Commit | Line | Data |
---|---|---|
65765700 | 1 | /* .eh_frame section optimization. |
acfe5567 | 2 | Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
65765700 JJ |
3 | Written by Jakub Jelinek <jakub@redhat.com>. |
4 | ||
5ed6aba4 | 5 | This file is part of BFD, the Binary File Descriptor library. |
65765700 | 6 | |
5ed6aba4 NC |
7 | This program is free software; you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
65765700 | 11 | |
5ed6aba4 NC |
12 | This program is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
65765700 | 16 | |
5ed6aba4 NC |
17 | You should have received a copy of the GNU General Public License |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
65765700 JJ |
20 | |
21 | #include "bfd.h" | |
22 | #include "sysdep.h" | |
23 | #include "libbfd.h" | |
24 | #include "elf-bfd.h" | |
25 | #include "elf/dwarf2.h" | |
26 | ||
27 | #define EH_FRAME_HDR_SIZE 8 | |
28 | ||
2c42be65 RS |
29 | /* If *ITER hasn't reached END yet, read the next byte into *RESULT and |
30 | move onto the next byte. Return true on success. */ | |
31 | ||
32 | static inline bfd_boolean | |
33 | read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result) | |
34 | { | |
35 | if (*iter >= end) | |
36 | return FALSE; | |
37 | *result = *((*iter)++); | |
38 | return TRUE; | |
39 | } | |
40 | ||
41 | /* Move *ITER over LENGTH bytes, or up to END, whichever is closer. | |
42 | Return true it was possible to move LENGTH bytes. */ | |
43 | ||
44 | static inline bfd_boolean | |
45 | skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length) | |
46 | { | |
47 | if ((bfd_size_type) (end - *iter) < length) | |
48 | { | |
49 | *iter = end; | |
50 | return FALSE; | |
51 | } | |
52 | *iter += length; | |
53 | return TRUE; | |
54 | } | |
55 | ||
56 | /* Move *ITER over an leb128, stopping at END. Return true if the end | |
57 | of the leb128 was found. */ | |
58 | ||
59 | static bfd_boolean | |
60 | skip_leb128 (bfd_byte **iter, bfd_byte *end) | |
61 | { | |
62 | unsigned char byte; | |
63 | do | |
64 | if (!read_byte (iter, end, &byte)) | |
65 | return FALSE; | |
66 | while (byte & 0x80); | |
67 | return TRUE; | |
68 | } | |
69 | ||
70 | /* Like skip_leb128, but treat the leb128 as an unsigned value and | |
71 | store it in *VALUE. */ | |
72 | ||
73 | static bfd_boolean | |
74 | read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value) | |
75 | { | |
76 | bfd_byte *start, *p; | |
77 | ||
78 | start = *iter; | |
79 | if (!skip_leb128 (iter, end)) | |
80 | return FALSE; | |
81 | ||
82 | p = *iter; | |
83 | *value = *--p; | |
84 | while (p > start) | |
85 | *value = (*value << 7) | (*--p & 0x7f); | |
86 | ||
87 | return TRUE; | |
88 | } | |
89 | ||
90 | /* Like read_uleb128, but for signed values. */ | |
91 | ||
92 | static bfd_boolean | |
93 | read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value) | |
94 | { | |
95 | bfd_byte *start, *p; | |
96 | ||
97 | start = *iter; | |
98 | if (!skip_leb128 (iter, end)) | |
99 | return FALSE; | |
100 | ||
101 | p = *iter; | |
102 | *value = ((*--p & 0x7f) ^ 0x40) - 0x40; | |
103 | while (p > start) | |
104 | *value = (*value << 7) | (*--p & 0x7f); | |
105 | ||
106 | return TRUE; | |
107 | } | |
65765700 JJ |
108 | |
109 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
110 | ||
111 | static | |
c39a58e6 | 112 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
65765700 JJ |
113 | { |
114 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
115 | was added to bfd. */ | |
116 | if ((encoding & 0x60) == 0x60) | |
117 | return 0; | |
118 | ||
119 | switch (encoding & 7) | |
120 | { | |
121 | case DW_EH_PE_udata2: return 2; | |
122 | case DW_EH_PE_udata4: return 4; | |
123 | case DW_EH_PE_udata8: return 8; | |
124 | case DW_EH_PE_absptr: return ptr_size; | |
125 | default: | |
126 | break; | |
127 | } | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
84f97cb6 AS |
132 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
133 | ||
9e2a4898 JJ |
134 | /* Read a width sized value from memory. */ |
135 | ||
136 | static bfd_vma | |
c39a58e6 | 137 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
9e2a4898 JJ |
138 | { |
139 | bfd_vma value; | |
140 | ||
141 | switch (width) | |
142 | { | |
84f97cb6 AS |
143 | case 2: |
144 | if (is_signed) | |
145 | value = bfd_get_signed_16 (abfd, buf); | |
146 | else | |
147 | value = bfd_get_16 (abfd, buf); | |
148 | break; | |
149 | case 4: | |
150 | if (is_signed) | |
151 | value = bfd_get_signed_32 (abfd, buf); | |
152 | else | |
153 | value = bfd_get_32 (abfd, buf); | |
154 | break; | |
155 | case 8: | |
156 | if (is_signed) | |
157 | value = bfd_get_signed_64 (abfd, buf); | |
158 | else | |
159 | value = bfd_get_64 (abfd, buf); | |
160 | break; | |
161 | default: | |
162 | BFD_FAIL (); | |
163 | return 0; | |
9e2a4898 JJ |
164 | } |
165 | ||
166 | return value; | |
167 | } | |
b34976b6 | 168 | |
9e2a4898 JJ |
169 | /* Store a width sized value to memory. */ |
170 | ||
171 | static void | |
c39a58e6 | 172 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
9e2a4898 JJ |
173 | { |
174 | switch (width) | |
175 | { | |
176 | case 2: bfd_put_16 (abfd, value, buf); break; | |
177 | case 4: bfd_put_32 (abfd, value, buf); break; | |
178 | case 8: bfd_put_64 (abfd, value, buf); break; | |
179 | default: BFD_FAIL (); | |
180 | } | |
181 | } | |
182 | ||
65765700 JJ |
183 | /* Return zero if C1 and C2 CIEs can be merged. */ |
184 | ||
185 | static | |
c39a58e6 | 186 | int cie_compare (struct cie *c1, struct cie *c2) |
65765700 JJ |
187 | { |
188 | if (c1->hdr.length == c2->hdr.length | |
189 | && c1->version == c2->version | |
190 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
191 | && strcmp (c1->augmentation, "eh") != 0 | |
192 | && c1->code_align == c2->code_align | |
193 | && c1->data_align == c2->data_align | |
194 | && c1->ra_column == c2->ra_column | |
195 | && c1->augmentation_size == c2->augmentation_size | |
196 | && c1->personality == c2->personality | |
197 | && c1->per_encoding == c2->per_encoding | |
198 | && c1->lsda_encoding == c2->lsda_encoding | |
199 | && c1->fde_encoding == c2->fde_encoding | |
c39a58e6 | 200 | && c1->initial_insn_length == c2->initial_insn_length |
65765700 JJ |
201 | && memcmp (c1->initial_instructions, |
202 | c2->initial_instructions, | |
203 | c1->initial_insn_length) == 0) | |
204 | return 0; | |
205 | ||
206 | return 1; | |
207 | } | |
208 | ||
353057a5 RS |
209 | /* Return the number of extra bytes that we'll be inserting into |
210 | ENTRY's augmentation string. */ | |
211 | ||
212 | static INLINE unsigned int | |
213 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) | |
