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e9174d1e SL |
1 | /* pecoff.c -- Get debug data from a PE/COFFF file for backtraces. |
2 | Copyright (C) 2015 Free Software Foundation, Inc. | |
3 | Adapted from elf.c by Tristan Gingold, AdaCore. | |
4 | ||
5 | Redistribution and use in source and binary forms, with or without | |
6 | modification, are permitted provided that the following conditions are | |
7 | met: | |
8 | ||
9 | (1) Redistributions of source code must retain the above copyright | |
10 | notice, this list of conditions and the following disclaimer. | |
11 | ||
12 | (2) Redistributions in binary form must reproduce the above copyright | |
13 | notice, this list of conditions and the following disclaimer in | |
14 | the documentation and/or other materials provided with the | |
15 | distribution. | |
16 | ||
17 | (3) The name of the author may not be used to | |
18 | endorse or promote products derived from this software without | |
19 | specific prior written permission. | |
20 | ||
21 | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
22 | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
23 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
24 | DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, | |
25 | INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
26 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
27 | SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
29 | STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
30 | IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
31 | POSSIBILITY OF SUCH DAMAGE. */ | |
32 | ||
33 | #include "config.h" | |
34 | ||
35 | #include <stdlib.h> | |
36 | #include <string.h> | |
37 | #include <sys/types.h> | |
38 | ||
39 | #include "backtrace.h" | |
40 | #include "internal.h" | |
41 | ||
42 | /* Coff file header. */ | |
43 | ||
44 | typedef struct { | |
45 | uint16_t machine; | |
46 | uint16_t number_of_sections; | |
47 | uint32_t time_date_stamp; | |
48 | uint32_t pointer_to_symbol_table; | |
49 | uint32_t number_of_symbols; | |
50 | uint16_t size_of_optional_header; | |
51 | uint16_t characteristics; | |
52 | } b_coff_file_header; | |
53 | ||
54 | /* Coff optional header. */ | |
55 | ||
56 | typedef struct { | |
57 | uint16_t magic; | |
58 | uint8_t major_linker_version; | |
59 | uint8_t minor_linker_version; | |
60 | uint32_t size_of_code; | |
61 | uint32_t size_of_initialized_data; | |
62 | uint32_t size_of_uninitialized_data; | |
63 | uint32_t address_of_entry_point; | |
64 | uint32_t base_of_code; | |
65 | union { | |
66 | struct { | |
67 | uint32_t base_of_data; | |
68 | uint32_t image_base; | |
69 | } pe; | |
70 | struct { | |
71 | uint64_t image_base; | |
72 | } pep; | |
73 | } u; | |
74 | } b_coff_optional_header; | |
75 | ||
76 | /* Values of magic in optional header. */ | |
77 | ||
78 | #define PE_MAGIC 0x10b /* PE32 executable. */ | |
79 | #define PEP_MAGIC 0x20b /* PE32+ executable (for 64bit targets). */ | |
80 | ||
81 | /* Coff section header. */ | |
82 | ||
83 | typedef struct { | |
84 | char name[8]; | |
85 | uint32_t virtual_size; | |
86 | uint32_t virtual_address; | |
87 | uint32_t size_of_raw_data; | |
88 | uint32_t pointer_to_raw_data; | |
89 | uint32_t pointer_to_relocations; | |
90 | uint32_t pointer_to_line_numbers; | |
91 | uint16_t number_of_relocations; | |
92 | uint16_t number_of_line_numbers; | |
93 | uint32_t characteristics; | |
94 | } b_coff_section_header; | |
95 | ||
96 | /* Coff symbol name. */ | |
97 | ||
98 | typedef union { | |
99 | char short_name[8]; | |
100 | struct { | |
101 | unsigned char zeroes[4]; | |
102 | unsigned char off[4]; | |
103 | } long_name; | |
104 | } b_coff_name; | |
105 | ||
