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)); | |
4e591bc1 EC |
715 | if (sym_sec != NULL |
716 | && sym_sec->kept_section != NULL) | |
f137a54e AM |
717 | sym_sec = sym_sec->kept_section; |
718 | if (sym_sec != NULL | |
719 | && sym_sec->output_section != NULL) | |
ef8c95ad | 720 | { |
f137a54e AM |
721 | val = (sym->st_value |
722 | + sym_sec->output_offset | |
723 | + sym_sec->output_section->vma); | |
724 | cie->personality.val = val; | |
725 | cie->local_personality = 1; | |
ef8c95ad AM |
726 | } |
727 | } | |
ef8c95ad | 728 | |
f4a6705c RS |
729 | /* Cope with MIPS-style composite relocations. */ |
730 | do | |
731 | cookie->rel++; | |
732 | while (GET_RELOC (buf) != NULL); | |
65765700 | 733 | } |
2c42be65 | 734 | REQUIRE (skip_bytes (&buf, end, per_width)); |
f137a54e | 735 | REQUIRE (cie->local_personality || cie->personality.h); |
65765700 JJ |
736 | } |
737 | break; | |
738 | default: | |
739 | /* Unrecognized augmentation. Better bail out. */ | |
740 | goto free_no_table; | |
741 | } | |
742 | } | |
743 | ||
744 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a | 745 | as possible. */ |
3472e2e9 | 746 | if (info->shared |
ec3391e7 AO |
747 | && (get_elf_backend_data (abfd) |
748 | ->elf_backend_can_make_relative_eh_frame | |
353057a5 RS |
749 | (abfd, info, sec))) |
750 | { | |
bce613b9 JJ |
751 | if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr) |
752 | cie->make_relative = 1; | |
353057a5 RS |
753 | /* If the CIE doesn't already have an 'R' entry, it's fairly |
754 | easy to add one, provided that there's no aligned data | |
755 | after the augmentation string. */ | |
bce613b9 JJ |
756 | else if (cie->fde_encoding == DW_EH_PE_omit |
757 | && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned) | |
353057a5 | 758 | { |
bce613b9 | 759 | if (*cie->augmentation == 0) |
353057a5 RS |
760 | this_inf->add_augmentation_size = 1; |
761 | this_inf->add_fde_encoding = 1; | |
bce613b9 | 762 | cie->make_relative = 1; |
353057a5 RS |
763 | } |
764 | } | |
65765700 | 765 | |
0bb2d96a | 766 | if (info->shared |
ec3391e7 AO |
767 | && (get_elf_backend_data (abfd) |
768 | ->elf_backend_can_make_lsda_relative_eh_frame | |
769 | (abfd, info, sec)) | |
bce613b9 JJ |
770 | && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
771 | cie->make_lsda_relative = 1; | |
9e2a4898 | 772 | |
65765700 JJ |
773 | /* If FDE encoding was not specified, it defaults to |
774 | DW_EH_absptr. */ | |
bce613b9 JJ |
775 | if (cie->fde_encoding == DW_EH_PE_omit) |
776 | cie->fde_encoding = DW_EH_PE_absptr; | |
65765700 | 777 | |
dcf507a6 | 778 | initial_insn_length = end - buf; |
bce613b9 | 779 | if (initial_insn_length <= sizeof (cie->initial_instructions)) |
65765700 | 780 | { |
bce613b9 JJ |
781 | cie->initial_insn_length = initial_insn_length; |
782 | memcpy (cie->initial_instructions, buf, initial_insn_length); | |
65765700 | 783 | } |
dcf507a6 | 784 | insns = buf; |
65765700 JJ |
785 | buf += initial_insn_length; |
786 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
787 | } |
788 | else | |
789 | { | |
bce613b9 JJ |
790 | /* Find the corresponding CIE. */ |
791 | unsigned int cie_offset = this_inf->offset + 4 - hdr_id; | |
792 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
793 | if (cie_offset == ecie->offset) | |
794 | break; | |
795 | ||
796 | /* Ensure this FDE references one of the CIEs in this input | |
797 | section. */ | |
798 | REQUIRE (ecie != ecies + ecie_count); | |
799 | cie = &ecie->cie; | |
65765700 JJ |
800 | |
801 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 802 | REQUIRE (GET_RELOC (buf)); |
fda3ecf2 | 803 | |
65765700 | 804 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
353057a5 RS |
805 | /* This is a FDE against a discarded section. It should |
806 | be deleted. */ | |
807 | this_inf->removed = 1; | |
65765700 JJ |
808 | else |
809 | { | |
0bb2d96a | 810 | if (info->shared |
bce613b9 JJ |
811 | && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr |
812 | && cie->make_relative == 0) | |
813 | || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 814 | { |
73722af0 | 815 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
816 | which we cannot turn into PC relative, |
817 | don't create the binary search table, | |
818 | since it is affected by runtime relocations. */ | |
b34976b6 | 819 | hdr_info->table = FALSE; |
64be1553 AM |
820 | (*info->callbacks->einfo) |
821 | (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr" | |
822 | " table being created.\n"), abfd, sec); | |
0bb2d96a | 823 | } |