214 | { | |
215 | unsigned int size = 0; | |
216 | if (entry->cie) | |
217 | { | |
218 | if (entry->add_augmentation_size) | |
219 | size++; | |
220 | if (entry->add_fde_encoding) | |
221 | size++; | |
222 | } | |
223 | return size; | |
224 | } | |
225 | ||
226 | /* Likewise ENTRY's augmentation data. */ | |
227 | ||
228 | static INLINE unsigned int | |
229 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) | |
230 | { | |
231 | unsigned int size = 0; | |
232 | if (entry->cie) | |
233 | { | |
234 | if (entry->add_augmentation_size) | |
235 | size++; | |
236 | if (entry->add_fde_encoding) | |
237 | size++; | |
238 | } | |
239 | else | |
240 | { | |
241 | if (entry->cie_inf->add_augmentation_size) | |
242 | size++; | |
243 | } | |
244 | return size; | |
245 | } | |
246 | ||
247 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the | |
248 | required alignment of ENTRY in bytes. */ | |
249 | ||
250 | static unsigned int | |
251 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) | |
252 | { | |
253 | if (entry->removed) | |
254 | return 0; | |
255 | if (entry->size == 4) | |
256 | return 4; | |
257 | return (entry->size | |
258 | + extra_augmentation_string_bytes (entry) | |
259 | + extra_augmentation_data_bytes (entry) | |
260 | + alignment - 1) & -alignment; | |
261 | } | |
262 | ||
dcf507a6 RS |
263 | /* Assume that the bytes between *ITER and END are CFA instructions. |
264 | Try to move *ITER past the first instruction and return true on | |
265 | success. ENCODED_PTR_WIDTH gives the width of pointer entries. */ | |
266 | ||
267 | static bfd_boolean | |
268 | skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width) | |
269 | { | |
270 | bfd_byte op; | |
271 | bfd_vma length; | |
272 | ||
273 | if (!read_byte (iter, end, &op)) | |
274 | return FALSE; | |
275 | ||
276 | switch (op & 0x80 ? op & 0xc0 : op) | |
277 | { | |
278 | case DW_CFA_nop: | |
279 | case DW_CFA_advance_loc: | |
280 | case DW_CFA_restore: | |
281 | /* No arguments. */ | |
282 | return TRUE; | |
283 | ||
284 | case DW_CFA_offset: | |
285 | case DW_CFA_restore_extended: | |
286 | case DW_CFA_undefined: | |
287 | case DW_CFA_same_value: | |
288 | case DW_CFA_def_cfa_register: | |
289 | case DW_CFA_def_cfa_offset: | |
290 | case DW_CFA_def_cfa_offset_sf: | |
291 | case DW_CFA_GNU_args_size: | |
292 | /* One leb128 argument. */ | |
293 | return skip_leb128 (iter, end); | |
294 | ||
295 | case DW_CFA_offset_extended: | |
296 | case DW_CFA_register: | |
297 | case DW_CFA_def_cfa: | |
298 | case DW_CFA_offset_extended_sf: | |
299 | case DW_CFA_GNU_negative_offset_extended: | |
300 | case DW_CFA_def_cfa_sf: | |
301 | /* Two leb128 arguments. */ | |
302 | return (skip_leb128 (iter, end) | |
303 | && skip_leb128 (iter, end)); | |
304 | ||
305 | case DW_CFA_def_cfa_expression: | |
306 | /* A variable-length argument. */ | |
307 | return (read_uleb128 (iter, end, &length) | |
308 | && skip_bytes (iter, end, length)); | |
309 | ||
310 | case DW_CFA_expression: | |
311 | /* A leb128 followed by a variable-length argument. */ | |
312 | return (skip_leb128 (iter, end) | |
313 | && read_uleb128 (iter, end, &length) | |
314 | && skip_bytes (iter, end, length)); | |
315 | ||
316 | case DW_CFA_set_loc: | |
317 | return skip_bytes (iter, end, encoded_ptr_width); | |
318 | ||
319 | case DW_CFA_advance_loc1: | |
320 | return skip_bytes (iter, end, 1); | |
321 | ||
322 | case DW_CFA_advance_loc2: | |
323 | return skip_bytes (iter, end, 2); | |
324 | ||
325 | case DW_CFA_advance_loc4: | |
326 | return skip_bytes (iter, end, 4); | |
327 | ||
328 | case DW_CFA_MIPS_advance_loc8: | |
329 | return skip_bytes (iter, end, 8); | |
330 | ||
331 | default: | |
332 | return FALSE; | |
333 | } | |
334 | } | |
335 | ||
336 | /* Try to interpret the bytes between BUF and END as CFA instructions. | |
337 | If every byte makes sense, return a pointer to the first DW_CFA_nop | |
338 | padding byte, or END if there is no padding. Return null otherwise. | |
339 | ENCODED_PTR_WIDTH is as for skip_cfa_op. */ | |
340 | ||
341 | static bfd_byte * | |
342 | skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width) | |
343 | { | |
344 | bfd_byte *last; | |
345 | ||
346 | last = buf; | |
347 | while (buf < end) | |
348 | if (*buf == DW_CFA_nop) | |
349 | buf++; | |
350 | else | |
351 | { | |
352 | if (!skip_cfa_op (&buf, end, encoded_ptr_width)) | |
353 | return 0; | |
354 | last = buf; | |
355 | } | |
356 | return last; | |
357 | } | |
358 | ||
65765700 JJ |
359 | /* This function is called for each input file before the .eh_frame |
360 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
b34976b6 | 361 | functions. The function returns TRUE iff any entries have been |
65765700 JJ |
362 | deleted. */ |
363 | ||
b34976b6 | 364 | bfd_boolean |
c39a58e6 AM |
365 | _bfd_elf_discard_section_eh_frame |
366 | (bfd *abfd, struct bfd_link_info *info, asection *sec, | |
367 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), | |
368 | struct elf_reloc_cookie *cookie) | |
65765700 | 369 | { |
acfe5567 RS |
370 | #define REQUIRE(COND) \ |
371 | do \ | |
372 | if (!(COND)) \ | |
373 | goto free_no_table; \ | |
374 | while (0) | |
375 | ||
65765700 JJ |
376 | bfd_byte *ehbuf = NULL, *buf; |
377 | bfd_byte *last_cie, *last_fde; | |
fda3ecf2 | 378 | struct eh_cie_fde *ent, *last_cie_inf, *this_inf; |
65765700 JJ |
379 | struct cie_header hdr; |
380 | struct cie cie; | |
126495ed | 381 | struct elf_link_hash_table *htab; |
65765700 | 382 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 383 | struct eh_frame_sec_info *sec_info = NULL; |
fda3ecf2 | 384 | unsigned int cie_usage_count, offset; |
65765700 JJ |
385 | unsigned int ptr_size; |
386 | ||
eea6121a | 387 | if (sec->size == 0) |
65765700 JJ |
388 | { |
389 | /* This file does not contain .eh_frame information. */ | |
b34976b6 | 390 | return FALSE; |
65765700 JJ |
391 | } |
392 | ||
393 | if ((sec->output_section != NULL | |
394 | && bfd_is_abs_section (sec->output_section))) | |
395 | { | |
396 | /* At least one of the sections is being discarded from the | |
3472e2e9 | 397 | link, so we should just ignore them. */ |
b34976b6 | 398 | return FALSE; |
65765700 JJ |
399 | } |
400 | ||
126495ed AM |
401 | htab = elf_hash_table (info); |
402 | hdr_info = &htab->eh_info; | |
68f69152 | 403 | |
65765700 JJ |
404 | /* Read the frame unwind information from abfd. */ |
405 | ||
acfe5567 | 406 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
68f69152 | 407 | |
eea6121a | 408 | if (sec->size >= 4 |
65765700 JJ |
409 | && bfd_get_32 (abfd, ehbuf) == 0 |
410 | && cookie->rel == cookie->relend) | |
411 | { | |
412 | /* Empty .eh_frame section. */ | |
