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 | |
cd123cb7 | 10 | the Free Software Foundation; either version 3 of the License, or |
5ed6aba4 | 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 | |
cd123cb7 NC |
20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
21 | MA 02110-1301, USA. */ | |
65765700 | 22 | |
65765700 | 23 | #include "sysdep.h" |
3db64b00 | 24 | #include "bfd.h" |
65765700 JJ |
25 | #include "libbfd.h" |
26 | #include "elf-bfd.h" | |
27 | #include "elf/dwarf2.h" | |
28 | ||
29 | #define EH_FRAME_HDR_SIZE 8 | |
30 | ||
bce613b9 JJ |
31 | struct cie |
32 | { | |
33 | unsigned int length; | |
34 | unsigned int hash; | |
35 | unsigned char version; | |
f137a54e | 36 | unsigned char local_personality; |
bce613b9 JJ |
37 | char augmentation[20]; |
38 | bfd_vma code_align; | |
39 | bfd_signed_vma data_align; | |
40 | bfd_vma ra_column; | |
41 | bfd_vma augmentation_size; | |
f137a54e AM |
42 | union { |
43 | struct elf_link_hash_entry *h; | |
44 | bfd_vma val; | |
45 | } personality; | |
bce613b9 JJ |
46 | asection *output_sec; |
47 | struct eh_cie_fde *cie_inf; | |
48 | unsigned char per_encoding; | |
49 | unsigned char lsda_encoding; | |
50 | unsigned char fde_encoding; | |
51 | unsigned char initial_insn_length; | |
52 | unsigned char make_relative; | |
53 | unsigned char make_lsda_relative; | |
54 | unsigned char initial_instructions[50]; | |
55 | }; | |
56 | ||
57 | ||
58 | ||
2c42be65 RS |
59 | /* If *ITER hasn't reached END yet, read the next byte into *RESULT and |
60 | move onto the next byte. Return true on success. */ | |
61 | ||
62 | static inline bfd_boolean | |
63 | read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result) | |
64 | { | |
65 | if (*iter >= end) | |
66 | return FALSE; | |
67 | *result = *((*iter)++); | |
68 | return TRUE; | |
69 | } | |
70 | ||
71 | /* Move *ITER over LENGTH bytes, or up to END, whichever is closer. | |
72 | Return true it was possible to move LENGTH bytes. */ | |
73 | ||
74 | static inline bfd_boolean | |
75 | skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length) | |
76 | { | |
77 | if ((bfd_size_type) (end - *iter) < length) | |
78 | { | |
79 | *iter = end; | |
80 | return FALSE; | |
81 | } | |
82 | *iter += length; | |
83 | return TRUE; | |
84 | } | |
85 | ||
86 | /* Move *ITER over an leb128, stopping at END. Return true if the end | |
87 | of the leb128 was found. */ | |
88 | ||
89 | static bfd_boolean | |
90 | skip_leb128 (bfd_byte **iter, bfd_byte *end) | |
91 | { | |
92 | unsigned char byte; | |
93 | do | |
94 | if (!read_byte (iter, end, &byte)) | |
95 | return FALSE; | |
96 | while (byte & 0x80); | |
97 | return TRUE; | |
98 | } | |
99 | ||
100 | /* Like skip_leb128, but treat the leb128 as an unsigned value and | |
101 | store it in *VALUE. */ | |
102 | ||
103 | static bfd_boolean | |
104 | read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value) | |
105 | { | |
106 | bfd_byte *start, *p; | |
107 | ||
108 | start = *iter; | |
109 | if (!skip_leb128 (iter, end)) | |
110 | return FALSE; | |
111 | ||
112 | p = *iter; | |
113 | *value = *--p; | |
114 | while (p > start) | |
115 | *value = (*value << 7) | (*--p & 0x7f); | |
116 | ||
117 | return TRUE; | |
118 | } | |
119 | ||
120 | /* Like read_uleb128, but for signed values. */ | |
121 | ||
122 | static bfd_boolean | |
123 | read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value) | |
124 | { | |
125 | bfd_byte *start, *p; | |
126 | ||
127 | start = *iter; | |
128 | if (!skip_leb128 (iter, end)) | |
129 | return FALSE; | |
130 | ||
131 | p = *iter; | |
132 | *value = ((*--p & 0x7f) ^ 0x40) - 0x40; | |
133 | while (p > start) | |
134 | *value = (*value << 7) | (*--p & 0x7f); | |
135 | ||
136 | return TRUE; | |
137 | } | |
65765700 JJ |
138 | |
139 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
140 | ||
141 | static | |
c39a58e6 | 142 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
65765700 JJ |
143 | { |
144 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
145 | was added to bfd. */ | |
146 | if ((encoding & 0x60) == 0x60) | |
147 | return 0; | |
148 | ||
149 | switch (encoding & 7) | |
150 | { | |
151 | case DW_EH_PE_udata2: return 2; | |
152 | case DW_EH_PE_udata4: return 4; | |
153 | case DW_EH_PE_udata8: return 8; | |
154 | case DW_EH_PE_absptr: return ptr_size; | |
155 | default: | |
156 | break; | |
157 | } | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
84f97cb6 AS |
162 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
163 | ||
9e2a4898 JJ |
164 | /* Read a width sized value from memory. */ |
165 | ||
166 | static bfd_vma | |
c39a58e6 | 167 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
9e2a4898 JJ |
168 | { |
169 | bfd_vma value; | |
170 | ||
171 | switch (width) | |
172 | { | |
84f97cb6 AS |
173 | case 2: |
174 | if (is_signed) | |
175 | value = bfd_get_signed_16 (abfd, buf); | |
176 | else | |
177 | value = bfd_get_16 (abfd, buf); | |
178 | break; | |
179 | case 4: | |
180 | if (is_signed) | |
181 | value = bfd_get_signed_32 (abfd, buf); | |
182 | else | |
183 | value = bfd_get_32 (abfd, buf); | |
184 | break; | |
185 | case 8: | |
186 | if (is_signed) | |
187 | value = bfd_get_signed_64 (abfd, buf); | |
188 | else | |
189 | value = bfd_get_64 (abfd, buf); | |
190 | break; | |
191 | default: | |
192 | BFD_FAIL (); | |
193 | return 0; | |
9e2a4898 JJ |
194 | } |
195 | ||
196 | return value; | |
197 | } | |
b34976b6 | 198 | |
9e2a4898 JJ |
199 | /* Store a width sized value to memory. */ |
200 | ||
201 | static void | |
c39a58e6 | 202 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
9e2a4898 JJ |
203 | { |
204 | switch (width) | |
205 | { | |
206 | case 2: bfd_put_16 (abfd, value, buf); break; | |
207 | case 4: bfd_put_32 (abfd, value, buf); break; | |
208 | case 8: bfd_put_64 (abfd, value, buf); break; | |
209 | default: BFD_FAIL (); | |
210 | } | |
211 | } | |
212 | ||
bce613b9 | 213 | /* Return one if C1 and C2 CIEs can be merged. */ |
65765700 | 214 | |
bce613b9 JJ |
215 | static int |
216 | cie_eq (const void *e1, const void *e2) | |
65765700 | 217 | { |
bce613b9 JJ |
218 | const struct cie *c1 = e1; |
219 | const struct cie *c2 = e2; | |
220 | ||
221 | if (c1->hash == c2->hash | |
222 | && c1->length == c2->length | |
65765700 | 223 | && c1->version == c2->version |
f137a54e | 224 | && c1->local_personality == c2->local_personality |
65765700 JJ |
225 | && strcmp (c1->augmentation, c2->augmentation) == 0 |
226 | && strcmp (c1->augmentation, "eh") != 0 | |
227 | && c1->code_align == c2->code_align | |
228 | && c1->data_align == c2->data_align | |
229 | && c1->ra_column == c2->ra_column | |
230 | && c1->augmentation_size == c2->augmentation_size | |
f137a54e AM |
231 | && memcmp (&c1->personality, &c2->personality, |
232 | sizeof (c1->personality)) == 0 | |
bce613b9 | 233 | && c1->output_sec == c2->output_sec |
65765700 JJ |
234 | && c1->per_encoding == c2->per_encoding |
235 | && c1->lsda_encoding == c2->lsda_encoding | |
236 | && c1->fde_encoding == c2->fde_encoding | |
c39a58e6 | 237 | && c1->initial_insn_length == c2->initial_insn_length |
65765700 JJ |
238 | && memcmp (c1->initial_instructions, |
239 | c2->initial_instructions, | |
240 | c1->initial_insn_length) == 0) | |
bce613b9 | 241 | return 1; |
65765700 | 242 | |
bce613b9 JJ |
243 | return 0; |
244 | } | |
245 | ||
246 | static hashval_t | |
247 | cie_hash (const void *e) | |
248 | { | |
249 | const struct cie *c = e; | |
250 | return c->hash; | |
251 | } | |
252 | ||
253 | static hashval_t | |
254 | cie_compute_hash (struct cie *c) | |
255 | { | |
256 | hashval_t h = 0; | |
