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ffa54e5c | 1 | /* simple-object.c -- simple routines to read and write object files. |
82704155 | 2 | Copyright (C) 2010-2019 Free Software Foundation, Inc. |
ffa54e5c DD |
3 | Written by Ian Lance Taylor, Google. |
4 | ||
5 | This program is free software; you can redistribute it and/or modify it | |
6 | under the terms of the GNU General Public License as published by the | |
7 | Free Software Foundation; either version 2, or (at your option) any | |
8 | later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, 51 Franklin Street - Fifth Floor, | |
18 | Boston, MA 02110-1301, USA. */ | |
19 | ||
20 | #include "config.h" | |
21 | #include "libiberty.h" | |
22 | #include "simple-object.h" | |
23 | ||
24 | #include <errno.h> | |
f8ad2513 | 25 | #include <fcntl.h> |
ffa54e5c DD |
26 | |
27 | #ifdef HAVE_STDLIB_H | |
28 | #include <stdlib.h> | |
29 | #endif | |
30 | ||
31 | #ifdef HAVE_STDINT_H | |
32 | #include <stdint.h> | |
33 | #endif | |
34 | ||
35 | #ifdef HAVE_STRING_H | |
36 | #include <string.h> | |
37 | #endif | |
38 | ||
39 | #ifdef HAVE_INTTYPES_H | |
40 | #include <inttypes.h> | |
41 | #endif | |
42 | ||
43 | #ifndef SEEK_SET | |
44 | #define SEEK_SET 0 | |
45 | #endif | |
46 | ||
07ffcfec AM |
47 | #ifndef O_BINARY |
48 | #define O_BINARY 0 | |
49 | #endif | |
50 | ||
ffa54e5c DD |
51 | #include "simple-object-common.h" |
52 | ||
53 | /* The known object file formats. */ | |
54 | ||
55 | static const struct simple_object_functions * const format_functions[] = | |
56 | { | |
57 | &simple_object_elf_functions, | |
58 | &simple_object_mach_o_functions, | |
07a8e9f0 DD |
59 | &simple_object_coff_functions, |
60 | &simple_object_xcoff_functions | |
ffa54e5c DD |
61 | }; |
62 | ||
63 | /* Read data from a file using the simple_object error reporting | |
64 | conventions. */ | |
65 | ||
66 | int | |
67 | simple_object_internal_read (int descriptor, off_t offset, | |
68 | unsigned char *buffer, size_t size, | |
69 | const char **errmsg, int *err) | |
70 | { | |
ffa54e5c DD |
71 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
72 | { | |
73 | *errmsg = "lseek"; | |
74 | *err = errno; | |
75 | return 0; | |
76 | } | |
77 | ||
81ad11e3 | 78 | do |
ffa54e5c | 79 | { |
81ad11e3 | 80 | ssize_t got = read (descriptor, buffer, size); |
81 | if (got == 0) | |
82 | break; | |
83 | else if (got > 0) | |
84 | { | |
85 | buffer += got; | |
86 | size -= got; | |
87 | } | |
88 | else if (errno != EINTR) | |
89 | { | |
90 | *errmsg = "read"; | |
91 | *err = errno; | |
92 | return 0; | |
93 | } | |
ffa54e5c | 94 | } |
81ad11e3 | 95 | while (size > 0); |
ffa54e5c | 96 | |
81ad11e3 | 97 | if (size > 0) |
ffa54e5c DD |
98 | { |
99 | *errmsg = "file too short"; | |
100 | *err = 0; | |
101 | return 0; | |
102 | } | |
103 | ||
104 | return 1; | |
105 | } | |
106 | ||
107 | /* Write data to a file using the simple_object error reporting | |
108 | conventions. */ | |
109 | ||
110 | int | |
111 | simple_object_internal_write (int descriptor, off_t offset, | |
112 | const unsigned char *buffer, size_t size, | |
113 | const char **errmsg, int *err) | |
114 | { | |
ffa54e5c DD |
115 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
116 | { | |
117 | *errmsg = "lseek"; | |
118 | *err = errno; | |
119 | return 0; | |
120 | } | |
121 | ||
c3c3c691 | 122 | do |
ffa54e5c | 123 | { |
c3c3c691 | 124 | ssize_t wrote = write (descriptor, buffer, size); |
125 | if (wrote == 0) | |
126 | break; | |
127 | else if (wrote > 0) | |
128 | { | |
129 | buffer += wrote; | |