413 | free (ehbuf); | |
b34976b6 | 414 | return FALSE; |
65765700 JJ |
415 | } |
416 | ||
65765700 JJ |
417 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
418 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
acfe5567 | 419 | REQUIRE (sec->size == (unsigned int) sec->size); |
65765700 JJ |
420 | |
421 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
422 | == ELFCLASS64) ? 8 : 4; | |
423 | buf = ehbuf; | |
424 | last_cie = NULL; | |
fda3ecf2 | 425 | last_cie_inf = NULL; |
65765700 JJ |
426 | memset (&cie, 0, sizeof (cie)); |
427 | cie_usage_count = 0; | |
65765700 JJ |
428 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
429 | + 99 * sizeof (struct eh_cie_fde)); | |
acfe5567 | 430 | REQUIRE (sec_info); |
eea6121a | 431 | |
65765700 JJ |
432 | sec_info->alloced = 100; |
433 | ||
434 | #define ENSURE_NO_RELOCS(buf) \ | |
acfe5567 RS |
435 | REQUIRE (!(cookie->rel < cookie->relend \ |
436 | && (cookie->rel->r_offset \ | |
437 | < (bfd_size_type) ((buf) - ehbuf)) \ | |
438 | && cookie->rel->r_info != 0)) | |
65765700 JJ |
439 | |
440 | #define SKIP_RELOCS(buf) \ | |
441 | while (cookie->rel < cookie->relend \ | |
3472e2e9 | 442 | && (cookie->rel->r_offset \ |
65765700 JJ |
443 | < (bfd_size_type) ((buf) - ehbuf))) \ |
444 | cookie->rel++ | |
445 | ||
446 | #define GET_RELOC(buf) \ | |
447 | ((cookie->rel < cookie->relend \ | |
448 | && (cookie->rel->r_offset \ | |
3472e2e9 | 449 | == (bfd_size_type) ((buf) - ehbuf))) \ |
65765700 JJ |
450 | ? cookie->rel : NULL) |
451 | ||
452 | for (;;) | |
453 | { | |
454 | unsigned char *aug; | |
dcf507a6 | 455 | bfd_byte *start, *end, *insns; |
2c42be65 | 456 | bfd_size_type length; |
65765700 JJ |
457 | |
458 | if (sec_info->count == sec_info->alloced) | |
459 | { | |
fda3ecf2 | 460 | struct eh_cie_fde *old_entry = sec_info->entry; |
65765700 JJ |
461 | sec_info = bfd_realloc (sec_info, |
462 | sizeof (struct eh_frame_sec_info) | |
fda3ecf2 AM |
463 | + ((sec_info->alloced + 99) |
464 | * sizeof (struct eh_cie_fde))); | |
acfe5567 | 465 | REQUIRE (sec_info); |
65765700 JJ |
466 | |
467 | memset (&sec_info->entry[sec_info->alloced], 0, | |
468 | 100 * sizeof (struct eh_cie_fde)); | |
469 | sec_info->alloced += 100; | |
fda3ecf2 AM |
470 | |
471 | /* Now fix any pointers into the array. */ | |
472 | if (last_cie_inf >= old_entry | |
473 | && last_cie_inf < old_entry + sec_info->count) | |
474 | last_cie_inf = sec_info->entry + (last_cie_inf - old_entry); | |
65765700 JJ |
475 | } |
476 | ||
fda3ecf2 | 477 | this_inf = sec_info->entry + sec_info->count; |
65765700 JJ |
478 | last_fde = buf; |
479 | /* If we are at the end of the section, we still need to decide | |
480 | on whether to output or discard last encountered CIE (if any). */ | |
eea6121a | 481 | if ((bfd_size_type) (buf - ehbuf) == sec->size) |
2c42be65 RS |
482 | { |
483 | hdr.id = (unsigned int) -1; | |
484 | end = buf; | |
485 | } | |
65765700 JJ |
486 | else |
487 | { | |
acfe5567 | 488 | /* Read the length of the entry. */ |
2c42be65 RS |
489 | REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4)); |
490 | hdr.length = bfd_get_32 (abfd, buf - 4); | |
acfe5567 RS |
491 | |
492 | /* 64-bit .eh_frame is not supported. */ | |
493 | REQUIRE (hdr.length != 0xffffffff); | |
494 | ||
495 | /* The CIE/FDE must be fully contained in this input section. */ | |
496 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr.length <= sec->size); | |
2c42be65 | 497 | end = buf + hdr.length; |
65765700 | 498 | |
fda3ecf2 AM |
499 | this_inf->offset = last_fde - ehbuf; |
500 | this_inf->size = 4 + hdr.length; | |
65765700 JJ |
501 | |
502 | if (hdr.length == 0) | |
503 | { | |
acfe5567 RS |
504 | /* A zero-length CIE should only be found at the end of |
505 | the section. */ | |
506 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); | |
65765700 JJ |
507 | ENSURE_NO_RELOCS (buf); |
508 | sec_info->count++; | |
509 | /* Now just finish last encountered CIE processing and break | |
510 | the loop. */ | |
511 | hdr.id = (unsigned int) -1; | |
512 | } | |
513 | else | |
514 | { | |
2c42be65 RS |
515 | REQUIRE (skip_bytes (&buf, end, 4)); |
516 | hdr.id = bfd_get_32 (abfd, buf - 4); | |
acfe5567 | 517 | REQUIRE (hdr.id != (unsigned int) -1); |
65765700 JJ |
518 | } |
519 | } | |
520 | ||
521 | if (hdr.id == 0 || hdr.id == (unsigned int) -1) | |
522 | { | |
523 | unsigned int initial_insn_length; | |
524 | ||
525 | /* CIE */ | |
526 | if (last_cie != NULL) | |
527 | { | |
73722af0 AM |
528 | /* Now check if this CIE is identical to the last CIE, |
529 | in which case we can remove it provided we adjust | |
530 | all FDEs. Also, it can be removed if we have removed | |
531 | all FDEs using it. */ | |
1049f94e | 532 | if ((!info->relocatable |
9da84788 L |
533 | && hdr_info->last_cie_sec |
534 | && (sec->output_section | |
535 | == hdr_info->last_cie_sec->output_section) | |
73722af0 | 536 | && cie_compare (&cie, &hdr_info->last_cie) == 0) |
65765700 | 537 | || cie_usage_count == 0) |
353057a5 | 538 | last_cie_inf->removed = 1; |
65765700 JJ |
539 | else |
540 | { | |
541 | hdr_info->last_cie = cie; | |
542 | hdr_info->last_cie_sec = sec; | |
fda3ecf2 AM |
543 | last_cie_inf->make_relative = cie.make_relative; |
544 | last_cie_inf->make_lsda_relative = cie.make_lsda_relative; | |
545 | last_cie_inf->per_encoding_relative | |
09ae86c2 | 546 | = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel; |
65765700 JJ |
547 | } |
548 | } | |
549 | ||
550 | if (hdr.id == (unsigned int) -1) | |
551 | break; | |
552 | ||
fda3ecf2 AM |
553 | last_cie_inf = this_inf; |
554 | this_inf->cie = 1; | |
65765700 JJ |
555 | |
556 | cie_usage_count = 0; | |
557 | memset (&cie, 0, sizeof (cie)); | |
558 | cie.hdr = hdr; | |
2c42be65 | 559 | REQUIRE (read_byte (&buf, end, &cie.version)); |
65765700 JJ |
560 | |
561 | /* Cannot handle unknown versions. */ | |
acfe5567 RS |
562 | REQUIRE (cie.version == 1 || cie.version == 3); |
563 | REQUIRE (strlen (buf) < sizeof (cie.augmentation)); | |
65765700 JJ |
564 | |
565 | strcpy (cie.augmentation, buf); | |
566 | buf = strchr (buf, '\0') + 1; | |
567 | ENSURE_NO_RELOCS (buf); | |
568 | if (buf[0] == 'e' && buf[1] == 'h') | |
569 | { | |
570 | /* GCC < 3.0 .eh_frame CIE */ | |
571 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
572 | is private to each CIE, so we don't need it for anything. | |
573 | Just skip it. */ | |
2c42be65 | 574 | REQUIRE (skip_bytes (&buf, end, ptr_size)); |
65765700 JJ |
575 | SKIP_RELOCS (buf); |
576 | } | |
2c42be65 RS |
577 | REQUIRE (read_uleb128 (&buf, end, &cie.code_align)); |
578 | REQUIRE (read_sleb128 (&buf, end, &cie.data_align)); | |
0da76f83 | 579 | if (cie.version == 1) |