257 | h = iterative_hash_object (c->length, h); | |
258 | h = iterative_hash_object (c->version, h); | |
259 | h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h); | |
260 | h = iterative_hash_object (c->code_align, h); | |
261 | h = iterative_hash_object (c->data_align, h); | |
262 | h = iterative_hash_object (c->ra_column, h); | |
263 | h = iterative_hash_object (c->augmentation_size, h); | |
264 | h = iterative_hash_object (c->personality, h); | |
265 | h = iterative_hash_object (c->output_sec, h); | |
266 | h = iterative_hash_object (c->per_encoding, h); | |
267 | h = iterative_hash_object (c->lsda_encoding, h); | |
268 | h = iterative_hash_object (c->fde_encoding, h); | |
269 | h = iterative_hash_object (c->initial_insn_length, h); | |
270 | h = iterative_hash (c->initial_instructions, c->initial_insn_length, h); | |
271 | c->hash = h; | |
272 | return h; | |
65765700 JJ |
273 | } |
274 | ||
353057a5 RS |
275 | /* Return the number of extra bytes that we'll be inserting into |
276 | ENTRY's augmentation string. */ | |
277 | ||
278 | static INLINE unsigned int | |
279 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) | |
280 | { | |
281 | unsigned int size = 0; | |
282 | if (entry->cie) | |
283 | { | |
284 | if (entry->add_augmentation_size) | |
285 | size++; | |
286 | if (entry->add_fde_encoding) | |
287 | size++; | |
288 | } | |
289 | return size; | |
290 | } | |
291 | ||
292 | /* Likewise ENTRY's augmentation data. */ | |
293 | ||
294 | static INLINE unsigned int | |
295 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) | |
296 | { | |
297 | unsigned int size = 0; | |
298 | if (entry->cie) | |
299 | { | |
300 | if (entry->add_augmentation_size) | |
301 | size++; | |
302 | if (entry->add_fde_encoding) | |
303 | size++; | |
304 | } | |
305 | else | |
306 | { | |
307 | if (entry->cie_inf->add_augmentation_size) | |
308 | size++; | |
309 | } | |
310 | return size; | |
311 | } | |
312 | ||
313 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the | |
314 | required alignment of ENTRY in bytes. */ | |
315 | ||
316 | static unsigned int | |
317 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) | |
318 | { | |
319 | if (entry->removed) | |
320 | return 0; | |
321 | if (entry->size == 4) | |
322 | return 4; | |
323 | return (entry->size | |
324 | + extra_augmentation_string_bytes (entry) | |
325 | + extra_augmentation_data_bytes (entry) | |
326 | + alignment - 1) & -alignment; | |
327 | } | |
328 | ||
dcf507a6 RS |
329 | /* Assume that the bytes between *ITER and END are CFA instructions. |
330 | Try to move *ITER past the first instruction and return true on | |
331 | success. ENCODED_PTR_WIDTH gives the width of pointer entries. */ | |
332 | ||
333 | static bfd_boolean | |
334 | skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width) | |
335 | { | |
336 | bfd_byte op; | |
337 | bfd_vma length; | |
338 | ||
339 | if (!read_byte (iter, end, &op)) | |
340 | return FALSE; | |
341 | ||
ac685e6a | 342 | switch (op & 0xc0 ? op & 0xc0 : op) |
dcf507a6 RS |
343 | { |
344 | case DW_CFA_nop: | |
345 | case DW_CFA_advance_loc: | |
346 | case DW_CFA_restore: | |
ac685e6a JJ |
347 | case DW_CFA_remember_state: |
348 | case DW_CFA_restore_state: | |
349 | case DW_CFA_GNU_window_save: | |
dcf507a6 RS |
350 | /* No arguments. */ |
351 | return TRUE; | |
352 | ||
353 | case DW_CFA_offset: | |
354 | case DW_CFA_restore_extended: | |
355 | case DW_CFA_undefined: | |
356 | case DW_CFA_same_value: | |
357 | case DW_CFA_def_cfa_register: | |
358 | case DW_CFA_def_cfa_offset: | |
359 | case DW_CFA_def_cfa_offset_sf: | |
360 | case DW_CFA_GNU_args_size: | |
361 | /* One leb128 argument. */ | |
362 | return skip_leb128 (iter, end); | |
363 | ||
ac685e6a JJ |
364 | case DW_CFA_val_offset: |
365 | case DW_CFA_val_offset_sf: | |
dcf507a6 RS |
366 | case DW_CFA_offset_extended: |
367 | case DW_CFA_register: | |
368 | case DW_CFA_def_cfa: | |
369 | case DW_CFA_offset_extended_sf: | |
370 | case DW_CFA_GNU_negative_offset_extended: | |
371 | case DW_CFA_def_cfa_sf: | |
372 | /* Two leb128 arguments. */ | |
373 | return (skip_leb128 (iter, end) | |
374 | && skip_leb128 (iter, end)); | |
375 | ||
376 | case DW_CFA_def_cfa_expression: | |
377 | /* A variable-length argument. */ | |
378 | return (read_uleb128 (iter, end, &length) | |
379 | && skip_bytes (iter, end, length)); | |
380 | ||
381 | case DW_CFA_expression: | |
ac685e6a | 382 | case DW_CFA_val_expression: |
dcf507a6 RS |
383 | /* A leb128 followed by a variable-length argument. */ |
384 | return (skip_leb128 (iter, end) | |
385 | && read_uleb128 (iter, end, &length) | |
386 | && skip_bytes (iter, end, length)); | |
387 | ||
388 | case DW_CFA_set_loc: | |
389 | return skip_bytes (iter, end, encoded_ptr_width); | |
390 | ||
391 | case DW_CFA_advance_loc1: | |
392 | return skip_bytes (iter, end, 1); | |
393 | ||
394 | case DW_CFA_advance_loc2: | |
395 | return skip_bytes (iter, end, 2); | |
396 | ||
397 | case DW_CFA_advance_loc4: | |
398 | return skip_bytes (iter, end, 4); | |
399 | ||
400 | case DW_CFA_MIPS_advance_loc8: | |
401 | return skip_bytes (iter, end, 8); | |
402 | ||
403 | default: | |
404 | return FALSE; | |
405 | } | |
406 | } | |
407 | ||
408 | /* Try to interpret the bytes between BUF and END as CFA instructions. | |
409 | If every byte makes sense, return a pointer to the first DW_CFA_nop | |
410 | padding byte, or END if there is no padding. Return null otherwise. | |
411 | ENCODED_PTR_WIDTH is as for skip_cfa_op. */ | |
412 | ||
413 | static bfd_byte * | |
ac685e6a JJ |
414 | skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width, |
415 | unsigned int *set_loc_count) | |
dcf507a6 RS |
416 | { |
417 | bfd_byte *last; | |
418 | ||
419 | last = buf; | |
420 | while (buf < end) | |
421 | if (*buf == DW_CFA_nop) | |
422 | buf++; | |
423 | else | |
424 | { | |
ac685e6a JJ |
425 | if (*buf == DW_CFA_set_loc) |
426 | ++*set_loc_count; | |
dcf507a6 RS |
427 | if (!skip_cfa_op (&buf, end, encoded_ptr_width)) |
428 | return 0; | |
429 | last = buf; | |
430 | } | |
431 | return last; | |
432 | } | |
433 | ||
65765700 JJ |
434 | /* This function is called for each input file before the .eh_frame |
435 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
b34976b6 | 436 | functions. The function returns TRUE iff any entries have been |
65765700 JJ |
437 | deleted. */ |
438 | ||
b34976b6 | 439 | bfd_boolean |
c39a58e6 AM |
440 | _bfd_elf_discard_section_eh_frame |
441 | (bfd *abfd, struct bfd_link_info *info, asection *sec, | |
442 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), | |
443 | struct elf_reloc_cookie *cookie) | |
65765700 | 444 | { |
acfe5567 RS |
445 | #define REQUIRE(COND) \ |
446 | do \ | |
447 | if (!(COND)) \ | |
448 | goto free_no_table; \ | |
449 | while (0) | |
450 | ||
65765700 | 451 | bfd_byte *ehbuf = NULL, *buf; |
bce613b9 JJ |
452 | bfd_byte *last_fde; |
453 | struct eh_cie_fde *ent, *this_inf; | |
454 | unsigned int hdr_length, hdr_id; | |
455 | struct extended_cie | |
456 | { | |
457 | struct cie cie; | |
458 | unsigned int offset; | |
459 | unsigned int usage_count; | |
460 | unsigned int entry; | |
461 | } *ecies = NULL, *ecie; | |
462 | unsigned int ecie_count = 0, ecie_alloced = 0; | |
463 | struct cie *cie; | |
126495ed | 464 | struct elf_link_hash_table *htab; |
65765700 | 465 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 466 | struct eh_frame_sec_info *sec_info = NULL; |
bce613b9 | 467 | unsigned int offset; |
65765700 | 468 | unsigned int ptr_size; |
bce613b9 | 469 | unsigned int entry_alloced; |
65765700 | 470 | |
eea6121a | 471 | if (sec->size == 0) |
65765700 JJ |
472 | { |
