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 | ||
65765700 JJ |
29 | #define read_uleb128(VAR, BUF) \ |
30 | do \ | |
31 | { \ | |
32 | (VAR) = read_unsigned_leb128 (abfd, buf, &leb128_tmp); \ | |
33 | (BUF) += leb128_tmp; \ | |
34 | } \ | |
35 | while (0) | |
36 | ||
37 | #define read_sleb128(VAR, BUF) \ | |
38 | do \ | |
39 | { \ | |
40 | (VAR) = read_signed_leb128 (abfd, buf, &leb128_tmp); \ | |
41 | (BUF) += leb128_tmp; \ | |
42 | } \ | |
43 | while (0) | |
44 | ||
45 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
46 | ||
47 | static | |
c39a58e6 | 48 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
65765700 JJ |
49 | { |
50 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
51 | was added to bfd. */ | |
52 | if ((encoding & 0x60) == 0x60) | |
53 | return 0; | |
54 | ||
55 | switch (encoding & 7) | |
56 | { | |
57 | case DW_EH_PE_udata2: return 2; | |
58 | case DW_EH_PE_udata4: return 4; | |
59 | case DW_EH_PE_udata8: return 8; | |
60 | case DW_EH_PE_absptr: return ptr_size; | |
61 | default: | |
62 | break; | |
63 | } | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
84f97cb6 AS |
68 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
69 | ||
9e2a4898 JJ |
70 | /* Read a width sized value from memory. */ |
71 | ||
72 | static bfd_vma | |
c39a58e6 | 73 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
9e2a4898 JJ |
74 | { |
75 | bfd_vma value; | |
76 | ||
77 | switch (width) | |
78 | { | |
84f97cb6 AS |
79 | case 2: |
80 | if (is_signed) | |
81 | value = bfd_get_signed_16 (abfd, buf); | |
82 | else | |
83 | value = bfd_get_16 (abfd, buf); | |
84 | break; | |
85 | case 4: | |
86 | if (is_signed) | |
87 | value = bfd_get_signed_32 (abfd, buf); | |
88 | else | |
89 | value = bfd_get_32 (abfd, buf); | |
90 | break; | |
91 | case 8: | |
92 | if (is_signed) | |
93 | value = bfd_get_signed_64 (abfd, buf); | |
94 | else | |
95 | value = bfd_get_64 (abfd, buf); | |
96 | break; | |
97 | default: | |
98 | BFD_FAIL (); | |
99 | return 0; | |
9e2a4898 JJ |
100 | } |
101 | ||
102 | return value; | |
103 | } | |
b34976b6 | 104 | |
9e2a4898 JJ |
105 | /* Store a width sized value to memory. */ |
106 | ||
107 | static void | |
c39a58e6 | 108 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
9e2a4898 JJ |
109 | { |
110 | switch (width) | |
111 | { | |
112 | case 2: bfd_put_16 (abfd, value, buf); break; | |
113 | case 4: bfd_put_32 (abfd, value, buf); break; | |
114 | case 8: bfd_put_64 (abfd, value, buf); break; | |
115 | default: BFD_FAIL (); | |
116 | } | |
117 | } | |
118 | ||
65765700 JJ |
119 | /* Return zero if C1 and C2 CIEs can be merged. */ |
120 | ||
121 | static | |
c39a58e6 | 122 | int cie_compare (struct cie *c1, struct cie *c2) |
65765700 JJ |
123 | { |
124 | if (c1->hdr.length == c2->hdr.length | |
125 | && c1->version == c2->version | |
126 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
127 | && strcmp (c1->augmentation, "eh") != 0 | |
128 | && c1->code_align == c2->code_align | |
129 | && c1->data_align == c2->data_align | |
130 | && c1->ra_column == c2->ra_column | |
131 | && c1->augmentation_size == c2->augmentation_size | |
132 | && c1->personality == c2->personality | |
133 | && c1->per_encoding == c2->per_encoding | |
134 | && c1->lsda_encoding == c2->lsda_encoding | |
135 | && c1->fde_encoding == c2->fde_encoding | |
c39a58e6 | 136 | && c1->initial_insn_length == c2->initial_insn_length |
65765700 JJ |
137 | && memcmp (c1->initial_instructions, |
138 | c2->initial_instructions, | |
139 | c1->initial_insn_length) == 0) | |
140 | return 0; | |
141 | ||
142 | return 1; | |
143 | } | |
144 | ||
353057a5 RS |
145 | /* Return the number of extra bytes that we'll be inserting into |
146 | ENTRY's augmentation string. */ | |
147 | ||
148 | static INLINE unsigned int | |
149 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) | |
150 | { | |
151 | unsigned int size = 0; | |
152 | if (entry->cie) | |
153 | { | |
154 | if (entry->add_augmentation_size) | |
155 | size++; | |
156 | if (entry->add_fde_encoding) | |
157 | size++; | |
158 | } | |
159 | return size; | |
160 | } | |
161 | ||
162 | /* Likewise ENTRY's augmentation data. */ | |
163 | ||
164 | static INLINE unsigned int | |
165 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) | |
166 | { | |
167 | unsigned int size = 0; | |
168 | if (entry->cie) | |
169 | { | |
170 | if (entry->add_augmentation_size) | |
171 | size++; | |
172 | if (entry->add_fde_encoding) | |
173 | size++; | |
174 | } | |
175 | else | |
176 | { | |
177 | if (entry->cie_inf->add_augmentation_size) | |
178 | size++; | |
179 | } | |
180 | return size; | |
181 | } | |
182 | ||
183 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the | |
184 | required alignment of ENTRY in bytes. */ | |
185 | ||
186 | static unsigned int | |
187 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) | |
188 | { | |
189 | if (entry->removed) | |
190 | return 0; | |
191 | if (entry->size == 4) | |
192 | return 4; | |
193 | return (entry->size | |
194 | + extra_augmentation_string_bytes (entry) | |
195 | + extra_augmentation_data_bytes (entry) | |
196 | + alignment - 1) & -alignment; | |
197 | } | |
198 | ||
65765700 JJ |
199 | /* This function is called for each input file before the .eh_frame |
200 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
b34976b6 | 201 | functions. The function returns TRUE iff any entries have been |
65765700 JJ |
202 | deleted. */ |
203 | ||
b34976b6 | 204 | bfd_boolean |
c39a58e6 AM |
205 | _bfd_elf_discard_section_eh_frame |
206 | (bfd *abfd, struct bfd_link_info *info, asection *sec, | |