bce613b9 | 824 | ecie->usage_count++; |
65765700 | 825 | hdr_info->fde_count++; |
bce613b9 | 826 | this_inf->cie_inf = (void *) (ecie - ecies); |
65765700 | 827 | } |
bce613b9 | 828 | |
2c42be65 RS |
829 | /* Skip the initial location and address range. */ |
830 | start = buf; | |
bce613b9 | 831 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
2c42be65 RS |
832 | REQUIRE (skip_bytes (&buf, end, 2 * length)); |
833 | ||
834 | /* Skip the augmentation size, if present. */ | |
bce613b9 | 835 | if (cie->augmentation[0] == 'z') |
dcf507a6 RS |
836 | REQUIRE (read_uleb128 (&buf, end, &length)); |
837 | else | |
838 | length = 0; | |
2c42be65 RS |
839 | |
840 | /* Of the supported augmentation characters above, only 'L' | |
841 | adds augmentation data to the FDE. This code would need to | |
842 | be adjusted if any future augmentations do the same thing. */ | |
bce613b9 | 843 | if (cie->lsda_encoding != DW_EH_PE_omit) |
dcf507a6 RS |
844 | { |
845 | this_inf->lsda_offset = buf - start; | |
846 | /* If there's no 'z' augmentation, we don't know where the | |
847 | CFA insns begin. Assume no padding. */ | |
bce613b9 | 848 | if (cie->augmentation[0] != 'z') |
dcf507a6 RS |
849 | length = end - buf; |
850 | } | |
851 | ||
852 | /* Skip over the augmentation data. */ | |
853 | REQUIRE (skip_bytes (&buf, end, length)); | |
854 | insns = buf; | |
9e2a4898 | 855 | |
bce613b9 | 856 | buf = last_fde + 4 + hdr_length; |
65765700 JJ |
857 | SKIP_RELOCS (buf); |
858 | } | |
859 | ||
dcf507a6 RS |
860 | /* Try to interpret the CFA instructions and find the first |
861 | padding nop. Shrink this_inf's size so that it doesn't | |
ac685e6a | 862 | include the padding. */ |
bce613b9 | 863 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
ac685e6a JJ |
864 | set_loc_count = 0; |
865 | insns_end = skip_non_nops (insns, end, length, &set_loc_count); | |
866 | /* If we don't understand the CFA instructions, we can't know | |
867 | what needs to be adjusted there. */ | |
868 | if (insns_end == NULL | |
869 | /* For the time being we don't support DW_CFA_set_loc in | |
870 | CIE instructions. */ | |
871 | || (set_loc_count && this_inf->cie)) | |
872 | goto free_no_table; | |
873 | this_inf->size -= end - insns_end; | |
bce613b9 JJ |
874 | if (insns_end != end && this_inf->cie) |
875 | { | |
876 | cie->initial_insn_length -= end - insns_end; | |
877 | cie->length -= end - insns_end; | |
878 | } | |
ac685e6a | 879 | if (set_loc_count |
bce613b9 JJ |
880 | && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel |
881 | || cie->make_relative)) | |
ac685e6a JJ |
882 | { |
883 | unsigned int cnt; | |
884 | bfd_byte *p; | |
885 | ||
886 | this_inf->set_loc = bfd_malloc ((set_loc_count + 1) | |
887 | * sizeof (unsigned int)); | |
888 | REQUIRE (this_inf->set_loc); | |
889 | this_inf->set_loc[0] = set_loc_count; | |
890 | p = insns; | |
891 | cnt = 0; | |
892 | while (p < end) | |
893 | { | |
894 | if (*p == DW_CFA_set_loc) | |
895 | this_inf->set_loc[++cnt] = p + 1 - start; | |
896 | REQUIRE (skip_cfa_op (&p, end, length)); | |
897 | } | |
898 | } | |
dcf507a6 | 899 | |
bce613b9 JJ |
900 | this_inf->fde_encoding = cie->fde_encoding; |
901 | this_inf->lsda_encoding = cie->lsda_encoding; | |
65765700 JJ |
902 | sec_info->count++; |
903 | } | |
904 | ||
905 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 906 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 | 907 | |
bce613b9 JJ |
908 | /* Look at all CIEs in this section and determine which can be |
909 | removed as unused, which can be merged with previous duplicate | |
910 | CIEs and which need to be kept. */ | |
911 | for (ecie = ecies; ecie < ecies + ecie_count; ++ecie) | |
912 | { | |
913 | if (ecie->usage_count == 0) | |
914 | { | |
915 | sec_info->entry[ecie->entry].removed = 1; | |
916 | continue; | |
917 | } | |
918 | ecie->cie.output_sec = sec->output_section; | |
919 | ecie->cie.cie_inf = sec_info->entry + ecie->entry; | |
920 | cie_compute_hash (&ecie->cie); | |
921 | if (hdr_info->cies != NULL) | |
922 | { | |
923 | void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie, | |
924 | ecie->cie.hash, INSERT); | |
925 | if (loc != NULL) | |
926 | { | |
927 | if (*loc != HTAB_EMPTY_ENTRY) | |
928 | { | |
929 | sec_info->entry[ecie->entry].removed = 1; | |
930 | ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf; | |
931 | continue; | |
932 | } | |
933 | ||
934 | *loc = malloc (sizeof (struct cie)); | |
935 | if (*loc == NULL) | |
936 | *loc = HTAB_DELETED_ENTRY; | |
937 | else | |
938 | memcpy (*loc, &ecie->cie, sizeof (struct cie)); | |
