type) ((buf) - ehbuf))) \ |
65765700 JJ |
527 | ? cookie->rel : NULL) |
528 | ||
529 | for (;;) | |
530 | { | |
f075ee0c | 531 | char *aug; |
ac685e6a | 532 | bfd_byte *start, *end, *insns, *insns_end; |
2c42be65 | 533 | bfd_size_type length; |
ac685e6a | 534 | unsigned int set_loc_count; |
65765700 | 535 | |
bce613b9 | 536 | if (sec_info->count == entry_alloced) |
65765700 JJ |
537 | { |
538 | sec_info = bfd_realloc (sec_info, | |
539 | sizeof (struct eh_frame_sec_info) | |
bce613b9 | 540 | + ((entry_alloced + 99) |
fda3ecf2 | 541 | * sizeof (struct eh_cie_fde))); |
acfe5567 | 542 | REQUIRE (sec_info); |
65765700 | 543 | |
bce613b9 | 544 | memset (&sec_info->entry[entry_alloced], 0, |
65765700 | 545 | 100 * sizeof (struct eh_cie_fde)); |
bce613b9 | 546 | entry_alloced += 100; |
65765700 JJ |
547 | } |
548 | ||
fda3ecf2 | 549 | this_inf = sec_info->entry + sec_info->count; |
65765700 | 550 | last_fde = buf; |
bce613b9 | 551 | |
eea6121a | 552 | if ((bfd_size_type) (buf - ehbuf) == sec->size) |
bce613b9 | 553 | break; |
acfe5567 | 554 | |
bce613b9 JJ |
555 | /* Read the length of the entry. */ |
556 | REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4)); | |
557 | hdr_length = bfd_get_32 (abfd, buf - 4); | |
acfe5567 | 558 | |
bce613b9 JJ |
559 | /* 64-bit .eh_frame is not supported. */ |
560 | REQUIRE (hdr_length != 0xffffffff); | |
65765700 | 561 | |
bce613b9 JJ |
562 | /* The CIE/FDE must be fully contained in this input section. */ |
563 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size); | |
564 | end = buf + hdr_length; | |
65765700 | 565 | |
bce613b9 JJ |
566 | this_inf->offset = last_fde - ehbuf; |
567 | this_inf->size = 4 + hdr_length; | |
568 | ||
569 | if (hdr_length == 0) | |
570 | { | |
571 | /* A zero-length CIE should only be found at the end of | |
572 | the section. */ | |
573 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); | |
574 | ENSURE_NO_RELOCS (buf); | |
575 | sec_info->count++; | |
576 | break; | |
65765700 JJ |
577 | } |
578 | ||
bce613b9 JJ |
579 | REQUIRE (skip_bytes (&buf, end, 4)); |
580 | hdr_id = bfd_get_32 (abfd, buf - 4); | |
581 | ||
582 | if (hdr_id == 0) | |
65765700 JJ |
583 | { |
584 | unsigned int initial_insn_length; | |
585 | ||
586 | /* CIE */ | |
bce613b9 JJ |
587 | this_inf->cie = 1; |
588 | ||
589 | if (ecie_count == ecie_alloced) | |
65765700 | 590 | { |
bce613b9 JJ |
591 | ecies = bfd_realloc (ecies, |
592 | (ecie_alloced + 20) * sizeof (*ecies)); | |
593 | REQUIRE (ecies); | |
594 | memset (&ecies[ecie_alloced], 0, 20 * sizeof (*ecies)); | |
595 | ecie_alloced += 20; | |
65765700 JJ |
596 | } |
597 | ||
bce613b9 JJ |
598 | cie = &ecies[ecie_count].cie; |
599 | ecies[ecie_count].offset = this_inf->offset; | |
600 | ecies[ecie_count++].entry = sec_info->count; | |
601 | cie->length = hdr_length; | |
ac685e6a | 602 | start = buf; |
bce613b9 | 603 | REQUIRE (read_byte (&buf, end, &cie->version)); |
65765700 JJ |
604 | |
605 | /* Cannot handle unknown versions. */ | |
bce613b9 JJ |
606 | REQUIRE (cie->version == 1 || cie->version == 3); |
607 | REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation)); | |
65765700 | 608 | |
bce613b9 | 609 | strcpy (cie->augmentation, (char *) buf); |
f075ee0c | 610 | buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1; |
65765700 JJ |
611 | ENSURE_NO_RELOCS (buf); |
612 | if (buf[0] == 'e' && buf[1] == 'h') | |
613 | { | |
614 | /* GCC < 3.0 .eh_frame CIE */ | |
615 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
616 | is private to each CIE, so we don't need it for anything. | |
617 | Just skip it. */ | |
2c42be65 | 618 | REQUIRE (skip_bytes (&buf, end, ptr_size)); |
65765700 JJ |
619 | SKIP_RELOCS (buf); |
620 | } | |
bce613b9 JJ |
621 | REQUIRE (read_uleb128 (&buf, end, &cie->code_align)); |
622 | REQUIRE (read_sleb128 (&buf, end, &cie->data_align)); | |
623 | if (cie->version == 1) | |
2c42be65 RS |
624 | { |
625 | REQUIRE (buf < end); | |
bce613b9 | 626 | cie->ra_column = *buf++; |
2c42be65 | 627 | } |
0da76f83 | 628 | else |
bce613b9 | 629 | REQUIRE (read_uleb128 (&buf, end, &cie->ra_column)); |
65765700 | 630 | ENSURE_NO_RELOCS (buf); |
bce613b9 JJ |
631 | cie->lsda_encoding = DW_EH_PE_omit; |
632 | cie->fde_encoding = DW_EH_PE_omit; | |
633 | cie->per_encoding = DW_EH_PE_omit; | |
634 | aug = cie->augmentation; | |
65765700 JJ |
635 | if (aug[0] != 'e' || aug[1] != 'h') |
636 | { | |
637 | if (*aug == 'z') | |
638 | { | |
639 | aug++; | |
bce613b9 | 640 | REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size)); |
65765700 JJ |
641 | ENSURE_NO_RELOCS (buf); |
642 | } | |
643 | ||
644 | while (*aug != '\0') | |
645 | switch (*aug++) | |
646 | { | |
647 | case 'L': | |
bce613b9 | 648 | REQUIRE (read_byte (&buf, end, &cie->lsda_encoding)); |
65765700 | 649 | ENSURE_NO_RELOCS (buf); |
bce613b9 | 650 | REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size)); |
65765700 JJ |
651 | break; |
652 | case 'R': | |
bce613b9 | 653 | REQUIRE (read_byte (&buf, end, &cie->fde_encoding)); |
65765700 | 654 | ENSURE_NO_RELOCS (buf); |
bce613b9 | 655 | REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size)); |
65765700 | 656 | break; |
63752a75 JJ |
657 | case 'S': |
658 | break; | |
65765700 JJ |
659 | case 'P': |
660 | { | |
661 | int per_width; | |
662 | ||
bce613b9 JJ |
