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