207 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), | |
208 | struct elf_reloc_cookie *cookie) | |
65765700 | 209 | { |
acfe5567 RS |
210 | #define REQUIRE(COND) \ |
211 | do \ | |
212 | if (!(COND)) \ | |
213 | goto free_no_table; \ | |
214 | while (0) | |
215 | ||
65765700 JJ |
216 | bfd_byte *ehbuf = NULL, *buf; |
217 | bfd_byte *last_cie, *last_fde; | |
fda3ecf2 | 218 | struct eh_cie_fde *ent, *last_cie_inf, *this_inf; |
65765700 JJ |
219 | struct cie_header hdr; |
220 | struct cie cie; | |
126495ed | 221 | struct elf_link_hash_table *htab; |
65765700 | 222 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 223 | struct eh_frame_sec_info *sec_info = NULL; |
65765700 | 224 | unsigned int leb128_tmp; |
fda3ecf2 | 225 | unsigned int cie_usage_count, offset; |
65765700 JJ |
226 | unsigned int ptr_size; |
227 | ||
eea6121a | 228 | if (sec->size == 0) |
65765700 JJ |
229 | { |
230 | /* This file does not contain .eh_frame information. */ | |
b34976b6 | 231 | return FALSE; |
65765700 JJ |
232 | } |
233 | ||
234 | if ((sec->output_section != NULL | |
235 | && bfd_is_abs_section (sec->output_section))) | |
236 | { | |
237 | /* At least one of the sections is being discarded from the | |
3472e2e9 | 238 | link, so we should just ignore them. */ |
b34976b6 | 239 | return FALSE; |
65765700 JJ |
240 | } |
241 | ||
126495ed AM |
242 | htab = elf_hash_table (info); |
243 | hdr_info = &htab->eh_info; | |
68f69152 | 244 | |
65765700 JJ |
245 | /* Read the frame unwind information from abfd. */ |
246 | ||
acfe5567 | 247 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
68f69152 | 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). */ | |
acfe5567 | 260 | REQUIRE (sec->size == (unsigned int) sec->size); |
65765700 JJ |
261 | |
262 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
263 | == ELFCLASS64) ? 8 : 4; | |
264 | buf = ehbuf; | |
265 | last_cie = NULL; | |
fda3ecf2 | 266 | last_cie_inf = NULL; |
65765700 JJ |
267 | memset (&cie, 0, sizeof (cie)); |
268 | cie_usage_count = 0; | |
65765700 JJ |
269 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
270 | + 99 * sizeof (struct eh_cie_fde)); | |
acfe5567 | 271 | REQUIRE (sec_info); |
eea6121a | 272 | |
65765700 JJ |
273 | sec_info->alloced = 100; |
274 | ||
275 | #define ENSURE_NO_RELOCS(buf) \ | |
acfe5567 RS |
276 | REQUIRE (!(cookie->rel < cookie->relend \ |
277 | && (cookie->rel->r_offset \ | |
278 | < (bfd_size_type) ((buf) - ehbuf)) \ | |
279 | && cookie->rel->r_info != 0)) | |
65765700 JJ |
280 | |
281 | #define SKIP_RELOCS(buf) \ | |
282 | while (cookie->rel < cookie->relend \ | |
3472e2e9 | 283 | && (cookie->rel->r_offset \ |
65765700 JJ |
284 | < (bfd_size_type) ((buf) - ehbuf))) \ |
285 | cookie->rel++ | |
286 | ||
287 | #define GET_RELOC(buf) \ | |
288 | ((cookie->rel < cookie->relend \ | |
289 | && (cookie->rel->r_offset \ | |
3472e2e9 | 290 | == (bfd_size_type) ((buf) - ehbuf))) \ |
65765700 JJ |
291 | ? cookie->rel : NULL) |
292 | ||
293 | for (;;) | |
294 | { | |
295 | unsigned char *aug; | |
296 | ||
297 | if (sec_info->count == sec_info->alloced) | |
298 | { | |
fda3ecf2 | 299 | struct eh_cie_fde *old_entry = sec_info->entry; |
65765700 JJ |
300 | sec_info = bfd_realloc (sec_info, |
301 | sizeof (struct eh_frame_sec_info) | |
fda3ecf2 AM |
302 | + ((sec_info->alloced + 99) |
303 | * sizeof (struct eh_cie_fde))); | |
acfe5567 | 304 | REQUIRE (sec_info); |
65765700 JJ |
305 | |
306 | memset (&sec_info->entry[sec_info->alloced], 0, | |
307 | 100 * sizeof (struct eh_cie_fde)); | |
308 | sec_info->alloced += 100; | |
fda3ecf2 AM |
309 | |
310 | /* Now fix any pointers into the array. */ | |
311 | if (last_cie_inf >= old_entry | |
312 | && last_cie_inf < old_entry + sec_info->count) | |
313 | last_cie_inf = sec_info->entry + (last_cie_inf - old_entry); | |
65765700 JJ |
314 | } |
315 | ||
fda3ecf2 | 316 | this_inf = sec_info->entry + sec_info->count; |
65765700 JJ |
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 | { | |
acfe5567 RS |
324 | /* Read the length of the entry. */ |
325 | REQUIRE ((bfd_size_type) (buf - ehbuf) + 4 <= sec->size); | |
65765700 | 326 | hdr.length = bfd_get_32 (abfd, buf); |
65765700 | 327 | buf += 4; |
acfe5567 RS |
328 | |
329 | /* 64-bit .eh_frame is not supported. */ | |
330 | REQUIRE (hdr.length != 0xffffffff); | |
331 | ||
332 | /* The CIE/FDE must be fully contained in this input section. */ | |
333 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr.length <= sec->size); | |
65765700 | 334 | |
fda3ecf2 AM |
335 | this_inf->offset = last_fde - ehbuf; |
336 | this_inf->size = 4 + hdr.length; | |
65765700 JJ |
337 | |
338 | if (hdr.length == 0) | |
339 | { | |
acfe5567 RS |
340 | /* A zero-length CIE should only be found at the end of |
341 | the section. */ | |
342 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); | |
65765700 JJ |
343 | ENSURE_NO_RELOCS (buf); |
344 | sec_info->count++; | |
345 | /* Now just finish last encountered CIE processing and break | |
346 | the loop. */ | |
347 | hdr.id = (unsigned int) -1; | |
348 | } | |
349 | else | |
350 | { | |
351 | hdr.id = bfd_get_32 (abfd, buf); | |
352 | buf += 4; | |
acfe5567 | 353 | REQUIRE (hdr.id != (unsigned int) -1); |
65765700 JJ |
354 | } |
355 | } | |
356 | ||
357 | if (hdr.id == 0 || hdr.id == (unsigned int) -1) | |
358 | { | |
359 | unsigned int initial_insn_length; | |
360 | ||
361 | /* CIE */ | |
362 | if (last_cie != NULL) | |
363 | { | |
73722af0 AM |
364 | /* Now check if this CIE is identical to the last CIE, |
365 | in which case we can remove it provided we adjust | |
366 | all FDEs. Also, it can be removed if we have removed | |