2c42be65 RS |
580 | { |
581 | REQUIRE (buf < end); | |
582 | cie.ra_column = *buf++; | |
583 | } | |
0da76f83 | 584 | else |
2c42be65 | 585 | REQUIRE (read_uleb128 (&buf, end, &cie.ra_column)); |
65765700 JJ |
586 | ENSURE_NO_RELOCS (buf); |
587 | cie.lsda_encoding = DW_EH_PE_omit; | |
588 | cie.fde_encoding = DW_EH_PE_omit; | |
589 | cie.per_encoding = DW_EH_PE_omit; | |
590 | aug = cie.augmentation; | |
591 | if (aug[0] != 'e' || aug[1] != 'h') | |
592 | { | |
593 | if (*aug == 'z') | |
594 | { | |
595 | aug++; | |
2c42be65 | 596 | REQUIRE (read_uleb128 (&buf, end, &cie.augmentation_size)); |
65765700 JJ |
597 | ENSURE_NO_RELOCS (buf); |
598 | } | |
599 | ||
600 | while (*aug != '\0') | |
601 | switch (*aug++) | |
602 | { | |
603 | case 'L': | |
2c42be65 | 604 | REQUIRE (read_byte (&buf, end, &cie.lsda_encoding)); |
65765700 | 605 | ENSURE_NO_RELOCS (buf); |
acfe5567 | 606 | REQUIRE (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size)); |
65765700 JJ |
607 | break; |
608 | case 'R': | |
2c42be65 | 609 | REQUIRE (read_byte (&buf, end, &cie.fde_encoding)); |
65765700 | 610 | ENSURE_NO_RELOCS (buf); |
acfe5567 | 611 | REQUIRE (get_DW_EH_PE_width (cie.fde_encoding, ptr_size)); |
65765700 JJ |
612 | break; |
613 | case 'P': | |
614 | { | |
615 | int per_width; | |
616 | ||
2c42be65 | 617 | REQUIRE (read_byte (&buf, end, &cie.per_encoding)); |
65765700 JJ |
618 | per_width = get_DW_EH_PE_width (cie.per_encoding, |
619 | ptr_size); | |
acfe5567 | 620 | REQUIRE (per_width); |
65765700 | 621 | if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned) |
2c42be65 RS |
622 | { |
623 | length = -(buf - ehbuf) & (per_width - 1); | |
624 | REQUIRE (skip_bytes (&buf, end, length)); | |
625 | } | |
65765700 | 626 | ENSURE_NO_RELOCS (buf); |
65765700 JJ |
627 | /* Ensure we have a reloc here, against |
628 | a global symbol. */ | |
99eb2ac8 | 629 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
630 | { |
631 | unsigned long r_symndx; | |
632 | ||
633 | #ifdef BFD64 | |
634 | if (ptr_size == 8) | |
635 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
636 | else | |
637 | #endif | |
638 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
639 | if (r_symndx >= cookie->locsymcount) | |
640 | { | |
641 | struct elf_link_hash_entry *h; | |
642 | ||
643 | r_symndx -= cookie->extsymoff; | |
644 | h = cookie->sym_hashes[r_symndx]; | |
645 | ||
646 | while (h->root.type == bfd_link_hash_indirect | |
647 | || h->root.type == bfd_link_hash_warning) | |
648 | h = (struct elf_link_hash_entry *) | |
649 | h->root.u.i.link; | |
650 | ||
651 | cie.personality = h; | |
652 | } | |
f4a6705c RS |
653 | /* Cope with MIPS-style composite relocations. */ |
654 | do | |
655 | cookie->rel++; | |
656 | while (GET_RELOC (buf) != NULL); | |
65765700 | 657 | } |
2c42be65 | 658 | REQUIRE (skip_bytes (&buf, end, per_width)); |
65765700 JJ |
659 | } |
660 | break; | |
661 | default: | |
662 | /* Unrecognized augmentation. Better bail out. */ | |
663 | goto free_no_table; | |
664 | } | |
665 | } | |
666 | ||
667 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a | 668 | as possible. */ |
3472e2e9 | 669 | if (info->shared |
ec3391e7 AO |
670 | && (get_elf_backend_data (abfd) |
671 | ->elf_backend_can_make_relative_eh_frame | |
353057a5 RS |
672 | (abfd, info, sec))) |
673 | { | |
674 | if ((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) | |
675 | cie.make_relative = 1; | |
676 | /* If the CIE doesn't already have an 'R' entry, it's fairly | |
677 | easy to add one, provided that there's no aligned data | |
678 | after the augmentation string. */ | |
679 | else if (cie.fde_encoding == DW_EH_PE_omit | |
680 | && (cie.per_encoding & 0xf0) != DW_EH_PE_aligned) | |
681 | { | |
682 | if (*cie.augmentation == 0) | |
683 | this_inf->add_augmentation_size = 1; | |
684 | this_inf->add_fde_encoding = 1; | |
685 | cie.make_relative = 1; | |
686 | } | |
687 | } | |
65765700 | 688 | |
0bb2d96a | 689 | if (info->shared |
ec3391e7 AO |
690 | && (get_elf_backend_data (abfd) |
691 | ->elf_backend_can_make_lsda_relative_eh_frame | |
692 | (abfd, info, sec)) | |
9e2a4898 JJ |
693 | && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
694 | cie.make_lsda_relative = 1; | |
695 | ||
65765700 JJ |
696 | /* If FDE encoding was not specified, it defaults to |
697 | DW_EH_absptr. */ | |
698 | if (cie.fde_encoding == DW_EH_PE_omit) | |
699 | cie.fde_encoding = DW_EH_PE_absptr; | |
700 | ||
dcf507a6 | 701 | initial_insn_length = end - buf; |
65765700 JJ |
702 | if (initial_insn_length <= 50) |
703 | { | |
704 | cie.initial_insn_length = initial_insn_length; | |
705 | memcpy (cie.initial_instructions, buf, initial_insn_length); | |
706 | } | |
dcf507a6 | 707 | insns = buf; |
65765700 JJ |
708 | buf += initial_insn_length; |
709 | ENSURE_NO_RELOCS (buf); | |
710 | last_cie = last_fde; | |
711 | } | |
712 | else | |
713 | { | |
714 | /* Ensure this FDE uses the last CIE encountered. */ | |
acfe5567 RS |
715 | REQUIRE (last_cie); |
716 | REQUIRE (hdr.id == (unsigned int) (buf - 4 - last_cie)); | |
65765700 JJ |
717 | |
718 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 719 | REQUIRE (GET_RELOC (buf)); |
fda3ecf2 | 720 | |
65765700 | 721 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
353057a5 RS |
722 | /* This is a FDE against a discarded section. It should |
723 | be deleted. */ | |
724 | this_inf->removed = 1; | |
65765700 JJ |
725 | else |
726 | { | |
0bb2d96a | 727 | if (info->shared |
af40ce3c JJ |
728 | && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr |
729 | && cie.make_relative == 0) | |
730 | || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 731 | { |
73722af0 | 732 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
733 | which we cannot turn into PC relative, |
734 | don't create the binary search table, | |
735 | since it is affected by runtime relocations. */ | |
b34976b6 | 736 | hdr_info->table = FALSE; |
0bb2d96a | 737 | } |
65765700 JJ |
738 | cie_usage_count++; |
739 | hdr_info->fde_count++; | |
740 | } | |
2c42be65 RS |
741 | /* Skip the initial location and address range. */ |
742 | start = buf; | |
743 | length = get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
744 | REQUIRE (skip_bytes (&buf, end, 2 * length)); | |
745 | ||
746 | /* Skip the augmentation size, if present. */ | |
747 | if (cie.augmentation[0] == 'z') | |
dcf507a6 RS |
748 | REQUIRE (read_uleb128 (&buf, end, &length)); |
749 | else | |
750 | length = 0; | |
2c42be65 RS |
751 | |
752 | /* Of the supported augmentation characters above, only 'L' | |
753 | adds augmentation data to the FDE. This code would need to | |