939 | } | |
940 | } | |
941 | ecie->cie.cie_inf->make_relative = ecie->cie.make_relative; | |
942 | ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative; | |
943 | ecie->cie.cie_inf->per_encoding_relative | |
944 | = (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
945 | } | |
946 | ||
65765700 JJ |
947 | /* Ok, now we can assign new offsets. */ |
948 | offset = 0; | |
fda3ecf2 AM |
949 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
950 | if (!ent->removed) | |
951 | { | |
bce613b9 JJ |
952 | if (!ent->cie) |
953 | { | |
954 | ecie = ecies + (unsigned long) ent->cie_inf; | |
955 | ent->cie_inf = ecie->cie.cie_inf; | |
956 | } | |
353057a5 RS |
957 | ent->new_offset = offset; |
958 | offset += size_of_output_cie_fde (ent, ptr_size); | |
fda3ecf2 | 959 | } |
65765700 | 960 | |
353057a5 | 961 | /* Resize the sec as needed. */ |
eea6121a | 962 | sec->rawsize = sec->size; |
353057a5 | 963 | sec->size = offset; |
65765700 | 964 | |
68f69152 | 965 | free (ehbuf); |
bce613b9 JJ |
966 | if (ecies) |
967 | free (ecies); | |
353057a5 | 968 | return offset != sec->rawsize; |
65765700 JJ |
969 | |
970 | free_no_table: | |
64be1553 AM |
971 | (*info->callbacks->einfo) |
972 | (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), | |
973 | abfd, sec); | |
68f69152 JJ |
974 | if (ehbuf) |
975 | free (ehbuf); | |
65765700 JJ |
976 | if (sec_info) |
977 | free (sec_info); | |
bce613b9 JJ |
978 | if (ecies) |
979 | free (ecies); | |
b34976b6 | 980 | hdr_info->table = FALSE; |
b34976b6 | 981 | return FALSE; |
acfe5567 RS |
982 | |
983 | #undef REQUIRE | |
65765700 JJ |
984 | } |
985 | ||
986 | /* This function is called for .eh_frame_hdr section after | |
987 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
988 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
989 | ||
b34976b6 | 990 | bfd_boolean |
c39a58e6 | 991 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 992 | { |
126495ed | 993 | struct elf_link_hash_table *htab; |
65765700 | 994 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 995 | asection *sec; |
65765700 | 996 | |
126495ed AM |
997 | htab = elf_hash_table (info); |
998 | hdr_info = &htab->eh_info; | |
bce613b9 JJ |
999 | |
1000 | if (hdr_info->cies != NULL) | |
1001 | { | |
1002 | htab_delete (hdr_info->cies); | |
1003 | hdr_info->cies = NULL; | |
1004 | } | |
1005 | ||
126495ed AM |
1006 | sec = hdr_info->hdr_sec; |
1007 | if (sec == NULL) | |
b34976b6 | 1008 | return FALSE; |
126495ed | 1009 | |
eea6121a | 1010 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 1011 | if (hdr_info->table) |
eea6121a | 1012 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 | 1013 | |
126495ed | 1014 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 1015 | return TRUE; |
65765700 JJ |
1016 | } |
1017 | ||
68f69152 JJ |
1018 | /* This function is called from size_dynamic_sections. |
1019 | It needs to decide whether .eh_frame_hdr should be output or not, | |
8423293d AM |
1020 | because when the dynamic symbol table has been sized it is too late |
1021 | to strip sections. */ | |
68f69152 | 1022 | |
b34976b6 | 1023 | bfd_boolean |
c39a58e6 | 1024 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 1025 | { |
126495ed | 1026 | asection *o; |
68f69152 | 1027 | bfd *abfd; |
126495ed | 1028 | struct elf_link_hash_table *htab; |
68f69152 JJ |
1029 | struct eh_frame_hdr_info *hdr_info; |
1030 | ||
126495ed AM |
1031 | htab = elf_hash_table (info); |
1032 | hdr_info = &htab->eh_info; | |
1033 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 1034 | return TRUE; |
68f69152 | 1035 | |
126495ed AM |
1036 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
1037 | { | |
1038 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 1039 | return TRUE; |
126495ed | 1040 | } |
68f69152 JJ |
1041 | |
1042 | abfd = NULL; | |
1043 | if (info->eh_frame_hdr) | |
1044 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
1045 | { | |
1046 | /* Count only sections which have at least a single CIE or FDE. | |
1047 | There cannot be any CIE or FDE <= 8 bytes. */ | |
1048 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 1049 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
1050 | break; |
1051 | } | |
1052 | ||
1053 | if (abfd == NULL) | |
1054 | { | |
8423293d | 1055 | hdr_info->hdr_sec->flags |= SEC_EXCLUDE; |
126495ed | 1056 | hdr_info->hdr_sec = NULL; |
b34976b6 | 1057 | return TRUE; |
68f69152 | 1058 | } |
126495ed | 1059 | |
b34976b6 AM |
1060 | hdr_info->table = TRUE; |
1061 | return TRUE; | |
68f69152 JJ |
1062 | } |