367 | all FDEs using it. */ | |
1049f94e | 368 | if ((!info->relocatable |
9da84788 L |
369 | && hdr_info->last_cie_sec |
370 | && (sec->output_section | |
371 | == hdr_info->last_cie_sec->output_section) | |
73722af0 | 372 | && cie_compare (&cie, &hdr_info->last_cie) == 0) |
65765700 | 373 | || cie_usage_count == 0) |
353057a5 | 374 | last_cie_inf->removed = 1; |
65765700 JJ |
375 | else |
376 | { | |
377 | hdr_info->last_cie = cie; | |
378 | hdr_info->last_cie_sec = sec; | |
fda3ecf2 AM |
379 | last_cie_inf->make_relative = cie.make_relative; |
380 | last_cie_inf->make_lsda_relative = cie.make_lsda_relative; | |
381 | last_cie_inf->per_encoding_relative | |
09ae86c2 | 382 | = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel; |
65765700 JJ |
383 | } |
384 | } | |
385 | ||
386 | if (hdr.id == (unsigned int) -1) | |
387 | break; | |
388 | ||
fda3ecf2 AM |
389 | last_cie_inf = this_inf; |
390 | this_inf->cie = 1; | |
65765700 JJ |
391 | |
392 | cie_usage_count = 0; | |
393 | memset (&cie, 0, sizeof (cie)); | |
394 | cie.hdr = hdr; | |
395 | cie.version = *buf++; | |
396 | ||
397 | /* Cannot handle unknown versions. */ | |
acfe5567 RS |
398 | REQUIRE (cie.version == 1 || cie.version == 3); |
399 | REQUIRE (strlen (buf) < sizeof (cie.augmentation)); | |
65765700 JJ |
400 | |
401 | strcpy (cie.augmentation, buf); | |
402 | buf = strchr (buf, '\0') + 1; | |
403 | ENSURE_NO_RELOCS (buf); | |
404 | if (buf[0] == 'e' && buf[1] == 'h') | |
405 | { | |
406 | /* GCC < 3.0 .eh_frame CIE */ | |
407 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
408 | is private to each CIE, so we don't need it for anything. | |
409 | Just skip it. */ | |
410 | buf += ptr_size; | |
411 | SKIP_RELOCS (buf); | |
412 | } | |
413 | read_uleb128 (cie.code_align, buf); | |
414 | read_sleb128 (cie.data_align, buf); | |
0da76f83 NC |
415 | if (cie.version == 1) |
416 | cie.ra_column = *buf++; | |
417 | else | |
418 | read_uleb128 (cie.ra_column, buf); | |
65765700 JJ |
419 | ENSURE_NO_RELOCS (buf); |
420 | cie.lsda_encoding = DW_EH_PE_omit; | |
421 | cie.fde_encoding = DW_EH_PE_omit; | |
422 | cie.per_encoding = DW_EH_PE_omit; | |
423 | aug = cie.augmentation; | |
424 | if (aug[0] != 'e' || aug[1] != 'h') | |
425 | { | |
426 | if (*aug == 'z') | |
427 | { | |
428 | aug++; | |
429 | read_uleb128 (cie.augmentation_size, buf); | |
430 | ENSURE_NO_RELOCS (buf); | |
431 | } | |
432 | ||
433 | while (*aug != '\0') | |
434 | switch (*aug++) | |
435 | { | |
436 | case 'L': | |
437 | cie.lsda_encoding = *buf++; | |
438 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 439 | REQUIRE (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size)); |
65765700 JJ |
440 | break; |
441 | case 'R': | |
442 | cie.fde_encoding = *buf++; | |
443 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 444 | REQUIRE (get_DW_EH_PE_width (cie.fde_encoding, ptr_size)); |
65765700 JJ |
445 | break; |
446 | case 'P': | |
447 | { | |
448 | int per_width; | |
449 | ||
450 | cie.per_encoding = *buf++; | |
451 | per_width = get_DW_EH_PE_width (cie.per_encoding, | |
452 | ptr_size); | |
acfe5567 | 453 | REQUIRE (per_width); |
65765700 JJ |
454 | if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned) |
455 | buf = (ehbuf | |
456 | + ((buf - ehbuf + per_width - 1) | |
457 | & ~((bfd_size_type) per_width - 1))); | |
458 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
459 | /* Ensure we have a reloc here, against |
460 | a global symbol. */ | |
99eb2ac8 | 461 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
462 | { |
463 | unsigned long r_symndx; | |
464 | ||
465 | #ifdef BFD64 | |
466 | if (ptr_size == 8) | |
467 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
468 | else | |
469 | #endif | |
470 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
471 | if (r_symndx >= cookie->locsymcount) | |
472 | { | |
473 | struct elf_link_hash_entry *h; | |
474 | ||
475 | r_symndx -= cookie->extsymoff; | |
476 | h = cookie->sym_hashes[r_symndx]; | |
477 | ||
478 | while (h->root.type == bfd_link_hash_indirect | |
479 | || h->root.type == bfd_link_hash_warning) | |
480 | h = (struct elf_link_hash_entry *) | |
481 | h->root.u.i.link; | |
482 | ||
483 | cie.personality = h; | |
484 | } | |
f4a6705c RS |
485 | /* Cope with MIPS-style composite relocations. */ |
486 | do | |
487 | cookie->rel++; | |
488 | while (GET_RELOC (buf) != NULL); | |
65765700 JJ |
489 | } |
490 | buf += per_width; | |
491 | } | |
492 | break; | |
493 | default: | |
494 | /* Unrecognized augmentation. Better bail out. */ | |
495 | goto free_no_table; | |
496 | } | |
497 | } | |
498 | ||
499 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a | 500 | as possible. */ |
3472e2e9 | 501 | if (info->shared |
ec3391e7 AO |
502 | && (get_elf_backend_data (abfd) |
503 | ->elf_backend_can_make_relative_eh_frame | |
353057a5 RS |
504 | (abfd, info, sec))) |
505 | { | |
506 | if ((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) | |
507 | cie.make_relative = 1; | |
508 | /* If the CIE doesn't already have an 'R' entry, it's fairly | |
509 | easy to add one, provided that there's no aligned data | |
510 | after the augmentation string. */ | |
511 | else if (cie.fde_encoding == DW_EH_PE_omit | |
512 | && (cie.per_encoding & 0xf0) != DW_EH_PE_aligned) | |
513 | { | |
514 | if (*cie.augmentation == 0) | |
515 | this_inf->add_augmentation_size = 1; | |
516 | this_inf->add_fde_encoding = 1; | |
517 | cie.make_relative = 1; | |
518 | } | |
519 | } | |
65765700 | 520 | |
0bb2d96a | 521 | if (info->shared |
ec3391e7 AO |
522 | && (get_elf_backend_data (abfd) |
523 | ->elf_backend_can_make_lsda_relative_eh_frame | |