663 | REQUIRE (read_byte (&buf, end, &cie->per_encoding)); |
664 | per_width = get_DW_EH_PE_width (cie->per_encoding, | |
65765700 | 665 | ptr_size); |
acfe5567 | 666 | REQUIRE (per_width); |
bce613b9 | 667 | if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned) |
2c42be65 RS |
668 | { |
669 | length = -(buf - ehbuf) & (per_width - 1); | |
670 | REQUIRE (skip_bytes (&buf, end, length)); | |
671 | } | |
65765700 | 672 | ENSURE_NO_RELOCS (buf); |
65765700 JJ |
673 | /* Ensure we have a reloc here, against |
674 | a global symbol. */ | |
99eb2ac8 | 675 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
676 | { |
677 | unsigned long r_symndx; | |
678 | ||
679 | #ifdef BFD64 | |
680 | if (ptr_size == 8) | |
681 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
682 | else | |
683 | #endif | |
684 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
685 | if (r_symndx >= cookie->locsymcount) | |
686 | { | |
687 | struct elf_link_hash_entry *h; | |
688 | ||
689 | r_symndx -= cookie->extsymoff; | |
690 | h = cookie->sym_hashes[r_symndx]; | |
691 | ||
692 | while (h->root.type == bfd_link_hash_indirect | |
693 | || h->root.type == bfd_link_hash_warning) | |
694 | h = (struct elf_link_hash_entry *) | |
695 | h->root.u.i.link; | |
696 | ||
bce613b9 | 697 | cie->personality = h; |
65765700 | 698 | } |
f4a6705c RS |
699 | /* Cope with MIPS-style composite relocations. */ |
700 | do | |
701 | cookie->rel++; | |
702 | while (GET_RELOC (buf) != NULL); | |
65765700 | 703 | } |
2c42be65 | 704 | REQUIRE (skip_bytes (&buf, end, per_width)); |
bce613b9 | 705 | REQUIRE (cie->personality); |
65765700 JJ |
706 | } |
707 | break; | |
708 | default: | |
709 | /* Unrecognized augmentation. Better bail out. */ | |
710 | goto free_no_table; | |
711 | } | |
712 | } | |
713 | ||
714 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a | 715 | as possible. */ |
3472e2e9 | 716 | if (info->shared |
ec3391e7 AO |
717 | && (get_elf_backend_data (abfd) |
718 | ->elf_backend_can_make_relative_eh_frame | |
353057a5 RS |
719 | (abfd, info, sec))) |
720 | { | |
bce613b9 JJ |
721 | if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr) |
722 | cie->make_relative = 1; | |
353057a5 RS |
723 | /* If the CIE doesn't already have an 'R' entry, it's fairly |
724 | easy to add one, provided that there's no aligned data | |
725 | after the augmentation string. */ | |
bce613b9 JJ |
726 | else if (cie->fde_encoding == DW_EH_PE_omit |
727 | && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned) | |
353057a5 | 728 | { |
bce613b9 | 729 | if (*cie->augmentation == 0) |
353057a5 RS |
730 | this_inf->add_augmentation_size = 1; |
731 | this_inf->add_fde_encoding = 1; | |
bce613b9 | 732 | cie->make_relative = 1; |
353057a5 RS |
733 | } |
734 | } | |
65765700 | 735 | |
0bb2d96a | 736 | if (info->shared |
ec3391e7 AO |
737 | && (get_elf_backend_data (abfd) |
738 | ->elf_backend_can_make_lsda_relative_eh_frame | |
739 | (abfd, info, sec)) | |
bce613b9 JJ |
740 | && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
741 | cie->make_lsda_relative = 1; | |
9e2a4898 | 742 | |
65765700 JJ |
743 | /* If FDE encoding was not specified, it defaults to |
744 | DW_EH_absptr. */ | |
bce613b9 JJ |
745 | if (cie->fde_encoding == DW_EH_PE_omit) |
746 | cie->fde_encoding = DW_EH_PE_absptr; | |
65765700 | 747 | |
dcf507a6 | 748 | initial_insn_length = end - buf; |
bce613b9 | 749 | if (initial_insn_length <= sizeof (cie->initial_instructions)) |
65765700 | 750 | { |
bce613b9 JJ |
751 | cie->initial_insn_length = initial_insn_length; |
752 | memcpy (cie->initial_instructions, buf, initial_insn_length); | |
65765700 | 753 | } |
dcf507a6 | 754 | insns = buf; |
65765700 JJ |
755 | buf += initial_insn_length; |
756 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
757 | } |
758 | else | |
759 | { | |
bce613b9 JJ |
760 | /* Find the corresponding CIE. */ |
761 | unsigned int cie_offset = this_inf->offset + 4 - hdr_id; | |
762 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
763 | if (cie_offset == ecie->offset) | |
764 | break; | |
765 | ||
766 | /* Ensure this FDE references one of the CIEs in this input | |
767 | section. */ | |
768 | REQUIRE (ecie != ecies + ecie_count); | |
769 | cie = &ecie->cie; | |
65765700 JJ |
770 | |
771 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 772 | REQUIRE (GET_RELOC (buf)); |
fda3ecf2 | 773 | |
65765700 | 774 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
353057a5 RS |
775 | /* This is a FDE against a discarded section. It should |
776 | be deleted. */ | |
777 | this_inf->removed = 1; | |
65765700 JJ |
778 | else |
779 | { | |
0bb2d96a | 780 | if (info->shared |
bce613b9 JJ |
781 | && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr |
782 | && cie->make_relative == 0) | |
783 | || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 784 | { |
73722af0 | 785 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
786 | which we cannot turn into PC relative, |
787 | don't create the binary search table, | |
788 | since it is affected by runtime relocations. */ | |
b34976b6 | 789 | hdr_info->table = FALSE; |
64be1553 AM |
790 | (*info->callbacks->einfo) |
791 | (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr" | |
792 | " table being created.\n"), abfd, sec); | |
0bb2d96a | 793 | } |