1063 | ||
65765700 JJ |
1064 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
1065 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
1066 | or -1 if the address refers to a CIE/FDE which has been removed | |
1067 | or to offset with dynamic relocation which is no longer needed. */ | |
1068 | ||
1069 | bfd_vma | |
c39a58e6 | 1070 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
92e4ec35 | 1071 | struct bfd_link_info *info, |
c39a58e6 AM |
1072 | asection *sec, |
1073 | bfd_vma offset) | |
65765700 JJ |
1074 | { |
1075 | struct eh_frame_sec_info *sec_info; | |
92e4ec35 AM |
1076 | struct elf_link_hash_table *htab; |
1077 | struct eh_frame_hdr_info *hdr_info; | |
65765700 JJ |
1078 | unsigned int lo, hi, mid; |
1079 | ||
68bfbfcc | 1080 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 1081 | return offset; |
c39a58e6 | 1082 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 1083 | |
eea6121a AM |
1084 | if (offset >= sec->rawsize) |
1085 | return offset - sec->rawsize + sec->size; | |
65765700 | 1086 | |
92e4ec35 AM |
1087 | htab = elf_hash_table (info); |
1088 | hdr_info = &htab->eh_info; | |
1089 | if (hdr_info->offsets_adjusted) | |
1090 | offset += sec->output_offset; | |
1091 | ||
65765700 JJ |
1092 | lo = 0; |
1093 | hi = sec_info->count; | |
1094 | mid = 0; | |
1095 | while (lo < hi) | |
1096 | { | |
1097 | mid = (lo + hi) / 2; | |
1098 | if (offset < sec_info->entry[mid].offset) | |
1099 | hi = mid; | |
1100 | else if (offset | |
1101 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
1102 | lo = mid + 1; | |
1103 | else | |
1104 | break; | |
1105 | } | |
1106 | ||
1107 | BFD_ASSERT (lo < hi); | |
1108 | ||
1109 | /* FDE or CIE was removed. */ | |
1110 | if (sec_info->entry[mid].removed) | |
1111 | return (bfd_vma) -1; | |
1112 | ||
1113 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
1114 | relocation against FDE's initial_location field. */ | |
fda3ecf2 AM |
1115 | if (!sec_info->entry[mid].cie |
1116 | && sec_info->entry[mid].cie_inf->make_relative | |
353057a5 RS |
1117 | && offset == sec_info->entry[mid].offset + 8) |
1118 | return (bfd_vma) -2; | |
65765700 | 1119 | |
9e2a4898 JJ |
1120 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
1121 | for run-time relocation against LSDA field. */ | |
fda3ecf2 AM |
1122 | if (!sec_info->entry[mid].cie |
1123 | && sec_info->entry[mid].cie_inf->make_lsda_relative | |
126495ed | 1124 | && (offset == (sec_info->entry[mid].offset + 8 |
92e4ec35 AM |
1125 | + sec_info->entry[mid].lsda_offset)) |
1126 | && (sec_info->entry[mid].cie_inf->need_lsda_relative | |
1127 | || !hdr_info->offsets_adjusted)) | |
8935b81f | 1128 | { |
fda3ecf2 | 1129 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
8935b81f AM |
1130 | return (bfd_vma) -2; |
1131 | } | |
9e2a4898 | 1132 | |
ac685e6a JJ |
1133 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
1134 | relocation against DW_CFA_set_loc's arguments. */ | |
1135 | if (sec_info->entry[mid].set_loc | |
1136 | && (sec_info->entry[mid].cie | |
1137 | ? sec_info->entry[mid].make_relative | |
1138 | : sec_info->entry[mid].cie_inf->make_relative) | |
1139 | && (offset >= sec_info->entry[mid].offset + 8 | |
1140 | + sec_info->entry[mid].set_loc[1])) | |
1141 | { | |
1142 | unsigned int cnt; | |
1143 | ||
1144 | for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++) | |
1145 | if (offset == sec_info->entry[mid].offset + 8 | |
1146 | + sec_info->entry[mid].set_loc[cnt]) | |
1147 | return (bfd_vma) -2; | |
1148 | } | |
1149 | ||
92e4ec35 AM |
1150 | if (hdr_info->offsets_adjusted) |
1151 | offset -= sec->output_offset; | |
353057a5 | 1152 | /* Any new augmentation bytes go before the first relocation. */ |
c68836a9 | 1153 | return (offset + sec_info->entry[mid].new_offset |
353057a5 RS |
1154 | - sec_info->entry[mid].offset |
1155 | + extra_augmentation_string_bytes (sec_info->entry + mid) | |
1156 | + extra_augmentation_data_bytes (sec_info->entry + mid)); | |
65765700 JJ |
1157 | } |
1158 | ||
1159 | /* Write out .eh_frame section. This is called with the relocated | |
1160 | contents. */ | |
1161 | ||
b34976b6 | 1162 | bfd_boolean |
c39a58e6 AM |
1163 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
1164 | struct bfd_link_info *info, | |
1165 | asection *sec, | |
1166 | bfd_byte *contents) | |
65765700 JJ |
1167 | { |
1168 | struct eh_frame_sec_info *sec_info; | |
126495ed | 1169 | struct elf_link_hash_table *htab; |
65765700 | 1170 | struct eh_frame_hdr_info *hdr_info; |
65765700 | 1171 | unsigned int ptr_size; |
fda3ecf2 | 1172 | struct eh_cie_fde *ent; |