524 | (abfd, info, sec)) | |
9e2a4898 JJ |
525 | && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
526 | cie.make_lsda_relative = 1; | |
527 | ||
65765700 JJ |
528 | /* If FDE encoding was not specified, it defaults to |
529 | DW_EH_absptr. */ | |
530 | if (cie.fde_encoding == DW_EH_PE_omit) | |
531 | cie.fde_encoding = DW_EH_PE_absptr; | |
532 | ||
533 | initial_insn_length = cie.hdr.length - (buf - last_fde - 4); | |
534 | if (initial_insn_length <= 50) | |
535 | { | |
536 | cie.initial_insn_length = initial_insn_length; | |
537 | memcpy (cie.initial_instructions, buf, initial_insn_length); | |
538 | } | |
539 | buf += initial_insn_length; | |
540 | ENSURE_NO_RELOCS (buf); | |
541 | last_cie = last_fde; | |
542 | } | |
543 | else | |
544 | { | |
545 | /* Ensure this FDE uses the last CIE encountered. */ | |
acfe5567 RS |
546 | REQUIRE (last_cie); |
547 | REQUIRE (hdr.id == (unsigned int) (buf - 4 - last_cie)); | |
65765700 JJ |
548 | |
549 | ENSURE_NO_RELOCS (buf); | |
acfe5567 | 550 | REQUIRE (GET_RELOC (buf)); |
fda3ecf2 | 551 | |
65765700 | 552 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) |
353057a5 RS |
553 | /* This is a FDE against a discarded section. It should |
554 | be deleted. */ | |
555 | this_inf->removed = 1; | |
65765700 JJ |
556 | else |
557 | { | |
0bb2d96a | 558 | if (info->shared |
af40ce3c JJ |
559 | && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr |
560 | && cie.make_relative == 0) | |
561 | || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 562 | { |
73722af0 | 563 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
564 | which we cannot turn into PC relative, |
565 | don't create the binary search table, | |
566 | since it is affected by runtime relocations. */ | |
b34976b6 | 567 | hdr_info->table = FALSE; |
0bb2d96a | 568 | } |
65765700 JJ |
569 | cie_usage_count++; |
570 | hdr_info->fde_count++; | |
571 | } | |
9e2a4898 JJ |
572 | if (cie.lsda_encoding != DW_EH_PE_omit) |
573 | { | |
574 | unsigned int dummy; | |
575 | ||
576 | aug = buf; | |
577 | buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
578 | if (cie.augmentation[0] == 'z') | |
579 | read_uleb128 (dummy, buf); | |
580 | /* If some new augmentation data is added before LSDA | |
581 | in FDE augmentation area, this need to be adjusted. */ | |
fda3ecf2 | 582 | this_inf->lsda_offset = (buf - aug); |
9e2a4898 | 583 | } |
65765700 JJ |
584 | buf = last_fde + 4 + hdr.length; |
585 | SKIP_RELOCS (buf); | |
586 | } | |
587 | ||
fda3ecf2 AM |
588 | this_inf->fde_encoding = cie.fde_encoding; |
589 | this_inf->lsda_encoding = cie.lsda_encoding; | |
65765700 JJ |
590 | sec_info->count++; |
591 | } | |
592 | ||
593 | elf_section_data (sec)->sec_info = sec_info; | |
68bfbfcc | 594 | sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME; |
65765700 JJ |
595 | |
596 | /* Ok, now we can assign new offsets. */ | |
597 | offset = 0; | |
fda3ecf2 AM |
598 | last_cie_inf = hdr_info->last_cie_inf; |
599 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
600 | if (!ent->removed) | |
601 | { | |
fda3ecf2 AM |
602 | if (ent->cie) |
603 | last_cie_inf = ent; | |
604 | else | |
605 | ent->cie_inf = last_cie_inf; | |
353057a5 RS |
606 | ent->new_offset = offset; |
607 | offset += size_of_output_cie_fde (ent, ptr_size); | |
fda3ecf2 AM |
608 | } |
609 | hdr_info->last_cie_inf = last_cie_inf; | |
65765700 | 610 | |
353057a5 | 611 | /* Resize the sec as needed. */ |
eea6121a | 612 | sec->rawsize = sec->size; |
353057a5 | 613 | sec->size = offset; |
eea6121a | 614 | if (sec->size == 0) |
65765700 JJ |
615 | sec->flags |= SEC_EXCLUDE; |
616 | ||
68f69152 | 617 | free (ehbuf); |
353057a5 | 618 | return offset != sec->rawsize; |
65765700 JJ |
619 | |
620 | free_no_table: | |
68f69152 JJ |
621 | if (ehbuf) |
622 | free (ehbuf); | |
65765700 JJ |
623 | if (sec_info) |
624 | free (sec_info); | |
b34976b6 | 625 | hdr_info->table = FALSE; |
65765700 | 626 | hdr_info->last_cie.hdr.length = 0; |
b34976b6 | 627 | return FALSE; |
acfe5567 RS |
628 | |
629 | #undef REQUIRE | |
65765700 JJ |
630 | } |
631 | ||
632 | /* This function is called for .eh_frame_hdr section after | |
633 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
634 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
635 | ||
b34976b6 | 636 | bfd_boolean |
c39a58e6 | 637 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 638 | { |
126495ed | 639 | struct elf_link_hash_table *htab; |
65765700 | 640 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 641 | asection *sec; |
65765700 | 642 | |
126495ed AM |
643 | htab = elf_hash_table (info); |
644 | hdr_info = &htab->eh_info; | |
645 | sec = hdr_info->hdr_sec; | |
646 | if (sec == NULL) | |
b34976b6 | 647 | return FALSE; |
126495ed | 648 | |
eea6121a | 649 | sec->size = EH_FRAME_HDR_SIZE; |
65765700 | 650 | if (hdr_info->table) |
eea6121a | 651 | sec->size += 4 + hdr_info->fde_count * 8; |
65765700 JJ |
652 | |
653 | /* Request program headers to be recalculated. */ | |
654 | elf_tdata (abfd)->program_header_size = 0; | |
126495ed | 655 | elf_tdata (abfd)->eh_frame_hdr = sec; |
b34976b6 | 656 | return TRUE; |
65765700 JJ |
657 | } |
658 | ||
68f69152 JJ |
659 | /* This function is called from size_dynamic_sections. |
660 | It needs to decide whether .eh_frame_hdr should be output or not, | |
661 | because later on it is too late for calling _bfd_strip_section_from_output, | |
662 | since dynamic symbol table has been sized. */ | |
663 | ||
b34976b6 | 664 | bfd_boolean |
c39a58e6 | 665 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
68f69152 | 666 | { |
126495ed | 667 | asection *o; |