130 | size -= wrote; | |
131 | } | |
132 | else if (errno != EINTR) | |
133 | { | |
134 | *errmsg = "write"; | |
135 | *err = errno; | |
136 | return 0; | |
137 | } | |
ffa54e5c | 138 | } |
c3c3c691 | 139 | while (size > 0); |
ffa54e5c | 140 | |
c3c3c691 | 141 | if (size > 0) |
ffa54e5c DD |
142 | { |
143 | *errmsg = "short write"; | |
144 | *err = 0; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | return 1; | |
149 | } | |
150 | ||
151 | /* Open for read. */ | |
152 | ||
153 | simple_object_read * | |
154 | simple_object_start_read (int descriptor, off_t offset, | |
155 | const char *segment_name, const char **errmsg, | |
156 | int *err) | |
157 | { | |
158 | unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN]; | |
159 | size_t len, i; | |
160 | ||
161 | if (!simple_object_internal_read (descriptor, offset, header, | |
162 | SIMPLE_OBJECT_MATCH_HEADER_LEN, | |
163 | errmsg, err)) | |
164 | return NULL; | |
165 | ||
166 | len = sizeof (format_functions) / sizeof (format_functions[0]); | |
167 | for (i = 0; i < len; ++i) | |
168 | { | |
169 | void *data; | |
170 | ||
171 | data = format_functions[i]->match (header, descriptor, offset, | |
172 | segment_name, errmsg, err); | |
173 | if (data != NULL) | |
174 | { | |
175 | simple_object_read *ret; | |
176 | ||
177 | ret = XNEW (simple_object_read); | |
178 | ret->descriptor = descriptor; | |
179 | ret->offset = offset; | |
180 | ret->functions = format_functions[i]; | |
181 | ret->data = data; | |
182 | return ret; | |
183 | } | |
184 | } | |
185 | ||
186 | *errmsg = "file not recognized"; | |
187 | *err = 0; | |
188 | return NULL; | |
189 | } | |
190 | ||
191 | /* Find all sections. */ | |
192 | ||
193 | const char * | |
194 | simple_object_find_sections (simple_object_read *sobj, | |
195 | int (*pfn) (void *, const char *, off_t, off_t), | |
196 | void *data, | |
197 | int *err) | |
198 | { | |
199 | return sobj->functions->find_sections (sobj, pfn, data, err); | |
200 | } | |
201 | ||
202 | /* Internal data passed to find_one_section. */ | |
203 | ||
204 | struct find_one_section_data | |
205 | { | |
206 | /* The section we are looking for. */ | |
207 | const char *name; | |
208 | /* Where to store the section offset. */ | |
209 | off_t *offset; | |
210 | /* Where to store the section length. */ | |
211 | off_t *length; | |
212 | /* Set if the name is found. */ | |
213 | int found; | |
214 | }; | |
215 | ||
216 | /* Internal function passed to find_sections. */ | |
217 | ||
218 | static int | |
219 | find_one_section (void *data, const char *name, off_t offset, off_t length) | |
220 | { | |
221 | struct find_one_section_data *fosd = (struct find_one_section_data *) data; | |
222 | ||
223 | if (strcmp (name, fosd->name) != 0) | |
224 | return 1; | |
225 | ||
226 | *fosd->offset = offset; | |
227 | *fosd->length = length; | |
228 | fosd->found = 1; | |
229 | ||
230 | /* Stop iteration. */ | |
231 | return 0; | |
232 | } | |
233 | ||
234 | /* Find a section. */ | |
235 | ||
236 | int | |
237 | simple_object_find_section (simple_object_read *sobj, const char *name, | |
238 | off_t *offset, off_t *length, | |
239 | const char **errmsg, int *err) | |
240 | { | |
241 | struct find_one_section_data fosd; | |
242 | ||
243 | fosd.name = name; | |
244 | fosd.offset = offset; | |
245 | fosd.length = length; | |
246 | fosd.found = 0; | |
247 | ||
248 | *errmsg = simple_object_find_sections (sobj, find_one_section, | |
249 | (void *) &fosd, err); | |
250 | if (*errmsg != NULL) | |
251 | return 0; | |
252 | if (!fosd.found) | |
253 | return 0; | |
254 | return 1; | |