106 | /* Coff symbol (external representation which is unaligned). */ | |
107 | ||
108 | typedef struct { | |
109 | b_coff_name name; | |
110 | unsigned char value[4]; | |
111 | unsigned char section_number[2]; | |
112 | unsigned char type[2]; | |
113 | unsigned char storage_class; | |
114 | unsigned char number_of_aux_symbols; | |
115 | } b_coff_external_symbol; | |
116 | ||
117 | /* Symbol types. */ | |
118 | ||
119 | #define N_TBSHFT 4 /* Shift for the derived type. */ | |
120 | #define IMAGE_SYM_DTYPE_FUNCTION 2 /* Function derived type. */ | |
121 | ||
122 | /* Size of a coff symbol. */ | |
123 | ||
124 | #define SYM_SZ 18 | |
125 | ||
126 | /* Coff symbol, internal representation (aligned). */ | |
127 | ||
128 | typedef struct { | |
129 | const char *name; | |
130 | uint32_t value; | |
131 | int16_t sec; | |
132 | uint16_t type; | |
133 | uint16_t sc; | |
134 | } b_coff_internal_symbol; | |
135 | ||
136 | /* An index of sections we care about. */ | |
137 | ||
138 | enum debug_section | |
139 | { | |
140 | DEBUG_INFO, | |
141 | DEBUG_LINE, | |
142 | DEBUG_ABBREV, | |
143 | DEBUG_RANGES, | |
144 | DEBUG_STR, | |
145 | DEBUG_MAX | |
146 | }; | |
147 | ||
148 | /* Names of sections, indexed by enum debug_section. */ | |
149 | ||
150 | static const char * const debug_section_names[DEBUG_MAX] = | |
151 | { | |
152 | ".debug_info", | |
153 | ".debug_line", | |
154 | ".debug_abbrev", | |
155 | ".debug_ranges", | |
156 | ".debug_str" | |
157 | }; | |
158 | ||
159 | /* Information we gather for the sections we care about. */ | |
160 | ||
161 | struct debug_section_info | |
162 | { | |
163 | /* Section file offset. */ | |
164 | off_t offset; | |
165 | /* Section size. */ | |
166 | size_t size; | |
167 | /* Section contents, after read from file. */ | |
168 | const unsigned char *data; | |
169 | }; | |
170 | ||
171 | /* Information we keep for an coff symbol. */ | |
172 | ||
173 | struct coff_symbol | |
174 | { | |
175 | /* The name of the symbol. */ | |
176 | const char *name; | |
177 | /* The address of the symbol. */ | |
178 | uintptr_t address; | |
179 | }; | |
180 | ||
181 | /* Information to pass to coff_syminfo. */ | |
182 | ||
183 | struct coff_syminfo_data | |
184 | { | |
185 | /* Symbols for the next module. */ | |
186 | struct coff_syminfo_data *next; | |
187 | /* The COFF symbols, sorted by address. */ | |
188 | struct coff_symbol *symbols; | |
189 | /* The number of symbols. */ | |
190 | size_t count; | |
191 | }; | |
192 | ||
193 | /* A dummy callback function used when we can't find any debug info. */ | |
194 | ||
195 | static int | |
196 | coff_nodebug (struct backtrace_state *state ATTRIBUTE_UNUSED, | |
197 | uintptr_t pc ATTRIBUTE_UNUSED, | |
198 | backtrace_full_callback callback ATTRIBUTE_UNUSED, | |
199 | backtrace_error_callback error_callback, void *data) | |
200 | { | |
201 | error_callback (data, "no debug info in PE/COFF executable", -1); | |
202 | return 0; | |
203 | } | |
204 | ||
205 | /* A dummy callback function used when we can't find a symbol | |
206 | table. */ | |
207 | ||
208 | static void | |
209 | coff_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED, | |
210 | uintptr_t addr ATTRIBUTE_UNUSED, | |
211 | backtrace_syminfo_callback callback ATTRIBUTE_UNUSED, | |
212 | backtrace_error_callback error_callback, void *data) | |
213 | { | |
214 | error_callback (data, "no symbol table in PE/COFF executable", -1); | |
215 | } | |
216 | ||
217 | /* Read a potentially unaligned 4 byte word at P, using native endianness. */ | |
218 | ||
219 | static uint32_t | |
220 | coff_read4 (const unsigned char *p) | |
221 | { | |
222 | uint32_t res; | |
223 | ||
224 | memcpy (&res, p, 4); | |
225 | return res; | |