68f69152 | 668 | bfd *abfd; |
126495ed | 669 | struct elf_link_hash_table *htab; |
68f69152 JJ |
670 | struct eh_frame_hdr_info *hdr_info; |
671 | ||
126495ed AM |
672 | htab = elf_hash_table (info); |
673 | hdr_info = &htab->eh_info; | |
674 | if (hdr_info->hdr_sec == NULL) | |
b34976b6 | 675 | return TRUE; |
68f69152 | 676 | |
126495ed AM |
677 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
678 | { | |
679 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 680 | return TRUE; |
126495ed | 681 | } |
68f69152 JJ |
682 | |
683 | abfd = NULL; | |
684 | if (info->eh_frame_hdr) | |
685 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
686 | { | |
687 | /* Count only sections which have at least a single CIE or FDE. | |
688 | There cannot be any CIE or FDE <= 8 bytes. */ | |
689 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
eea6121a | 690 | if (o && o->size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
691 | break; |
692 | } | |
693 | ||
694 | if (abfd == NULL) | |
695 | { | |
126495ed AM |
696 | _bfd_strip_section_from_output (info, hdr_info->hdr_sec); |
697 | hdr_info->hdr_sec = NULL; | |
b34976b6 | 698 | return TRUE; |
68f69152 | 699 | } |
126495ed | 700 | |
b34976b6 AM |
701 | hdr_info->table = TRUE; |
702 | return TRUE; | |
68f69152 JJ |
703 | } |
704 | ||
65765700 JJ |
705 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
706 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
707 | or -1 if the address refers to a CIE/FDE which has been removed | |
708 | or to offset with dynamic relocation which is no longer needed. */ | |
709 | ||
710 | bfd_vma | |
c39a58e6 | 711 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
92e4ec35 | 712 | struct bfd_link_info *info, |
c39a58e6 AM |
713 | asection *sec, |
714 | bfd_vma offset) | |
65765700 JJ |
715 | { |
716 | struct eh_frame_sec_info *sec_info; | |
92e4ec35 AM |
717 | struct elf_link_hash_table *htab; |
718 | struct eh_frame_hdr_info *hdr_info; | |
65765700 JJ |
719 | unsigned int lo, hi, mid; |
720 | ||
68bfbfcc | 721 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
65765700 | 722 | return offset; |
c39a58e6 | 723 | sec_info = elf_section_data (sec)->sec_info; |
65765700 | 724 | |
eea6121a AM |
725 | if (offset >= sec->rawsize) |
726 | return offset - sec->rawsize + sec->size; | |
65765700 | 727 | |
92e4ec35 AM |
728 | htab = elf_hash_table (info); |
729 | hdr_info = &htab->eh_info; | |
730 | if (hdr_info->offsets_adjusted) | |
731 | offset += sec->output_offset; | |
732 | ||
65765700 JJ |
733 | lo = 0; |
734 | hi = sec_info->count; | |
735 | mid = 0; | |
736 | while (lo < hi) | |
737 | { | |
738 | mid = (lo + hi) / 2; | |
739 | if (offset < sec_info->entry[mid].offset) | |
740 | hi = mid; | |
741 | else if (offset | |
742 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
743 | lo = mid + 1; | |
744 | else | |
745 | break; | |
746 | } | |
747 | ||
748 | BFD_ASSERT (lo < hi); | |
749 | ||
750 | /* FDE or CIE was removed. */ | |
751 | if (sec_info->entry[mid].removed) | |
752 | return (bfd_vma) -1; | |
753 | ||
754 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
755 | relocation against FDE's initial_location field. */ | |
fda3ecf2 AM |
756 | if (!sec_info->entry[mid].cie |
757 | && sec_info->entry[mid].cie_inf->make_relative | |
353057a5 RS |
758 | && offset == sec_info->entry[mid].offset + 8) |
759 | return (bfd_vma) -2; | |
65765700 | 760 | |
9e2a4898 JJ |
761 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
762 | for run-time relocation against LSDA field. */ | |
fda3ecf2 AM |
763 | if (!sec_info->entry[mid].cie |
764 | && sec_info->entry[mid].cie_inf->make_lsda_relative | |
126495ed | 765 | && (offset == (sec_info->entry[mid].offset + 8 |
92e4ec35 AM |
766 | + sec_info->entry[mid].lsda_offset)) |
767 | && (sec_info->entry[mid].cie_inf->need_lsda_relative | |
768 | || !hdr_info->offsets_adjusted)) | |
8935b81f | 769 | { |
fda3ecf2 | 770 | sec_info->entry[mid].cie_inf->need_lsda_relative = 1; |
8935b81f AM |
771 | return (bfd_vma) -2; |
772 | } | |
9e2a4898 | 773 | |
92e4ec35 AM |
774 | if (hdr_info->offsets_adjusted) |
775 | offset -= sec->output_offset; | |
353057a5 | 776 | /* Any new augmentation bytes go before the first relocation. */ |
c68836a9 | 777 | return (offset + sec_info->entry[mid].new_offset |
353057a5 RS |
778 | - sec_info->entry[mid].offset |
779 | + extra_augmentation_string_bytes (sec_info->entry + mid) | |
780 | + extra_augmentation_data_bytes (sec_info->entry + mid)); | |
65765700 JJ |
781 | } |
782 | ||
783 | /* Write out .eh_frame section. This is called with the relocated | |
784 | contents. */ | |
785 | ||
b34976b6 | 786 | bfd_boolean |
c39a58e6 AM |
787 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
788 | struct bfd_link_info *info, | |
789 | asection *sec, | |
790 | bfd_byte *contents) | |
65765700 JJ |
791 | { |
792 | struct eh_frame_sec_info *sec_info; | |
126495ed | 793 | struct elf_link_hash_table *htab; |
65765700 | 794 | struct eh_frame_hdr_info *hdr_info; |
65765700 | 795 | unsigned int leb128_tmp; |
65765700 | 796 | unsigned int ptr_size; |
fda3ecf2 | 797 | struct eh_cie_fde *ent; |
65765700 JJ |
798 | |
799 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
800 | == ELFCLASS64) ? 8 : 4; | |
801 | ||
68bfbfcc | 802 | if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME) |
c39a58e6 | 803 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
eea6121a | 804 | sec->output_offset, sec->size); |
c39a58e6 | 805 | sec_info = elf_section_data (sec)->sec_info; |
126495ed AM |
806 | htab = elf_hash_table (info); |
807 | hdr_info = &htab->eh_info; | |
3472e2e9 AM |