473 | /* This file does not contain .eh_frame information. */ | |
b34976b6 | 474 | return FALSE; |
65765700 JJ |
475 | } |
476 | ||
e460dd0d | 477 | if (bfd_is_abs_section (sec->output_section)) |
65765700 JJ |
478 | { |
479 | /* At least one of the sections is being discarded from the | |
3472e2e9 | 480 | link, so we should just ignore them. */ |
b34976b6 | 481 | return FALSE; |
65765700 JJ |
482 | } |
483 | ||
126495ed AM |
484 | htab = elf_hash_table (info); |
485 | hdr_info = &htab->eh_info; | |
68f69152 | 486 | |
bce613b9 JJ |
487 | if (hdr_info->cies == NULL && !info->relocatable) |
488 | hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free); | |
489 | ||
65765700 JJ |
490 | /* Read the frame unwind information from abfd. */ |
491 | ||
acfe5567 | 492 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
68f69152 | 493 | |
eea6121a | 494 | if (sec->size >= 4 |
65765700 JJ |
495 | && bfd_get_32 (abfd, ehbuf) == 0 |
496 | && cookie->rel == cookie->relend) | |
497 | { | |
498 | /* Empty .eh_frame section. */ | |
499 | free (ehbuf); | |
b34976b6 | 500 | return FALSE; |
65765700 JJ |
501 | } |
502 | ||
65765700 JJ |
503 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
504 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
acfe5567 | 505 | REQUIRE (sec->size == (unsigned int) sec->size); |
65765700 | 506 | |
8c946ed5 RS |
507 | ptr_size = (get_elf_backend_data (abfd) |
508 | ->elf_backend_eh_frame_address_size (abfd, sec)); | |
509 | REQUIRE (ptr_size != 0); | |
510 | ||
65765700 | 511 | buf = ehbuf; |
65765700 JJ |
512 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
513 | + 99 * sizeof (struct eh_cie_fde)); | |
acfe5567 | 514 | REQUIRE (sec_info); |
eea6121a | 515 | |
bce613b9 | 516 | entry_alloced = 100; |
65765700 JJ |
517 | |
518 | #define ENSURE_NO_RELOCS(buf) \ | |
acfe5567 RS |
519 | REQUIRE (!(cookie->rel < cookie->relend \ |
520 | && (cookie->rel->r_offset \ | |
521 | < (bfd_size_type) ((buf) - ehbuf)) \ | |
522 | && cookie->rel->r_info != 0)) | |
65765700 JJ |
523 | |
524 | #define SKIP_RELOCS(buf) \ | |
525 | while (cookie->rel < cookie->relend \ | |
3472e2e9 | 526 | && (cookie->rel->r_offset \ |
65765700 JJ |
527 | < (bfd_size_type) ((buf) - ehbuf))) \ |
528 | cookie->rel++ | |
529 | ||
530 | #define GET_RELOC(buf) \ | |
531 | ((cookie->rel < cookie->relend \ | |
532 | && (cookie->rel->r_offset \ | |
3472e2e9 | 533 | == (bfd_size_type) ((buf) - ehbuf))) \ |
65765700 JJ |
534 | ? cookie->rel : NULL) |
535 | ||
536 | for (;;) | |
537 | { | |
f075ee0c | 538 | char *aug; |
ac685e6a | 539 | bfd_byte *start, *end, *insns, *insns_end; |
2c42be65 | 540 | bfd_size_type length; |
ac685e6a | 541 | unsigned int set_loc_count; |
65765700 | 542 | |
bce613b9 | 543 | if (sec_info->count == entry_alloced) |
65765700 JJ |
544 | { |
545 | sec_info = bfd_realloc (sec_info, | |
546 | sizeof (struct eh_frame_sec_info) | |
bce613b9 | 547 | + ((entry_alloced + 99) |
fda3ecf2 | 548 | * sizeof (struct eh_cie_fde))); |
acfe5567 | 549 | REQUIRE (sec_info); |
65765700 | 550 | |
bce613b9 | 551 | memset (&sec_info->entry[entry_alloced], 0, |
65765700 | 552 | 100 * sizeof (struct eh_cie_fde)); |
bce613b9 | 553 | entry_alloced += 100; |
65765700 JJ |
554 | } |
555 | ||
fda3ecf2 | 556 | this_inf = sec_info->entry + sec_info->count; |
65765700 | 557 | last_fde = buf; |
bce613b9 | 558 | |
eea6121a | 559 | if ((bfd_size_type) (buf - ehbuf) == sec->size) |
bce613b9 | 560 | break; |
acfe5567 | 561 | |
bce613b9 JJ |
562 | /* Read the length of the entry. */ |
563 | REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4)); | |
564 | hdr_length = bfd_get_32 (abfd, buf - 4); | |
acfe5567 | 565 | |
bce613b9 JJ |
566 | /* 64-bit .eh_frame is not supported. */ |
567 | REQUIRE (hdr_length != 0xffffffff); | |
65765700 | 568 | |
bce613b9 JJ |
569 | /* The CIE/FDE must be fully contained in this input section. */ |
570 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size); | |
571 | end = buf + hdr_length; | |
65765700 | 572 | |
bce613b9 JJ |
573 | this_inf->offset = last_fde - ehbuf; |
574 | this_inf->size = 4 + hdr_length; | |
575 | ||
576 | if (hdr_length == 0) | |
577 | { | |
578 | /* A zero-length CIE should only be found at the end of | |
579 | the section. */ | |
580 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); | |
581 | ENSURE_NO_RELOCS (buf); | |
582 | sec_info->count++; | |
583 | break; | |
65765700 JJ |
584 | } |
585 | ||
bce613b9 JJ |
586 | REQUIRE (skip_bytes (&buf, end, 4)); |
587 | hdr_id = bfd_get_32 (abfd, buf - 4); | |
588 | ||
589 | if (hdr_id == 0) | |
65765700 JJ |
590 | { |
591 | unsigned int initial_insn_length; | |
592 | ||
593 | /* CIE */ | |
bce613b9 JJ |
594 | this_inf->cie = 1; |
595 | ||
596 | if (ecie_count == ecie_alloced) | |
65765700 | 597 | { |
bce613b9 JJ |
598 | ecies = bfd_realloc (ecies, |
599 | (ecie_alloced + 20) * sizeof (*ecies)); | |
600 | REQUIRE (ecies); | |
601 | memset (&ecies[ecie_alloced], 0, 20 * sizeof (*ecies)); | |
602 | ecie_alloced += 20; | |
65765700 JJ |
603 | } |
604 | ||
bce613b9 JJ |
605 | cie = &ecies[ecie_count].cie; |
606 | ecies[ecie_count].offset = this_inf->offset; | |
607 | ecies[ecie_count++].entry = sec_info->count; | |
608 | cie->length = hdr_length; | |
ac685e6a | 609 | start = buf; |
bce613b9 | 610 | REQUIRE (read_byte (&buf, end, &cie->version)); |
65765700 JJ |
611 | |
612 | /* Cannot handle unknown versions. */ | |
bce613b9 JJ |
613 | REQUIRE (cie->version == 1 || cie->version == 3); |
614 | REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation)); | |
65765700 | 615 | |
bce613b9 | 616 | strcpy (cie->augmentation, (char *) buf); |
f075ee0c | 617 | buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1; |
65765700 JJ |
618 | ENSURE_NO_RELOCS (buf); |
619 | if (buf[0] == 'e' && buf[1] == 'h') | |
620 | { | |
621 | /* GCC < 3.0 .eh_frame CIE */ | |
622 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
623 | is private to each CIE, so we don't need it for anything. | |
624 | Just skip it. */ | |
2c42be65 | 625 | REQUIRE (skip_bytes (&buf, end, ptr_size)); |
65765700 JJ |
626 | SKIP_RELOCS (buf); |
627 | } | |
bce613b9 JJ |
628 | REQUIRE (read_uleb128 (&buf, end, &cie->code_align)); |
629 | REQUIRE (read_sleb128 (&buf, end, &cie->data_align)); | |
630 | if (cie->version == 1) | |
2c42be65 RS |
631 | { |
632 | REQUIRE (buf < end); | |
bce613b9 | 633 | cie->ra_column = *buf++; |
2c42be65 | 634 | } |
0da76f83 | 635 | else |
bce613b9 | 636 | REQUIRE (read_uleb128 (&buf, end, &cie->ra_column)); |
65765700 | 637 | ENSURE_NO_RELOCS (buf); |
bce613b9 JJ |
638 | cie->lsda_encoding = DW_EH_PE_omit; |
639 | cie->fde_encoding = DW_EH_PE_omit; | |
640 | cie->per_encoding = DW_EH_PE_omit; | |
641 | aug = cie->augmentation; | |
65765700 JJ |
642 | if (aug[0] != 'e' || aug[1] != 'h') |
643 | { | |
644 | if (*aug == 'z') | |
645 | { | |
646 | aug++; | |
bce613b9 | 647 | REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size)); |
65765700 JJ |
648 | ENSURE_NO_RELOCS (buf); |
649 | } | |
650 | ||
651 | while (*aug != '\0') | |
652 | switch (*aug++) | |
653 | { | |
654 | case 'L': | |
bce613b9 | 655 | REQUIRE (read_byte (&buf, end, &cie->lsda_encoding)); |
65765700 | 656 | ENSURE_NO_RELOCS (buf); |
bce613b9 | 657 | REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size)); |
65765700 JJ |
658 | break; |
659 | case 'R': | |
bce613b9 | 660 | REQUIRE (read_byte (&buf, end, &cie->fde_encoding)); |
65765700 | 661 | ENSURE_NO_RELOCS (buf); |
bce613b9 | 662 | REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size)); |
65765700 | 663 | break; |
63752a75 JJ |
664 | case 'S': |
665 | break; | |
65765700 JJ |
