Commit | Line | Data |
---|---|---|
65765700 | 1 | /* .eh_frame section optimization. |
0da76f83 | 2 | Copyright 2001, 2002, 2003, 2004 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 | ||
65765700 JJ |
29 | /* Helper function for reading uleb128 encoded data. */ |
30 | ||
31 | static bfd_vma | |
c39a58e6 AM |
32 | read_unsigned_leb128 (bfd *abfd ATTRIBUTE_UNUSED, |
33 | char *buf, | |
34 | unsigned int *bytes_read_ptr) | |
65765700 | 35 | { |
c39a58e6 AM |
36 | bfd_vma result; |
37 | unsigned int num_read; | |
38 | int shift; | |
65765700 JJ |
39 | unsigned char byte; |
40 | ||
c39a58e6 AM |
41 | result = 0; |
42 | shift = 0; | |
65765700 JJ |
43 | num_read = 0; |
44 | do | |
45 | { | |
46 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
c39a58e6 AM |
47 | buf++; |
48 | num_read++; | |
65765700 JJ |
49 | result |= (((bfd_vma) byte & 0x7f) << shift); |
50 | shift += 7; | |
51 | } | |
52 | while (byte & 0x80); | |
c39a58e6 | 53 | *bytes_read_ptr = num_read; |
65765700 JJ |
54 | return result; |
55 | } | |
56 | ||
57 | /* Helper function for reading sleb128 encoded data. */ | |
58 | ||
59 | static bfd_signed_vma | |
c39a58e6 AM |
60 | read_signed_leb128 (bfd *abfd ATTRIBUTE_UNUSED, |
61 | char *buf, | |
62 | unsigned int * bytes_read_ptr) | |
65765700 | 63 | { |
c39a58e6 AM |
64 | bfd_vma result; |
65 | int shift; | |
66 | int num_read; | |
65765700 JJ |
67 | unsigned char byte; |
68 | ||
69 | result = 0; | |
70 | shift = 0; | |
71 | num_read = 0; | |
72 | do | |
73 | { | |
74 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
75 | buf ++; | |
76 | num_read ++; | |
77 | result |= (((bfd_vma) byte & 0x7f) << shift); | |
78 | shift += 7; | |
79 | } | |
80 | while (byte & 0x80); | |
81 | if (byte & 0x40) | |
82 | result |= (((bfd_vma) -1) << (shift - 7)) << 7; | |
c39a58e6 | 83 | *bytes_read_ptr = num_read; |
65765700 JJ |
84 | return result; |
85 | } | |
86 | ||
87 | #define read_uleb128(VAR, BUF) \ | |
88 | do \ | |
89 | { \ | |
90 | (VAR) = read_unsigned_leb128 (abfd, buf, &leb128_tmp); \ | |
91 | (BUF) += leb128_tmp; \ | |
92 | } \ | |
93 | while (0) | |
94 | ||
95 | #define read_sleb128(VAR, BUF) \ | |
96 | do \ | |
97 | { \ | |
98 | (VAR) = read_signed_leb128 (abfd, buf, &leb128_tmp); \ | |
99 | (BUF) += leb128_tmp; \ | |
100 | } \ | |
101 | while (0) | |
102 | ||
103 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
104 | ||
105 | static | |
c39a58e6 | 106 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
65765700 JJ |
107 | { |
108 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
109 | was added to bfd. */ | |
110 | if ((encoding & 0x60) == 0x60) | |
111 | return 0; | |
112 | ||
113 | switch (encoding & 7) | |
114 | { | |
115 | case DW_EH_PE_udata2: return 2; | |
116 | case DW_EH_PE_udata4: return 4; | |
117 | case DW_EH_PE_udata8: return 8; | |
118 | case DW_EH_PE_absptr: return ptr_size; | |
119 | default: | |
120 | break; | |
121 | } | |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
84f97cb6 AS |
126 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
127 | ||
9e2a4898 JJ |
128 | /* Read a width sized value from memory. */ |
129 | ||
130 | static bfd_vma | |
c39a58e6 | 131 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
9e2a4898 JJ |
132 | { |
133 | bfd_vma value; | |
134 | ||
135 | switch (width) | |
136 | { | |
84f97cb6 AS |
137 | case 2: |
138 | if (is_signed) | |
139 | value = bfd_get_signed_16 (abfd, buf); | |
140 | else | |
141 | value = bfd_get_16 (abfd, buf); | |
142 | break; | |
143 | case 4: | |
144 | if (is_signed) | |
145 | value = bfd_get_signed_32 (abfd, buf); | |
146 | else | |
147 | value = bfd_get_32 (abfd, buf); | |
148 | break; | |
149 | case 8: | |
150 | if (is_signed) | |
151 | value = bfd_get_signed_64 (abfd, buf); | |
152 | else | |
153 | value = bfd_get_64 (abfd, buf); | |
154 | break; | |
155 | default: | |
156 | BFD_FAIL (); | |
157 | return 0; | |
9e2a4898 JJ |
158 | } |
159 | ||
160 | return value; | |
161 | } | |
b34976b6 | 162 | |
9e2a4898 JJ |
163 | /* Store a width sized value to memory. */ |
164 | ||
165 | static void | |
c39a58e6 | 166 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
9e2a4898 JJ |
167 | { |
168 | switch (width) | |
169 | { | |
170 | case 2: bfd_put_16 (abfd, value, buf); break; | |
171 | case 4: bfd_put_32 (abfd, value, buf); break; | |
172 | case 8: bfd_put_64 (abfd, value, buf); break; | |
173 | default: BFD_FAIL (); | |
174 | } | |
175 | } | |
176 | ||
65765700 JJ |
177 | /* Return zero if C1 and C2 CIEs can be merged. */ |
178 | ||
179 | static | |
c39a58e6 | 180 | int cie_compare (struct cie *c1, struct cie *c2) |
65765700 JJ |
181 | { |
182 | if (c1->hdr.length == c2->hdr.length | |
183 | && c1->version == c2->version | |
184 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
185 | && strcmp (c1->augmentation, "eh") != 0 | |
186 | && c1->code_align == c2->code_align | |
187 | && c1->data_align == c2->data_align | |
188 | && c1->ra_column == c2->ra_column | |
189 | && c1->augmentation_size == c2->augmentation_size | |
190 | && c1->personality == c2->personality | |
191 | && c1->per_encoding == c2->per_encoding | |
192 | && c1->lsda_encoding == c2->lsda_encoding | |
193 | && c1->fde_encoding == c2->fde_encoding | |
c39a58e6 | 194 | && c1->initial_insn_length == c2->initial_insn_length |
65765700 JJ |