808 | |
809 | /* First convert all offsets to output section offsets, so that a | |
810 | CIE offset is valid if the CIE is used by a FDE from some other | |
811 | section. This can happen when duplicate CIEs are deleted in | |
812 | _bfd_elf_discard_section_eh_frame. We do all sections here because | |
813 | this function might not be called on sections in the same order as | |
814 | _bfd_elf_discard_section_eh_frame. */ | |
815 | if (!hdr_info->offsets_adjusted) | |
816 | { | |
817 | bfd *ibfd; | |
818 | asection *eh; | |
819 | struct eh_frame_sec_info *eh_inf; | |
820 | ||
821 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) | |
822 | { | |
823 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour | |
824 | || (ibfd->flags & DYNAMIC) != 0) | |
825 | continue; | |
826 | ||
827 | eh = bfd_get_section_by_name (ibfd, ".eh_frame"); | |
828 | if (eh == NULL || eh->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
829 | continue; | |
830 | ||
831 | eh_inf = elf_section_data (eh)->sec_info; | |
832 | for (ent = eh_inf->entry; ent < eh_inf->entry + eh_inf->count; ++ent) | |
833 | { | |
834 | ent->offset += eh->output_offset; | |
835 | ent->new_offset += eh->output_offset; | |
836 | } | |
837 | } | |
838 | hdr_info->offsets_adjusted = TRUE; | |
839 | } | |
840 | ||
126495ed AM |
841 | if (hdr_info->table && hdr_info->array == NULL) |
842 | hdr_info->array | |
843 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
844 | if (hdr_info->array == NULL) | |
845 | hdr_info = NULL; | |
65765700 | 846 | |
353057a5 RS |
847 | /* The new offsets can be bigger or smaller than the original offsets. |
848 | We therefore need to make two passes over the section: one backward | |
849 | pass to move entries up and one forward pass to move entries down. | |
850 | The two passes won't interfere with each other because entries are | |
851 | not reordered */ | |
852 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) | |
853 | if (!ent->removed && ent->new_offset > ent->offset) | |
854 | memmove (contents + ent->new_offset - sec->output_offset, | |
855 | contents + ent->offset - sec->output_offset, ent->size); | |
856 | ||
857 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) | |
858 | if (!ent->removed && ent->new_offset < ent->offset) | |
859 | memmove (contents + ent->new_offset - sec->output_offset, | |
860 | contents + ent->offset - sec->output_offset, ent->size); | |
861 | ||
fda3ecf2 | 862 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
65765700 | 863 | { |
353057a5 RS |
864 | unsigned char *buf, *end; |
865 | unsigned int new_size; | |
866 | ||
fda3ecf2 AM |
867 | if (ent->removed) |
868 | continue; | |
869 | ||
353057a5 RS |
870 | if (ent->size == 4) |
871 | { | |
872 | /* Any terminating FDE must be at the end of the section. */ | |
873 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); | |
874 | continue; | |
875 | } | |
876 | ||
877 | buf = contents + ent->new_offset - sec->output_offset; | |
878 | end = buf + ent->size; | |
879 | new_size = size_of_output_cie_fde (ent, ptr_size); | |
880 | ||
881 | /* Install the new size, filling the extra bytes with DW_CFA_nops. */ | |
882 | if (new_size != ent->size) | |
883 | { | |
884 | memset (end, 0, new_size - ent->size); | |
885 | bfd_put_32 (abfd, new_size - 4, buf); | |
886 | } | |
887 | ||
fda3ecf2 | 888 | if (ent->cie) |
65765700 JJ |
889 | { |
890 | /* CIE */ | |
353057a5 | 891 | if (ent->make_relative |
fda3ecf2 AM |
892 | || ent->need_lsda_relative |
893 | || ent->per_encoding_relative) | |
65765700 JJ |
894 | { |
895 | unsigned char *aug; | |
353057a5 | 896 | unsigned int action, extra_string, extra_data; |
65765700 JJ |
897 | unsigned int dummy, per_width, per_encoding; |
898 | ||
9e2a4898 | 899 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 900 | DW_EH_PE_* value. */ |
353057a5 | 901 | action = ((ent->make_relative ? 1 : 0) |
fda3ecf2 AM |
902 | | (ent->need_lsda_relative ? 2 : 0) |
903 | | (ent->per_encoding_relative ? 4 : 0)); | |
353057a5 RS |
904 | extra_string = extra_augmentation_string_bytes (ent); |
905 | extra_data = extra_augmentation_data_bytes (ent); | |
906 | ||
65765700 JJ |
907 | /* Skip length, id and version. */ |
908 | buf += 9; | |
909 | aug = buf; | |
910 | buf = strchr (buf, '\0') + 1; | |
911 | read_uleb128 (dummy, buf); | |
912 | read_sleb128 (dummy, buf); | |
913 | read_uleb128 (dummy, buf); | |
914 | if (*aug == 'z') | |
915 | { | |
353057a5 RS |
916 | /* The uleb128 will always be a single byte for the kind |
917 | of augmentation strings that we're prepared to handle. */ | |
918 | *buf++ += extra_data; | |
65765700 JJ |
919 | aug++; |
920 | } | |
921 | ||
353057a5 RS |
922 | /* Make room for the new augmentation string and data bytes. */ |
923 | memmove (buf + extra_string + extra_data, buf, end - buf); | |
924 | memmove (aug + extra_string, aug, buf - aug); | |
925 | buf += extra_string; | |
926 | ||
927 | if (ent->add_augmentation_size) | |
928 | { | |
929 | *aug++ = 'z'; | |
930 | *buf++ = extra_data - 1; | |
931 | } | |
932 | if (ent->add_fde_encoding) | |
933 | { | |
934 | BFD_ASSERT (action & 1); | |
935 | *aug++ = 'R'; | |
936 | *buf++ = DW_EH_PE_pcrel; | |
937 | action &= ~1; | |
938 | } | |
939 | ||
9e2a4898 | 940 | while (action) |
65765700 JJ |
941 | switch (*aug++) |
942 | { | |
943 | case 'L': | |
9e2a4898 JJ |
944 | if (action & 2) |
945 | { | |
fda3ecf2 | 946 | BFD_ASSERT (*buf == ent->lsda_encoding); |
9e2a4898 JJ |
947 | *buf |= DW_EH_PE_pcrel; |
948 | action &= ~2; | |
949 | } | |
65765700 JJ |
950 | buf++; |
951 | break; | |
952 | case 'P': | |
953 | per_encoding = *buf++; | |