226 | } | |
227 | ||
228 | /* Read a potentially unaligned 2 byte word at P, using native endianness. | |
229 | All 2 byte word in symbols are always aligned, but for coherency all | |
230 | fields are declared as char arrays. */ | |
231 | ||
232 | static uint16_t | |
233 | coff_read2 (const unsigned char *p) | |
234 | { | |
235 | uint16_t res; | |
236 | ||
237 | memcpy (&res, p, sizeof (res)); | |
238 | return res; | |
239 | } | |
240 | ||
241 | /* Return the length (without the trailing 0) of a COFF short name. */ | |
242 | ||
243 | static size_t | |
244 | coff_short_name_len (const char *name) | |
245 | { | |
246 | int i; | |
247 | ||
248 | for (i = 0; i < 8; i++) | |
249 | if (name[i] == 0) | |
250 | return i; | |
251 | return 8; | |
252 | } | |
253 | ||
254 | /* Return true iff COFF short name CNAME is the same as NAME (a NUL-terminated | |
255 | string). */ | |
256 | ||
257 | static int | |
258 | coff_short_name_eq (const char *name, const char *cname) | |
259 | { | |
260 | int i; | |
261 | ||
262 | for (i = 0; i < 8; i++) | |
263 | { | |
264 | if (name[i] != cname[i]) | |
265 | return 0; | |
266 | if (name[i] == 0) | |
267 | return 1; | |
268 | } | |
269 | return name[8] == 0; | |
270 | } | |
271 | ||
272 | /* Return true iff NAME is the same as string at offset OFF. */ | |
273 | ||
274 | static int | |
275 | coff_long_name_eq (const char *name, unsigned int off, | |
276 | struct backtrace_view *str_view) | |
277 | { | |
278 | if (off >= str_view->len) | |
279 | return 0; | |
280 | return strcmp (name, (const char *)str_view->data + off) == 0; | |
281 | } | |
282 | ||
283 | /* Compare struct coff_symbol for qsort. */ | |
284 | ||
285 | static int | |
286 | coff_symbol_compare (const void *v1, const void *v2) | |
287 | { | |
288 | const struct coff_symbol *e1 = (const struct coff_symbol *) v1; | |
289 | const struct coff_symbol *e2 = (const struct coff_symbol *) v2; | |
290 | ||
291 | if (e1->address < e2->address) | |
292 | return -1; | |
293 | else if (e1->address > e2->address) | |
294 | return 1; | |
295 | else | |
296 | return 0; | |
297 | } | |
298 | ||
299 | /* Convert SYM to internal (and aligned) format ISYM, using string table | |
300 | from STRTAB and STRTAB_SIZE, and number of sections SECTS_NUM. | |
301 | Return -1 in case of error (invalid section number or string index). */ | |
302 | ||
303 | static int | |
304 | coff_expand_symbol (b_coff_internal_symbol *isym, | |
305 | const b_coff_external_symbol *sym, | |
306 | uint16_t sects_num, | |
307 | const unsigned char *strtab, size_t strtab_size) | |
308 | { | |
309 | isym->type = coff_read2 (sym->type); | |
310 | isym->sec = coff_read2 (sym->section_number); | |
311 | isym->sc = sym->storage_class; | |
312 | ||
313 | if (isym->sec > 0 && (uint16_t) isym->sec > sects_num) | |
314 | return -1; | |
315 | if (sym->name.short_name[0] != 0) | |
316 | isym->name = sym->name.short_name; | |
317 | else | |
318 | { | |
319 | uint32_t off = coff_read4 (sym->name.long_name.off); | |
320 | ||
321 | if (off >= strtab_size) | |
322 | return -1; | |
323 | isym->name = (const char *) strtab + off; | |
324 | } | |
325 | return 0; | |
326 | } | |
327 | ||
328 | /* Return true iff SYM is a defined symbol for a function. Data symbols | |
329 | aren't considered because they aren't easily identified (same type as | |
330 | section names, presence of symbols defined by the linker script). */ | |
331 | ||
332 | static int | |
333 | coff_is_function_symbol (const b_coff_internal_symbol *isym) | |
334 | { | |
335 | return (isym->type >> N_TBSHFT) == IMAGE_SYM_DTYPE_FUNCTION | |
336 | && isym->sec > 0; | |
337 | } | |
338 | ||
339 | /* Initialize the symbol table info for coff_syminfo. */ | |