195 | && memcmp (c1->initial_instructions, |
196 | c2->initial_instructions, | |
197 | c1->initial_insn_length) == 0) | |
198 | return 0; | |
199 | ||
200 | return 1; | |
201 | } | |
202 | ||
203 | /* This function is called for each input file before the .eh_frame | |
204 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
b34976b6 | 205 | functions. The function returns TRUE iff any entries have been |
65765700 JJ |
206 | deleted. */ |
207 | ||
b34976b6 | 208 | bfd_boolean |
c39a58e6 AM |
209 | _bfd_elf_discard_section_eh_frame |
210 | (bfd *abfd, struct bfd_link_info *info, asection *sec, | |
211 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), | |
212 | struct elf_reloc_cookie *cookie) | |
65765700 JJ |
213 | { |
214 | bfd_byte *ehbuf = NULL, *buf; | |
215 | bfd_byte *last_cie, *last_fde; | |
216 | struct cie_header hdr; | |
217 | struct cie cie; | |
126495ed | 218 | struct elf_link_hash_table *htab; |
65765700 | 219 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 220 | struct eh_frame_sec_info *sec_info = NULL; |
65765700 | 221 | unsigned int leb128_tmp; |
9e2a4898 JJ |
222 | unsigned int cie_usage_count, last_cie_ndx, i, offset; |
223 | unsigned int make_relative, make_lsda_relative; | |
65765700 JJ |
224 | bfd_size_type new_size; |
225 | unsigned int ptr_size; | |
226 | ||
eea6121a | 227 | if (sec->size == 0) |
65765700 JJ |
228 | { |
229 | /* This file does not contain .eh_frame information. */ | |
b34976b6 | 230 | return FALSE; |
65765700 JJ |
231 | } |
232 | ||
233 | if ((sec->output_section != NULL | |
234 | && bfd_is_abs_section (sec->output_section))) | |
235 | { | |
236 | /* At least one of the sections is being discarded from the | |
237 | link, so we should just ignore them. */ | |
b34976b6 | 238 | return FALSE; |
65765700 JJ |
239 | } |
240 | ||
126495ed AM |
241 | htab = elf_hash_table (info); |
242 | hdr_info = &htab->eh_info; | |
68f69152 | 243 | |
65765700 JJ |
244 | /* Read the frame unwind information from abfd. */ |
245 | ||
eea6121a | 246 | if (!bfd_malloc_and_get_section (abfd, sec, &ehbuf)) |
68f69152 JJ |
247 | goto free_no_table; |
248 | ||
eea6121a | 249 | if (sec->size >= 4 |
65765700 JJ |
250 | && bfd_get_32 (abfd, ehbuf) == 0 |
251 | && cookie->rel == cookie->relend) | |
252 | { | |
253 | /* Empty .eh_frame section. */ | |
254 | free (ehbuf); | |
b34976b6 | 255 | return FALSE; |
65765700 JJ |
256 | } |
257 | ||
65765700 JJ |
258 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
259 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
eea6121a | 260 | if (sec->size != (unsigned int) sec->size) |
68f69152 | 261 | goto free_no_table; |
65765700 JJ |
262 | |
263 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
264 | == ELFCLASS64) ? 8 : 4; | |
265 | buf = ehbuf; | |
266 | last_cie = NULL; | |
267 | last_cie_ndx = 0; | |
268 | memset (&cie, 0, sizeof (cie)); | |
269 | cie_usage_count = 0; | |
eea6121a | 270 | new_size = sec->size; |
65765700 | 271 | make_relative = hdr_info->last_cie.make_relative; |
9e2a4898 | 272 | make_lsda_relative = hdr_info->last_cie.make_lsda_relative; |
65765700 JJ |
273 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
274 | + 99 * sizeof (struct eh_cie_fde)); | |
275 | if (sec_info == NULL) | |
276 | goto free_no_table; | |
eea6121a | 277 | |
65765700 JJ |
278 | sec_info->alloced = 100; |
279 | ||
280 | #define ENSURE_NO_RELOCS(buf) \ | |
281 | if (cookie->rel < cookie->relend \ | |
282 | && (cookie->rel->r_offset \ | |
73722af0 AM |
283 | < (bfd_size_type) ((buf) - ehbuf)) \ |
284 | && cookie->rel->r_info != 0) \ | |
65765700 JJ |
285 | goto free_no_table |
286 | ||
287 | #define SKIP_RELOCS(buf) \ | |
288 | while (cookie->rel < cookie->relend \ | |
289 | && (cookie->rel->r_offset \ | |
290 | < (bfd_size_type) ((buf) - ehbuf))) \ | |
291 | cookie->rel++ | |
292 | ||
293 | #define GET_RELOC(buf) \ | |
294 | ((cookie->rel < cookie->relend \ | |
295 | && (cookie->rel->r_offset \ | |
296 | == (bfd_size_type) ((buf) - ehbuf))) \ | |
297 | ? cookie->rel : NULL) | |
298 | ||
299 | for (;;) | |
300 | { | |
301 | unsigned char *aug; | |
302 | ||
303 | if (sec_info->count == sec_info->alloced) | |
304 | { | |
305 | sec_info = bfd_realloc (sec_info, | |
306 | sizeof (struct eh_frame_sec_info) | |
307 | + (sec_info->alloced + 99) | |
308 | * sizeof (struct eh_cie_fde)); | |
309 | if (sec_info == NULL) | |
310 | goto free_no_table; | |
311 | ||
312 | memset (&sec_info->entry[sec_info->alloced], 0, | |
313 | 100 * sizeof (struct eh_cie_fde)); | |
314 | sec_info->alloced += 100; | |
315 | } | |
316 | ||
317 | last_fde = buf; | |
318 | /* If we are at the end of the section, we still need to decide | |
319 | on whether to output or discard last encountered CIE (if any). */ | |
eea6121a | 320 | if ((bfd_size_type) (buf - ehbuf) == sec->size) |
65765700 JJ |
321 | hdr.id = (unsigned int) -1; |
322 | else | |
323 | { | |
eea6121a | 324 | if ((bfd_size_type) (buf + 4 - ehbuf) > sec->size) |
65765700 JJ |
325 | /* No space for CIE/FDE header length. */ |
326 | goto free_no_table; | |
327 | ||
328 | hdr.length = bfd_get_32 (abfd, buf); | |
329 | if (hdr.length == 0xffffffff) | |
330 | /* 64-bit .eh_frame is not supported. */ | |
331 | goto free_no_table; | |
332 | buf += 4; | |
eea6121a | 333 | if ((bfd_size_type) (buf - ehbuf) + hdr.length > sec->size) |
65765700 JJ |
