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ffa54e5c | 1 | /* simple-object.c -- simple routines to read and write object files. |
2a8ae714 | 2 | Copyright (C) 2010-2018 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 | ||
47 | #include "simple-object-common.h" | |
48 | ||
49 | /* The known object file formats. */ | |
50 | ||
51 | static const struct simple_object_functions * const format_functions[] = | |
52 | { | |
53 | &simple_object_elf_functions, | |
54 | &simple_object_mach_o_functions, | |
07a8e9f0 DD |
55 | &simple_object_coff_functions, |
56 | &simple_object_xcoff_functions | |
ffa54e5c DD |
57 | }; |
58 | ||
59 | /* Read data from a file using the simple_object error reporting | |
60 | conventions. */ | |
61 | ||
62 | int | |
63 | simple_object_internal_read (int descriptor, off_t offset, | |
64 | unsigned char *buffer, size_t size, | |
65 | const char **errmsg, int *err) | |
66 | { | |
ffa54e5c DD |
67 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
68 | { | |
69 | *errmsg = "lseek"; | |
70 | *err = errno; | |
71 | return 0; | |
72 | } | |
73 | ||
81ad11e3 | 74 | do |
ffa54e5c | 75 | { |
81ad11e3 | 76 | ssize_t got = read (descriptor, buffer, size); |
77 | if (got == 0) | |
78 | break; | |
79 | else if (got > 0) | |
80 | { | |
81 | buffer += got; | |
82 | size -= got; | |
83 | } | |
84 | else if (errno != EINTR) | |
85 | { | |
86 | *errmsg = "read"; | |
87 | *err = errno; | |
88 | return 0; | |
89 | } | |
ffa54e5c | 90 | } |
81ad11e3 | 91 | while (size > 0); |
ffa54e5c | 92 | |
81ad11e3 | 93 | if (size > 0) |
ffa54e5c DD |
94 | { |
95 | *errmsg = "file too short"; | |
96 | *err = 0; | |
97 | return 0; | |
98 | } | |
99 | ||
100 | return 1; | |
101 | } | |
102 | ||
103 | /* Write data to a file using the simple_object error reporting | |
104 | conventions. */ | |
105 | ||
106 | int | |
107 | simple_object_internal_write (int descriptor, off_t offset, | |
108 | const unsigned char *buffer, size_t size, | |
109 | const char **errmsg, int *err) | |
110 | { | |
ffa54e5c DD |
111 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
112 | { | |
113 | *errmsg = "lseek"; | |
114 | *err = errno; | |
115 | return 0; | |
116 | } | |
117 | ||
c3c3c691 | 118 | do |
ffa54e5c | 119 | { |
c3c3c691 | 120 | ssize_t wrote = write (descriptor, buffer, size); |
121 | if (wrote == 0) | |
122 | break; | |
123 | else if (wrote > 0) | |
124 | { | |
125 | buffer += wrote; | |
126 | size -= wrote; | |
127 | } | |
128 | else if (errno != EINTR) | |
129 | { | |
130 | *errmsg = "write"; | |
131 | *err = errno; | |
132 | return 0; | |
133 | } | |
ffa54e5c | 134 | } |
c3c3c691 | 135 | while (size > 0); |
ffa54e5c | 136 | |
c3c3c691 | 137 | if (size > 0) |
ffa54e5c DD |
138 | { |
139 | *errmsg = "short write"; | |
140 | *err = 0; | |
141 | return 0; | |
142 | } | |
143 | ||
144 | return 1; | |
145 | } | |
146 | ||
147 | /* Open for read. */ | |
148 | ||
149 | simple_object_read * | |
150 | simple_object_start_read (int descriptor, off_t offset, | |
151 | const char *segment_name, const char **errmsg, | |
152 | int *err) | |
153 | { | |
154 | unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN]; | |
155 | size_t len, i; | |
156 | ||
157 | if (!simple_object_internal_read (descriptor, offset, header, | |
158 | SIMPLE_OBJECT_MATCH_HEADER_LEN, | |
159 | errmsg, err)) | |
160 | return NULL; | |
161 | ||
162 | len = sizeof (format_functions) / sizeof (format_functions[0]); | |
163 | for (i = 0; i < len; ++i) | |
164 | { | |
165 | void *data; | |
166 | ||
167 | data = format_functions[i]->match (header, descriptor, offset, | |
168 | segment_name, errmsg, err); | |
169 | if (data != NULL) | |
170 | { | |
171 | simple_object_read *ret; | |
172 | ||
173 | ret = XNEW (simple_object_read); | |
174 | ret->descriptor = descriptor; | |
175 | ret->offset = offset; | |
176 | ret->functions = format_functions[i]; | |
177 | ret->data = data; | |
178 | return ret; | |