65765700 | 1173 | |
68bfbfcc | 1174 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 1175 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 1176 | sec->output_offset, sec->size); |
8c946ed5 RS |
1177 | |
1178 | ptr_size = (get_elf_backend_data (abfd) | |
1179 | ->elf_backend_eh_frame_address_size (abfd, sec)); | |
1180 | BFD_ASSERT (ptr_size != 0); | |
1181 | ||
c39a58e6 | 1182 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
1183 | htab = elf_hash_table (info); |
1184 | hdr_info = &htab->eh_info; | |
3472e2e9 AM |
1185 | |
1186 | /* First convert all offsets to output section offsets, so that a | |
1187 | CIE offset is valid if the CIE is used by a FDE from some other | |
1188 | section. This can happen when duplicate CIEs are deleted in | |
1189 | _bfd_elf_discard_section_eh_frame. We do all sections here because | |
1190 | this function might not be called on sections in the same order as | |
1191 | _bfd_elf_discard_section_eh_frame. */ | |
1192 | if (!hdr_info->offsets_adjusted) | |
1193 | { | |
1194 | bfd *ibfd; | |
1195 | asection *eh; | |
1196 | struct eh_frame_sec_info *eh_inf; | |
1197 | ||
1198 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) | |
1199 | { | |
1200 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour | |
1201 | || (ibfd->flags & DYNAMIC) != 0) | |
1202 | continue; | |
1203 | ||
1204 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); | |
1205 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
1206 | continue; | |
1207 | ||
1208 | eh_inf = elf_section_data (eh)->sec_info; | |
1209 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) | |
1210 | { | |
1211 | ent->offset += eh->output_offset; | |
1212 | ent->new_offset += eh->output_offset; | |
1213 | } | |
1214 | } | |
1215 | hdr_info->offsets_adjusted = TRUE; | |
1216 | } | |
1217 | ||
126495ed AM |
1218 | if (hdr_info->table && hdr_info->array == NULL) |
1219 | hdr_info->array | |
1220 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
1221 | if (hdr_info->array == NULL) | |
1222 | hdr_info = NULL; | |
65765700 | 1223 | |
353057a5 RS |
1224 | /* The new offsets can be bigger or smaller than the original offsets. |
1225 | We therefore need to make two passes over the section: one backward | |
1226 | pass to move entries up and one forward pass to move entries down. | |
1227 | The two passes won't interfere with each other because entries are | |
1228 | not reordered */ | |
1229 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) | |
1230 | if (!ent->removed && ent->new_offset > ent->offset) | |
1231 | memmove (contents + ent->new_offset - sec->output_offset, | |
1232 | contents + ent->offset - sec->output_offset, ent->size); | |
1233 | ||
1234 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
1235 | if (!ent->removed && ent->new_offset < ent->offset) | |
1236 | memmove (contents + ent->new_offset - sec->output_offset, | |
1237 | contents + ent->offset - sec->output_offset, ent->size); | |
1238 | ||
fda3ecf2 | 1239 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
65765700 | 1240 | { |
353057a5 RS |
1241 | unsigned char *buf, *end; |
1242 | unsigned int new_size; | |
1243 | ||
fda3ecf2 AM |
1244 | if (ent->removed) |
1245 | continue; | |
1246 | ||
353057a5 RS |
1247 | if (ent->size == 4) |
1248 | { | |
1249 | /* Any terminating FDE must be at the end of the section. */ | |
1250 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); | |
1251 | continue; | |
1252 | } | |
1253 | ||
1254 | buf = contents + ent->new_offset - sec->output_offset; | |
1255 | end = buf + ent->size; | |
1256 | new_size = size_of_output_cie_fde (ent, ptr_size); | |
1257 | ||
a34a056a L |
1258 | /* Update the size. It may be shrinked. */ |
1259 | bfd_put_32 (abfd, new_size - 4, buf); | |
1260 | ||
1261 | /* Filling the extra bytes with DW_CFA_nops. */ | |
353057a5 | 1262 | if (new_size != ent->size) |
a34a056a | 1263 | memset (end, 0, new_size - ent->size); |
353057a5 | 1264 | |
fda3ecf2 | 1265 | if (ent->cie) |
65765700 JJ |
1266 | { |
1267 | /* CIE */ | |
353057a5 | 1268 | if (ent->make_relative |
fda3ecf2 AM |
1269 | || ent->need_lsda_relative |
1270 | || ent->per_encoding_relative) | |
65765700 | 1271 | { |
f075ee0c | 1272 | char *aug; |
353057a5 | 1273 | unsigned int action, extra_string, extra_data; |
2c42be65 | 1274 | unsigned int per_width, per_encoding; |
65765700 | 1275 | |
9e2a4898 | 1276 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 1277 | DW_EH_PE_* value. */ |
353057a5 | 1278 | action = ((ent->make_relative ? 1 : 0) |
fda3ecf2 AM |