334 | /* CIE/FDE not contained fully in this .eh_frame input section. */ |
335 | goto free_no_table; | |
336 | ||
337 | sec_info->entry[sec_info->count].offset = last_fde - ehbuf; | |
338 | sec_info->entry[sec_info->count].size = 4 + hdr.length; | |
339 | ||
340 | if (hdr.length == 0) | |
341 | { | |
342 | /* CIE with length 0 must be only the last in the section. */ | |
eea6121a | 343 | if ((bfd_size_type) (buf - ehbuf) < sec->size) |
65765700 JJ |
344 | goto free_no_table; |
345 | ENSURE_NO_RELOCS (buf); | |
346 | sec_info->count++; | |
347 | /* Now just finish last encountered CIE processing and break | |
348 | the loop. */ | |
349 | hdr.id = (unsigned int) -1; | |
350 | } | |
351 | else | |
352 | { | |
353 | hdr.id = bfd_get_32 (abfd, buf); | |
354 | buf += 4; | |
355 | if (hdr.id == (unsigned int) -1) | |
356 | goto free_no_table; | |
357 | } | |
358 | } | |
359 | ||
360 | if (hdr.id == 0 || hdr.id == (unsigned int) -1) | |
361 | { | |
362 | unsigned int initial_insn_length; | |
363 | ||
364 | /* CIE */ | |
365 | if (last_cie != NULL) | |
366 | { | |
73722af0 AM |
367 | /* Now check if this CIE is identical to the last CIE, |
368 | in which case we can remove it provided we adjust | |
369 | all FDEs. Also, it can be removed if we have removed | |
370 | all FDEs using it. */ | |
1049f94e | 371 | if ((!info->relocatable |
9da84788 L |
372 | && hdr_info->last_cie_sec |
373 | && (sec->output_section | |
374 | == hdr_info->last_cie_sec->output_section) | |
73722af0 | 375 | && cie_compare (&cie, &hdr_info->last_cie) == 0) |
65765700 JJ |
376 | || cie_usage_count == 0) |
377 | { | |
378 | new_size -= cie.hdr.length + 4; | |
379 | sec_info->entry[last_cie_ndx].removed = 1; | |
380 | sec_info->entry[last_cie_ndx].sec = hdr_info->last_cie_sec; | |
381 | sec_info->entry[last_cie_ndx].new_offset | |
382 | = hdr_info->last_cie_offset; | |
383 | } | |
384 | else | |
385 | { | |
386 | hdr_info->last_cie = cie; | |
387 | hdr_info->last_cie_sec = sec; | |
388 | hdr_info->last_cie_offset = last_cie - ehbuf; | |
389 | sec_info->entry[last_cie_ndx].make_relative | |
390 | = cie.make_relative; | |
9e2a4898 JJ |
391 | sec_info->entry[last_cie_ndx].make_lsda_relative |
392 | = cie.make_lsda_relative; | |
09ae86c2 JJ |
393 | sec_info->entry[last_cie_ndx].per_encoding_relative |
394 | = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
65765700 JJ |
395 | } |
396 | } | |
397 | ||
398 | if (hdr.id == (unsigned int) -1) | |
399 | break; | |
400 | ||
401 | last_cie_ndx = sec_info->count; | |
402 | sec_info->entry[sec_info->count].cie = 1; | |
403 | ||
404 | cie_usage_count = 0; | |
405 | memset (&cie, 0, sizeof (cie)); | |
406 | cie.hdr = hdr; | |
407 | cie.version = *buf++; | |
408 | ||
409 | /* Cannot handle unknown versions. */ | |
0da76f83 | 410 | if (cie.version != 1 && cie.version != 3) |
65765700 JJ |
411 | goto free_no_table; |
412 | if (strlen (buf) > sizeof (cie.augmentation) - 1) | |
413 | goto free_no_table; | |
414 | ||
415 | strcpy (cie.augmentation, buf); | |
416 | buf = strchr (buf, '\0') + 1; | |
417 | ENSURE_NO_RELOCS (buf); | |
418 | if (buf[0] == 'e' && buf[1] == 'h') | |
419 | { | |
420 | /* GCC < 3.0 .eh_frame CIE */ | |
421 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
422 | is private to each CIE, so we don't need it for anything. | |
423 | Just skip it. */ | |
424 | buf += ptr_size; | |
425 | SKIP_RELOCS (buf); | |
426 | } | |
427 | read_uleb128 (cie.code_align, buf); | |
428 | read_sleb128 (cie.data_align, buf); | |
0da76f83 NC |
429 | if (cie.version == 1) |
430 | cie.ra_column = *buf++; | |
431 | else | |
432 | read_uleb128 (cie.ra_column, buf); | |
65765700 JJ |
433 | ENSURE_NO_RELOCS (buf); |
434 | cie.lsda_encoding = DW_EH_PE_omit; | |
435 | cie.fde_encoding = DW_EH_PE_omit; | |
436 | cie.per_encoding = DW_EH_PE_omit; | |
437 | aug = cie.augmentation; | |
438 | if (aug[0] != 'e' || aug[1] != 'h') | |
439 | { | |
440 | if (*aug == 'z') | |
441 | { | |
442 | aug++; | |
443 | read_uleb128 (cie.augmentation_size, buf); | |
444 | ENSURE_NO_RELOCS (buf); | |
445 | } | |
446 | ||
447 | while (*aug != '\0') | |
448 | switch (*aug++) | |
449 | { | |
450 | case 'L': | |
451 | cie.lsda_encoding = *buf++; | |
452 | ENSURE_NO_RELOCS (buf); | |
453 | if (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size) == 0) | |
454 | goto free_no_table; | |
455 | break; | |
456 | case 'R': | |
457 | cie.fde_encoding = *buf++; | |
458 | ENSURE_NO_RELOCS (buf); | |
459 | if (get_DW_EH_PE_width (cie.fde_encoding, ptr_size) == 0) | |
460 | goto free_no_table; | |
461 | break; | |
462 | case 'P': | |
463 | { | |
464 | int per_width; | |
465 | ||
466 | cie.per_encoding = *buf++; | |
467 | per_width = get_DW_EH_PE_width (cie.per_encoding, | |
468 | ptr_size); | |
469 | if (per_width == 0) | |
470 | goto free_no_table; | |
471 | if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned) | |
472 | buf = (ehbuf | |
473 | + ((buf - ehbuf + per_width - 1) | |
474 | & ~((bfd_size_type) per_width - 1))); | |
475 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
476 | /* Ensure we have a reloc here, against |
477 | a global symbol. */ | |
99eb2ac8 | 478 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
479 | { |
480 | unsigned long r_symndx; | |
481 | ||
482 | #ifdef BFD64 | |
483 | if (ptr_size == 8) | |
484 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