754 | be adjusted if any future augmentations do the same thing. */ | |
9e2a4898 | 755 | if (cie.lsda_encoding != DW_EH_PE_omit) |
dcf507a6 RS |
756 | { |
757 | this_inf->lsda_offset = buf - start; | |
758 | /* If there's no 'z' augmentation, we don't know where the | |
759 | CFA insns begin. Assume no padding. */ | |
760 | if (cie.augmentation[0] != 'z') | |
761 | length = end - buf; | |
762 | } | |
763 | ||
764 | /* Skip over the augmentation data. */ | |
765 | REQUIRE (skip_bytes (&buf, end, length)); | |
766 | insns = buf; | |
9e2a4898 | 767 | |
65765700 JJ |
768 | buf = last_fde + 4 + hdr.length; |
769 | SKIP_RELOCS (buf); | |
770 | } | |
771 | ||
dcf507a6 RS |
772 | /* Try to interpret the CFA instructions and find the first |
773 | padding nop. Shrink this_inf's size so that it doesn't | |
774 | including the padding. */ | |
775 | length = get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
776 | insns = skip_non_nops (insns, end, length); | |
777 | if (insns != 0) | |
778 | this_inf->size -= end - insns; | |
779 | ||
fda3ecf2 AM |
780 | this_inf->fde_encoding = cie.fde_encoding; |
781 | this_inf->lsda_encoding = cie.lsda_encoding; | |
65765700 JJ |
782 | sec_info->count++; |
783 | } | |
784 | ||
785 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 786 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 JJ |
787 | |
788 | /* Ok, now we can assign new offsets. */ | |
789 | offset = 0; | |
fda3ecf2 AM |
790 | last_cie_inf = hdr_info->last_cie_inf; |
791 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
792 | if (!ent->removed) | |
793 | { | |
fda3ecf2 AM |
794 | if (ent->cie) |
795 | last_cie_inf = ent; | |
796 | else | |
797 | ent->cie_inf = last_cie_inf; | |
353057a5 RS |
798 | ent->new_offset = offset; |
799 | offset += size_of_output_cie_fde (ent, ptr_size); | |
fda3ecf2 AM |
800 | } |
801 | hdr_info->last_cie_inf = last_cie_inf; | |
65765700 | 802 | |
353057a5 | 803 | /* Resize the sec as needed. */ |
eea6121a | 804 | sec->rawsize = sec->size; |
353057a5 | 805 | sec->size = offset; |
eea6121a | 806 | if (sec->size == 0) |
65765700 JJ |
807 | sec->flags |= SEC_EXCLUDE; |
808 | ||
68f69152 | 809 | free (ehbuf); |
353057a5 | 810 | return offset != sec->rawsize; |
65765700 JJ |
811 | |
812 | free_no_table: | |
68f69152 JJ |
813 | if (ehbuf) |
814 | free (ehbuf); | |
65765700 JJ |
815 | if (sec_info) |
816 | free (sec_info); | |
b34976b6 | 817 | hdr_info->table = FALSE; |
65765700 | 818 | hdr_info->last_cie.hdr.length = 0; |
b34976b6 | 819 | return FALSE; |
acfe5567 RS |
820 | |
821 | #undef REQUIRE | |
65765700 JJ |
822 | } |
823 | ||
824 | /* This function is called for .eh_frame_hdr section after | |
825 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
826 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
827 | ||
b34976b6 | 828 | bfd_boolean |
c39a58e6 | 829 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 830 | { |
126495ed | 831 | struct elf_link_hash_table *htab; |
65765700 | 832 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 833 | asection *sec; |
65765700 | 834 | |
126495ed AM |
835 | htab = elf_hash_table (info); |
836 | hdr_info = &htab->eh_info; | |
837 | sec = hdr_info->hdr_sec; | |
838 | if (sec == NULL) | |
b34976b6 | 839 | return FALSE; |
126495ed | 840 | |
eea6121a | 841 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 842 | if (hdr_info->table) |
eea6121a | 843 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 JJ |
844 | |
845 | /* Request program headers to be recalculated. */ | |
846 | elf_tdata (abfd)->program_header_size = 0; | |
126495ed | 847 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 848 | return TRUE; |
65765700 JJ |
849 | } |
850 | ||
68f69152 JJ |
851 | /* This function is called from size_dynamic_sections. |
852 | It needs to decide whether .eh_frame_hdr should be output or not, | |
853 | because later on it is too late for calling _bfd_strip_section_from_output, | |
854 | since dynamic symbol table has been sized. */ | |
855 | ||
b34976b6 | 856 | bfd_boolean |
c39a58e6 | 857 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 858 | { |
126495ed | 859 | asection *o; |
68f69152 | 860 | bfd *abfd; |
126495ed | 861 | struct elf_link_hash_table *htab; |
68f69152 JJ |
862 | struct eh_frame_hdr_info *hdr_info; |
863 | ||
126495ed AM |
864 | htab = elf_hash_table (info); |
865 | hdr_info = &htab->eh_info; | |
866 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 867 | return TRUE; |
68f69152 | 868 | |
126495ed AM |
869 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
870 | { | |
871 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 872 | return TRUE; |
126495ed | 873 | } |
68f69152 JJ |
874 | |
875 | abfd = NULL; | |
876 | if (info->eh_frame_hdr) | |
877 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
878 | { | |
879 | /* Count only sections which have at least a single CIE or FDE. | |
880 | There cannot be any CIE or FDE <= 8 bytes. */ | |
881 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 882 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
883 | break; |
884 | } | |
885 | ||
886 | if (abfd == NULL) | |
887 | { | |
126495ed AM |
888 | _bfd_strip_section_from_output (info, hdr_info->hdr_sec); |
889 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 890 | return TRUE; |
68f69152 | 891 | } |
126495ed | 892 | |
b34976b6 AM |
893 | hdr_info->table = TRUE; |
894 | return TRUE; | |
68f69152 JJ |
895 | } |
896 | ||
65765700 JJ |
897 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
898 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
899 | or -1 if the address refers to a CIE/FDE which has been removed | |
900 | or to offset with dynamic relocation which is no longer needed. */ | |
901 | ||
902 | bfd_vma | |
c39a58e6 | 903 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
92e4ec35 | 904 | struct bfd_link_info *info, |
c39a58e6 AM |
905 | asection *sec, |
906 | bfd_vma offset) | |
65765700 JJ |
907 | { |
908 | struct eh_frame_sec_info *sec_info; | |
92e4ec35 AM |
909 | struct elf_link_hash_table *htab; |
910 | struct eh_frame_hdr_info *hdr_info; | |
65765700 JJ |
911 | unsigned int lo, hi, mid; |
912 | ||
68bfbfcc | 913 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 914 | return offset; |
c39a58e6 | 915 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 916 | |
eea6121a AM |
917 | if (offset >= sec->rawsize) |
918 | return offset - sec->rawsize + sec->size; | |
65765700 | 919 | |
92e4ec35 AM |
920 | htab = elf_hash_table (info); |
921 | hdr_info = &htab->eh_info; | |
922 | if (hdr_info->offsets_adjusted) | |
923 | offset += sec->output_offset; | |
924 | ||
65765700 JJ |
925 | lo = 0; |