3472e2e9 | 954 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
65765700 | 955 | BFD_ASSERT (per_width != 0); |
09ae86c2 | 956 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
fda3ecf2 | 957 | == ent->per_encoding_relative); |
65765700 JJ |
958 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
959 | buf = (contents | |
960 | + ((buf - contents + per_width - 1) | |
961 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
962 | if (action & 4) |
963 | { | |
fda3ecf2 AM |
964 | bfd_vma val; |
965 | ||
966 | val = read_value (abfd, buf, per_width, | |
967 | get_DW_EH_PE_signed (per_encoding)); | |
968 | val += ent->offset - ent->new_offset; | |
353057a5 | 969 | val -= extra_string + extra_data; |
fda3ecf2 | 970 | write_value (abfd, buf, val, per_width); |
09ae86c2 JJ |
971 | action &= ~4; |
972 | } | |
65765700 JJ |
973 | buf += per_width; |
974 | break; | |
9e2a4898 JJ |
975 | case 'R': |
976 | if (action & 1) | |
977 | { | |
fda3ecf2 | 978 | BFD_ASSERT (*buf == ent->fde_encoding); |
9e2a4898 JJ |
979 | *buf |= DW_EH_PE_pcrel; |
980 | action &= ~1; | |
981 | } | |
982 | buf++; | |
983 | break; | |
65765700 JJ |
984 | default: |
985 | BFD_FAIL (); | |
986 | } | |
65765700 JJ |
987 | } |
988 | } | |
353057a5 | 989 | else |
65765700 JJ |
990 | { |
991 | /* FDE */ | |
fda3ecf2 | 992 | bfd_vma value, address; |
9e2a4898 | 993 | unsigned int width; |
65765700 | 994 | |
b34976b6 | 995 | /* Skip length. */ |
65765700 | 996 | buf += 4; |
fda3ecf2 AM |
997 | value = ent->new_offset + 4 - ent->cie_inf->new_offset; |
998 | bfd_put_32 (abfd, value, buf); | |
65765700 | 999 | buf += 4; |
fda3ecf2 AM |
1000 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
1001 | value = read_value (abfd, buf, width, | |
1002 | get_DW_EH_PE_signed (ent->fde_encoding)); | |
1003 | address = value; | |
9e2a4898 | 1004 | if (value) |
65765700 | 1005 | { |
fda3ecf2 | 1006 | switch (ent->fde_encoding & 0xf0) |
9e2a4898 JJ |
1007 | { |
1008 | case DW_EH_PE_indirect: | |
1009 | case DW_EH_PE_textrel: | |
1010 | BFD_ASSERT (hdr_info == NULL); | |
1011 | break; | |
1012 | case DW_EH_PE_datarel: | |
1013 | { | |
1014 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
1015 | ||
1016 | BFD_ASSERT (got != NULL); | |
1017 | address += got->vma; | |
1018 | } | |
1019 | break; | |
1020 | case DW_EH_PE_pcrel: | |
fda3ecf2 AM |
1021 | value += ent->offset - ent->new_offset; |
1022 | address += sec->output_section->vma + ent->offset + 8; | |
9e2a4898 JJ |
1023 | break; |
1024 | } | |
353057a5 | 1025 | if (ent->cie_inf->make_relative) |
fda3ecf2 | 1026 | value -= sec->output_section->vma + ent->new_offset + 8; |
9e2a4898 | 1027 | write_value (abfd, buf, value, width); |
65765700 JJ |
1028 | } |
1029 | ||
1030 | if (hdr_info) | |
1031 | { | |
1032 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
1033 | hdr_info->array[hdr_info->array_count++].fde | |
fda3ecf2 | 1034 | = sec->output_section->vma + ent->new_offset; |
65765700 | 1035 | } |
9e2a4898 | 1036 | |
fda3ecf2 AM |
1037 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel |
1038 | || ent->cie_inf->need_lsda_relative) | |
9e2a4898 | 1039 | { |
fda3ecf2 AM |
1040 | buf += ent->lsda_offset; |
1041 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); | |
84f97cb6 | 1042 | value = read_value (abfd, buf, width, |
fda3ecf2 | 1043 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
9e2a4898 JJ |
1044 | if (value) |
1045 | { | |
fda3ecf2 AM |
1046 | if ((ent->lsda_encoding & 0xf0) == DW_EH_PE_pcrel) |
1047 | value += ent->offset - ent->new_offset; | |
1048 | else if (ent->cie_inf->need_lsda_relative) | |
1049 | value -= (sec->output_section->vma + ent->new_offset + 8 | |
1050 | + ent->lsda_offset); | |
9e2a4898 JJ |
1051 | write_value (abfd, buf, value, width); |
1052 | } | |
1053 | } | |
353057a5 RS |
1054 | else if (ent->cie_inf->add_augmentation_size) |
1055 | { | |
1056 | /* Skip the PC and length and insert a zero byte for the | |
1057 | augmentation size. */ | |
1058 | buf += width * 2; | |
1059 | memmove (buf + 1, buf, end - buf); | |
1060 | *buf = 0; | |
1061 | } | |
65765700 | 1062 | } |
65765700 JJ |
1063 | } |
1064 | ||
10cf14ea L |
1065 | { |
1066 | unsigned int alignment = 1 << sec->alignment_power; | |
eea6121a | 1067 | unsigned int pad = sec->size % alignment; |
10cf14ea | 1068 | |
9da84788 L |
1069 | /* Don't pad beyond the raw size of the output section. It |
1070 | can happen at the last input section. */ | |
1071 | if (pad | |
eea6121a AM |
1072 | && ((sec->output_offset + sec->size + pad) |
1073 | <= sec->output_section->size)) | |
10cf14ea | 1074 | { |
353057a5 RS |
1075 | bfd_byte *buf; |
1076 | unsigned int new_size; | |
1077 | ||
10cf14ea | 1078 | /* Find the last CIE/FDE. */ |
fda3ecf2 AM |
1079 | ent = sec_info->entry + sec_info->count; |
1080 | while (--ent != sec_info->entry) | |
1081 | if (!ent->removed) | |
10cf14ea L |
1082 | break; |
1083 | ||
1084 | /* The size of the last CIE/FDE must be at least 4. */ | |
fda3ecf2 | 1085 | if (ent->removed || ent->size < 4) |
10cf14ea L |
1086 | abort (); |
1087 | ||
1088 | pad = alignment - pad; | |
fda3ecf2 | 1089 | buf = contents + ent->new_offset - sec->output_offset; |
353057a5 | 1090 | new_size = size_of_output_cie_fde (ent, ptr_size); |
10cf14ea L |
1091 | |
1092 | /* Pad it with DW_CFA_nop */ | |
353057a5 RS |
1093 | memset (buf + new_size, 0, pad); |
1094 | bfd_put_32 (abfd, new_size + pad - 4, buf); | |
10cf14ea | 1095 | |
eea6121a | 1096 | sec->size += pad; |
10cf14ea L |
1097 | } |
1098 | } | |
a5eb27e6 | 1099 | |
65765700 | 1100 | return bfd_set_section_contents (abfd, sec->output_section, |
3472e2e9 AM |