485 | else | |
486 | #endif | |
487 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
488 | if (r_symndx >= cookie->locsymcount) | |
489 | { | |
490 | struct elf_link_hash_entry *h; | |
491 | ||
492 | r_symndx -= cookie->extsymoff; | |
493 | h = cookie->sym_hashes[r_symndx]; | |
494 | ||
495 | while (h->root.type == bfd_link_hash_indirect | |
496 | || h->root.type == bfd_link_hash_warning) | |
497 | h = (struct elf_link_hash_entry *) | |
498 | h->root.u.i.link; | |
499 | ||
500 | cie.personality = h; | |
501 | } | |
502 | cookie->rel++; | |
503 | } | |
504 | buf += per_width; | |
505 | } | |
506 | break; | |
507 | default: | |
508 | /* Unrecognized augmentation. Better bail out. */ | |
509 | goto free_no_table; | |
510 | } | |
511 | } | |
512 | ||
513 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a JJ |
514 | as possible. */ |
515 | if (info->shared | |
ec3391e7 AO |
516 | && (get_elf_backend_data (abfd) |
517 | ->elf_backend_can_make_relative_eh_frame | |
518 | (abfd, info, sec)) | |
65765700 JJ |
519 | && (cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) |
520 | cie.make_relative = 1; | |
521 | ||
0bb2d96a | 522 | if (info->shared |
ec3391e7 AO |
523 | && (get_elf_backend_data (abfd) |
524 | ->elf_backend_can_make_lsda_relative_eh_frame | |
525 | (abfd, info, sec)) | |
9e2a4898 JJ |
526 | && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
527 | cie.make_lsda_relative = 1; | |
528 | ||
65765700 JJ |
529 | /* If FDE encoding was not specified, it defaults to |
530 | DW_EH_absptr. */ | |
531 | if (cie.fde_encoding == DW_EH_PE_omit) | |
532 | cie.fde_encoding = DW_EH_PE_absptr; | |
533 | ||
534 | initial_insn_length = cie.hdr.length - (buf - last_fde - 4); | |
535 | if (initial_insn_length <= 50) | |
536 | { | |
537 | cie.initial_insn_length = initial_insn_length; | |
538 | memcpy (cie.initial_instructions, buf, initial_insn_length); | |
539 | } | |
540 | buf += initial_insn_length; | |
541 | ENSURE_NO_RELOCS (buf); | |
542 | last_cie = last_fde; | |
543 | } | |
544 | else | |
545 | { | |
546 | /* Ensure this FDE uses the last CIE encountered. */ | |
547 | if (last_cie == NULL | |
548 | || hdr.id != (unsigned int) (buf - 4 - last_cie)) | |
549 | goto free_no_table; | |
550 | ||
551 | ENSURE_NO_RELOCS (buf); | |
99eb2ac8 | 552 | if (GET_RELOC (buf) == NULL) |
65765700 JJ |
553 | /* This should not happen. */ |
554 | goto free_no_table; | |
555 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) | |
556 | { | |
73722af0 | 557 | /* This is a FDE against a discarded section. It should |
65765700 JJ |
558 | be deleted. */ |
559 | new_size -= hdr.length + 4; | |
560 | sec_info->entry[sec_info->count].removed = 1; | |
561 | } | |
562 | else | |
563 | { | |
0bb2d96a | 564 | if (info->shared |
af40ce3c JJ |
565 | && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr |
566 | && cie.make_relative == 0) | |
567 | || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 568 | { |
73722af0 | 569 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
570 | which we cannot turn into PC relative, |
571 | don't create the binary search table, | |
572 | since it is affected by runtime relocations. */ | |
b34976b6 | 573 | hdr_info->table = FALSE; |
0bb2d96a | 574 | } |
65765700 JJ |
575 | cie_usage_count++; |
576 | hdr_info->fde_count++; | |
577 | } | |
9e2a4898 JJ |
578 | if (cie.lsda_encoding != DW_EH_PE_omit) |
579 | { | |
580 | unsigned int dummy; | |
581 | ||
582 | aug = buf; | |
583 | buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
584 | if (cie.augmentation[0] == 'z') | |
585 | read_uleb128 (dummy, buf); | |
586 | /* If some new augmentation data is added before LSDA | |
587 | in FDE augmentation area, this need to be adjusted. */ | |
588 | sec_info->entry[sec_info->count].lsda_offset = (buf - aug); | |
589 | } | |
65765700 JJ |
590 | buf = last_fde + 4 + hdr.length; |
591 | SKIP_RELOCS (buf); | |
592 | } | |
593 | ||
594 | sec_info->entry[sec_info->count].fde_encoding = cie.fde_encoding; | |
9e2a4898 | 595 | sec_info->entry[sec_info->count].lsda_encoding = cie.lsda_encoding; |
65765700 JJ |
596 | sec_info->count++; |
597 | } | |
598 | ||
599 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 600 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 JJ |
601 | |
602 | /* Ok, now we can assign new offsets. */ | |
603 | offset = 0; | |
604 | last_cie_ndx = 0; | |
605 | for (i = 0; i < sec_info->count; i++) | |
606 | { | |
607 | if (! sec_info->entry[i].removed) | |
608 | { | |
609 | sec_info->entry[i].new_offset = offset; | |
610 | offset += sec_info->entry[i].size; | |
611 | if (sec_info->entry[i].cie) | |
612 | { | |
613 | last_cie_ndx = i; | |
614 | make_relative = sec_info->entry[i].make_relative; | |
9e2a4898 | 615 | make_lsda_relative = sec_info->entry[i].make_lsda_relative; |
65765700 JJ |
616 | } |
617 | else | |
9e2a4898 JJ |
618 | { |
619 | sec_info->entry[i].make_relative = make_relative; | |
620 | sec_info->entry[i].make_lsda_relative = make_lsda_relative; | |
09ae86c2 | 621 | sec_info->entry[i].per_encoding_relative = 0; |
9e2a4898 | 622 | } |
65765700 JJ |
623 | } |
624 | else if (sec_info->entry[i].cie && sec_info->entry[i].sec == sec) | |
625 | { | |
626 | /* Need to adjust new_offset too. */ | |
627 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