340 | ||
341 | static int | |
342 | coff_initialize_syminfo (struct backtrace_state *state, | |
343 | uintptr_t base_address, | |
344 | const b_coff_section_header *sects, size_t sects_num, | |
345 | const b_coff_external_symbol *syms, size_t syms_size, | |
346 | const unsigned char *strtab, size_t strtab_size, | |
347 | backtrace_error_callback error_callback, | |
348 | void *data, struct coff_syminfo_data *sdata) | |
349 | { | |
350 | size_t syms_count; | |
351 | char *coff_symstr; | |
352 | size_t coff_symstr_len; | |
353 | size_t coff_symbol_count; | |
354 | size_t coff_symbol_size; | |
355 | struct coff_symbol *coff_symbols; | |
356 | struct coff_symbol *coff_sym; | |
357 | char *coff_str; | |
358 | size_t i; | |
359 | ||
360 | syms_count = syms_size / SYM_SZ; | |
361 | ||
362 | /* We only care about function symbols. Count them. Also count size of | |
363 | strings for in-symbol names. */ | |
364 | coff_symbol_count = 0; | |
365 | coff_symstr_len = 0; | |
366 | for (i = 0; i < syms_count; ++i) | |
367 | { | |
368 | const b_coff_external_symbol *asym = &syms[i]; | |
369 | b_coff_internal_symbol isym; | |
370 | ||
371 | if (coff_expand_symbol (&isym, asym, sects_num, strtab, strtab_size) < 0) | |
372 | { | |
373 | error_callback (data, "invalid section or offset in coff symbol", 0); | |
374 | return 0; | |
375 | } | |
376 | if (coff_is_function_symbol (&isym)) | |
377 | { | |
378 | ++coff_symbol_count; | |
379 | if (asym->name.short_name[0] != 0) | |
380 | coff_symstr_len += coff_short_name_len (asym->name.short_name) + 1; | |
381 | } | |
382 | ||
383 | i += asym->number_of_aux_symbols; | |
384 | } | |
385 | ||
386 | coff_symbol_size = (coff_symbol_count + 1) * sizeof (struct coff_symbol); | |
387 | coff_symbols = ((struct coff_symbol *) | |
388 | backtrace_alloc (state, coff_symbol_size, error_callback, | |
389 | data)); | |
390 | if (coff_symbols == NULL) | |
391 | return 0; | |
392 | ||
393 | /* Allocate memory for symbols strings. */ | |
394 | if (coff_symstr_len > 0) | |
395 | { | |
396 | coff_symstr = ((char *) | |
397 | backtrace_alloc (state, coff_symstr_len, error_callback, | |
398 | data)); | |
399 | if (coff_symstr == NULL) | |
400 | { | |
401 | backtrace_free (state, coff_symbols, coff_symbol_size, | |
402 | error_callback, data); | |
403 | return 0; | |
404 | } | |
405 | } | |
406 | else | |
407 | coff_symstr = NULL; | |
408 | ||
409 | /* Copy symbols. */ | |
410 | coff_sym = coff_symbols; | |
411 | coff_str = coff_symstr; | |
412 | for (i = 0; i < syms_count; ++i) | |
413 | { | |
414 | const b_coff_external_symbol *asym = &syms[i]; | |
415 | b_coff_internal_symbol isym; | |
416 | ||
417 | if (coff_expand_symbol (&isym, asym, sects_num, strtab, strtab_size)) | |
418 | { | |
419 | /* Should not fail, as it was already tested in the previous | |
420 | loop. */ | |
421 | abort (); | |
422 | } | |
423 | if (coff_is_function_symbol (&isym)) | |
424 | { | |
425 | const char *name; | |
426 | int16_t secnum; | |
427 | ||
428 | if (asym->name.short_name[0] != 0) | |
429 | { | |
430 | size_t len = coff_short_name_len (isym.name); | |
431 | name = coff_str; | |
432 | memcpy (coff_str, isym.name, len); | |
433 | coff_str[len] = 0; | |
434 | coff_str += len + 1; | |
435 | } | |
436 | else | |
437 | name = isym.name; | |
438 | ||
439 | /* Strip leading '_'. */ | |
440 | if (name[0] == '_') | |
441 | name++; | |
442 | ||
443 | /* Symbol value is section relative, so we need to read the address | |
444 | of its section. */ | |
445 | secnum = coff_read2 (asym->section_number); | |
446 | ||
447 | coff_sym->name = name; | |
448 | coff_sym->address = (coff_read4 (asym->value) | |
449 | + sects[secnum - 1].virtual_address | |