666 | case 'P': |
667 | { | |
668 | int per_width; | |
669 | ||
bce613b9 JJ |
670 | REQUIRE (read_byte (&buf, end, &cie->per_encoding)); |
671 | per_width = get_DW_EH_PE_width (cie->per_encoding, | |
65765700 | 672 | ptr_size); |
acfe5567 | 673 | REQUIRE (per_width); |
bce613b9 | 674 | if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned) |
2c42be65 RS |
675 | { |
676 | length = -(buf - ehbuf) & (per_width - 1); | |
677 | REQUIRE (skip_bytes (&buf, end, length)); | |
678 | } | |
65765700 | 679 | ENSURE_NO_RELOCS (buf); |
f137a54e | 680 | /* Ensure we have a reloc here. */ |
99eb2ac8 | 681 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
682 | { |
683 | unsigned long r_symndx; | |
684 | ||
685 | #ifdef BFD64 | |
686 | if (ptr_size == 8) | |
687 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
688 | else | |
689 | #endif | |
690 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
f137a54e AM |
691 | if (r_symndx >= cookie->locsymcount |
692 | || ELF_ST_BIND (cookie->locsyms[r_symndx] | |
693 | .st_info) != STB_LOCAL) | |
65765700 JJ |
694 | { |
695 | struct elf_link_hash_entry *h; | |
696 | ||
697 | r_symndx -= cookie->extsymoff; | |
698 | h = cookie->sym_hashes[r_symndx]; | |
699 | ||
700 | while (h->root.type == bfd_link_hash_indirect | |
701 | || h->root.type == bfd_link_hash_warning) | |
702 | h = (struct elf_link_hash_entry *) | |
703 | h->root.u.i.link; | |
704 | ||
f137a54e | 705 | cie->personality.h = h; |
65765700 | 706 | } |
ef8c95ad AM |
707 | else |
708 | { | |
ef8c95ad | 709 | Elf_Internal_Sym *sym; |
f137a54e AM |
710 | asection *sym_sec; |
711 | bfd_vma val; | |
712 | ||
713 | sym = &cookie->locsyms[r_symndx]; | |
714 | sym_sec = (bfd_section_from_elf_index | |
715 | (abfd, sym->st_shndx)); | |
3e5484db | 716 | if (sym_sec != NULL) |
ef8c95ad | 717 | { |
3e5484db AM |
718 | if (sym_sec->kept_section != NULL) |
719 | sym_sec = sym_sec->kept_section; | |
720 | if (sym_sec->output_section != NULL) | |
721 | { | |
722 | val = (sym->st_value | |
723 | + sym_sec->output_offset | |
724 | + sym_sec->output_section->vma); | |
725 | cie->personality.val = val; | |
726 | cie->local_personality = 1; | |
727 | } | |
ef8c95ad AM |
728 | } |
729 | } | |
ef8c95ad | 730 | |
f4a6705c RS |
731 | /* Cope with MIPS-style composite relocations. */ |
732 | do | |
733 | cookie->rel++; | |
734 | while (GET_RELOC (buf) != NULL); | |
65765700 | 735 | } |
2c42be65 | 736 | REQUIRE (skip_bytes (&buf, end, per_width)); |
f137a54e | 737 | REQUIRE (cie->local_personality || cie->personality.h); |
65765700 JJ |
738 | } |
739 | break; | |
740 | default: | |
741 | /* Unrecognized augmentation. Better bail out. */ | |
742 | goto free_no_table; | |
743 | } | |
744 | } | |
745 | ||
746 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a | 747 | as possible. */ |
3472e2e9 | 748 | if (info->shared |
ec3391e7 AO |
749 | && (get_elf_backend_data (abfd) |
750 | ->elf_backend_can_make_relative_eh_frame | |
353057a5 RS |
751 | (abfd, info, sec))) |
752 | { | |
bce613b9 JJ |
753 | if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr) |
754 | cie->make_relative = 1; | |
353057a5 RS |
755 | /* If the CIE doesn't already have an 'R' entry, it's fairly |
756 | easy to add one, provided that there's no aligned data | |
757 | after the augmentation string. */ | |
bce613b9 JJ |
758 | else if (cie->fde_encoding == DW_EH_PE_omit |
759 | && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned) | |
353057a5 | 760 | { |
bce613b9 | 761 | if (*cie->augmentation == 0) |
353057a5 RS |
762 | this_inf->add_augmentation_size = 1; |
763 | this_inf->add_fde_encoding = 1; | |
bce613b9 | 764 | cie->make_relative = 1; |
353057a5 RS |
765 | } |
766 | } | |
65765700 | 767 | |
0bb2d96a | 768 | if (info->shared |
ec3391e7 AO |
769 | && (get_elf_backend_data (abfd) |
770 | ->elf_backend_can_make_lsda_relative_eh_frame | |
771 | (abfd, info, sec)) | |
bce613b9 JJ |
772 | && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
773 | cie->make_lsda_relative = 1; | |
9e2a4898 | 774 | |
65765700 JJ |
775 | /* If FDE encoding was not specified, it defaults to |
776 | DW_EH_absptr. */ | |
bce613b9 JJ |
777 | if (cie->fde_encoding == DW_EH_PE_omit) |
778 | cie->fde_encoding = DW_EH_PE_absptr; | |
65765700 | 779 | |
dcf507a6 | 780 | initial_insn_length = end - buf; |
bce613b9 | 781 | if (initial_insn_length <= sizeof (cie->initial_instructions)) |
65765700 | 782 | { |
bce613b9 JJ |
783 | cie->initial_insn_length = initial_insn_length; |
784 | memcpy (cie->initial_instructions, buf, initial_insn_length); | |
65765700 | 785 | } |
dcf507a6 | 786 | insns = buf; |
65765700 JJ |
787 | buf += initial_insn_length; |
788 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
789 | } |
790 | else | |
791 | { | |
bce613b9 JJ |
792 | /* Find the corresponding CIE. */ |
793 | unsigned int cie_offset = this_inf->offset + 4 - hdr_id; | |
794 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
795 | if (cie_offset == ecie->offset) | |
796 | break; | |
797 | ||
798 | /* Ensure this FDE references one of the CIEs in this input | |
799 | section. */ | |
800 | REQUIRE (ecie != ecies + ecie_count); | |
801 | cie = &ecie->cie; | |
65765700 JJ |
802 | |
803 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 804 | REQUIRE (GET_RELOC (buf)); |
fda3ecf2 | 805 | |
65765700 | 806 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
353057a5 RS |
807 | /* This is a FDE against a discarded section. It should |
808 | be deleted. */ | |
809 | this_inf->removed = 1; | |
65765700 JJ |
810 | else |
811 | { | |
0bb2d96a | 812 | if (info->shared |
bce613b9 JJ |
813 | && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr |
814 | && cie->make_relative == 0) | |
815 | || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 816 | { |
73722af0 | 817 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
818 | which we cannot turn into PC relative, |
819 | don't create the binary search table, | |
820 | since it is affected by runtime relocations. */ | |
b34976b6 | 821 | hdr_info->table = FALSE; |
64be1553 AM |
822 | (*info->callbacks->einfo) |
823 | (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr" | |
824 | " table being created.\n"), abfd, sec); | |
0bb2d96a | 825 | } |
bce613b9 | 826 | ecie->usage_count++; |
65765700 | 827 | hdr_info->fde_count++; |
bce613b9 | 828 | this_inf->cie_inf = (void *) (ecie - ecies); |
65765700 | 829 | } |
bce613b9 | 830 | |
2c42be65 RS |
831 | /* Skip the initial location and address range. */ |
832 | start = buf; | |
bce613b9 | 833 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
2c42be65 RS |
834 | REQUIRE (skip_bytes (&buf, end, 2 * length)); |
835 | ||
836 | /* Skip the augmentation size, if present. */ | |
bce613b9 | 837 | if (cie->augmentation[0] == 'z') |
dcf507a6 RS |
838 | REQUIRE (read_uleb128 (&buf, end, &length)); |
839 | else | |
840 | length = 0; | |
2c42be65 RS |
841 | |
842 | /* Of the supported augmentation characters above, only 'L' | |
843 | adds augmentation data to the FDE. This code would need to | |
844 | be adjusted if any future augmentations do the same thing. */ | |
bce613b9 | 845 | if (cie->lsda_encoding != DW_EH_PE_omit) |
dcf507a6 RS |
846 | { |
847 | this_inf->lsda_offset = buf - start; | |
848 | /* If there's no 'z' augmentation, we don't know where the | |
849 | CFA insns begin. Assume no padding. */ | |
bce613b9 | 850 | if (cie->augmentation[0] != 'z') |
dcf507a6 RS |
851 | length = end - buf; |
852 | } | |
853 | ||
854 | /* Skip over the augmentation data. */ | |
855 | REQUIRE (skip_bytes (&buf, end, length)); | |
856 | insns = buf; | |
9e2a4898 | 857 | |