628 | == sec_info->entry[i].new_offset); | |
629 | sec_info->entry[i].new_offset | |
630 | = sec_info->entry[last_cie_ndx].new_offset; | |
631 | } | |
632 | } | |
633 | if (hdr_info->last_cie_sec == sec) | |
634 | { | |
635 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
636 | == hdr_info->last_cie_offset); | |
637 | hdr_info->last_cie_offset = sec_info->entry[last_cie_ndx].new_offset; | |
638 | } | |
639 | ||
640 | /* Shrink the sec as needed. */ | |
eea6121a AM |
641 | sec->rawsize = sec->size; |
642 | sec->size = new_size; | |
643 | if (sec->size == 0) | |
65765700 JJ |
644 | sec->flags |= SEC_EXCLUDE; |
645 | ||
68f69152 | 646 | free (ehbuf); |
eea6121a | 647 | return new_size != sec->rawsize; |
65765700 JJ |
648 | |
649 | free_no_table: | |
68f69152 JJ |
650 | if (ehbuf) |
651 | free (ehbuf); | |
65765700 JJ |
652 | if (sec_info) |
653 | free (sec_info); | |
b34976b6 | 654 | hdr_info->table = FALSE; |
65765700 | 655 | hdr_info->last_cie.hdr.length = 0; |
b34976b6 | 656 | return FALSE; |
65765700 JJ |
657 | } |
658 | ||
659 | /* This function is called for .eh_frame_hdr section after | |
660 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
661 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
662 | ||
b34976b6 | 663 | bfd_boolean |
c39a58e6 | 664 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 665 | { |
126495ed | 666 | struct elf_link_hash_table *htab; |
65765700 | 667 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 668 | asection *sec; |
65765700 | 669 | |
126495ed AM |
670 | htab = elf_hash_table (info); |
671 | hdr_info = &htab->eh_info; | |
672 | sec = hdr_info->hdr_sec; | |
673 | if (sec == NULL) | |
b34976b6 | 674 | return FALSE; |
126495ed | 675 | |
eea6121a | 676 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 677 | if (hdr_info->table) |
eea6121a | 678 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 JJ |
679 | |
680 | /* Request program headers to be recalculated. */ | |
681 | elf_tdata (abfd)->program_header_size = 0; | |
126495ed | 682 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 683 | return TRUE; |
65765700 JJ |
684 | } |
685 | ||
68f69152 JJ |
686 | /* This function is called from size_dynamic_sections. |
687 | It needs to decide whether .eh_frame_hdr should be output or not, | |
688 | because later on it is too late for calling _bfd_strip_section_from_output, | |
689 | since dynamic symbol table has been sized. */ | |
690 | ||
b34976b6 | 691 | bfd_boolean |
c39a58e6 | 692 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 693 | { |
126495ed | 694 | asection *o; |
68f69152 | 695 | bfd *abfd; |
126495ed | 696 | struct elf_link_hash_table *htab; |
68f69152 JJ |
697 | struct eh_frame_hdr_info *hdr_info; |
698 | ||
126495ed AM |
699 | htab = elf_hash_table (info); |
700 | hdr_info = &htab->eh_info; | |
701 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 702 | return TRUE; |
68f69152 | 703 | |
126495ed AM |
704 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
705 | { | |
706 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 707 | return TRUE; |
126495ed | 708 | } |
68f69152 JJ |
709 | |
710 | abfd = NULL; | |
711 | if (info->eh_frame_hdr) | |
712 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
713 | { | |
714 | /* Count only sections which have at least a single CIE or FDE. | |
715 | There cannot be any CIE or FDE <= 8 bytes. */ | |
716 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 717 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
718 | break; |
719 | } | |
720 | ||
721 | if (abfd == NULL) | |
722 | { | |
126495ed AM |
723 | _bfd_strip_section_from_output (info, hdr_info->hdr_sec); |
724 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 725 | return TRUE; |
68f69152 | 726 | } |
126495ed | 727 | |
b34976b6 AM |
728 | hdr_info->table = TRUE; |
729 | return TRUE; | |
68f69152 JJ |
730 | } |
731 | ||
65765700 JJ |
732 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
733 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
734 | or -1 if the address refers to a CIE/FDE which has been removed | |
735 | or to offset with dynamic relocation which is no longer needed. */ | |
736 | ||
737 | bfd_vma | |
c39a58e6 AM |
738 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
739 | asection *sec, | |
740 | bfd_vma offset) | |
65765700 JJ |
741 | { |
742 | struct eh_frame_sec_info *sec_info; | |
743 | unsigned int lo, hi, mid; | |
744 | ||
68bfbfcc | 745 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 746 | return offset; |
c39a58e6 | 747 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 748 | |
eea6121a AM |
749 | if (offset >= sec->rawsize) |
750 | return offset - sec->rawsize + sec->size; | |
65765700 JJ |
751 | |
752 | lo = 0; | |
753 | hi = sec_info->count; | |
754 | mid = 0; | |
755 | while (lo < hi) | |
756 | { | |
757 | mid = (lo + hi) / 2; | |
758 | if (offset < sec_info->entry[mid].offset) | |
759 | hi = mid; | |
760 | else if (offset | |
761 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
762 | lo = mid + 1; | |
763 | else | |
764 | break; | |
765 | } | |
766 | ||
767 | BFD_ASSERT (lo < hi); | |
768 | ||
769 | /* FDE or CIE was removed. */ | |
770 | if (sec_info->entry[mid].removed) | |
771 | return (bfd_vma) -1; | |
772 | ||
773 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
774 | relocation against FDE's initial_location field. */ | |