255 | } | |
256 | ||
f8ad2513 | 257 | /* Callback to identify and rename LTO debug sections by name. |
978588dc SM |
258 | Returns non-NULL if NAME is a LTO debug section, NULL if not. |
259 | If RENAME is true it will rename LTO debug sections to non-LTO | |
260 | ones. */ | |
f8ad2513 | 261 | |
e9301e76 | 262 | static char * |
978588dc | 263 | handle_lto_debug_sections (const char *name, int rename) |
f8ad2513 | 264 | { |
978588dc SM |
265 | char *newname = rename ? XCNEWVEC (char, strlen (name) + 1) |
266 | : xstrdup (name); | |
e9301e76 | 267 | |
f8ad2513 NC |
268 | /* ??? So we can't use .gnu.lto_ prefixed sections as the assembler |
269 | complains about bogus section flags. Which means we need to arrange | |
270 | for that to be fixed or .gnu.debuglto_ marked as SHF_EXCLUDE (to make | |
271 | fat lto object tooling work for the fat part). */ | |
e9301e76 NC |
272 | /* Also include corresponding reloc sections. */ |
273 | if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0) | |
f8ad2513 | 274 | { |
978588dc SM |
275 | if (rename) |
276 | strncpy (newname, name, sizeof (".rela") - 1); | |
e9301e76 | 277 | name += sizeof (".rela") - 1; |
f8ad2513 | 278 | } |
e9301e76 | 279 | else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0) |
f8ad2513 | 280 | { |
978588dc SM |
281 | if (rename) |
282 | strncpy (newname, name, sizeof (".rel") - 1); | |
e9301e76 | 283 | name += sizeof (".rel") - 1; |
f8ad2513 | 284 | } |
e9301e76 NC |
285 | /* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed |
286 | sections. */ | |
287 | /* Copy LTO debug sections and rename them to their non-LTO name. */ | |
288 | if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0) | |
978588dc | 289 | return rename ? strcat (newname, name + sizeof (".gnu.debuglto_") - 1) : newname; |
e9301e76 NC |
290 | else if (strncmp (name, ".gnu.lto_.debug_", |
291 | sizeof (".gnu.lto_.debug_") -1) == 0) | |
978588dc | 292 | return rename ? strcat (newname, name + sizeof (".gnu.lto_") - 1) : newname; |
2a8ae714 | 293 | /* Copy over .note.GNU-stack section under the same name if present. */ |
e9301e76 NC |
294 | else if (strcmp (name, ".note.GNU-stack") == 0) |
295 | return strcpy (newname, name); | |
296 | /* Copy over .comment section under the same name if present. Solaris | |
297 | ld uses them to relax its checking of ELF gABI access rules for | |
298 | COMDAT sections in objects produced by GCC. */ | |
299 | else if (strcmp (name, ".comment") == 0) | |
300 | return strcpy (newname, name); | |
978588dc | 301 | free (newname); |
e9301e76 | 302 | return NULL; |
f8ad2513 NC |
303 | } |
304 | ||
978588dc SM |
305 | /* Wrapper for handle_lto_debug_sections. */ |
306 | ||
307 | static char * | |
308 | handle_lto_debug_sections_rename (const char *name) | |
309 | { | |
310 | return handle_lto_debug_sections (name, 1); | |
311 | } | |
312 | ||
313 | /* Wrapper for handle_lto_debug_sections. */ | |
314 | ||
315 | static char * | |
316 | handle_lto_debug_sections_norename (const char *name) | |
317 | { | |
318 | return handle_lto_debug_sections (name, 0); | |
319 | } | |
320 | ||
f8ad2513 NC |
321 | /* Copy LTO debug sections. */ |
322 | ||
323 | const char * | |
324 | simple_object_copy_lto_debug_sections (simple_object_read *sobj, | |
978588dc | 325 | const char *dest, int *err, int rename) |
f8ad2513 NC |
326 | { |
327 | const char *errmsg; | |
328 | simple_object_write *dest_sobj; | |
329 | simple_object_attributes *attrs; | |
330 | int outfd; | |
331 | ||
332 | if (! sobj->functions->copy_lto_debug_sections) | |
333 | { | |