179 | } | |
180 | } | |
181 | ||
182 | *errmsg = "file not recognized"; | |
183 | *err = 0; | |
184 | return NULL; | |
185 | } | |
186 | ||
187 | /* Find all sections. */ | |
188 | ||
189 | const char * | |
190 | simple_object_find_sections (simple_object_read *sobj, | |
191 | int (*pfn) (void *, const char *, off_t, off_t), | |
192 | void *data, | |
193 | int *err) | |
194 | { | |
195 | return sobj->functions->find_sections (sobj, pfn, data, err); | |
196 | } | |
197 | ||
198 | /* Internal data passed to find_one_section. */ | |
199 | ||
200 | struct find_one_section_data | |
201 | { | |
202 | /* The section we are looking for. */ | |
203 | const char *name; | |
204 | /* Where to store the section offset. */ | |
205 | off_t *offset; | |
206 | /* Where to store the section length. */ | |
207 | off_t *length; | |
208 | /* Set if the name is found. */ | |
209 | int found; | |
210 | }; | |
211 | ||
212 | /* Internal function passed to find_sections. */ | |
213 | ||
214 | static int | |
215 | find_one_section (void *data, const char *name, off_t offset, off_t length) | |
216 | { | |
217 | struct find_one_section_data *fosd = (struct find_one_section_data *) data; | |
218 | ||
219 | if (strcmp (name, fosd->name) != 0) | |
220 | return 1; | |
221 | ||
222 | *fosd->offset = offset; | |
223 | *fosd->length = length; | |
224 | fosd->found = 1; | |
225 | ||
226 | /* Stop iteration. */ | |
227 | return 0; | |
228 | } | |
229 | ||
230 | /* Find a section. */ | |
231 | ||
232 | int | |
233 | simple_object_find_section (simple_object_read *sobj, const char *name, | |
234 | off_t *offset, off_t *length, | |
235 | const char **errmsg, int *err) | |
236 | { | |
237 | struct find_one_section_data fosd; | |
238 | ||
239 | fosd.name = name; | |
240 | fosd.offset = offset; | |
241 | fosd.length = length; | |
242 | fosd.found = 0; | |
243 | ||
244 | *errmsg = simple_object_find_sections (sobj, find_one_section, | |
245 | (void *) &fosd, err); | |
246 | if (*errmsg != NULL) | |
247 | return 0; | |
248 | if (!fosd.found) | |
249 | return 0; | |
250 | return 1; | |
251 | } | |
252 | ||
f8ad2513 NC |
253 | /* Callback to identify and rename LTO debug sections by name. |
254 | Returns 1 if NAME is a LTO debug section, 0 if not. */ | |
255 | ||
e9301e76 NC |
256 | static char * |
257 | handle_lto_debug_sections (const char *name) | |
f8ad2513 | 258 | { |
e9301e76 NC |
259 | char *newname = XCNEWVEC (char, strlen (name) + 1); |
260 | ||
f8ad2513 NC |
261 | /* ??? So we can't use .gnu.lto_ prefixed sections as the assembler |
262 | complains about bogus section flags. Which means we need to arrange | |
263 | for that to be fixed or .gnu.debuglto_ marked as SHF_EXCLUDE (to make | |
264 | fat lto object tooling work for the fat part). */ | |
e9301e76 NC |
265 | /* Also include corresponding reloc sections. */ |
266 | if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0) | |
f8ad2513 | 267 | { |
e9301e76 NC |
268 | strncpy (newname, name, sizeof (".rela") - 1); |
269 | name += sizeof (".rela") - 1; | |
f8ad2513 | 270 | } |
e9301e76 | 271 | else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0) |
f8ad2513 | 272 | { |
e9301e76 NC |
273 | strncpy (newname, name, sizeof (".rel") - 1); |
274 | name += sizeof (".rel") - 1; | |
f8ad2513 | 275 | } |
e9301e76 NC |
276 | /* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed |
277 | sections. */ | |
278 | /* Copy LTO debug sections and rename them to their non-LTO name. */ | |
279 | if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0) | |
280 | return strcat (newname, name + sizeof (".gnu.debuglto_") - 1); | |
281 | else if (strncmp (name, ".gnu.lto_.debug_", | |
282 | sizeof (".gnu.lto_.debug_") -1) == 0) | |
283 | return strcat (newname, name + sizeof (".gnu.lto_") - 1); | |
2a8ae714 | 284 | /* Copy over .note.GNU-stack section under the same name if present. */ |
e9301e76 NC |
285 | else if (strcmp (name, ".note.GNU-stack") == 0) |