bce613b9 | 858 | buf = last_fde + 4 + hdr_length; |
65765700 JJ |
859 | SKIP_RELOCS (buf); |
860 | } | |
861 | ||
dcf507a6 RS |
862 | /* Try to interpret the CFA instructions and find the first |
863 | padding nop. Shrink this_inf's size so that it doesn't | |
ac685e6a | 864 | include the padding. */ |
bce613b9 | 865 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
ac685e6a JJ |
866 | set_loc_count = 0; |
867 | insns_end = skip_non_nops (insns, end, length, &set_loc_count); | |
868 | /* If we don't understand the CFA instructions, we can't know | |
869 | what needs to be adjusted there. */ | |
870 | if (insns_end == NULL | |
871 | /* For the time being we don't support DW_CFA_set_loc in | |
872 | CIE instructions. */ | |
873 | || (set_loc_count && this_inf->cie)) | |
874 | goto free_no_table; | |
875 | this_inf->size -= end - insns_end; | |
bce613b9 JJ |
876 | if (insns_end != end && this_inf->cie) |
877 | { | |
878 | cie->initial_insn_length -= end - insns_end; | |
879 | cie->length -= end - insns_end; | |
880 | } | |
ac685e6a | 881 | if (set_loc_count |
bce613b9 JJ |
882 | && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel |
883 | || cie->make_relative)) | |
ac685e6a JJ |
884 | { |
885 | unsigned int cnt; | |
886 | bfd_byte *p; | |
887 | ||
888 | this_inf->set_loc = bfd_malloc ((set_loc_count + 1) | |
889 | * sizeof (unsigned int)); | |
890 | REQUIRE (this_inf->set_loc); | |
891 | this_inf->set_loc[0] = set_loc_count; | |
892 | p = insns; | |
893 | cnt = 0; | |
894 | while (p < end) | |
895 | { | |
896 | if (*p == DW_CFA_set_loc) | |
897 | this_inf->set_loc[++cnt] = p + 1 - start; | |
898 | REQUIRE (skip_cfa_op (&p, end, length)); | |
899 | } | |
900 | } | |
dcf507a6 | 901 | |
bce613b9 JJ |
902 | this_inf->fde_encoding = cie->fde_encoding; |
903 | this_inf->lsda_encoding = cie->lsda_encoding; | |
65765700 JJ |
904 | sec_info->count++; |
905 | } | |
906 | ||
907 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 908 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 | 909 | |
bce613b9 JJ |
910 | /* Look at all CIEs in this section and determine which can be |
911 | removed as unused, which can be merged with previous duplicate | |
912 | CIEs and which need to be kept. */ | |
913 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
914 | { | |
915 | if (ecie->usage_count == 0) | |
916 | { | |
917 | sec_info->entry[ecie->entry].removed = 1; | |
918 | continue; | |
919 | } | |
920 | ecie->cie.output_sec = sec->output_section; | |
921 | ecie->cie.cie_inf = sec_info->entry + ecie->entry; | |
922 | cie_compute_hash (&ecie->cie); | |
923 | if (hdr_info->cies != NULL) | |
924 | { | |
925 | void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie, | |
926 | ecie->cie.hash, INSERT); | |
927 | if (loc != NULL) | |
928 | { | |
929 | if (*loc != HTAB_EMPTY_ENTRY) | |
930 | { | |
931 | sec_info->entry[ecie->entry].removed = 1; | |
932 | ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf; | |
933 | continue; | |
934 | } | |
935 | ||
936 | *loc = malloc (sizeof (struct cie)); | |
937 | if (*loc == NULL) | |
938 | *loc = HTAB_DELETED_ENTRY; | |
939 | else | |
940 | memcpy (*loc, &ecie->cie, sizeof (struct cie)); | |
941 | } | |
942 | } | |
943 | ecie->cie.cie_inf->make_relative = ecie->cie.make_relative; | |
944 | ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative; | |
945 | ecie->cie.cie_inf->per_encoding_relative | |
946 | = (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
947 | } | |
948 | ||
65765700 JJ |
949 | /* Ok, now we can assign new offsets. */ |
950 | offset = 0; | |
fda3ecf2 AM |
951 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
952 | if (!ent->removed) | |
953 | { | |
bce613b9 JJ |
954 | if (!ent->cie) |
955 | { | |
d2df793a | 956 | ecie = ecies + (bfd_hostptr_t) ent->cie_inf; |
bce613b9 JJ |
957 | ent->cie_inf = ecie->cie.cie_inf; |
958 | } | |
353057a5 RS |
959 | ent->new_offset = offset; |
960 | offset += size_of_output_cie_fde (ent, ptr_size); | |
fda3ecf2 | 961 | } |
65765700 | 962 | |
353057a5 | 963 | /* Resize the sec as needed. */ |
eea6121a | 964 | sec->rawsize = sec->size; |
353057a5 | 965 | sec->size = offset; |
65765700 | 966 | |
68f69152 | 967 | free (ehbuf); |
bce613b9 JJ |
968 | if (ecies) |
969 | free (ecies); | |
353057a5 | 970 | return offset != sec->rawsize; |
65765700 JJ |
971 | |
972 | free_no_table: | |
64be1553 AM |
973 | (*info->callbacks->einfo) |
974 | (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), | |
975 | abfd, sec); | |
68f69152 JJ |
976 | if (ehbuf) |
977 | free (ehbuf); | |
65765700 JJ |
978 | if (sec_info) |
979 | free (sec_info); | |
bce613b9 JJ |
980 | if (ecies) |
981 | free (ecies); | |
b34976b6 | 982 | hdr_info->table = FALSE; |
b34976b6 | 983 | return FALSE; |
acfe5567 RS |
984 | |
985 | #undef REQUIRE | |
65765700 JJ |
986 | } |
987 | ||
988 | /* This function is called for .eh_frame_hdr section after | |
989 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
990 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
991 | ||
b34976b6 | 992 | bfd_boolean |
c39a58e6 | 993 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 994 | { |
126495ed | 995 | struct elf_link_hash_table *htab; |
65765700 | 996 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 997 | asection *sec; |
65765700 | 998 | |
126495ed AM |
999 | htab = elf_hash_table (info); |
1000 | hdr_info = &htab->eh_info; | |
bce613b9 JJ |
1001 | |
1002 | if (hdr_info->cies != NULL) | |
1003 | { | |
1004 | htab_delete (hdr_info->cies); | |
1005 | hdr_info->cies = NULL; | |
1006 | } | |
1007 | ||
126495ed AM |
1008 | sec = hdr_info->hdr_sec; |
1009 | if (sec == NULL) | |
b34976b6 | 1010 | return FALSE; |
126495ed | 1011 | |
eea6121a | 1012 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 1013 | if (hdr_info->table) |
eea6121a | 1014 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 | 1015 | |
126495ed | 1016 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 1017 | return TRUE; |
65765700 JJ |
1018 | } |
1019 | ||
68f69152 JJ |
1020 | /* This function is called from size_dynamic_sections. |
1021 | It needs to decide whether .eh_frame_hdr should be output or not, | |
8423293d AM |
1022 | because when the dynamic symbol table has been sized it is too late |
1023 | to strip sections. */ | |
68f69152 | 1024 | |
b34976b6 | 1025 | bfd_boolean |
c39a58e6 | 1026 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 1027 | { |
126495ed | 1028 | asection *o; |
68f69152 | 1029 | bfd *abfd; |
126495ed | 1030 | struct elf_link_hash_table *htab; |
68f69152 JJ |
1031 | struct eh_frame_hdr_info *hdr_info; |
1032 | ||
126495ed AM |
1033 | htab = elf_hash_table (info); |
1034 | hdr_info = &htab->eh_info; | |
1035 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 1036 | return TRUE; |
68f69152 | 1037 | |
126495ed AM |
1038 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
1039 | { | |
1040 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 1041 | return TRUE; |
126495ed | 1042 | } |
68f69152 JJ |
1043 | |
1044 | abfd = NULL; | |
1045 | if (info->eh_frame_hdr) | |
1046 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
1047 | { | |
1048 | /* Count only sections which have at least a single CIE or FDE. | |
1049 | There cannot be any CIE or FDE <= 8 bytes. */ | |
1050 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 1051 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
1052 | break; |
1053 | } | |
1054 | ||
1055 | if (abfd == NULL) | |
1056 | { | |
8423293d | 1057 | hdr_info->hdr_sec->flags |= SEC_EXCLUDE; |
126495ed | 1058 | hdr_info->hdr_sec = NULL; |
b34976b6 | 1059 | return TRUE; |
68f69152 | 1060 | } |