bce613b9 | 794 | ecie->usage_count++; |
65765700 | 795 | hdr_info->fde_count++; |
bce613b9 | 796 | this_inf->cie_inf = (void *) (ecie - ecies); |
65765700 | 797 | } |
bce613b9 | 798 | |
2c42be65 RS |
799 | /* Skip the initial location and address range. */ |
800 | start = buf; | |
bce613b9 | 801 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
2c42be65 RS |
802 | REQUIRE (skip_bytes (&buf, end, 2 * length)); |
803 | ||
804 | /* Skip the augmentation size, if present. */ | |
bce613b9 | 805 | if (cie->augmentation[0] == 'z') |
dcf507a6 RS |
806 | REQUIRE (read_uleb128 (&buf, end, &length)); |
807 | else | |
808 | length = 0; | |
2c42be65 RS |
809 | |
810 | /* Of the supported augmentation characters above, only 'L' | |
811 | adds augmentation data to the FDE. This code would need to | |
812 | be adjusted if any future augmentations do the same thing. */ | |
bce613b9 | 813 | if (cie->lsda_encoding != DW_EH_PE_omit) |
dcf507a6 RS |
814 | { |
815 | this_inf->lsda_offset = buf - start; | |
816 | /* If there's no 'z' augmentation, we don't know where the | |
817 | CFA insns begin. Assume no padding. */ | |
bce613b9 | 818 | if (cie->augmentation[0] != 'z') |
dcf507a6 RS |
819 | length = end - buf; |
820 | } | |
821 | ||
822 | /* Skip over the augmentation data. */ | |
823 | REQUIRE (skip_bytes (&buf, end, length)); | |
824 | insns = buf; | |
9e2a4898 | 825 | |
bce613b9 | 826 | buf = last_fde + 4 + hdr_length; |
65765700 JJ |
827 | SKIP_RELOCS (buf); |
828 | } | |
829 | ||
dcf507a6 RS |
830 | /* Try to interpret the CFA instructions and find the first |
831 | padding nop. Shrink this_inf's size so that it doesn't | |
ac685e6a | 832 | include the padding. */ |
bce613b9 | 833 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
ac685e6a JJ |
834 | set_loc_count = 0; |
835 | insns_end = skip_non_nops (insns, end, length, &set_loc_count); | |
836 | /* If we don't understand the CFA instructions, we can't know | |
837 | what needs to be adjusted there. */ | |
838 | if (insns_end == NULL | |
839 | /* For the time being we don't support DW_CFA_set_loc in | |
840 | CIE instructions. */ | |
841 | || (set_loc_count && this_inf->cie)) | |
842 | goto free_no_table; | |
843 | this_inf->size -= end - insns_end; | |
bce613b9 JJ |
844 | if (insns_end != end && this_inf->cie) |
845 | { | |
846 | cie->initial_insn_length -= end - insns_end; | |
847 | cie->length -= end - insns_end; | |
848 | } | |
ac685e6a | 849 | if (set_loc_count |
bce613b9 JJ |
850 | && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel |
851 | || cie->make_relative)) | |
ac685e6a JJ |
852 | { |
853 | unsigned int cnt; | |
854 | bfd_byte *p; | |
855 | ||
856 | this_inf->set_loc = bfd_malloc ((set_loc_count + 1) | |
857 | * sizeof (unsigned int)); | |
858 | REQUIRE (this_inf->set_loc); | |
859 | this_inf->set_loc[0] = set_loc_count; | |
860 | p = insns; | |
861 | cnt = 0; | |
862 | while (p < end) | |
863 | { | |
864 | if (*p == DW_CFA_set_loc) | |
865 | this_inf->set_loc[++cnt] = p + 1 - start; | |
866 | REQUIRE (skip_cfa_op (&p, end, length)); | |
867 | } | |
868 | } | |
dcf507a6 | 869 | |
bce613b9 JJ |
870 | this_inf->fde_encoding = cie->fde_encoding; |
871 | this_inf->lsda_encoding = cie->lsda_encoding; | |
65765700 JJ |
872 | sec_info->count++; |
873 | } | |
874 | ||
875 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 876 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 | 877 | |
bce613b9 JJ |
878 | /* Look at all CIEs in this section and determine which can be |
879 | removed as unused, which can be merged with previous duplicate | |
880 | CIEs and which need to be kept. */ | |
881 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
882 | { | |
883 | if (ecie->usage_count == 0) | |
884 | { | |
885 | sec_info->entry[ecie->entry].removed = 1; | |
886 | continue; | |
887 | } | |
888 | ecie->cie.output_sec = sec->output_section; | |
889 | ecie->cie.cie_inf = sec_info->entry + ecie->entry; | |
890 | cie_compute_hash (&ecie->cie); | |
891 | if (hdr_info->cies != NULL) | |
892 | { | |
893 | void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie, | |
894 | ecie->cie.hash, INSERT); | |
895 | if (loc != NULL) | |
896 | { | |
897 | if (*loc != HTAB_EMPTY_ENTRY) | |
898 | { | |
899 | sec_info->entry[ecie->entry].removed = 1; | |
900 | ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf; | |
901 | continue; | |
902 | } | |
903 | ||
904 | *loc = malloc (sizeof (struct cie)); | |
905 | if (*loc == NULL) | |
906 | *loc = HTAB_DELETED_ENTRY; | |
907 | else | |
908 | memcpy (*loc, &ecie->cie, sizeof (struct cie)); | |
909 | } | |
910 | } | |
911 | ecie->cie.cie_inf->make_relative = ecie->cie.make_relative; | |
912 | ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative; | |
913 | ecie->cie.cie_inf->per_encoding_relative | |
914 | = (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
915 | } | |
916 | ||
65765700 JJ |
917 | /* Ok, now we can assign new offsets. */ |
918 | offset = 0; | |
fda3ecf2 AM |
919 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
920 | if (!ent->removed) | |
921 | { | |
bce613b9 JJ |
922 | if (!ent->cie) |
923 | { | |
924 | ecie = ecies + (unsigned long) ent->cie_inf; | |
925 | ent->cie_inf = ecie->cie.cie_inf; | |
926 | } | |
353057a5 RS |
927 | ent->new_offset = offset; |
928 | offset += size_of_output_cie_fde (ent, ptr_size); | |