1101 | contents, (file_ptr) sec->output_offset, |
1102 | sec->size); | |
65765700 JJ |
1103 | } |
1104 | ||
1105 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1106 | VMA of FDE initial location. */ | |
1107 | ||
1108 | static int | |
c39a58e6 | 1109 | vma_compare (const void *a, const void *b) |
65765700 | 1110 | { |
c39a58e6 AM |
1111 | const struct eh_frame_array_ent *p = a; |
1112 | const struct eh_frame_array_ent *q = b; | |
65765700 JJ |
1113 | if (p->initial_loc > q->initial_loc) |
1114 | return 1; | |
1115 | if (p->initial_loc < q->initial_loc) | |
1116 | return -1; | |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | /* Write out .eh_frame_hdr section. This must be called after | |
1121 | _bfd_elf_write_section_eh_frame has been called on all input | |
1122 | .eh_frame sections. | |
1123 | .eh_frame_hdr format: | |
1124 | ubyte version (currently 1) | |
1125 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1126 | .eh_frame section) | |
1127 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1128 | number (or DW_EH_PE_omit if there is no | |
1129 | binary search table computed)) | |
1130 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1131 | or DW_EH_PE_omit if not present. | |
1132 | DW_EH_PE_datarel is using address of | |
1133 | .eh_frame_hdr section start as base) | |
1134 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1135 | optionally followed by: | |
1136 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1137 | fde_count x [encoded] initial_loc, fde | |
1138 | (array of encoded pairs containing | |
1139 | FDE initial_location field and FDE address, | |
5ed6aba4 | 1140 | sorted by increasing initial_loc). */ |
65765700 | 1141 | |
b34976b6 | 1142 | bfd_boolean |
c39a58e6 | 1143 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
65765700 | 1144 | { |
126495ed | 1145 | struct elf_link_hash_table *htab; |
65765700 | 1146 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1147 | asection *sec; |
65765700 JJ |
1148 | bfd_byte *contents; |
1149 | asection *eh_frame_sec; | |
1150 | bfd_size_type size; | |
5ed6aba4 | 1151 | bfd_boolean retval; |
ec3391e7 | 1152 | bfd_vma encoded_eh_frame; |
65765700 | 1153 | |
126495ed AM |
1154 | htab = elf_hash_table (info); |
1155 | hdr_info = &htab->eh_info; | |
1156 | sec = hdr_info->hdr_sec; | |
1157 | if (sec == NULL) | |
b34976b6 | 1158 | return TRUE; |
57a72197 | 1159 | |
65765700 JJ |
1160 | size = EH_FRAME_HDR_SIZE; |
1161 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1162 | size += 4 + hdr_info->fde_count * 8; | |
1163 | contents = bfd_malloc (size); | |
1164 | if (contents == NULL) | |
b34976b6 | 1165 | return FALSE; |
65765700 JJ |
1166 | |
1167 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1168 | if (eh_frame_sec == NULL) | |
5ed6aba4 NC |
1169 | { |
1170 | free (contents); | |
1171 | return FALSE; | |
1172 | } | |
65765700 JJ |
1173 | |
1174 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
5ed6aba4 | 1175 | contents[0] = 1; /* Version. */ |
ec3391e7 AO |
1176 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
1177 | (abfd, info, eh_frame_sec, 0, sec, 4, | |
1178 | &encoded_eh_frame); /* .eh_frame offset. */ | |
1179 | ||
65765700 JJ |
1180 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) |
1181 | { | |
5ed6aba4 NC |
1182 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding. */ |
1183 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc. */ | |
65765700 JJ |
1184 | } |
1185 | else | |
1186 | { | |
1187 | contents[2] = DW_EH_PE_omit; | |
1188 | contents[3] = DW_EH_PE_omit; | |
1189 | } | |
ec3391e7 AO |
1190 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
1191 | ||
65765700 JJ |
1192 | if (contents[2] != DW_EH_PE_omit) |
1193 | { | |
1194 | unsigned int i; | |
1195 | ||
1196 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1197 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1198 | vma_compare); | |
1199 | for (i = 0; i < hdr_info->fde_count; i++) | |
1200 | { | |
1201 | bfd_put_32 (abfd, | |
1202 | hdr_info->array[i].initial_loc | |
1203 | - sec->output_section->vma, | |
1204 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1205 | bfd_put_32 (abfd, | |
1206 | hdr_info->array[i].fde - sec->output_section->vma, | |
1207 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1208 | } | |
1209 | } | |
1210 | ||
5ed6aba4 NC |
1211 | retval = bfd_set_section_contents (abfd, sec->output_section, |
1212 | contents, (file_ptr) sec->output_offset, | |
eea6121a | 1213 | sec->size); |
5ed6aba4 NC |
1214 | free (contents); |
1215 | return retval; | |
65765700 | 1216 | } |
ec3391e7 AO |
1217 | |
1218 | /* Decide whether we can use a PC-relative encoding within the given | |
1219 | EH frame section. This is the default implementation. */ | |
1220 | ||
1221 | bfd_boolean | |
1222 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, | |
1223 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1224 | asection *eh_frame_section ATTRIBUTE_UNUSED) | |
1225 | { | |
1226 | return TRUE; | |
1227 | } | |
1228 | ||
1229 | /* Select an encoding for the given address. Preference is given to | |
1230 | PC-relative addressing modes. */ | |
1231 | ||
1232 | bfd_byte | |
1233 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, | |
1234 | struct bfd_link_info *info ATTRIBUTE_UNUSED, | |
1235 | asection *osec, bfd_vma offset, | |
1236 | asection *loc_sec, bfd_vma loc_offset, | |
1237 | bfd_vma *encoded) | |
1238 | { | |
1239 | *encoded = osec->vma + offset - | |
1240 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); | |
1241 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; | |
1242 | } |