126495ed | 1061 | |
b34976b6 AM |
1062 | hdr_info->table = TRUE; |
1063 | return TRUE; | |
68f69152 JJ |
1064 | } |
1065 | ||
65765700 JJ |
1066 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
1067 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
1068 | or -1 if the address refers to a CIE/FDE which has been removed | |
1069 | or to offset with dynamic relocation which is no longer needed. */ | |
1070 | ||
1071 | bfd_vma | |
c39a58e6 | 1072 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
92e4ec35 | 1073 | struct bfd_link_info *info, |
c39a58e6 AM |
1074 | asection *sec, |
1075 | bfd_vma offset) | |
65765700 JJ |
1076 | { |
1077 | struct eh_frame_sec_info *sec_info; | |
92e4ec35 AM |
1078 | struct elf_link_hash_table *htab; |
1079 | struct eh_frame_hdr_info *hdr_info; | |
65765700 JJ |
1080 | unsigned int lo, hi, mid; |
1081 | ||
68bfbfcc | 1082 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 1083 | return offset; |
c39a58e6 | 1084 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 1085 | |
eea6121a AM |
1086 | if (offset >= sec->rawsize) |
1087 | return offset - sec->rawsize + sec->size; | |
65765700 | 1088 | |
92e4ec35 AM |
1089 | htab = elf_hash_table (info); |
1090 | hdr_info = &htab->eh_info; | |
1091 | if (hdr_info->offsets_adjusted) | |
1092 | offset += sec->output_offset; | |
1093 | ||
65765700 JJ |
1094 | lo = 0; |
1095 | hi = sec_info->count; | |
1096 | mid = 0; | |
1097 | while (lo < hi) | |
1098 | { | |
1099 | mid = (lo + hi) / 2; | |
1100 | if (offset < sec_info->entry[mid].offset) | |
1101 | hi = mid; | |
1102 | else if (offset | |
1103 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
1104 | lo = mid + 1; | |
1105 | else | |
1106 | break; | |
1107 | } | |
1108 | ||
1109 | BFD_ASSERT (lo < hi); | |
1110 | ||
1111 | /* FDE or CIE was removed. */ | |
1112 | if (sec_info->entry[mid].removed) | |
1113 | return (bfd_vma) -1; | |
1114 | ||
1115 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
1116 | relocation against FDE's initial_location field. */ | |
fda3ecf2 AM |
1117 | if (!sec_info->entry[mid].cie |
1118 | && sec_info->entry[mid].cie_inf->make_relative | |
353057a5 RS |
1119 | && offset == sec_info->entry[mid].offset + 8) |
1120 | return (bfd_vma) -2; | |
65765700 | 1121 | |
9e2a4898 JJ |
1122 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
1123 | for run-time relocation against LSDA field. */ | |
fda3ecf2 AM |
1124 | if (!sec_info->entry[mid].cie |
1125 | && sec_info->entry[mid].cie_inf->make_lsda_relative | |
126495ed | 1126 | && (offset == (sec_info->entry[mid].offset + 8 |
92e4ec35 AM |
1127 | + sec_info->entry[mid].lsda_offset)) |
1128 | && (sec_info->entry[mid].cie_inf->need_lsda_relative | |
1129 | || !hdr_info->offsets_adjusted)) | |
8935b81f | 1130 | { |
fda3ecf2 | 1131 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
8935b81f AM |
1132 | return (bfd_vma) -2; |
1133 | } | |
9e2a4898 | 1134 | |
ac685e6a JJ |
1135 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
1136 | relocation against DW_CFA_set_loc's arguments. */ | |
1137 | if (sec_info->entry[mid].set_loc | |
1138 | && (sec_info->entry[mid].cie | |
1139 | ? sec_info->entry[mid].make_relative | |
1140 | : sec_info->entry[mid].cie_inf->make_relative) | |
1141 | && (offset >= sec_info->entry[mid].offset + 8 | |
1142 | + sec_info->entry[mid].set_loc[1])) | |
1143 | { | |
1144 | unsigned int cnt; | |
1145 | ||
1146 | for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++) | |
1147 | if (offset == sec_info->entry[mid].offset + 8 | |
1148 | + sec_info->entry[mid].set_loc[cnt]) | |
1149 | return (bfd_vma) -2; | |
1150 | } | |
1151 | ||
92e4ec35 AM |
1152 | if (hdr_info->offsets_adjusted) |
1153 | offset -= sec->output_offset; | |
353057a5 | 1154 | /* Any new augmentation bytes go before the first relocation. */ |
c68836a9 | 1155 | return (offset + sec_info->entry[mid].new_offset |
353057a5 RS |
1156 | - sec_info->entry[mid].offset |
1157 | + extra_augmentation_string_bytes (sec_info->entry + mid) | |
1158 | + extra_augmentation_data_bytes (sec_info->entry + mid)); | |
65765700 JJ |
1159 | } |
1160 | ||
1161 | /* Write out .eh_frame section. This is called with the relocated | |
1162 | contents. */ | |
1163 | ||
b34976b6 | 1164 | bfd_boolean |
c39a58e6 AM |
1165 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
1166 | struct bfd_link_info *info, | |
1167 | asection *sec, | |
1168 | bfd_byte *contents) | |
65765700 JJ |
1169 | { |
1170 | struct eh_frame_sec_info *sec_info; | |
126495ed | 1171 | struct elf_link_hash_table *htab; |
65765700 | 1172 | struct eh_frame_hdr_info *hdr_info; |
65765700 | 1173 | unsigned int ptr_size; |
fda3ecf2 | 1174 | struct eh_cie_fde *ent; |
65765700 | 1175 | |
68bfbfcc | 1176 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 1177 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 1178 | sec->output_offset, sec->size); |
8c946ed5 RS |
1179 | |
1180 | ptr_size = (get_elf_backend_data (abfd) | |
1181 | ->elf_backend_eh_frame_address_size (abfd, sec)); | |
1182 | BFD_ASSERT (ptr_size != 0); | |
1183 | ||
c39a58e6 | 1184 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
1185 | htab = elf_hash_table (info); |
1186 | hdr_info = &htab->eh_info; | |
3472e2e9 AM |
1187 | |
1188 | /* First convert all offsets to output section offsets, so that a | |
1189 | CIE offset is valid if the CIE is used by a FDE from some other | |
1190 | section. This can happen when duplicate CIEs are deleted in | |
1191 | _bfd_elf_discard_section_eh_frame. We do all sections here because | |
1192 | this function might not be called on sections in the same order as | |
1193 | _bfd_elf_discard_section_eh_frame. */ | |
1194 | if (!hdr_info->offsets_adjusted) | |
1195 | { | |
1196 | bfd *ibfd; | |
1197 | asection *eh; | |
1198 | struct eh_frame_sec_info *eh_inf; | |
1199 | ||
1200 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) | |
1201 | { | |
1202 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour | |
1203 | || (ibfd->flags & DYNAMIC) != 0) | |
1204 | continue; | |
1205 | ||
1206 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); | |
1207 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
1208 | continue; | |
1209 | ||
1210 | eh_inf = elf_section_data (eh)->sec_info; | |
1211 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) | |
1212 | { | |
1213 | ent->offset += eh->output_offset; | |
1214 | ent->new_offset += eh->output_offset; | |
1215 | } | |
1216 | } | |
1217 | hdr_info->offsets_adjusted = TRUE; | |
1218 | } | |
1219 | ||
126495ed AM |
1220 | if (hdr_info->table && hdr_info->array == NULL) |
1221 | hdr_info->array | |
1222 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
1223 | if (hdr_info->array == NULL) | |
1224 | hdr_info = NULL; | |
65765700 | 1225 | |
353057a5 RS |
1226 | /* The new offsets can be bigger or smaller than the original offsets. |
1227 | We therefore need to make two passes over the section: one backward | |
1228 | pass to move entries up and one forward pass to move entries down. | |
1229 | The two passes won't interfere with each other because entries are | |
1230 | not reordered */ | |
1231 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) | |
1232 | if (!ent->removed && ent->new_offset > ent->offset) | |
1233 | memmove (contents + ent->new_offset - sec->output_offset, | |
1234 | contents + ent->offset - sec->output_offset, ent->size); | |
1235 | ||
1236 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
1237 | if (!ent->removed && ent->new_offset < ent->offset) | |
1238 | memmove (contents + ent->new_offset - sec->output_offset, | |
1239 | contents + ent->offset - sec->output_offset, ent->size); | |