fda3ecf2 | 929 | } |
65765700 | 930 | |
353057a5 | 931 | /* Resize the sec as needed. */ |
eea6121a | 932 | sec->rawsize = sec->size; |
353057a5 | 933 | sec->size = offset; |
65765700 | 934 | |
68f69152 | 935 | free (ehbuf); |
bce613b9 JJ |
936 | if (ecies) |
937 | free (ecies); | |
353057a5 | 938 | return offset != sec->rawsize; |
65765700 JJ |
939 | |
940 | free_no_table: | |
64be1553 AM |
941 | (*info->callbacks->einfo) |
942 | (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), | |
943 | abfd, sec); | |
68f69152 JJ |
944 | if (ehbuf) |
945 | free (ehbuf); | |
65765700 JJ |
946 | if (sec_info) |
947 | free (sec_info); | |
bce613b9 JJ |
948 | if (ecies) |
949 | free (ecies); | |
b34976b6 | 950 | hdr_info->table = FALSE; |
b34976b6 | 951 | return FALSE; |
acfe5567 RS |
952 | |
953 | #undef REQUIRE | |
65765700 JJ |
954 | } |
955 | ||
956 | /* This function is called for .eh_frame_hdr section after | |
957 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
958 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
959 | ||
b34976b6 | 960 | bfd_boolean |
c39a58e6 | 961 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 962 | { |
126495ed | 963 | struct elf_link_hash_table *htab; |
65765700 | 964 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 965 | asection *sec; |
65765700 | 966 | |
126495ed AM |
967 | htab = elf_hash_table (info); |
968 | hdr_info = &htab->eh_info; | |
bce613b9 JJ |
969 | |
970 | if (hdr_info->cies != NULL) | |
971 | { | |
972 | htab_delete (hdr_info->cies); | |
973 | hdr_info->cies = NULL; | |
974 | } | |
975 | ||
126495ed AM |
976 | sec = hdr_info->hdr_sec; |
977 | if (sec == NULL) | |
b34976b6 | 978 | return FALSE; |
126495ed | 979 | |
eea6121a | 980 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 981 | if (hdr_info->table) |
eea6121a | 982 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 | 983 | |
126495ed | 984 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 985 | return TRUE; |
65765700 JJ |
986 | } |
987 | ||
68f69152 JJ |
988 | /* This function is called from size_dynamic_sections. |
989 | It needs to decide whether .eh_frame_hdr should be output or not, | |
8423293d AM |
990 | because when the dynamic symbol table has been sized it is too late |
991 | to strip sections. */ | |
68f69152 | 992 | |
b34976b6 | 993 | bfd_boolean |
c39a58e6 | 994 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 995 | { |
126495ed | 996 | asection *o; |
68f69152 | 997 | bfd *abfd; |
126495ed | 998 | struct elf_link_hash_table *htab; |
68f69152 JJ |
999 | struct eh_frame_hdr_info *hdr_info; |
1000 | ||
126495ed AM |
1001 | htab = elf_hash_table (info); |
1002 | hdr_info = &htab->eh_info; | |
1003 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 1004 | return TRUE; |
68f69152 | 1005 | |
126495ed AM |
1006 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
1007 | { | |
1008 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 1009 | return TRUE; |
126495ed | 1010 | } |
68f69152 JJ |
1011 | |
1012 | abfd = NULL; | |
1013 | if (info->eh_frame_hdr) | |
1014 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
1015 | { | |
1016 | /* Count only sections which have at least a single CIE or FDE. | |
1017 | There cannot be any CIE or FDE <= 8 bytes. */ | |
1018 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 1019 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
1020 | break; |
1021 | } | |
1022 | ||
1023 | if (abfd == NULL) | |
1024 | { | |
8423293d | 1025 | hdr_info->hdr_sec->flags |= SEC_EXCLUDE; |
126495ed | 1026 | hdr_info->hdr_sec = NULL; |
b34976b6 | 1027 | return TRUE; |
68f69152 | 1028 | } |
126495ed | 1029 | |
b34976b6 AM |
1030 | hdr_info->table = TRUE; |
1031 | return TRUE; | |
68f69152 JJ |
1032 | } |
1033 | ||
65765700 JJ |
1034 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
1035 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
1036 | or -1 if the address refers to a CIE/FDE which has been removed | |
1037 | or to offset with dynamic relocation which is no longer needed. */ | |
1038 | ||
1039 | bfd_vma | |
c39a58e6 | 1040 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
92e4ec35 | 1041 | struct bfd_link_info *info, |
c39a58e6 AM |
1042 | asection *sec, |
1043 | bfd_vma offset) | |
65765700 JJ |
1044 | { |
1045 | struct eh_frame_sec_info *sec_info; | |
92e4ec35 AM |
1046 | struct elf_link_hash_table *htab; |
1047 | struct eh_frame_hdr_info *hdr_info; | |
65765700 JJ |
1048 | unsigned int lo, hi, mid; |
1049 | ||
68bfbfcc | 1050 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 1051 | return offset; |
c39a58e6 | 1052 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 1053 | |
eea6121a AM |
1054 | if (offset >= sec->rawsize) |
1055 | return offset - sec->rawsize + sec->size; | |
65765700 | 1056 | |
92e4ec35 AM |
1057 | htab = elf_hash_table (info); |
1058 | hdr_info = &htab->eh_info; | |
1059 | if (hdr_info->offsets_adjusted) | |
1060 | offset += sec->output_offset; | |
1061 | ||
65765700 JJ |
1062 | lo = 0; |
1063 | hi = sec_info->count; | |
1064 | mid = 0; | |
1065 | while (lo < hi) | |
1066 | { | |
1067 | mid = (lo + hi) / 2; | |
1068 | if (offset < sec_info->entry[mid].offset) | |
1069 | hi = mid; | |
1070 | else if (offset | |
1071 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