775 | if (sec_info->entry[mid].make_relative | |
776 | && ! sec_info->entry[mid].cie | |
777 | && offset == sec_info->entry[mid].offset + 8) | |
0bb2d96a | 778 | return (bfd_vma) -2; |
65765700 | 779 | |
9e2a4898 JJ |
780 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
781 | for run-time relocation against LSDA field. */ | |
782 | if (sec_info->entry[mid].make_lsda_relative | |
783 | && ! sec_info->entry[mid].cie | |
126495ed AM |
784 | && (offset == (sec_info->entry[mid].offset + 8 |
785 | + sec_info->entry[mid].lsda_offset))) | |
0bb2d96a | 786 | return (bfd_vma) -2; |
9e2a4898 | 787 | |
c68836a9 AM |
788 | return (offset + sec_info->entry[mid].new_offset |
789 | - sec_info->entry[mid].offset); | |
65765700 JJ |
790 | } |
791 | ||
792 | /* Write out .eh_frame section. This is called with the relocated | |
793 | contents. */ | |
794 | ||
b34976b6 | 795 | bfd_boolean |
c39a58e6 AM |
796 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
797 | struct bfd_link_info *info, | |
798 | asection *sec, | |
799 | bfd_byte *contents) | |
65765700 JJ |
800 | { |
801 | struct eh_frame_sec_info *sec_info; | |
126495ed | 802 | struct elf_link_hash_table *htab; |
65765700 JJ |
803 | struct eh_frame_hdr_info *hdr_info; |
804 | unsigned int i; | |
805 | bfd_byte *p, *buf; | |
806 | unsigned int leb128_tmp; | |
807 | unsigned int cie_offset = 0; | |
808 | unsigned int ptr_size; | |
809 | ||
810 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
811 | == ELFCLASS64) ? 8 : 4; | |
812 | ||
68bfbfcc | 813 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 814 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 815 | sec->output_offset, sec->size); |
c39a58e6 | 816 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
817 | htab = elf_hash_table (info); |
818 | hdr_info = &htab->eh_info; | |
819 | if (hdr_info->table && hdr_info->array == NULL) | |
820 | hdr_info->array | |
821 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
822 | if (hdr_info->array == NULL) | |
823 | hdr_info = NULL; | |
65765700 JJ |
824 | |
825 | p = contents; | |
826 | for (i = 0; i < sec_info->count; ++i) | |
827 | { | |
828 | if (sec_info->entry[i].removed) | |
829 | { | |
830 | if (sec_info->entry[i].cie) | |
831 | { | |
a3aa38ee JJ |
832 | /* If CIE is removed due to no remaining FDEs referencing it |
833 | and there were no CIEs kept before it, sec_info->entry[i].sec | |
834 | will be zero. */ | |
835 | if (sec_info->entry[i].sec == NULL) | |
836 | cie_offset = 0; | |
837 | else | |
838 | { | |
839 | cie_offset = sec_info->entry[i].new_offset; | |
840 | cie_offset += (sec_info->entry[i].sec->output_section->vma | |
841 | + sec_info->entry[i].sec->output_offset | |
842 | - sec->output_section->vma | |
843 | - sec->output_offset); | |
844 | } | |
65765700 JJ |
845 | } |
846 | continue; | |
847 | } | |
a3aa38ee | 848 | |
65765700 JJ |
849 | if (sec_info->entry[i].cie) |
850 | { | |
851 | /* CIE */ | |
852 | cie_offset = sec_info->entry[i].new_offset; | |
9e2a4898 | 853 | if (sec_info->entry[i].make_relative |
09ae86c2 JJ |
854 | || sec_info->entry[i].make_lsda_relative |
855 | || sec_info->entry[i].per_encoding_relative) | |
65765700 JJ |
856 | { |
857 | unsigned char *aug; | |
9e2a4898 | 858 | unsigned int action; |
65765700 JJ |
859 | unsigned int dummy, per_width, per_encoding; |
860 | ||
9e2a4898 | 861 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 862 | DW_EH_PE_* value. */ |
9e2a4898 | 863 | action = (sec_info->entry[i].make_relative ? 1 : 0) |
09ae86c2 JJ |
864 | | (sec_info->entry[i].make_lsda_relative ? 2 : 0) |
865 | | (sec_info->entry[i].per_encoding_relative ? 4 : 0); | |
65765700 JJ |
866 | buf = contents + sec_info->entry[i].offset; |
867 | /* Skip length, id and version. */ | |
868 | buf += 9; | |
869 | aug = buf; | |
870 | buf = strchr (buf, '\0') + 1; | |
871 | read_uleb128 (dummy, buf); | |
872 | read_sleb128 (dummy, buf); | |
873 | read_uleb128 (dummy, buf); | |
874 | if (*aug == 'z') | |
875 | { | |
876 | read_uleb128 (dummy, buf); | |
877 | aug++; | |
878 | } | |
879 | ||
9e2a4898 | 880 | while (action) |
65765700 JJ |
881 | switch (*aug++) |
882 | { | |
883 | case 'L': | |
9e2a4898 JJ |
884 | if (action & 2) |
885 | { | |
886 | BFD_ASSERT (*buf == sec_info->entry[i].lsda_encoding); | |
887 | *buf |= DW_EH_PE_pcrel; | |
888 | action &= ~2; | |
889 | } | |
65765700 JJ |
890 | buf++; |
891 | break; | |
892 | case 'P': | |
893 | per_encoding = *buf++; | |
894 | per_width = get_DW_EH_PE_width (per_encoding, | |
895 | ptr_size); | |
896 | BFD_ASSERT (per_width != 0); | |
09ae86c2 JJ |
897 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
898 | == sec_info->entry[i].per_encoding_relative); | |
65765700 JJ |
899 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
900 | buf = (contents | |
901 | + ((buf - contents + per_width - 1) | |
902 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
903 | if (action & 4) |
904 | { | |
905 | bfd_vma value; | |
906 | ||
84f97cb6 AS |
907 | value = read_value (abfd, buf, per_width, |
908 | get_DW_EH_PE_signed | |
909 | (per_encoding)); | |
09ae86c2 JJ |
910 | value += (sec_info->entry[i].offset |
911 | - sec_info->entry[i].new_offset); | |
912 | write_value (abfd, buf, value, per_width); | |
913 | action &= ~4; | |
914 | } | |
65765700 JJ |
915 | buf += per_width; |