926 | hi = sec_info->count; | |
927 | mid = 0; | |
928 | while (lo < hi) | |
929 | { | |
930 | mid = (lo + hi) / 2; | |
931 | if (offset < sec_info->entry[mid].offset) | |
932 | hi = mid; | |
933 | else if (offset | |
934 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
935 | lo = mid + 1; | |
936 | else | |
937 | break; | |
938 | } | |
939 | ||
940 | BFD_ASSERT (lo < hi); | |
941 | ||
942 | /* FDE or CIE was removed. */ | |
943 | if (sec_info->entry[mid].removed) | |
944 | return (bfd_vma) -1; | |
945 | ||
946 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
947 | relocation against FDE's initial_location field. */ | |
fda3ecf2 AM |
948 | if (!sec_info->entry[mid].cie |
949 | && sec_info->entry[mid].cie_inf->make_relative | |
353057a5 RS |
950 | && offset == sec_info->entry[mid].offset + 8) |
951 | return (bfd_vma) -2; | |
65765700 | 952 | |
9e2a4898 JJ |
953 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
954 | for run-time relocation against LSDA field. */ | |
fda3ecf2 AM |
955 | if (!sec_info->entry[mid].cie |
956 | && sec_info->entry[mid].cie_inf->make_lsda_relative | |
126495ed | 957 | && (offset == (sec_info->entry[mid].offset + 8 |
92e4ec35 AM |
958 | + sec_info->entry[mid].lsda_offset)) |
959 | && (sec_info->entry[mid].cie_inf->need_lsda_relative | |
960 | || !hdr_info->offsets_adjusted)) | |
8935b81f | 961 | { |
fda3ecf2 | 962 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
8935b81f AM |
963 | return (bfd_vma) -2; |
964 | } | |
9e2a4898 | 965 | |
92e4ec35 AM |
966 | if (hdr_info->offsets_adjusted) |
967 | offset -= sec->output_offset; | |
353057a5 | 968 | /* Any new augmentation bytes go before the first relocation. */ |
c68836a9 | 969 | return (offset + sec_info->entry[mid].new_offset |
353057a5 RS |
970 | - sec_info->entry[mid].offset |
971 | + extra_augmentation_string_bytes (sec_info->entry + mid) | |
972 | + extra_augmentation_data_bytes (sec_info->entry + mid)); | |
65765700 JJ |
973 | } |
974 | ||
975 | /* Write out .eh_frame section. This is called with the relocated | |
976 | contents. */ | |
977 | ||
b34976b6 | 978 | bfd_boolean |
c39a58e6 AM |
979 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
980 | struct bfd_link_info *info, | |
981 | asection *sec, | |
982 | bfd_byte *contents) | |
65765700 JJ |
983 | { |
984 | struct eh_frame_sec_info *sec_info; | |
126495ed | 985 | struct elf_link_hash_table *htab; |
65765700 | 986 | struct eh_frame_hdr_info *hdr_info; |
65765700 | 987 | unsigned int ptr_size; |
fda3ecf2 | 988 | struct eh_cie_fde *ent; |
65765700 JJ |
989 | |
990 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
991 | == ELFCLASS64) ? 8 : 4; | |
992 | ||
68bfbfcc | 993 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 994 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 995 | sec->output_offset, sec->size); |
c39a58e6 | 996 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
997 | htab = elf_hash_table (info); |
998 | hdr_info = &htab->eh_info; | |
3472e2e9 AM |
999 | |
1000 | /* First convert all offsets to output section offsets, so that a | |
1001 | CIE offset is valid if the CIE is used by a FDE from some other | |
1002 | section. This can happen when duplicate CIEs are deleted in | |
1003 | _bfd_elf_discard_section_eh_frame. We do all sections here because | |
1004 | this function might not be called on sections in the same order as | |
1005 | _bfd_elf_discard_section_eh_frame. */ | |
1006 | if (!hdr_info->offsets_adjusted) | |
1007 | { | |
1008 | bfd *ibfd; | |
1009 | asection *eh; | |
1010 | struct eh_frame_sec_info *eh_inf; | |
1011 | ||
1012 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) | |
1013 | { | |
1014 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour | |
1015 | || (ibfd->flags & DYNAMIC) != 0) | |
1016 | continue; | |
1017 | ||
1018 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); | |
1019 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
1020 | continue; | |
1021 | ||
1022 | eh_inf = elf_section_data (eh)->sec_info; | |
1023 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) | |
1024 | { | |
1025 | ent->offset += eh->output_offset; | |
1026 | ent->new_offset += eh->output_offset; | |
1027 | } | |
1028 | } | |
1029 | hdr_info->offsets_adjusted = TRUE; | |
1030 | } | |
1031 | ||
126495ed AM |
1032 | if (hdr_info->table && hdr_info->array == NULL) |
1033 | hdr_info->array | |
1034 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
1035 | if (hdr_info->array == NULL) | |
1036 | hdr_info = NULL; | |
65765700 | 1037 | |
353057a5 RS |
1038 | /* The new offsets can be bigger or smaller than the original offsets. |
1039 | We therefore need to make two passes over the section: one backward | |
1040 | pass to move entries up and one forward pass to move entries down. | |
1041 | The two passes won't interfere with each other because entries are | |
1042 | not reordered */ | |
1043 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) | |
1044 | if (!ent->removed && ent->new_offset > ent->offset) | |
1045 | memmove (contents + ent->new_offset - sec->output_offset, | |
1046 | contents + ent->offset - sec->output_offset, ent->size); | |
1047 | ||
1048 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
1049 | if (!ent->removed && ent->new_offset < ent->offset) | |
1050 | memmove (contents + ent->new_offset - sec->output_offset, | |
1051 | contents + ent->offset - sec->output_offset, ent->size); | |
1052 | ||
fda3ecf2 | 1053 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
65765700 | 1054 | { |
353057a5 RS |
1055 | unsigned char *buf, *end; |
1056 | unsigned int new_size; | |
1057 | ||
fda3ecf2 AM |
1058 | if (ent->removed) |
1059 | continue; | |
1060 | ||
353057a5 RS |
1061 | if (ent->size == 4) |
1062 | { | |
1063 | /* Any terminating FDE must be at the end of the section. */ | |
1064 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); | |
1065 | continue; | |
1066 | } | |
1067 | ||
1068 | buf = contents + ent->new_offset - sec->output_offset; | |
1069 | end = buf + ent->size; | |
1070 | new_size = size_of_output_cie_fde (ent, ptr_size); | |
1071 | ||
1072 | /* Install the new size, filling the extra bytes with DW_CFA_nops. */ | |
1073 | if (new_size != ent->size) | |
1074 | { | |
1075 | memset (end, 0, new_size - ent->size); | |
1076 | bfd_put_32 (abfd, new_size - 4, buf); | |
1077 | } | |
1078 | ||
fda3ecf2 | 1079 | if (ent->cie) |
65765700 JJ |
1080 | { |
1081 | /* CIE */ | |
353057a5 | 1082 | if (ent->make_relative |
fda3ecf2 AM |
1083 | || ent->need_lsda_relative |
1084 | || ent->per_encoding_relative) | |
65765700 JJ |
1085 | { |
1086 | unsigned char *aug; | |
353057a5 | 1087 | unsigned int action, extra_string, extra_data; |