286 | return strcpy (newname, name); | |
287 | /* Copy over .comment section under the same name if present. Solaris | |
288 | ld uses them to relax its checking of ELF gABI access rules for | |
289 | COMDAT sections in objects produced by GCC. */ | |
290 | else if (strcmp (name, ".comment") == 0) | |
291 | return strcpy (newname, name); | |
292 | return NULL; | |
f8ad2513 NC |
293 | } |
294 | ||
295 | /* Copy LTO debug sections. */ | |
296 | ||
297 | const char * | |
298 | simple_object_copy_lto_debug_sections (simple_object_read *sobj, | |
299 | const char *dest, int *err) | |
300 | { | |
301 | const char *errmsg; | |
302 | simple_object_write *dest_sobj; | |
303 | simple_object_attributes *attrs; | |
304 | int outfd; | |
305 | ||
306 | if (! sobj->functions->copy_lto_debug_sections) | |
307 | { | |
308 | *err = EINVAL; | |
309 | return "simple_object_copy_lto_debug_sections not implemented"; | |
310 | } | |
311 | ||
312 | attrs = simple_object_fetch_attributes (sobj, &errmsg, err); | |
313 | if (! attrs) | |
314 | return errmsg; | |
315 | dest_sobj = simple_object_start_write (attrs, NULL, &errmsg, err); | |
316 | simple_object_release_attributes (attrs); | |
317 | if (! dest_sobj) | |
318 | return errmsg; | |
319 | ||
320 | errmsg = sobj->functions->copy_lto_debug_sections (sobj, dest_sobj, | |
321 | handle_lto_debug_sections, | |
322 | err); | |
323 | if (errmsg) | |
324 | { | |
325 | simple_object_release_write (dest_sobj); | |
326 | return errmsg; | |
327 | } | |
328 | ||
329 | outfd = creat (dest, 00777); | |
330 | if (outfd == -1) | |
331 | { | |
332 | *err = errno; | |
333 | simple_object_release_write (dest_sobj); | |
334 | return "open failed"; | |
335 | } | |
336 | ||
337 | errmsg = simple_object_write_to_file (dest_sobj, outfd, err); | |
338 | close (outfd); | |
339 | if (errmsg) | |
340 | { | |
341 | simple_object_release_write (dest_sobj); | |
342 | return errmsg; | |
343 | } | |
344 | ||
345 | simple_object_release_write (dest_sobj); | |
346 | return NULL; | |
347 | } | |
348 | ||
ffa54e5c DD |
349 | /* Fetch attributes. */ |
350 | ||
351 | simple_object_attributes * | |
352 | simple_object_fetch_attributes (simple_object_read *sobj, const char **errmsg, | |
353 | int *err) | |
354 | { | |
355 | void *data; | |
356 | simple_object_attributes *ret; | |
357 | ||
358 | data = sobj->functions->fetch_attributes (sobj, errmsg, err); | |
359 | if (data == NULL) | |
360 | return NULL; | |
361 | ret = XNEW (simple_object_attributes); | |
362 | ret->functions = sobj->functions; | |
363 | ret->data = data; | |
364 | return ret; | |
365 | } | |
366 | ||
367 | /* Release an simple_object_read. */ | |
368 | ||
369 | void | |
370 | simple_object_release_read (simple_object_read *sobj) | |
371 | { | |
372 | sobj->functions->release_read (sobj->data); | |
373 | XDELETE (sobj); | |
374 | } | |
375 | ||
f9e6589d | 376 | /* Merge attributes. */ |
ffa54e5c DD |
377 | |
378 | const char * | |
f9e6589d DD |
379 | simple_object_attributes_merge (simple_object_attributes *to, |
380 | simple_object_attributes *from, | |
381 | int *err) | |
ffa54e5c | 382 | { |
f9e6589d | 383 | if (to->functions != from->functions) |
ffa54e5c DD |
384 | { |
385 | *err = 0; | |
386 | return "different object file format"; | |
387 | } | |
f9e6589d | 388 | return to->functions->attributes_merge (to->data, from->data, err); |
ffa54e5c DD |
389 | } |
390 | ||
391 | /* Release an attributes structure. */ | |
392 | ||
393 | void | |
394 | simple_object_release_attributes (simple_object_attributes *attrs) | |
395 | { | |
396 | attrs->functions->release_attributes (attrs->data); | |
397 | XDELETE (attrs); | |
398 | } | |
399 | ||
400 | /* Start creating an object file. */ | |
401 | ||
402 | simple_object_write * | |
403 | simple_object_start_write (simple_object_attributes *attrs, | |
404 | const char *segment_name, const char **errmsg, | |
405 | int *err) | |