1072 | lo = mid + 1; | |
1073 | else | |
1074 | break; | |
1075 | } | |
1076 | ||
1077 | BFD_ASSERT (lo < hi); | |
1078 | ||
1079 | /* FDE or CIE was removed. */ | |
1080 | if (sec_info->entry[mid].removed) | |
1081 | return (bfd_vma) -1; | |
1082 | ||
1083 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
1084 | relocation against FDE's initial_location field. */ | |
fda3ecf2 AM |
1085 | if (!sec_info->entry[mid].cie |
1086 | && sec_info->entry[mid].cie_inf->make_relative | |
353057a5 RS |
1087 | && offset == sec_info->entry[mid].offset + 8) |
1088 | return (bfd_vma) -2; | |
65765700 | 1089 | |
9e2a4898 JJ |
1090 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
1091 | for run-time relocation against LSDA field. */ | |
fda3ecf2 AM |
1092 | if (!sec_info->entry[mid].cie |
1093 | && sec_info->entry[mid].cie_inf->make_lsda_relative | |
126495ed | 1094 | && (offset == (sec_info->entry[mid].offset + 8 |
92e4ec35 AM |
1095 | + sec_info->entry[mid].lsda_offset)) |
1096 | && (sec_info->entry[mid].cie_inf->need_lsda_relative | |
1097 | || !hdr_info->offsets_adjusted)) | |
8935b81f | 1098 | { |
fda3ecf2 | 1099 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
8935b81f AM |
1100 | return (bfd_vma) -2; |
1101 | } | |
9e2a4898 | 1102 | |
ac685e6a JJ |
1103 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
1104 | relocation against DW_CFA_set_loc's arguments. */ | |
1105 | if (sec_info->entry[mid].set_loc | |
1106 | && (sec_info->entry[mid].cie | |
1107 | ? sec_info->entry[mid].make_relative | |
1108 | : sec_info->entry[mid].cie_inf->make_relative) | |
1109 | && (offset >= sec_info->entry[mid].offset + 8 | |
1110 | + sec_info->entry[mid].set_loc[1])) | |
1111 | { | |
1112 | unsigned int cnt; | |
1113 | ||
1114 | for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++) | |
1115 | if (offset == sec_info->entry[mid].offset + 8 | |
1116 | + sec_info->entry[mid].set_loc[cnt]) | |
1117 | return (bfd_vma) -2; | |
1118 | } | |
1119 | ||
92e4ec35 AM |
1120 | if (hdr_info->offsets_adjusted) |
1121 | offset -= sec->output_offset; | |
353057a5 | 1122 | /* Any new augmentation bytes go before the first relocation. */ |
c68836a9 | 1123 | return (offset + sec_info->entry[mid].new_offset |
353057a5 RS |
1124 | - sec_info->entry[mid].offset |
1125 | + extra_augmentation_string_bytes (sec_info->entry + mid) | |
1126 | + extra_augmentation_data_bytes (sec_info->entry + mid)); | |
65765700 JJ |
1127 | } |
1128 | ||
1129 | /* Write out .eh_frame section. This is called with the relocated | |
1130 | contents. */ | |
1131 | ||
b34976b6 | 1132 | bfd_boolean |
c39a58e6 AM |
1133 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
1134 | struct bfd_link_info *info, | |
1135 | asection *sec, | |
1136 | bfd_byte *contents) | |
65765700 JJ |
1137 | { |
1138 | struct eh_frame_sec_info *sec_info; | |
126495ed | 1139 | struct elf_link_hash_table *htab; |
65765700 | 1140 | struct eh_frame_hdr_info *hdr_info; |
65765700 | 1141 | unsigned int ptr_size; |
fda3ecf2 | 1142 | struct eh_cie_fde *ent; |
65765700 | 1143 | |
68bfbfcc | 1144 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 1145 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 1146 | sec->output_offset, sec->size); |
8c946ed5 RS |
1147 | |
1148 | ptr_size = (get_elf_backend_data (abfd) | |
1149 | ->elf_backend_eh_frame_address_size (abfd, sec)); | |
1150 | BFD_ASSERT (ptr_size != 0); | |
1151 | ||
c39a58e6 | 1152 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
1153 | htab = elf_hash_table (info); |
1154 | hdr_info = &htab->eh_info; | |
3472e2e9 AM |
1155 | |
1156 | /* First convert all offsets to output section offsets, so that a | |
1157 | CIE offset is valid if the CIE is used by a FDE from some other | |
1158 | section. This can happen when duplicate CIEs are deleted in | |
1159 | _bfd_elf_discard_section_eh_frame. We do all sections here because | |
1160 | this function might not be called on sections in the same order as | |
1161 | _bfd_elf_discard_section_eh_frame. */ | |
1162 | if (!hdr_info->offsets_adjusted) | |
1163 | { | |
1164 | bfd *ibfd; | |
1165 | asection *eh; | |
1166 | struct eh_frame_sec_info *eh_inf; | |
1167 | ||
1168 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) | |
1169 | { | |
1170 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour | |
1171 | || (ibfd->flags & DYNAMIC) != 0) | |
1172 | continue; | |
1173 | ||
1174 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); | |
1175 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
1176 | continue; | |
1177 | ||
1178 | eh_inf = elf_section_data (eh)->sec_info; | |
1179 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) | |
1180 | { | |
1181 | ent->offset += eh->output_offset; | |
1182 | ent->new_offset += eh->output_offset; | |
1183 | } | |
1184 | } | |
1185 | hdr_info->offsets_adjusted = TRUE; | |
1186 | } | |
1187 | ||
126495ed AM |
1188 | if (hdr_info->table && hdr_info->array == NULL) |
1189 | hdr_info->array | |
1190 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
1191 | if (hdr_info->array == NULL) | |
1192 | hdr_info = NULL; | |
65765700 | 1193 | |
353057a5 RS |
1194 | /* The new offsets can be bigger or smaller than the original offsets. |
1195 | We therefore need to make two passes over the section: one backward | |