450 | + base_address); | |
451 | coff_sym++; | |
452 | } | |
453 | ||
454 | i += asym->number_of_aux_symbols; | |
455 | } | |
456 | ||
457 | /* End of symbols marker. */ | |
458 | coff_sym->name = NULL; | |
459 | coff_sym->address = -1; | |
460 | ||
461 | backtrace_qsort (coff_symbols, coff_symbol_count, | |
462 | sizeof (struct coff_symbol), coff_symbol_compare); | |
463 | ||
464 | sdata->next = NULL; | |
465 | sdata->symbols = coff_symbols; | |
466 | sdata->count = coff_symbol_count; | |
467 | ||
468 | return 1; | |
469 | } | |
470 | ||
471 | /* Add EDATA to the list in STATE. */ | |
472 | ||
473 | static void | |
474 | coff_add_syminfo_data (struct backtrace_state *state, | |
475 | struct coff_syminfo_data *sdata) | |
476 | { | |
477 | if (!state->threaded) | |
478 | { | |
479 | struct coff_syminfo_data **pp; | |
480 | ||
481 | for (pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
482 | *pp != NULL; | |
483 | pp = &(*pp)->next) | |
484 | ; | |
485 | *pp = sdata; | |
486 | } | |
487 | else | |
488 | { | |
489 | while (1) | |
490 | { | |
491 | struct coff_syminfo_data **pp; | |
492 | ||
493 | pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
494 | ||
495 | while (1) | |
496 | { | |
497 | struct coff_syminfo_data *p; | |
498 | ||
499 | p = backtrace_atomic_load_pointer (pp); | |
500 | ||
501 | if (p == NULL) | |
502 | break; | |
503 | ||
504 | pp = &p->next; | |
505 | } | |
506 | ||
507 | if (__sync_bool_compare_and_swap (pp, NULL, sdata)) | |
508 | break; | |
509 | } | |
510 | } | |
511 | } | |
512 | ||
513 | /* Compare an ADDR against an elf_symbol for bsearch. We allocate one | |
514 | extra entry in the array so that this can look safely at the next | |
515 | entry. */ | |
516 | ||
517 | static int | |
518 | coff_symbol_search (const void *vkey, const void *ventry) | |
519 | { | |
520 | const uintptr_t *key = (const uintptr_t *) vkey; | |
521 | const struct coff_symbol *entry = (const struct coff_symbol *) ventry; | |
522 | uintptr_t addr; | |
523 | ||
524 | addr = *key; | |
525 | if (addr < entry->address) | |
526 | return -1; | |
527 | else if (addr >= entry[1].address) | |
528 | return 1; | |
529 | else | |
530 | return 0; | |
531 | } | |
532 | ||
533 | /* Return the symbol name and value for an ADDR. */ | |
534 | ||
535 | static void | |
536 | coff_syminfo (struct backtrace_state *state, uintptr_t addr, | |
537 | backtrace_syminfo_callback callback, | |
538 | backtrace_error_callback error_callback ATTRIBUTE_UNUSED, | |
539 | void *data) | |
540 | { | |
541 | struct coff_syminfo_data *sdata; | |
542 | struct coff_symbol *sym = NULL; | |
543 | ||
544 | if (!state->threaded) | |
545 | { | |
546 | for (sdata = (struct coff_syminfo_data *) state->syminfo_data; | |
547 | sdata != NULL; | |
548 | sdata = sdata->next) | |
549 | { | |
550 | sym = ((struct coff_symbol *) | |
551 | bsearch (&addr, sdata->symbols, sdata->count, | |
552 | sizeof (struct coff_symbol), coff_symbol_search)); | |
553 | if (sym != NULL) | |
554 | break; | |
555 | } | |
556 | } | |
557 | else | |
558 | { | |
559 | struct coff_syminfo_data **pp; | |
560 | ||
561 | pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
562 | while (1) | |
563 | { | |
564 | sdata = backtrace_atomic_load_pointer (pp); | |
565 | if (sdata == NULL) | |
566 | break; | |
567 | ||
568 | sym = ((struct coff_symbol *) | |
569 | bsearch (&addr, sdata->symbols, sdata->count, | |
570 | sizeof (struct coff_symbol), coff_symbol_search)); | |
571 | if (sym != NULL) | |
572 | break; | |
573 | ||
574 | pp = &sdata->next; | |
575 | } | |
576 | } | |
577 | ||
578 | if (sym == NULL) | |
579 | callback (data, addr, NULL, 0, 0); | |
580 | else | |