916 | break; | |
9e2a4898 JJ |
917 | case 'R': |
918 | if (action & 1) | |
919 | { | |
920 | BFD_ASSERT (*buf == sec_info->entry[i].fde_encoding); | |
921 | *buf |= DW_EH_PE_pcrel; | |
922 | action &= ~1; | |
923 | } | |
924 | buf++; | |
925 | break; | |
65765700 JJ |
926 | default: |
927 | BFD_FAIL (); | |
928 | } | |
65765700 JJ |
929 | } |
930 | } | |
af40ce3c | 931 | else if (sec_info->entry[i].size > 4) |
65765700 JJ |
932 | { |
933 | /* FDE */ | |
934 | bfd_vma value = 0, address; | |
9e2a4898 | 935 | unsigned int width; |
65765700 JJ |
936 | |
937 | buf = contents + sec_info->entry[i].offset; | |
b34976b6 | 938 | /* Skip length. */ |
65765700 JJ |
939 | buf += 4; |
940 | bfd_put_32 (abfd, | |
941 | sec_info->entry[i].new_offset + 4 - cie_offset, buf); | |
942 | buf += 4; | |
9e2a4898 JJ |
943 | width = get_DW_EH_PE_width (sec_info->entry[i].fde_encoding, |
944 | ptr_size); | |
84f97cb6 AS |
945 | address = value = read_value (abfd, buf, width, |
946 | get_DW_EH_PE_signed | |
947 | (sec_info->entry[i].fde_encoding)); | |
9e2a4898 | 948 | if (value) |
65765700 | 949 | { |
9e2a4898 JJ |
950 | switch (sec_info->entry[i].fde_encoding & 0xf0) |
951 | { | |
952 | case DW_EH_PE_indirect: | |
953 | case DW_EH_PE_textrel: | |
954 | BFD_ASSERT (hdr_info == NULL); | |
955 | break; | |
956 | case DW_EH_PE_datarel: | |
957 | { | |
958 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
959 | ||
960 | BFD_ASSERT (got != NULL); | |
961 | address += got->vma; | |
962 | } | |
963 | break; | |
964 | case DW_EH_PE_pcrel: | |
965 | value += (sec_info->entry[i].offset | |
966 | - sec_info->entry[i].new_offset); | |
967 | address += (sec->output_section->vma + sec->output_offset | |
968 | + sec_info->entry[i].offset + 8); | |
969 | break; | |
970 | } | |
971 | if (sec_info->entry[i].make_relative) | |
972 | value -= (sec->output_section->vma + sec->output_offset | |
65765700 | 973 | + sec_info->entry[i].new_offset + 8); |
9e2a4898 | 974 | write_value (abfd, buf, value, width); |
65765700 JJ |
975 | } |
976 | ||
977 | if (hdr_info) | |
978 | { | |
979 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
980 | hdr_info->array[hdr_info->array_count++].fde | |
981 | = (sec->output_section->vma + sec->output_offset | |
982 | + sec_info->entry[i].new_offset); | |
983 | } | |
9e2a4898 JJ |
984 | |
985 | if ((sec_info->entry[i].lsda_encoding & 0xf0) == DW_EH_PE_pcrel | |
986 | || sec_info->entry[i].make_lsda_relative) | |
987 | { | |
988 | buf += sec_info->entry[i].lsda_offset; | |
989 | width = get_DW_EH_PE_width (sec_info->entry[i].lsda_encoding, | |
990 | ptr_size); | |
84f97cb6 AS |
991 | value = read_value (abfd, buf, width, |
992 | get_DW_EH_PE_signed | |
993 | (sec_info->entry[i].lsda_encoding)); | |
9e2a4898 JJ |
994 | if (value) |
995 | { | |
996 | if ((sec_info->entry[i].lsda_encoding & 0xf0) | |
997 | == DW_EH_PE_pcrel) | |
998 | value += (sec_info->entry[i].offset | |
999 | - sec_info->entry[i].new_offset); | |
1000 | else if (sec_info->entry[i].make_lsda_relative) | |
1001 | value -= (sec->output_section->vma + sec->output_offset | |
1002 | + sec_info->entry[i].new_offset + 8 | |
1003 | + sec_info->entry[i].lsda_offset); | |
1004 | write_value (abfd, buf, value, width); | |
1005 | } | |
1006 | } | |
65765700 | 1007 | } |
af40ce3c JJ |
1008 | else |
1009 | /* Terminating FDE must be at the end of .eh_frame section only. */ | |
1010 | BFD_ASSERT (i == sec_info->count - 1); | |
65765700 JJ |
1011 | |
1012 | BFD_ASSERT (p == contents + sec_info->entry[i].new_offset); | |
1013 | memmove (p, contents + sec_info->entry[i].offset, | |
1014 | sec_info->entry[i].size); | |
1015 | p += sec_info->entry[i].size; | |
1016 | } | |
1017 | ||
10cf14ea L |
1018 | { |
1019 | unsigned int alignment = 1 << sec->alignment_power; | |
eea6121a | 1020 | unsigned int pad = sec->size % alignment; |
10cf14ea | 1021 | |
9da84788 L |
1022 | /* Don't pad beyond the raw size of the output section. It |
1023 | can happen at the last input section. */ | |
1024 | if (pad | |
eea6121a AM |
1025 | && ((sec->output_offset + sec->size + pad) |
1026 | <= sec->output_section->size)) | |
10cf14ea L |
1027 | { |
1028 | /* Find the last CIE/FDE. */ | |
1029 | for (i = sec_info->count - 1; i > 0; i--) | |
1030 | if (! sec_info->entry[i].removed) | |
1031 | break; | |
1032 | ||
1033 | /* The size of the last CIE/FDE must be at least 4. */ | |
1034 | if (sec_info->entry[i].removed | |
1035 | || sec_info->entry[i].size < 4) | |
1036 | abort (); | |
1037 | ||
1038 | pad = alignment - pad; | |
1039 | ||
1040 | buf = contents + sec_info->entry[i].new_offset; | |
1041 | ||
1042 | /* Update length. */ | |
1043 | sec_info->entry[i].size += pad; | |
1044 | bfd_put_32 (abfd, sec_info->entry[i].size - 4, buf); | |
1045 | ||
1046 | /* Pad it with DW_CFA_nop */ | |
1047 | memset (p, 0, pad); | |
1048 | p += pad; | |
1049 | ||
eea6121a | 1050 | sec->size += pad; |
10cf14ea L |
1051 | } |
1052 | } | |
a5eb27e6 | 1053 | |
eea6121a | 1054 | BFD_ASSERT ((bfd_size_type) (p - contents) == sec->size); |
65765700 JJ |
1055 | |
1056 | return bfd_set_section_contents (abfd, sec->output_section, | |
1057 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1058 | sec->size); |
65765700 JJ |
1059 | } |
1060 | ||
1061 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1062 | VMA of FDE initial location. */ | |