1196 | pass to move entries up and one forward pass to move entries down. | |
1197 | The two passes won't interfere with each other because entries are | |
1198 | not reordered */ | |
1199 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) | |
1200 | if (!ent->removed && ent->new_offset > ent->offset) | |
1201 | memmove (contents + ent->new_offset - sec->output_offset, | |
1202 | contents + ent->offset - sec->output_offset, ent->size); | |
1203 | ||
1204 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
1205 | if (!ent->removed && ent->new_offset < ent->offset) | |
1206 | memmove (contents + ent->new_offset - sec->output_offset, | |
1207 | contents + ent->offset - sec->output_offset, ent->size); | |
1208 | ||
fda3ecf2 | 1209 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
65765700 | 1210 | { |
353057a5 RS |
1211 | unsigned char *buf, *end; |
1212 | unsigned int new_size; | |
1213 | ||
fda3ecf2 AM |
1214 | if (ent->removed) |
1215 | continue; | |
1216 | ||
353057a5 RS |
1217 | if (ent->size == 4) |
1218 | { | |
1219 | /* Any terminating FDE must be at the end of the section. */ | |
1220 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); | |
1221 | continue; | |
1222 | } | |
1223 | ||
1224 | buf = contents + ent->new_offset - sec->output_offset; | |
1225 | end = buf + ent->size; | |
1226 | new_size = size_of_output_cie_fde (ent, ptr_size); | |
1227 | ||
a34a056a L |
1228 | /* Update the size. It may be shrinked. */ |
1229 | bfd_put_32 (abfd, new_size - 4, buf); | |
1230 | ||
1231 | /* Filling the extra bytes with DW_CFA_nops. */ | |
353057a5 | 1232 | if (new_size != ent->size) |
a34a056a | 1233 | memset (end, 0, new_size - ent->size); |
353057a5 | 1234 | |
fda3ecf2 | 1235 | if (ent->cie) |
65765700 JJ |
1236 | { |
1237 | /* CIE */ | |
353057a5 | 1238 | if (ent->make_relative |
fda3ecf2 AM |
1239 | || ent->need_lsda_relative |
1240 | || ent->per_encoding_relative) | |
65765700 | 1241 | { |
f075ee0c | 1242 | char *aug; |
353057a5 | 1243 | unsigned int action, extra_string, extra_data; |
2c42be65 | 1244 | unsigned int per_width, per_encoding; |
65765700 | 1245 | |
9e2a4898 | 1246 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 1247 | DW_EH_PE_* value. */ |
353057a5 | 1248 | action = ((ent->make_relative ? 1 : 0) |
fda3ecf2 AM |
1249 | | (ent->need_lsda_relative ? 2 : 0) |
1250 | | (ent->per_encoding_relative ? 4 : 0)); | |
353057a5 RS |
1251 | extra_string = extra_augmentation_string_bytes (ent); |
1252 | extra_data = extra_augmentation_data_bytes (ent); | |
1253 | ||
65765700 JJ |
1254 | /* Skip length, id and version. */ |
1255 | buf += 9; | |
f075ee0c AM |
1256 | aug = (char *) buf; |
1257 | buf += strlen (aug) + 1; | |
2c42be65 RS |
1258 | skip_leb128 (&buf, end); |
1259 | skip_leb128 (&buf, end); | |
1260 | skip_leb128 (&buf, end); | |
65765700 JJ |
1261 | if (*aug == 'z') |
1262 | { | |
353057a5 RS |
1263 | /* The uleb128 will always be a single byte for the kind |
1264 | of augmentation strings that we're prepared to handle. */ | |
1265 | *buf++ += extra_data; | |
65765700 JJ |
1266 | aug++; |
1267 | } | |
1268 | ||
353057a5 RS |
1269 | /* Make room for the new augmentation string and data bytes. */ |
1270 | memmove (buf + extra_string + extra_data, buf, end - buf); | |
f075ee0c | 1271 | memmove (aug + extra_string, aug, buf - (bfd_byte *) aug); |
353057a5 | 1272 | buf += extra_string; |
2c42be65 | 1273 | end += extra_string + extra_data; |
353057a5 RS |
1274 | |
1275 | if (ent->add_augmentation_size) | |
1276 | { | |
1277 | *aug++ = 'z'; | |
1278 | *buf++ = extra_data - 1; | |
1279 | } | |
1280 | if (ent->add_fde_encoding) | |
1281 | { | |
1282 | BFD_ASSERT (action & 1); | |
1283 | *aug++ = 'R'; | |
1284 | *buf++ = DW_EH_PE_pcrel; | |
1285 | action &= ~1; | |
1286 | } | |
1287 | ||
9e2a4898 | 1288 | while (action) |
65765700 JJ |
1289 | switch (*aug++) |
1290 | { | |
1291 | case 'L': | |
9e2a4898 JJ |
1292 | if (action & 2) |
1293 | { | |
fda3ecf2 | 1294 | BFD_ASSERT (*buf == ent->lsda_encoding); |
9e2a4898 JJ |
1295 | *buf |= DW_EH_PE_pcrel; |
1296 | action &= ~2; | |
1297 | } | |
65765700 JJ |
1298 | buf++; |
1299 | break; | |
1300 | case 'P': | |
1301 | per_encoding = *buf++; | |
3472e2e9 | 1302 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
65765700 | 1303 | BFD_ASSERT (per_width != 0); |
09ae86c2 | 1304 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
fda3ecf2 | 1305 | == ent->per_encoding_relative); |
65765700 JJ |
1306 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
1307 | buf = (contents | |
1308 | + ((buf - contents + per_width - 1) | |
1309 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
1310 | if (action & 4) |
1311 | { | |
fda3ecf2 AM |
1312 | bfd_vma val; |
1313 | ||
1314 | val = read_value (abfd, buf, per_width, | |
1315 | get_DW_EH_PE_signed (per_encoding)); | |
1316 | val += ent->offset - ent->new_offset; | |
353057a5 | 1317 | val -= extra_string + extra_data; |
fda3ecf2 | 1318 | write_value (abfd, buf, val, per_width); |
09ae86c2 JJ |
1319 | action &= ~4; |
1320 | } | |
65765700 JJ |
1321 | buf += per_width; |
1322 | break; | |
9e2a4898 JJ |
1323 | case 'R': |
1324 | if (action & 1) | |
1325 | { | |
fda3ecf2 | 1326 | BFD_ASSERT (*buf == ent->fde_encoding); |
9e2a4898 JJ |
1327 | *buf |= DW_EH_PE_pcrel; |
1328 | action &= ~1; | |
1329 | } | |