1279 | | (ent->need_lsda_relative ? 2 : 0) |
1280 | | (ent->per_encoding_relative ? 4 : 0)); | |
353057a5 RS |
1281 | extra_string = extra_augmentation_string_bytes (ent); |
1282 | extra_data = extra_augmentation_data_bytes (ent); | |
1283 | ||
65765700 JJ |
1284 | /* Skip length, id and version. */ |
1285 | buf += 9; | |
f075ee0c AM |
1286 | aug = (char *) buf; |
1287 | buf += strlen (aug) + 1; | |
2c42be65 RS |
1288 | skip_leb128 (&buf, end); |
1289 | skip_leb128 (&buf, end); | |
1290 | skip_leb128 (&buf, end); | |
65765700 JJ |
1291 | if (*aug == 'z') |
1292 | { | |
353057a5 RS |
1293 | /* The uleb128 will always be a single byte for the kind |
1294 | of augmentation strings that we're prepared to handle. */ | |
1295 | *buf++ += extra_data; | |
65765700 JJ |
1296 | aug++; |
1297 | } | |
1298 | ||
353057a5 RS |
1299 | /* Make room for the new augmentation string and data bytes. */ |
1300 | memmove (buf + extra_string + extra_data, buf, end - buf); | |
f075ee0c | 1301 | memmove (aug + extra_string, aug, buf - (bfd_byte *) aug); |
353057a5 | 1302 | buf += extra_string; |
2c42be65 | 1303 | end += extra_string + extra_data; |
353057a5 RS |
1304 | |
1305 | if (ent->add_augmentation_size) | |
1306 | { | |
1307 | *aug++ = 'z'; | |
1308 | *buf++ = extra_data - 1; | |
1309 | } | |
1310 | if (ent->add_fde_encoding) | |
1311 | { | |
1312 | BFD_ASSERT (action & 1); | |
1313 | *aug++ = 'R'; | |
1314 | *buf++ = DW_EH_PE_pcrel; | |
1315 | action &= ~1; | |
1316 | } | |
1317 | ||
9e2a4898 | 1318 | while (action) |
65765700 JJ |
1319 | switch (*aug++) |
1320 | { | |
1321 | case 'L': | |
9e2a4898 JJ |
1322 | if (action & 2) |
1323 | { | |
fda3ecf2 | 1324 | BFD_ASSERT (*buf == ent->lsda_encoding); |
9e2a4898 JJ |
1325 | *buf |= DW_EH_PE_pcrel; |
1326 | action &= ~2; | |
1327 | } | |
65765700 JJ |
1328 | buf++; |
1329 | break; | |
1330 | case 'P': | |
1331 | per_encoding = *buf++; | |
3472e2e9 | 1332 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
65765700 | 1333 | BFD_ASSERT (per_width != 0); |
09ae86c2 | 1334 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
fda3ecf2 | 1335 | == ent->per_encoding_relative); |
65765700 JJ |
1336 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
1337 | buf = (contents | |
1338 | + ((buf - contents + per_width - 1) | |
1339 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
1340 | if (action & 4) |
1341 | { | |
fda3ecf2 AM |
1342 | bfd_vma val; |
1343 | ||
1344 | val = read_value (abfd, buf, per_width, | |
1345 | get_DW_EH_PE_signed (per_encoding)); | |
1346 | val += ent->offset - ent->new_offset; | |
353057a5 | 1347 | val -= extra_string + extra_data; |
fda3ecf2 | 1348 | write_value (abfd, buf, val, per_width); |
09ae86c2 JJ |
1349 | action &= ~4; |
1350 | } | |
65765700 JJ |
1351 | buf += per_width; |
1352 | break; | |
9e2a4898 JJ |
1353 | case 'R': |
1354 | if (action & 1) | |
1355 | { | |
fda3ecf2 | 1356 | BFD_ASSERT (*buf == ent->fde_encoding); |
9e2a4898 JJ |
1357 | *buf |= DW_EH_PE_pcrel; |
1358 | action &= ~1; | |
1359 | } | |
1360 | buf++; | |
1361 | break; | |
63752a75 JJ |
1362 | case 'S': |
1363 | break; | |
65765700 JJ |
1364 | default: |
1365 | BFD_FAIL (); | |
1366 | } | |
65765700 JJ |
1367 | } |
1368 | } | |
353057a5 | 1369 | else |
65765700 JJ |
1370 | { |
1371 | /* FDE */ | |
fda3ecf2 | 1372 | bfd_vma value, address; |
9e2a4898 | 1373 | unsigned int width; |
ac685e6a | 1374 | bfd_byte *start; |
65765700 | 1375 | |
b34976b6 | 1376 | /* Skip length. */ |
65765700 | 1377 | buf += 4; |
fda3ecf2 AM |
1378 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
1379 | bfd_put_32 (abfd, value, buf); | |
65765700 | 1380 | buf += 4; |
fda3ecf2 AM |
1381 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
1382 | value = read_value (abfd, buf, width, | |
1383 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1384 | address = value; | |
9e2a4898 | 1385 | if (value) |
65765700 | 1386 | { |
fda3ecf2 | 1387 | switch (ent->fde_encoding & 0xf0) |
9e2a4898 JJ |
1388 | { |
1389 | case DW_EH_PE_indirect: | |
1390 | case DW_EH_PE_textrel: | |
1391 | BFD_ASSERT (hdr_info == NULL); | |
1392 | break; | |
1393 | case DW_EH_PE_datarel: | |
1394 | { | |
1395 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1396 | ||
1397 | BFD_ASSERT (got != NULL); | |
1398 | address += got->vma; | |
1399 | } | |
1400 | break; | |
1401 | case DW_EH_PE_pcrel: | |
fda3ecf2 AM |
1402 | value += ent->offset - ent->new_offset; |
1403 | address += sec->output_section->vma + ent->offset + 8; | |
9e2a4898 JJ |
1404 | break; |
1405 | } | |