334 | *err = EINVAL; | |
335 | return "simple_object_copy_lto_debug_sections not implemented"; | |
336 | } | |
337 | ||
338 | attrs = simple_object_fetch_attributes (sobj, &errmsg, err); | |
339 | if (! attrs) | |
340 | return errmsg; | |
341 | dest_sobj = simple_object_start_write (attrs, NULL, &errmsg, err); | |
342 | simple_object_release_attributes (attrs); | |
343 | if (! dest_sobj) | |
344 | return errmsg; | |
345 | ||
978588dc SM |
346 | errmsg = sobj->functions->copy_lto_debug_sections |
347 | (sobj, dest_sobj, | |
348 | rename ? handle_lto_debug_sections_rename | |
349 | : handle_lto_debug_sections_norename, err); | |
f8ad2513 NC |
350 | if (errmsg) |
351 | { | |
352 | simple_object_release_write (dest_sobj); | |
353 | return errmsg; | |
354 | } | |
355 | ||
07ffcfec | 356 | outfd = open (dest, O_CREAT|O_WRONLY|O_TRUNC|O_BINARY, 00777); |
f8ad2513 NC |
357 | if (outfd == -1) |
358 | { | |
359 | *err = errno; | |
360 | simple_object_release_write (dest_sobj); | |
361 | return "open failed"; | |
362 | } | |
363 | ||
364 | errmsg = simple_object_write_to_file (dest_sobj, outfd, err); | |
365 | close (outfd); | |
366 | if (errmsg) | |
367 | { | |
368 | simple_object_release_write (dest_sobj); | |
369 | return errmsg; | |
370 | } | |
371 | ||
372 | simple_object_release_write (dest_sobj); | |
373 | return NULL; | |
374 | } | |
375 | ||
ffa54e5c DD |
376 | /* Fetch attributes. */ |
377 | ||
378 | simple_object_attributes * | |
379 | simple_object_fetch_attributes (simple_object_read *sobj, const char **errmsg, | |
380 | int *err) | |
381 | { | |
382 | void *data; | |
383 | simple_object_attributes *ret; | |
384 | ||
385 | data = sobj->functions->fetch_attributes (sobj, errmsg, err); | |
386 | if (data == NULL) | |
387 | return NULL; | |
388 | ret = XNEW (simple_object_attributes); | |
389 | ret->functions = sobj->functions; | |
390 | ret->data = data; | |
391 | return ret; | |
392 | } | |
393 | ||
394 | /* Release an simple_object_read. */ | |
395 | ||
396 | void | |
397 | simple_object_release_read (simple_object_read *sobj) | |
398 | { | |
399 | sobj->functions->release_read (sobj->data); | |
400 | XDELETE (sobj); | |
401 | } | |
402 | ||
f9e6589d | 403 | /* Merge attributes. */ |
ffa54e5c DD |
404 | |
405 | const char * | |
f9e6589d DD |
406 | simple_object_attributes_merge (simple_object_attributes *to, |
407 | simple_object_attributes *from, | |
408 | int *err) | |
ffa54e5c | 409 | { |
f9e6589d | 410 | if (to->functions != from->functions) |
ffa54e5c DD |
411 | { |
412 | *err = 0; | |
413 | return "different object file format"; | |
414 | } | |
f9e6589d | 415 | return to->functions->attributes_merge (to->data, from->data, err); |
ffa54e5c DD |
416 | } |
417 | ||
418 | /* Release an attributes structure. */ | |
419 | ||
420 | void | |
421 | simple_object_release_attributes (simple_object_attributes *attrs) | |
422 | { | |
423 | attrs->functions->release_attributes (attrs->data); | |
424 | XDELETE (attrs); | |
425 | } | |
426 | ||
427 | /* Start creating an object file. */ | |
428 | ||
429 | simple_object_write * | |
430 | simple_object_start_write (simple_object_attributes *attrs, | |
431 | const char *segment_name, const char **errmsg, | |
432 | int *err) | |
433 | { | |
434 | void *data; | |
435 | simple_object_write *ret; | |
436 | ||
437 | data = attrs->functions->start_write (attrs->data, errmsg, err); | |
438 | if (data == NULL) | |
439 | return NULL; | |
440 | ret = XNEW (simple_object_write); | |
441 | ret->functions = attrs->functions; | |
f8ad2513 | 442 | ret->segment_name = segment_name ? xstrdup (segment_name) : NULL; |