1330 | buf++; | |
1331 | break; | |
63752a75 JJ |
1332 | case 'S': |
1333 | break; | |
65765700 JJ |
1334 | default: |
1335 | BFD_FAIL (); | |
1336 | } | |
65765700 JJ |
1337 | } |
1338 | } | |
353057a5 | 1339 | else |
65765700 JJ |
1340 | { |
1341 | /* FDE */ | |
fda3ecf2 | 1342 | bfd_vma value, address; |
9e2a4898 | 1343 | unsigned int width; |
ac685e6a | 1344 | bfd_byte *start; |
65765700 | 1345 | |
b34976b6 | 1346 | /* Skip length. */ |
65765700 | 1347 | buf += 4; |
fda3ecf2 AM |
1348 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
1349 | bfd_put_32 (abfd, value, buf); | |
65765700 | 1350 | buf += 4; |
fda3ecf2 AM |
1351 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
1352 | value = read_value (abfd, buf, width, | |
1353 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1354 | address = value; | |
9e2a4898 | 1355 | if (value) |
65765700 | 1356 | { |
fda3ecf2 | 1357 | switch (ent->fde_encoding & 0xf0) |
9e2a4898 JJ |
1358 | { |
1359 | case DW_EH_PE_indirect: | |
1360 | case DW_EH_PE_textrel: | |
1361 | BFD_ASSERT (hdr_info == NULL); | |
1362 | break; | |
1363 | case DW_EH_PE_datarel: | |
1364 | { | |
1365 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1366 | ||
1367 | BFD_ASSERT (got != NULL); | |
1368 | address += got->vma; | |
1369 | } | |
1370 | break; | |
1371 | case DW_EH_PE_pcrel: | |
fda3ecf2 AM |
1372 | value += ent->offset - ent->new_offset; |
1373 | address += sec->output_section->vma + ent->offset + 8; | |
9e2a4898 JJ |
1374 | break; |
1375 | } | |
353057a5 | 1376 | if (ent->cie_inf->make_relative) |
fda3ecf2 | 1377 | value -= sec->output_section->vma + ent->new_offset + 8; |
9e2a4898 | 1378 | write_value (abfd, buf, value, width); |
65765700 JJ |
1379 | } |
1380 | ||
ac685e6a JJ |
1381 | start = buf; |
1382 | ||
65765700 JJ |
1383 | if (hdr_info) |
1384 | { | |
1385 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1386 | hdr_info->array[hdr_info->array_count++].fde | |
fda3ecf2 | 1387 | = sec->output_section->vma + ent->new_offset; |
65765700 | 1388 | } |
9e2a4898 | 1389 | |
fda3ecf2 AM |
1390 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
1391 | || ent->cie_inf->need_lsda_relative) | |
9e2a4898 | 1392 | { |
fda3ecf2 AM |
1393 | buf += ent->lsda_offset; |
1394 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); | |
84f97cb6 | 1395 | value = read_value (abfd, buf, width, |
fda3ecf2 | 1396 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
9e2a4898 JJ |
1397 | if (value) |
1398 | { | |
fda3ecf2 AM |
1399 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
1400 | value += ent->offset - ent->new_offset; | |
1401 | else if (ent->cie_inf->need_lsda_relative) | |
1402 | value -= (sec->output_section->vma + ent->new_offset + 8 | |
1403 | + ent->lsda_offset); | |
9e2a4898 JJ |
1404 | write_value (abfd, buf, value, width); |
1405 | } | |
1406 | } | |
353057a5 RS |
1407 | else if (ent->cie_inf->add_augmentation_size) |
1408 | { | |
1409 | /* Skip the PC and length and insert a zero byte for the | |
1410 | augmentation size. */ | |
1411 | buf += width * 2; | |
1412 | memmove (buf + 1, buf, end - buf); | |
1413 | *buf = 0; | |
1414 | } | |
ac685e6a JJ |
1415 | |
1416 | if (ent->set_loc) | |
1417 | { | |
1418 | /* Adjust DW_CFA_set_loc. */ | |
1419 | unsigned int cnt, width; | |
1420 | bfd_vma new_offset; | |
1421 | ||
1422 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); | |
1423 | new_offset = ent->new_offset + 8 | |
1424 | + extra_augmentation_string_bytes (ent) | |
1425 | + extra_augmentation_data_bytes (ent); | |
1426 | ||
1427 | for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) | |
1428 | { | |
1429 | bfd_vma value; | |
1430 | buf = start + ent->set_loc[cnt]; | |
1431 | ||
1432 | value = read_value (abfd, buf, width, | |
1433 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1434 | if (!value) | |
1435 | continue; | |
1436 | ||
1437 | if ((ent->fde_encoding & 0xf0) == DW_EH_PE_pcrel) | |
1438 | value += ent->offset + 8 - new_offset; | |
1439 | if (ent->cie_inf->make_relative) | |
1440 | value -= sec->output_section->vma + new_offset | |
1441 | + ent->set_loc[cnt]; | |
1442 | write_value (abfd, buf, value, width); | |
1443 | } | |
1444 | } | |
65765700 | 1445 | } |
65765700 JJ |
1446 | } |
1447 | ||
a34a056a L |
1448 | /* We don't align the section to its section alignment since the |
1449 | runtime library only expects all CIE/FDE records aligned at | |
1450 | the pointer size. _bfd_elf_discard_section_eh_frame should | |
1451 | have padded CIE/FDE records to multiple of pointer size with | |
1452 | size_of_output_cie_fde. */ | |
1453 | if ((sec->size % ptr_size) != 0) | |
1454 | abort (); | |
a5eb27e6 | 1455 | |
65765700 | 1456 | return bfd_set_section_contents (abfd, sec->output_section, |
3472e2e9 AM |
1457 | contents, (file_ptr) sec->output_offset, |
1458 | sec->size); | |
65765700 JJ |
1459 | } |
1460 | ||
1461 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1462 | VMA of FDE initial location. */ | |
1463 | ||
1464 | static int | |
c39a58e6 | 1465 | vma_compare (const void *a, const void *b) |
65765700 | 1466 | { |
c39a58e6 AM |
1467 | const struct eh_frame_array_ent *p = a; |
1468 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1469 | if (p->initial_loc > q->initial_loc) |
1470 | return 1; | |
1471 | if (p->initial_loc < q->initial_loc) | |