353057a5 | 1406 | if (ent->cie_inf->make_relative) |
fda3ecf2 | 1407 | value -= sec->output_section->vma + ent->new_offset + 8; |
9e2a4898 | 1408 | write_value (abfd, buf, value, width); |
65765700 JJ |
1409 | } |
1410 | ||
ac685e6a JJ |
1411 | start = buf; |
1412 | ||
65765700 JJ |
1413 | if (hdr_info) |
1414 | { | |
1415 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1416 | hdr_info->array[hdr_info->array_count++].fde | |
fda3ecf2 | 1417 | = sec->output_section->vma + ent->new_offset; |
65765700 | 1418 | } |
9e2a4898 | 1419 | |
fda3ecf2 AM |
1420 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
1421 | || ent->cie_inf->need_lsda_relative) | |
9e2a4898 | 1422 | { |
fda3ecf2 AM |
1423 | buf += ent->lsda_offset; |
1424 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); | |
84f97cb6 | 1425 | value = read_value (abfd, buf, width, |
fda3ecf2 | 1426 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
9e2a4898 JJ |
1427 | if (value) |
1428 | { | |
fda3ecf2 AM |
1429 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
1430 | value += ent->offset - ent->new_offset; | |
1431 | else if (ent->cie_inf->need_lsda_relative) | |
1432 | value -= (sec->output_section->vma + ent->new_offset + 8 | |
1433 | + ent->lsda_offset); | |
9e2a4898 JJ |
1434 | write_value (abfd, buf, value, width); |
1435 | } | |
1436 | } | |
353057a5 RS |
1437 | else if (ent->cie_inf->add_augmentation_size) |
1438 | { | |
1439 | /* Skip the PC and length and insert a zero byte for the | |
1440 | augmentation size. */ | |
1441 | buf += width * 2; | |
1442 | memmove (buf + 1, buf, end - buf); | |
1443 | *buf = 0; | |
1444 | } | |
ac685e6a JJ |
1445 | |
1446 | if (ent->set_loc) | |
1447 | { | |
1448 | /* Adjust DW_CFA_set_loc. */ | |
1449 | unsigned int cnt, width; | |
1450 | bfd_vma new_offset; | |
1451 | ||
1452 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); | |
1453 | new_offset = ent->new_offset + 8 | |
1454 | + extra_augmentation_string_bytes (ent) | |
1455 | + extra_augmentation_data_bytes (ent); | |
1456 | ||
1457 | for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) | |
1458 | { | |
1459 | bfd_vma value; | |
1460 | buf = start + ent->set_loc[cnt]; | |
1461 | ||
1462 | value = read_value (abfd, buf, width, | |
1463 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1464 | if (!value) | |
1465 | continue; | |
1466 | ||
1467 | if ((ent->fde_encoding & 0xf0) == DW_EH_PE_pcrel) | |
1468 | value += ent->offset + 8 - new_offset; | |
1469 | if (ent->cie_inf->make_relative) | |
1470 | value -= sec->output_section->vma + new_offset | |
1471 | + ent->set_loc[cnt]; | |
1472 | write_value (abfd, buf, value, width); | |
1473 | } | |
1474 | } | |
65765700 | 1475 | } |
65765700 JJ |
1476 | } |
1477 | ||
a34a056a L |
1478 | /* We don't align the section to its section alignment since the |
1479 | runtime library only expects all CIE/FDE records aligned at | |
4e591bc1 | 1480 | the pointer size. _bfd_elf_discard_section_eh_frame should |
a34a056a L |
1481 | have padded CIE/FDE records to multiple of pointer size with |
1482 | size_of_output_cie_fde. */ | |
1483 | if ((sec->size % ptr_size) != 0) | |
1484 | abort (); | |
a5eb27e6 | 1485 | |
65765700 | 1486 | return bfd_set_section_contents (abfd, sec->output_section, |
3472e2e9 AM |
1487 | contents, (file_ptr) sec->output_offset, |
1488 | sec->size); | |
65765700 JJ |
1489 | } |
1490 | ||
1491 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1492 | VMA of FDE initial location. */ | |
1493 | ||
1494 | static int | |
c39a58e6 | 1495 | vma_compare (const void *a, const void *b) |
65765700 | 1496 | { |
c39a58e6 AM |
1497 | const struct eh_frame_array_ent *p = a; |
1498 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1499 | if (p->initial_loc > q->initial_loc) |
1500 | return 1; | |
1501 | if (p->initial_loc < q->initial_loc) | |
1502 | return -1; | |
1503 | return 0; | |
1504 | } | |
1505 | ||
1506 | /* Write out .eh_frame_hdr section. This must be called after | |
1507 | _bfd_elf_write_section_eh_frame has been called on all input | |
1508 | .eh_frame sections. | |
1509 | .eh_frame_hdr format: | |
1510 | ubyte version (currently 1) | |
1511 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1512 | .eh_frame section) | |
1513 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1514 | number (or DW_EH_PE_omit if there is no | |
1515 | binary search table computed)) | |
1516 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1517 | or DW_EH_PE_omit if not present. | |
1518 | DW_EH_PE_datarel is using address of | |