1240 | ||
fda3ecf2 | 1241 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
65765700 | 1242 | { |
353057a5 RS |
1243 | unsigned char *buf, *end; |
1244 | unsigned int new_size; | |
1245 | ||
fda3ecf2 AM |
1246 | if (ent->removed) |
1247 | continue; | |
1248 | ||
353057a5 RS |
1249 | if (ent->size == 4) |
1250 | { | |
1251 | /* Any terminating FDE must be at the end of the section. */ | |
1252 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); | |
1253 | continue; | |
1254 | } | |
1255 | ||
1256 | buf = contents + ent->new_offset - sec->output_offset; | |
1257 | end = buf + ent->size; | |
1258 | new_size = size_of_output_cie_fde (ent, ptr_size); | |
1259 | ||
a34a056a L |
1260 | /* Update the size. It may be shrinked. */ |
1261 | bfd_put_32 (abfd, new_size - 4, buf); | |
1262 | ||
1263 | /* Filling the extra bytes with DW_CFA_nops. */ | |
353057a5 | 1264 | if (new_size != ent->size) |
a34a056a | 1265 | memset (end, 0, new_size - ent->size); |
353057a5 | 1266 | |
fda3ecf2 | 1267 | if (ent->cie) |
65765700 JJ |
1268 | { |
1269 | /* CIE */ | |
353057a5 | 1270 | if (ent->make_relative |
fda3ecf2 AM |
1271 | || ent->need_lsda_relative |
1272 | || ent->per_encoding_relative) | |
65765700 | 1273 | { |
f075ee0c | 1274 | char *aug; |
353057a5 | 1275 | unsigned int action, extra_string, extra_data; |
2c42be65 | 1276 | unsigned int per_width, per_encoding; |
65765700 | 1277 | |
9e2a4898 | 1278 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 1279 | DW_EH_PE_* value. */ |
353057a5 | 1280 | action = ((ent->make_relative ? 1 : 0) |
fda3ecf2 AM |
1281 | | (ent->need_lsda_relative ? 2 : 0) |
1282 | | (ent->per_encoding_relative ? 4 : 0)); | |
353057a5 RS |
1283 | extra_string = extra_augmentation_string_bytes (ent); |
1284 | extra_data = extra_augmentation_data_bytes (ent); | |
1285 | ||
65765700 JJ |
1286 | /* Skip length, id and version. */ |
1287 | buf += 9; | |
f075ee0c AM |
1288 | aug = (char *) buf; |
1289 | buf += strlen (aug) + 1; | |
2c42be65 RS |
1290 | skip_leb128 (&buf, end); |
1291 | skip_leb128 (&buf, end); | |
1292 | skip_leb128 (&buf, end); | |
65765700 JJ |
1293 | if (*aug == 'z') |
1294 | { | |
353057a5 RS |
1295 | /* The uleb128 will always be a single byte for the kind |
1296 | of augmentation strings that we're prepared to handle. */ | |
1297 | *buf++ += extra_data; | |
65765700 JJ |
1298 | aug++; |
1299 | } | |
1300 | ||
353057a5 RS |
1301 | /* Make room for the new augmentation string and data bytes. */ |
1302 | memmove (buf + extra_string + extra_data, buf, end - buf); | |
f075ee0c | 1303 | memmove (aug + extra_string, aug, buf - (bfd_byte *) aug); |
353057a5 | 1304 | buf += extra_string; |
2c42be65 | 1305 | end += extra_string + extra_data; |
353057a5 RS |
1306 | |
1307 | if (ent->add_augmentation_size) | |
1308 | { | |
1309 | *aug++ = 'z'; | |
1310 | *buf++ = extra_data - 1; | |
1311 | } | |
1312 | if (ent->add_fde_encoding) | |
1313 | { | |
1314 | BFD_ASSERT (action & 1); | |
1315 | *aug++ = 'R'; | |
1316 | *buf++ = DW_EH_PE_pcrel; | |
1317 | action &= ~1; | |
1318 | } | |
1319 | ||
9e2a4898 | 1320 | while (action) |
65765700 JJ |
1321 | switch (*aug++) |
1322 | { | |
1323 | case 'L': | |
9e2a4898 JJ |
1324 | if (action & 2) |
1325 | { | |
fda3ecf2 | 1326 | BFD_ASSERT (*buf == ent->lsda_encoding); |
9e2a4898 JJ |
1327 | *buf |= DW_EH_PE_pcrel; |
1328 | action &= ~2; | |
1329 | } | |
65765700 JJ |
1330 | buf++; |
1331 | break; | |
1332 | case 'P': | |
1333 | per_encoding = *buf++; | |
3472e2e9 | 1334 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
65765700 | 1335 | BFD_ASSERT (per_width != 0); |
09ae86c2 | 1336 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
fda3ecf2 | 1337 | == ent->per_encoding_relative); |
65765700 JJ |
1338 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
1339 | buf = (contents | |
1340 | + ((buf - contents + per_width - 1) | |
1341 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
1342 | if (action & 4) |
1343 | { | |
fda3ecf2 AM |
1344 | bfd_vma val; |
1345 | ||
1346 | val = read_value (abfd, buf, per_width, | |
1347 | get_DW_EH_PE_signed (per_encoding)); | |
1348 | val += ent->offset - ent->new_offset; | |
353057a5 | 1349 | val -= extra_string + extra_data; |
fda3ecf2 | 1350 | write_value (abfd, buf, val, per_width); |
09ae86c2 JJ |
1351 | action &= ~4; |
1352 | } | |
65765700 JJ |
1353 | buf += per_width; |
1354 | break; | |
9e2a4898 JJ |
1355 | case 'R': |
1356 | if (action & 1) | |
1357 | { | |
fda3ecf2 | 1358 | BFD_ASSERT (*buf == ent->fde_encoding); |
9e2a4898 JJ |
1359 | *buf |= DW_EH_PE_pcrel; |
1360 | action &= ~1; | |
1361 | } | |
1362 | buf++; | |
1363 | break; | |
63752a75 JJ |
1364 | case 'S': |
1365 | break; | |
65765700 JJ |
1366 | default: |
1367 | BFD_FAIL (); | |
1368 | } | |
65765700 JJ |
1369 | } |
1370 | } | |
353057a5 | 1371 | else |
65765700 JJ |
1372 | { |
1373 | /* FDE */ | |
fda3ecf2 | 1374 | bfd_vma value, address; |
9e2a4898 | 1375 | unsigned int width; |
ac685e6a | 1376 | bfd_byte *start; |
65765700 | 1377 | |
b34976b6 | 1378 | /* Skip length. */ |
65765700 | 1379 | buf += 4; |
fda3ecf2 AM |
1380 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
1381 | bfd_put_32 (abfd, value, buf); | |
65765700 | 1382 | buf += 4; |
fda3ecf2 AM |
1383 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
1384 | value = read_value (abfd, buf, width, | |
1385 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1386 | address = value; | |
9e2a4898 | 1387 | if (value) |
65765700 | 1388 | { |
fda3ecf2 | 1389 | switch (ent->fde_encoding & 0xf0) |
9e2a4898 JJ |
1390 | { |
1391 | case DW_EH_PE_indirect: | |
1392 | case DW_EH_PE_textrel: | |
1393 | BFD_ASSERT (hdr_info == NULL); | |
1394 | break; | |
1395 | case DW_EH_PE_datarel: | |
1396 | { | |
1397 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1398 | ||
1399 | BFD_ASSERT (got != NULL); | |
1400 | address += got->vma; | |
1401 | } | |
1402 | break; | |
1403 | case DW_EH_PE_pcrel: | |
fda3ecf2 AM |
1404 | value += ent->offset - ent->new_offset; |
1405 | address += sec->output_section->vma + ent->offset + 8; | |
9e2a4898 JJ |
1406 | break; |
1407 | } | |
353057a5 | 1408 | if (ent->cie_inf->make_relative) |
fda3ecf2 | 1409 | value -= sec->output_section->vma + ent->new_offset + 8; |
9e2a4898 | 1410 | write_value (abfd, buf, value, width); |
65765700 JJ |
1411 | } |
1412 | ||
ac685e6a JJ |
1413 | start = buf; |
1414 | ||
65765700 JJ |
1415 | if (hdr_info) |
1416 | { | |
1417 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1418 | hdr_info->array[hdr_info->array_count++].fde | |
fda3ecf2 | 1419 | = sec->output_section->vma + ent->new_offset; |
65765700 | 1420 | } |
9e2a4898 | 1421 | |
fda3ecf2 AM |
1422 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
1423 | || ent->cie_inf->need_lsda_relative) | |
9e2a4898 | 1424 | { |
fda3ecf2 AM |
1425 | buf += ent->lsda_offset; |
1426 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); | |
84f97cb6 | 1427 | value = read_value (abfd, buf, width, |
fda3ecf2 | 1428 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
9e2a4898 JJ |
1429 | if (value) |
1430 | { | |
fda3ecf2 AM |
1431 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
1432 | value += ent->offset - ent->new_offset; | |
1433 | else if (ent->cie_inf->need_lsda_relative) | |
1434 | value -= (sec->output_section->vma + ent->new_offset + 8 | |
1435 | + ent->lsda_offset); | |
9e2a4898 JJ |
1436 | write_value (abfd, buf, value, width); |
1437 | } | |
1438 | } | |
353057a5 RS |
1439 | else if (ent->cie_inf->add_augmentation_size) |
1440 | { | |
1441 | /* Skip the PC and length and insert a zero byte for the | |