1472 | return -1; | |
1473 | return 0; | |
1474 | } | |
1475 | ||
1476 | /* Write out .eh_frame_hdr section. This must be called after | |
1477 | _bfd_elf_write_section_eh_frame has been called on all input | |
1478 | .eh_frame sections. | |
1479 | .eh_frame_hdr format: | |
1480 | ubyte version (currently 1) | |
1481 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1482 | .eh_frame section) | |
1483 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1484 | number (or DW_EH_PE_omit if there is no | |
1485 | binary search table computed)) | |
1486 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1487 | or DW_EH_PE_omit if not present. | |
1488 | DW_EH_PE_datarel is using address of | |
1489 | .eh_frame_hdr section start as base) | |
1490 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1491 | optionally followed by: | |
1492 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1493 | fde_count x [encoded] initial_loc, fde | |
1494 | (array of encoded pairs containing | |
1495 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1496 | sorted by increasing initial_loc). */ |
65765700 | 1497 | |
b34976b6 | 1498 | bfd_boolean |
c39a58e6 | 1499 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1500 | { |
126495ed | 1501 | struct elf_link_hash_table *htab; |
65765700 | 1502 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1503 | asection *sec; |
65765700 JJ |
1504 | bfd_byte *contents; |
1505 | asection *eh_frame_sec; | |
1506 | bfd_size_type size; | |
5ed6aba4 | 1507 | bfd_boolean retval; |
ec3391e7 | 1508 | bfd_vma encoded_eh_frame; |
65765700 | 1509 | |
126495ed AM |
1510 | htab = elf_hash_table (info); |
1511 | hdr_info = &htab->eh_info; | |
1512 | sec = hdr_info->hdr_sec; | |
1513 | if (sec == NULL) | |
b34976b6 | 1514 | return TRUE; |
57a72197 | 1515 | |
65765700 JJ |
1516 | size = EH_FRAME_HDR_SIZE; |
1517 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1518 | size += 4 + hdr_info->fde_count * 8; | |
1519 | contents = bfd_malloc (size); | |
1520 | if (contents == NULL) | |
b34976b6 | 1521 | return FALSE; |
65765700 JJ |
1522 | |
1523 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1524 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1525 | { |
1526 | free (contents); | |
1527 | return FALSE; | |
1528 | } | |
65765700 JJ |
1529 | |
1530 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1531 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1532 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1533 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1534 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1535 | ||
65765700 JJ |
1536 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1537 | { | |
5ed6aba4 NC |
1538 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1539 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1540 | } |
1541 | else | |
1542 | { | |
1543 | contents[2] = DW_EH_PE_omit; | |
1544 | contents[3] = DW_EH_PE_omit; | |
1545 | } | |
ec3391e7 AO |
1546 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1547 | ||
65765700 JJ |
1548 | if (contents[2] != DW_EH_PE_omit) |
1549 | { | |
1550 | unsigned int i; | |
1551 | ||
1552 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1553 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1554 | vma_compare); | |
1555 | for (i = 0; i < hdr_info->fde_count; i++) | |
1556 | { | |
1557 | bfd_put_32 (abfd, | |
1558 | hdr_info->array[i].initial_loc | |
1559 | - sec->output_section->vma, | |
1560 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1561 | bfd_put_32 (abfd, | |
1562 | hdr_info->array[i].fde - sec->output_section->vma, | |
1563 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1564 | } | |
1565 | } | |
1566 | ||
5ed6aba4 NC |
1567 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1568 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1569 | sec->size); |
5ed6aba4 NC |
1570 | free (contents); |
1571 | return retval; | |
65765700 | 1572 | } |
ec3391e7 | 1573 | |
8c946ed5 RS |
1574 | /* Return the width of FDE addresses. This is the default implementation. */ |
1575 | ||
1576 | unsigned int | |
1577 | _bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) | |
1578 | { | |
1579 | return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; | |
1580 | } | |
1581 | ||
ec3391e7 AO |
1582 | /* Decide whether we can use a PC-relative encoding within the given |
1583 | EH frame section. This is the default implementation. */ | |
1584 | ||
1585 | bfd_boolean | |
1586 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1587 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1588 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1589 | { | |
1590 | return TRUE; | |
1591 | } | |
1592 | ||
1593 | /* Select an encoding for the given address. Preference is given to | |
1594 | PC-relative addressing modes. */ | |
1595 | ||
1596 | bfd_byte | |
1597 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1598 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1599 | asection *osec, bfd_vma offset, | |
1600 | asection *loc_sec, bfd_vma loc_offset, | |
1601 | bfd_vma *encoded) | |
1602 | { | |
1603 | *encoded = osec->vma + offset - | |
1604 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1605 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1606 | } |