1519 | .eh_frame_hdr section start as base) | |
1520 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1521 | optionally followed by: | |
1522 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1523 | fde_count x [encoded] initial_loc, fde | |
1524 | (array of encoded pairs containing | |
1525 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1526 | sorted by increasing initial_loc). */ |
65765700 | 1527 | |
b34976b6 | 1528 | bfd_boolean |
c39a58e6 | 1529 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1530 | { |
126495ed | 1531 | struct elf_link_hash_table *htab; |
65765700 | 1532 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1533 | asection *sec; |
65765700 JJ |
1534 | bfd_byte *contents; |
1535 | asection *eh_frame_sec; | |
1536 | bfd_size_type size; | |
5ed6aba4 | 1537 | bfd_boolean retval; |
ec3391e7 | 1538 | bfd_vma encoded_eh_frame; |
65765700 | 1539 | |
126495ed AM |
1540 | htab = elf_hash_table (info); |
1541 | hdr_info = &htab->eh_info; | |
1542 | sec = hdr_info->hdr_sec; | |
1543 | if (sec == NULL) | |
b34976b6 | 1544 | return TRUE; |
57a72197 | 1545 | |
65765700 JJ |
1546 | size = EH_FRAME_HDR_SIZE; |
1547 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1548 | size += 4 + hdr_info->fde_count * 8; | |
1549 | contents = bfd_malloc (size); | |
1550 | if (contents == NULL) | |
b34976b6 | 1551 | return FALSE; |
65765700 JJ |
1552 | |
1553 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1554 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1555 | { |
1556 | free (contents); | |
1557 | return FALSE; | |
1558 | } | |
65765700 JJ |
1559 | |
1560 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1561 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1562 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1563 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1564 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1565 | ||
65765700 JJ |
1566 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1567 | { | |
5ed6aba4 NC |
1568 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1569 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1570 | } |
1571 | else | |
1572 | { | |
1573 | contents[2] = DW_EH_PE_omit; | |
1574 | contents[3] = DW_EH_PE_omit; | |
1575 | } | |
ec3391e7 AO |
1576 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1577 | ||
65765700 JJ |
1578 | if (contents[2] != DW_EH_PE_omit) |
1579 | { | |
1580 | unsigned int i; | |
1581 | ||
1582 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1583 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1584 | vma_compare); | |
1585 | for (i = 0; i < hdr_info->fde_count; i++) | |
1586 | { | |
1587 | bfd_put_32 (abfd, | |
1588 | hdr_info->array[i].initial_loc | |
1589 | - sec->output_section->vma, | |
1590 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1591 | bfd_put_32 (abfd, | |
1592 | hdr_info->array[i].fde - sec->output_section->vma, | |
1593 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1594 | } | |
1595 | } | |
1596 | ||
5ed6aba4 NC |
1597 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1598 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1599 | sec->size); |
5ed6aba4 NC |
1600 | free (contents); |
1601 | return retval; | |
65765700 | 1602 | } |
ec3391e7 | 1603 | |
8c946ed5 RS |
1604 | /* Return the width of FDE addresses. This is the default implementation. */ |
1605 | ||
1606 | unsigned int | |
1607 | _bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) | |
1608 | { | |
1609 | return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; | |
1610 | } | |
1611 | ||
ec3391e7 AO |
1612 | /* Decide whether we can use a PC-relative encoding within the given |
1613 | EH frame section. This is the default implementation. */ | |
1614 | ||
1615 | bfd_boolean | |
1616 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1617 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1618 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1619 | { | |
1620 | return TRUE; | |
1621 | } | |
1622 | ||
1623 | /* Select an encoding for the given address. Preference is given to | |
1624 | PC-relative addressing modes. */ | |
1625 | ||
1626 | bfd_byte | |
1627 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1628 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1629 | asection *osec, bfd_vma offset, | |
1630 | asection *loc_sec, bfd_vma loc_offset, | |
1631 | bfd_vma *encoded) | |
1632 | { | |
1633 | *encoded = osec->vma + offset - | |
1634 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1635 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1636 | } |