406 | { | |
407 | void *data; | |
408 | simple_object_write *ret; | |
409 | ||
410 | data = attrs->functions->start_write (attrs->data, errmsg, err); | |
411 | if (data == NULL) | |
412 | return NULL; | |
413 | ret = XNEW (simple_object_write); | |
414 | ret->functions = attrs->functions; | |
f8ad2513 | 415 | ret->segment_name = segment_name ? xstrdup (segment_name) : NULL; |
ffa54e5c DD |
416 | ret->sections = NULL; |
417 | ret->last_section = NULL; | |
418 | ret->data = data; | |
419 | return ret; | |
420 | } | |
421 | ||
422 | /* Start creating a section. */ | |
423 | ||
424 | simple_object_write_section * | |
425 | simple_object_write_create_section (simple_object_write *sobj, const char *name, | |
426 | unsigned int align, | |
427 | const char **errmsg ATTRIBUTE_UNUSED, | |
428 | int *err ATTRIBUTE_UNUSED) | |
429 | { | |
430 | simple_object_write_section *ret; | |
431 | ||
432 | ret = XNEW (simple_object_write_section); | |
433 | ret->next = NULL; | |
434 | ret->name = xstrdup (name); | |
435 | ret->align = align; | |
436 | ret->buffers = NULL; | |
437 | ret->last_buffer = NULL; | |
438 | ||
439 | if (sobj->last_section == NULL) | |
440 | { | |
441 | sobj->sections = ret; | |
442 | sobj->last_section = ret; | |
443 | } | |
444 | else | |
445 | { | |
446 | sobj->last_section->next = ret; | |
447 | sobj->last_section = ret; | |
448 | } | |
449 | ||
450 | return ret; | |
451 | } | |
452 | ||
453 | /* Add data to a section. */ | |
454 | ||
455 | const char * | |
456 | simple_object_write_add_data (simple_object_write *sobj ATTRIBUTE_UNUSED, | |
457 | simple_object_write_section *section, | |
458 | const void *buffer, | |
459 | size_t size, int copy, | |
460 | int *err ATTRIBUTE_UNUSED) | |
461 | { | |
462 | struct simple_object_write_section_buffer *wsb; | |
463 | ||
464 | wsb = XNEW (struct simple_object_write_section_buffer); | |
465 | wsb->next = NULL; | |
466 | wsb->size = size; | |
467 | ||
468 | if (!copy) | |
469 | { | |
470 | wsb->buffer = buffer; | |
471 | wsb->free_buffer = NULL; | |
472 | } | |
473 | else | |
474 | { | |
475 | wsb->free_buffer = (void *) XNEWVEC (char, size); | |
476 | memcpy (wsb->free_buffer, buffer, size); | |
477 | wsb->buffer = wsb->free_buffer; | |
478 | } | |
479 | ||
480 | if (section->last_buffer == NULL) | |
481 | { | |
482 | section->buffers = wsb; | |
483 | section->last_buffer = wsb; | |
484 | } | |
485 | else | |
486 | { | |
487 | section->last_buffer->next = wsb; | |
488 | section->last_buffer = wsb; | |
489 | } | |
490 | ||
491 | return NULL; | |
492 | } | |
493 | ||
494 | /* Write the complete object file. */ | |
495 | ||
496 | const char * | |
497 | simple_object_write_to_file (simple_object_write *sobj, int descriptor, | |
498 | int *err) | |
499 | { | |
500 | return sobj->functions->write_to_file (sobj, descriptor, err); | |
501 | } | |
502 | ||
503 | /* Release an simple_object_write. */ | |
504 | ||
505 | void | |
506 | simple_object_release_write (simple_object_write *sobj) | |
507 | { | |
508 | simple_object_write_section *section; | |
509 | ||
510 | free (sobj->segment_name); | |
511 | ||
512 | section = sobj->sections; | |
513 | while (section != NULL) | |
514 | { | |
515 | struct simple_object_write_section_buffer *buffer; | |
516 | simple_object_write_section *next_section; | |
517 | ||
518 | buffer = section->buffers; | |
519 | while (buffer != NULL) | |
520 | { | |
521 | struct simple_object_write_section_buffer *next_buffer; | |
522 | ||
523 | if (buffer->free_buffer != NULL) | |
524 | XDELETEVEC (buffer->free_buffer); | |
525 | next_buffer = buffer->next; | |
526 | XDELETE (buffer); | |
527 | buffer = next_buffer; | |
528 | } | |
529 | ||
530 | next_section = section->next; | |
531 | free (section->name); | |
532 | XDELETE (section); | |
533 | section = next_section; | |
534 | } | |
535 | ||
536 | sobj->functions->release_write (sobj->data); | |
537 | XDELETE (sobj); | |
538 | } |