1442 | augmentation size. */ | |
1443 | buf += width * 2; | |
1444 | memmove (buf + 1, buf, end - buf); | |
1445 | *buf = 0; | |
1446 | } | |
ac685e6a JJ |
1447 | |
1448 | if (ent->set_loc) | |
1449 | { | |
1450 | /* Adjust DW_CFA_set_loc. */ | |
1451 | unsigned int cnt, width; | |
1452 | bfd_vma new_offset; | |
1453 | ||
1454 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); | |
1455 | new_offset = ent->new_offset + 8 | |
1456 | + extra_augmentation_string_bytes (ent) | |
1457 | + extra_augmentation_data_bytes (ent); | |
1458 | ||
1459 | for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) | |
1460 | { | |
1461 | bfd_vma value; | |
1462 | buf = start + ent->set_loc[cnt]; | |
1463 | ||
1464 | value = read_value (abfd, buf, width, | |
1465 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1466 | if (!value) | |
1467 | continue; | |
1468 | ||
1469 | if ((ent->fde_encoding & 0xf0) == DW_EH_PE_pcrel) | |
1470 | value += ent->offset + 8 - new_offset; | |
1471 | if (ent->cie_inf->make_relative) | |
1472 | value -= sec->output_section->vma + new_offset | |
1473 | + ent->set_loc[cnt]; | |
1474 | write_value (abfd, buf, value, width); | |
1475 | } | |
1476 | } | |
65765700 | 1477 | } |
65765700 JJ |
1478 | } |
1479 | ||
a34a056a L |
1480 | /* We don't align the section to its section alignment since the |
1481 | runtime library only expects all CIE/FDE records aligned at | |
4e591bc1 | 1482 | the pointer size. _bfd_elf_discard_section_eh_frame should |
a34a056a L |
1483 | have padded CIE/FDE records to multiple of pointer size with |
1484 | size_of_output_cie_fde. */ | |
1485 | if ((sec->size % ptr_size) != 0) | |
1486 | abort (); | |
a5eb27e6 | 1487 | |
65765700 | 1488 | return bfd_set_section_contents (abfd, sec->output_section, |
3472e2e9 AM |
1489 | contents, (file_ptr) sec->output_offset, |
1490 | sec->size); | |
65765700 JJ |
1491 | } |
1492 | ||
1493 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1494 | VMA of FDE initial location. */ | |
1495 | ||
1496 | static int | |
c39a58e6 | 1497 | vma_compare (const void *a, const void *b) |
65765700 | 1498 | { |
c39a58e6 AM |
1499 | const struct eh_frame_array_ent *p = a; |
1500 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1501 | if (p->initial_loc > q->initial_loc) |
1502 | return 1; | |
1503 | if (p->initial_loc < q->initial_loc) | |
1504 | return -1; | |
1505 | return 0; | |
1506 | } | |
1507 | ||
1508 | /* Write out .eh_frame_hdr section. This must be called after | |
1509 | _bfd_elf_write_section_eh_frame has been called on all input | |
1510 | .eh_frame sections. | |
1511 | .eh_frame_hdr format: | |
1512 | ubyte version (currently 1) | |
1513 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1514 | .eh_frame section) | |
1515 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1516 | number (or DW_EH_PE_omit if there is no | |
1517 | binary search table computed)) | |
1518 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1519 | or DW_EH_PE_omit if not present. | |
1520 | DW_EH_PE_datarel is using address of | |
1521 | .eh_frame_hdr section start as base) | |
1522 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1523 | optionally followed by: | |
1524 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1525 | fde_count x [encoded] initial_loc, fde | |
1526 | (array of encoded pairs containing | |
1527 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1528 | sorted by increasing initial_loc). */ |
65765700 | 1529 | |
b34976b6 | 1530 | bfd_boolean |
c39a58e6 | 1531 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1532 | { |
126495ed | 1533 | struct elf_link_hash_table *htab; |
65765700 | 1534 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1535 | asection *sec; |
65765700 JJ |
1536 | bfd_byte *contents; |
1537 | asection *eh_frame_sec; | |
1538 | bfd_size_type size; | |
5ed6aba4 | 1539 | bfd_boolean retval; |
ec3391e7 | 1540 | bfd_vma encoded_eh_frame; |
65765700 | 1541 | |
126495ed AM |
1542 | htab = elf_hash_table (info); |
1543 | hdr_info = &htab->eh_info; | |
1544 | sec = hdr_info->hdr_sec; | |
1545 | if (sec == NULL) | |
b34976b6 | 1546 | return TRUE; |
57a72197 | 1547 | |
65765700 JJ |
1548 | size = EH_FRAME_HDR_SIZE; |
1549 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1550 | size += 4 + hdr_info->fde_count * 8; | |
1551 | contents = bfd_malloc (size); | |
1552 | if (contents == NULL) | |
b34976b6 | 1553 | return FALSE; |
65765700 JJ |
1554 | |
1555 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1556 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1557 | { |
1558 | free (contents); | |
1559 | return FALSE; | |
1560 | } | |
65765700 JJ |
1561 | |
1562 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1563 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1564 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1565 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1566 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1567 | ||
65765700 JJ |
1568 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1569 | { | |
5ed6aba4 NC |
1570 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1571 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1572 | } |
1573 | else | |
1574 | { | |
1575 | contents[2] = DW_EH_PE_omit; | |
1576 | contents[3] = DW_EH_PE_omit; | |
1577 | } | |
ec3391e7 AO |
1578 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1579 | ||
65765700 JJ |
1580 | if (contents[2] != DW_EH_PE_omit) |
1581 | { | |
1582 | unsigned int i; | |
1583 | ||
1584 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1585 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1586 | vma_compare); | |
1587 | for (i = 0; i < hdr_info->fde_count; i++) | |
1588 | { | |
1589 | bfd_put_32 (abfd, | |
1590 | hdr_info->array[i].initial_loc | |
1591 | - sec->output_section->vma, | |
1592 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1593 | bfd_put_32 (abfd, | |
1594 | hdr_info->array[i].fde - sec->output_section->vma, | |
1595 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1596 | } | |
1597 | } | |
1598 | ||
5ed6aba4 NC |
1599 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1600 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1601 | sec->size); |
5ed6aba4 NC |
1602 | free (contents); |
1603 | return retval; | |
65765700 | 1604 | } |
ec3391e7 | 1605 | |
8c946ed5 RS |
1606 | /* Return the width of FDE addresses. This is the default implementation. */ |
1607 | ||
1608 | unsigned int | |
1609 | _bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) | |
1610 | { | |
1611 | return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; | |
1612 | } | |
1613 | ||
ec3391e7 AO |
1614 | /* Decide whether we can use a PC-relative encoding within the given |
1615 | EH frame section. This is the default implementation. */ | |
1616 | ||
1617 | bfd_boolean | |
1618 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1619 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1620 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1621 | { | |
1622 | return TRUE; | |
1623 | } | |
1624 | ||
1625 | /* Select an encoding for the given address. Preference is given to | |
1626 | PC-relative addressing modes. */ | |
1627 | ||
1628 | bfd_byte | |
1629 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1630 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1631 | asection *osec, bfd_vma offset, | |
1632 | asection *loc_sec, bfd_vma loc_offset, | |
1633 | bfd_vma *encoded) | |
1634 | { | |
1635 | *encoded = osec->vma + offset - | |
1636 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1637 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1638 | } |