ffa54e5c DD |
443 | ret->sections = NULL; |
444 | ret->last_section = NULL; | |
445 | ret->data = data; | |
446 | return ret; | |
447 | } | |
448 | ||
449 | /* Start creating a section. */ | |
450 | ||
451 | simple_object_write_section * | |
452 | simple_object_write_create_section (simple_object_write *sobj, const char *name, | |
453 | unsigned int align, | |
454 | const char **errmsg ATTRIBUTE_UNUSED, | |
455 | int *err ATTRIBUTE_UNUSED) | |
456 | { | |
457 | simple_object_write_section *ret; | |
458 | ||
459 | ret = XNEW (simple_object_write_section); | |
460 | ret->next = NULL; | |
461 | ret->name = xstrdup (name); | |
462 | ret->align = align; | |
463 | ret->buffers = NULL; | |
464 | ret->last_buffer = NULL; | |
465 | ||
466 | if (sobj->last_section == NULL) | |
467 | { | |
468 | sobj->sections = ret; | |
469 | sobj->last_section = ret; | |
470 | } | |
471 | else | |
472 | { | |
473 | sobj->last_section->next = ret; | |
474 | sobj->last_section = ret; | |
475 | } | |
476 | ||
477 | return ret; | |
478 | } | |
479 | ||
480 | /* Add data to a section. */ | |
481 | ||
482 | const char * | |
483 | simple_object_write_add_data (simple_object_write *sobj ATTRIBUTE_UNUSED, | |
484 | simple_object_write_section *section, | |
485 | const void *buffer, | |
486 | size_t size, int copy, | |
487 | int *err ATTRIBUTE_UNUSED) | |
488 | { | |
489 | struct simple_object_write_section_buffer *wsb; | |
490 | ||
491 | wsb = XNEW (struct simple_object_write_section_buffer); | |
492 | wsb->next = NULL; | |
493 | wsb->size = size; | |
494 | ||
495 | if (!copy) | |
496 | { | |
497 | wsb->buffer = buffer; | |
498 | wsb->free_buffer = NULL; | |
499 | } | |
500 | else | |
501 | { | |
502 | wsb->free_buffer = (void *) XNEWVEC (char, size); | |
503 | memcpy (wsb->free_buffer, buffer, size); | |
504 | wsb->buffer = wsb->free_buffer; | |
505 | } | |
506 | ||
507 | if (section->last_buffer == NULL) | |
508 | { | |
509 | section->buffers = wsb; | |
510 | section->last_buffer = wsb; | |
511 | } | |
512 | else | |
513 | { | |
514 | section->last_buffer->next = wsb; | |
515 | section->last_buffer = wsb; | |
516 | } | |
517 | ||
518 | return NULL; | |
519 | } | |
520 | ||
521 | /* Write the complete object file. */ | |
522 | ||
523 | const char * | |
524 | simple_object_write_to_file (simple_object_write *sobj, int descriptor, | |
525 | int *err) | |
526 | { | |
527 | return sobj->functions->write_to_file (sobj, descriptor, err); | |
528 | } | |
529 | ||
530 | /* Release an simple_object_write. */ | |
531 | ||
532 | void | |
533 | simple_object_release_write (simple_object_write *sobj) | |
534 | { | |
535 | simple_object_write_section *section; | |
536 | ||
537 | free (sobj->segment_name); | |
538 | ||
539 | section = sobj->sections; | |
540 | while (section != NULL) | |
541 | { | |
542 | struct simple_object_write_section_buffer *buffer; | |
543 | simple_object_write_section *next_section; | |
544 | ||
545 | buffer = section->buffers; | |
546 | while (buffer != NULL) | |
547 | { | |
548 | struct simple_object_write_section_buffer *next_buffer; | |
549 | ||
550 | if (buffer->free_buffer != NULL) | |
551 | XDELETEVEC (buffer->free_buffer); | |
552 | next_buffer = buffer->next; | |
553 | XDELETE (buffer); | |
554 | buffer = next_buffer; | |
555 | } | |
556 | ||
557 | next_section = section->next; | |
558 | free (section->name); | |
559 | XDELETE (section); | |
560 | section = next_section; | |
561 | } | |
562 | ||
563 | sobj->functions->release_write (sobj->data); | |
564 | XDELETE (sobj); | |
565 | } |