2c42be65 | 1088 | unsigned int per_width, per_encoding; |
65765700 | 1089 | |
9e2a4898 | 1090 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 1091 | DW_EH_PE_* value. */ |
353057a5 | 1092 | action = ((ent->make_relative ? 1 : 0) |
fda3ecf2 AM |
1093 | | (ent->need_lsda_relative ? 2 : 0) |
1094 | | (ent->per_encoding_relative ? 4 : 0)); | |
353057a5 RS |
1095 | extra_string = extra_augmentation_string_bytes (ent); |
1096 | extra_data = extra_augmentation_data_bytes (ent); | |
1097 | ||
65765700 JJ |
1098 | /* Skip length, id and version. */ |
1099 | buf += 9; | |
1100 | aug = buf; | |
1101 | buf = strchr (buf, '\0') + 1; | |
2c42be65 RS |
1102 | skip_leb128 (&buf, end); |
1103 | skip_leb128 (&buf, end); | |
1104 | skip_leb128 (&buf, end); | |
65765700 JJ |
1105 | if (*aug == 'z') |
1106 | { | |
353057a5 RS |
1107 | /* The uleb128 will always be a single byte for the kind |
1108 | of augmentation strings that we're prepared to handle. */ | |
1109 | *buf++ += extra_data; | |
65765700 JJ |
1110 | aug++; |
1111 | } | |
1112 | ||
353057a5 RS |
1113 | /* Make room for the new augmentation string and data bytes. */ |
1114 | memmove (buf + extra_string + extra_data, buf, end - buf); | |
1115 | memmove (aug + extra_string, aug, buf - aug); | |
1116 | buf += extra_string; | |
2c42be65 | 1117 | end += extra_string + extra_data; |
353057a5 RS |
1118 | |
1119 | if (ent->add_augmentation_size) | |
1120 | { | |
1121 | *aug++ = 'z'; | |
1122 | *buf++ = extra_data - 1; | |
1123 | } | |
1124 | if (ent->add_fde_encoding) | |
1125 | { | |
1126 | BFD_ASSERT (action & 1); | |
1127 | *aug++ = 'R'; | |
1128 | *buf++ = DW_EH_PE_pcrel; | |
1129 | action &= ~1; | |
1130 | } | |
1131 | ||
9e2a4898 | 1132 | while (action) |
65765700 JJ |
1133 | switch (*aug++) |
1134 | { | |
1135 | case 'L': | |
9e2a4898 JJ |
1136 | if (action & 2) |
1137 | { | |
fda3ecf2 | 1138 | BFD_ASSERT (*buf == ent->lsda_encoding); |
9e2a4898 JJ |
1139 | *buf |= DW_EH_PE_pcrel; |
1140 | action &= ~2; | |
1141 | } | |
65765700 JJ |
1142 | buf++; |
1143 | break; | |
1144 | case 'P': | |
1145 | per_encoding = *buf++; | |
3472e2e9 | 1146 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
65765700 | 1147 | BFD_ASSERT (per_width != 0); |
09ae86c2 | 1148 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
fda3ecf2 | 1149 | == ent->per_encoding_relative); |
65765700 JJ |
1150 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
1151 | buf = (contents | |
1152 | + ((buf - contents + per_width - 1) | |
1153 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
1154 | if (action & 4) |
1155 | { | |
fda3ecf2 AM |
1156 | bfd_vma val; |
1157 | ||
1158 | val = read_value (abfd, buf, per_width, | |
1159 | get_DW_EH_PE_signed (per_encoding)); | |
1160 | val += ent->offset - ent->new_offset; | |
353057a5 | 1161 | val -= extra_string + extra_data; |
fda3ecf2 | 1162 | write_value (abfd, buf, val, per_width); |
09ae86c2 JJ |
1163 | action &= ~4; |
1164 | } | |
65765700 JJ |
1165 | buf += per_width; |
1166 | break; | |
9e2a4898 JJ |
1167 | case 'R': |
1168 | if (action & 1) | |
1169 | { | |
fda3ecf2 | 1170 | BFD_ASSERT (*buf == ent->fde_encoding); |
9e2a4898 JJ |
1171 | *buf |= DW_EH_PE_pcrel; |
1172 | action &= ~1; | |
1173 | } | |
1174 | buf++; | |
1175 | break; | |
65765700 JJ |
1176 | default: |
1177 | BFD_FAIL (); | |
1178 | } | |
65765700 JJ |
1179 | } |
1180 | } | |
353057a5 | 1181 | else |
65765700 JJ |
1182 | { |
1183 | /* FDE */ | |
fda3ecf2 | 1184 | bfd_vma value, address; |
9e2a4898 | 1185 | unsigned int width; |
65765700 | 1186 | |
b34976b6 | 1187 | /* Skip length. */ |
65765700 | 1188 | buf += 4; |
fda3ecf2 AM |
1189 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
1190 | bfd_put_32 (abfd, value, buf); | |
65765700 | 1191 | buf += 4; |
fda3ecf2 AM |
1192 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
1193 | value = read_value (abfd, buf, width, | |
1194 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1195 | address = value; | |
9e2a4898 | 1196 | if (value) |
65765700 | 1197 | { |
fda3ecf2 | 1198 | switch (ent->fde_encoding & 0xf0) |
9e2a4898 JJ |
1199 | { |
1200 | case DW_EH_PE_indirect: | |
1201 | case DW_EH_PE_textrel: | |
1202 | BFD_ASSERT (hdr_info == NULL); | |
1203 | break; | |
1204 | case DW_EH_PE_datarel: | |
1205 | { | |
1206 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1207 | ||
1208 | BFD_ASSERT (got != NULL); | |
1209 | address += got->vma; | |
1210 | } | |
1211 | break; | |
1212 | case DW_EH_PE_pcrel: | |
fda3ecf2 AM |
1213 | value += ent->offset - ent->new_offset; |
1214 | address += sec->output_section->vma + ent->offset + 8; | |
9e2a4898 JJ |
1215 | break; |
1216 | } | |
353057a5 | 1217 | if (ent->cie_inf->make_relative) |
fda3ecf2 | 1218 | value -= sec->output_section->vma + ent->new_offset + 8; |
9e2a4898 | 1219 | write_value (abfd, buf, value, width); |
65765700 JJ |
1220 | } |
1221 | ||
1222 | if (hdr_info) | |
1223 | { | |
1224 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1225 | hdr_info->array[hdr_info->array_count++].fde | |
fda3ecf2 | 1226 | = sec->output_section->vma + ent->new_offset; |
65765700 | 1227 | } |
9e2a4898 | 1228 | |
fda3ecf2 AM |
1229 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
1230 | || ent->cie_inf->need_lsda_relative) | |
9e2a4898 | 1231 | { |
fda3ecf2 AM |
1232 | buf += ent->lsda_offset; |
1233 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); | |
84f97cb6 | 1234 | value = read_value (abfd, buf, width, |
fda3ecf2 | 1235 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
9e2a4898 JJ |
1236 | if (value) |
1237 | { | |
fda3ecf2 AM |
1238 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
1239 | value += ent->offset - ent->new_offset; | |
1240 | else if (ent->cie_inf->need_lsda_relative) | |
1241 | value -= (sec->output_section->vma + ent->new_offset + 8 | |
1242 | + ent->lsda_offset); | |
9e2a4898 JJ |
1243 | write_value (abfd, buf, value, width); |
1244 | } | |
1245 | } | |
353057a5 RS |
1246 | else if (ent->cie_inf->add_augmentation_size) |
1247 | { | |
1248 | /* Skip the PC and length and insert a zero byte for the | |
1249 | augmentation size. */ | |
1250 | buf += width * 2; | |
1251 | memmove (buf + 1, buf, end - buf); | |
1252 | *buf = 0; | |
1253 | } | |
65765700 | 1254 | } |
65765700 JJ |
1255 | } |
1256 | ||
10cf14ea L |
1257 | { |
1258 | unsigned int alignment = 1 << sec->alignment_power; | |
eea6121a | 1259 | unsigned int pad = sec->size % alignment; |
10cf14ea | 1260 | |
9da84788 L |
1261 | /* Don't pad beyond the raw size of the output section. It |
1262 | can happen at the last input section. */ | |
1263 | if (pad | |
eea6121a AM |