1063 | ||
1064 | static int | |
c39a58e6 | 1065 | vma_compare (const void *a, const void *b) |
65765700 | 1066 | { |
c39a58e6 AM |
1067 | const struct eh_frame_array_ent *p = a; |
1068 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1069 | if (p->initial_loc > q->initial_loc) |
1070 | return 1; | |
1071 | if (p->initial_loc < q->initial_loc) | |
1072 | return -1; | |
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | /* Write out .eh_frame_hdr section. This must be called after | |
1077 | _bfd_elf_write_section_eh_frame has been called on all input | |
1078 | .eh_frame sections. | |
1079 | .eh_frame_hdr format: | |
1080 | ubyte version (currently 1) | |
1081 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1082 | .eh_frame section) | |
1083 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1084 | number (or DW_EH_PE_omit if there is no | |
1085 | binary search table computed)) | |
1086 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1087 | or DW_EH_PE_omit if not present. | |
1088 | DW_EH_PE_datarel is using address of | |
1089 | .eh_frame_hdr section start as base) | |
1090 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1091 | optionally followed by: | |
1092 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1093 | fde_count x [encoded] initial_loc, fde | |
1094 | (array of encoded pairs containing | |
1095 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1096 | sorted by increasing initial_loc). */ |
65765700 | 1097 | |
b34976b6 | 1098 | bfd_boolean |
c39a58e6 | 1099 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1100 | { |
126495ed | 1101 | struct elf_link_hash_table *htab; |
65765700 | 1102 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1103 | asection *sec; |
65765700 JJ |
1104 | bfd_byte *contents; |
1105 | asection *eh_frame_sec; | |
1106 | bfd_size_type size; | |
5ed6aba4 | 1107 | bfd_boolean retval; |
ec3391e7 | 1108 | bfd_vma encoded_eh_frame; |
65765700 | 1109 | |
126495ed AM |
1110 | htab = elf_hash_table (info); |
1111 | hdr_info = &htab->eh_info; | |
1112 | sec = hdr_info->hdr_sec; | |
1113 | if (sec == NULL) | |
b34976b6 | 1114 | return TRUE; |
57a72197 | 1115 | |
65765700 JJ |
1116 | size = EH_FRAME_HDR_SIZE; |
1117 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1118 | size += 4 + hdr_info->fde_count * 8; | |
1119 | contents = bfd_malloc (size); | |
1120 | if (contents == NULL) | |
b34976b6 | 1121 | return FALSE; |
65765700 JJ |
1122 | |
1123 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1124 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1125 | { |
1126 | free (contents); | |
1127 | return FALSE; | |
1128 | } | |
65765700 JJ |
1129 | |
1130 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1131 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1132 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1133 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1134 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1135 | ||
65765700 JJ |
1136 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1137 | { | |
5ed6aba4 NC |
1138 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1139 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1140 | } |
1141 | else | |
1142 | { | |
1143 | contents[2] = DW_EH_PE_omit; | |
1144 | contents[3] = DW_EH_PE_omit; | |
1145 | } | |
ec3391e7 AO |
1146 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1147 | ||
65765700 JJ |
1148 | if (contents[2] != DW_EH_PE_omit) |
1149 | { | |
1150 | unsigned int i; | |
1151 | ||
1152 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1153 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1154 | vma_compare); | |
1155 | for (i = 0; i < hdr_info->fde_count; i++) | |
1156 | { | |
1157 | bfd_put_32 (abfd, | |
1158 | hdr_info->array[i].initial_loc | |
1159 | - sec->output_section->vma, | |
1160 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1161 | bfd_put_32 (abfd, | |
1162 | hdr_info->array[i].fde - sec->output_section->vma, | |
1163 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1164 | } | |
1165 | } | |
1166 | ||
5ed6aba4 NC |
1167 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1168 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1169 | sec->size); |
5ed6aba4 NC |
1170 | free (contents); |
1171 | return retval; | |
65765700 | 1172 | } |
ec3391e7 AO |
1173 | |
1174 | /* Decide whether we can use a PC-relative encoding within the given | |
1175 | EH frame section. This is the default implementation. */ | |
1176 | ||
1177 | bfd_boolean | |
1178 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1179 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1180 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1181 | { | |
1182 | return TRUE; | |
1183 | } | |
1184 | ||
1185 | /* Select an encoding for the given address. Preference is given to | |
1186 | PC-relative addressing modes. */ | |
1187 | ||
1188 | bfd_byte | |
1189 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1190 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1191 | asection *osec, bfd_vma offset, | |
1192 | asection *loc_sec, bfd_vma loc_offset, | |
1193 | bfd_vma *encoded) | |
1194 | { | |
1195 | *encoded = osec->vma + offset - | |
1196 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1197 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1198 | } |