1264 | && ((sec->output_offset + sec->size + pad) |
1265 | <= sec->output_section->size)) | |
10cf14ea | 1266 | { |
353057a5 RS |
1267 | bfd_byte *buf; |
1268 | unsigned int new_size; | |
1269 | ||
10cf14ea | 1270 | /* Find the last CIE/FDE. */ |
fda3ecf2 AM |
1271 | ent = sec_info->entry + sec_info->count; |
1272 | while (--ent != sec_info->entry) | |
1273 | if (!ent->removed) | |
10cf14ea L |
1274 | break; |
1275 | ||
1276 | /* The size of the last CIE/FDE must be at least 4. */ | |
fda3ecf2 | 1277 | if (ent->removed || ent->size < 4) |
10cf14ea L |
1278 | abort (); |
1279 | ||
1280 | pad = alignment - pad; | |
fda3ecf2 | 1281 | buf = contents + ent->new_offset - sec->output_offset; |
353057a5 | 1282 | new_size = size_of_output_cie_fde (ent, ptr_size); |
10cf14ea L |
1283 | |
1284 | /* Pad it with DW_CFA_nop */ | |
353057a5 RS |
1285 | memset (buf + new_size, 0, pad); |
1286 | bfd_put_32 (abfd, new_size + pad - 4, buf); | |
10cf14ea | 1287 | |
eea6121a | 1288 | sec->size += pad; |
10cf14ea L |
1289 | } |
1290 | } | |
a5eb27e6 | 1291 | |
65765700 | 1292 | return bfd_set_section_contents (abfd, sec->output_section, |
3472e2e9 AM |
1293 | contents, (file_ptr) sec->output_offset, |
1294 | sec->size); | |
65765700 JJ |
1295 | } |
1296 | ||
1297 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1298 | VMA of FDE initial location. */ | |
1299 | ||
1300 | static int | |
c39a58e6 | 1301 | vma_compare (const void *a, const void *b) |
65765700 | 1302 | { |
c39a58e6 AM |
1303 | const struct eh_frame_array_ent *p = a; |
1304 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1305 | if (p->initial_loc > q->initial_loc) |
1306 | return 1; | |
1307 | if (p->initial_loc < q->initial_loc) | |
1308 | return -1; | |
1309 | return 0; | |
1310 | } | |
1311 | ||
1312 | /* Write out .eh_frame_hdr section. This must be called after | |
1313 | _bfd_elf_write_section_eh_frame has been called on all input | |
1314 | .eh_frame sections. | |
1315 | .eh_frame_hdr format: | |
1316 | ubyte version (currently 1) | |
1317 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1318 | .eh_frame section) | |
1319 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1320 | number (or DW_EH_PE_omit if there is no | |
1321 | binary search table computed)) | |
1322 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1323 | or DW_EH_PE_omit if not present. | |
1324 | DW_EH_PE_datarel is using address of | |
1325 | .eh_frame_hdr section start as base) | |
1326 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1327 | optionally followed by: | |
1328 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1329 | fde_count x [encoded] initial_loc, fde | |
1330 | (array of encoded pairs containing | |
1331 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1332 | sorted by increasing initial_loc). */ |
65765700 | 1333 | |
b34976b6 | 1334 | bfd_boolean |
c39a58e6 | 1335 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1336 | { |
126495ed | 1337 | struct elf_link_hash_table *htab; |
65765700 | 1338 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1339 | asection *sec; |
65765700 JJ |
1340 | bfd_byte *contents; |
1341 | asection *eh_frame_sec; | |
1342 | bfd_size_type size; | |
5ed6aba4 | 1343 | bfd_boolean retval; |
ec3391e7 | 1344 | bfd_vma encoded_eh_frame; |
65765700 | 1345 | |
126495ed AM |
1346 | htab = elf_hash_table (info); |
1347 | hdr_info = &htab->eh_info; | |
1348 | sec = hdr_info->hdr_sec; | |
1349 | if (sec == NULL) | |
b34976b6 | 1350 | return TRUE; |
57a72197 | 1351 | |
65765700 JJ |
1352 | size = EH_FRAME_HDR_SIZE; |
1353 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1354 | size += 4 + hdr_info->fde_count * 8; | |
1355 | contents = bfd_malloc (size); | |
1356 | if (contents == NULL) | |
b34976b6 | 1357 | return FALSE; |
65765700 JJ |
1358 | |
1359 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1360 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1361 | { |
1362 | free (contents); | |
1363 | return FALSE; | |
1364 | } | |
65765700 JJ |
1365 | |
1366 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1367 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1368 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1369 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1370 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1371 | ||
65765700 JJ |
1372 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1373 | { | |
5ed6aba4 NC |
1374 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1375 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1376 | } |
1377 | else | |
1378 | { | |
1379 | contents[2] = DW_EH_PE_omit; | |
1380 | contents[3] = DW_EH_PE_omit; | |
1381 | } | |
ec3391e7 AO |
1382 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1383 | ||
65765700 JJ |
1384 | if (contents[2] != DW_EH_PE_omit) |
1385 | { | |
1386 | unsigned int i; | |
1387 | ||
1388 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1389 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1390 | vma_compare); | |
1391 | for (i = 0; i < hdr_info->fde_count; i++) | |
1392 | { | |
1393 | bfd_put_32 (abfd, | |
1394 | hdr_info->array[i].initial_loc | |
1395 | - sec->output_section->vma, | |
1396 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1397 | bfd_put_32 (abfd, | |
1398 | hdr_info->array[i].fde - sec->output_section->vma, | |
1399 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1400 | } | |
1401 | } | |
1402 | ||
5ed6aba4 NC |
1403 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1404 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1405 | sec->size); |
5ed6aba4 NC |
1406 | free (contents); |
1407 | return retval; | |
65765700 | 1408 | } |
ec3391e7 AO |
1409 | |
1410 | /* Decide whether we can use a PC-relative encoding within the given | |
1411 | EH frame section. This is the default implementation. */ | |
1412 | ||
1413 | bfd_boolean | |
1414 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1415 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1416 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1417 | { | |
1418 | return TRUE; | |
1419 | } | |
1420 | ||
1421 | /* Select an encoding for the given address. Preference is given to | |
1422 | PC-relative addressing modes. */ | |
1423 | ||
1424 | bfd_byte | |
1425 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1426 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1427 | asection *osec, bfd_vma offset, | |
1428 | asection *loc_sec, bfd_vma loc_offset, | |
1429 | bfd_vma *encoded) | |
1430 | { | |
1431 | *encoded = osec->vma + offset - | |
1432 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1433 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1434 | } |