581 | callback (data, addr, sym->name, sym->address, 0); | |
582 | } | |
583 | ||
584 | /* Add the backtrace data for one PE/COFF file. Returns 1 on success, | |
585 | 0 on failure (in both cases descriptor is closed). */ | |
586 | ||
587 | static int | |
588 | coff_add (struct backtrace_state *state, int descriptor, | |
589 | backtrace_error_callback error_callback, void *data, | |
590 | fileline *fileline_fn, int *found_sym, int *found_dwarf) | |
591 | { | |
592 | struct backtrace_view fhdr_view; | |
593 | off_t fhdr_off; | |
594 | int magic_ok; | |
595 | b_coff_file_header fhdr; | |
596 | off_t opt_sects_off; | |
597 | size_t opt_sects_size; | |
598 | unsigned int sects_num; | |
599 | struct backtrace_view sects_view; | |
600 | int sects_view_valid; | |
601 | const b_coff_optional_header *opt_hdr; | |
602 | const b_coff_section_header *sects; | |
603 | struct backtrace_view str_view; | |
604 | int str_view_valid; | |
605 | size_t str_size; | |
606 | off_t str_off; | |
607 | struct backtrace_view syms_view; | |
608 | off_t syms_off; | |
609 | size_t syms_size; | |
610 | int syms_view_valid; | |
611 | unsigned int syms_num; | |
612 | unsigned int i; | |
613 | struct debug_section_info sections[DEBUG_MAX]; | |
614 | off_t min_offset; | |
615 | off_t max_offset; | |
616 | struct backtrace_view debug_view; | |
617 | int debug_view_valid; | |
618 | uintptr_t image_base; | |
619 | ||
620 | *found_sym = 0; | |
621 | *found_dwarf = 0; | |
622 | ||
623 | sects_view_valid = 0; | |
624 | syms_view_valid = 0; | |
625 | str_view_valid = 0; | |
626 | debug_view_valid = 0; | |
627 | ||
628 | /* Map the MS-DOS stub (if any) and extract file header offset. */ | |
629 | if (!backtrace_get_view (state, descriptor, 0, 0x40, error_callback, | |
630 | data, &fhdr_view)) | |
631 | goto fail; | |
632 | ||
633 | { | |
634 | const char *vptr = (const char *)fhdr_view.data; | |
635 | ||
636 | if (vptr[0] == 'M' && vptr[1] == 'Z') | |
637 | memcpy (&fhdr_off, vptr + 0x3c, 4); | |
638 | else | |
639 | fhdr_off = 0; | |
640 | } | |
641 | ||
642 | backtrace_release_view (state, &fhdr_view, error_callback, data); | |
643 | ||
644 | /* Map the coff file header. */ | |
645 | if (!backtrace_get_view (state, descriptor, fhdr_off, | |
646 | sizeof (b_coff_file_header) + 4, | |
647 | error_callback, data, &fhdr_view)) | |
648 | goto fail; | |
649 | ||
650 | if (fhdr_off != 0) | |
651 | { | |
652 | const char *magic = (const char *) fhdr_view.data; | |
653 | magic_ok = memcmp (magic, "PE\0", 4) == 0; | |
654 | fhdr_off += 4; | |
655 | ||
656 | memcpy (&fhdr, fhdr_view.data + 4, sizeof fhdr); | |
657 | } | |
658 | else | |
659 | { | |
660 | memcpy (&fhdr, fhdr_view.data, sizeof fhdr); | |
661 | /* TODO: test fhdr.machine for coff but non-PE platforms. */ | |
662 | magic_ok = 0; | |
663 | } | |
664 | backtrace_release_view (state, &fhdr_view, error_callback, data); | |
665 | ||
666 | if (!magic_ok) | |
667 | { | |
668 | error_callback (data, "executable file is not COFF", 0); | |
669 | goto fail; | |
670 | } | |
671 | ||
672 | sects_num = fhdr.number_of_sections; | |
673 | syms_num = fhdr.number_of_symbols; | |
674 | ||
675 | opt_sects_off = fhdr_off + sizeof (fhdr); | |
676 | opt_sects_size = (fhdr.size_of_optional_header | |
677 | + sects_num * sizeof (b_coff_section_header)); | |
678 | ||
679 | /* To translate PC to file/line when using DWARF, we need to find | |
680 | the .debug_info and .debug_line sections. */ | |
681 | ||
682 | /* Read the optional header and the section headers. */ | |
683 | ||
684 | if (!backtrace_get_view (state, descriptor, opt_sects_off, opt_sects_size, | |
685 | error_callback, data, §s_view)) | |
686 | goto fail; | |
687 | sects_view_valid = 1; | |
688 | opt_hdr = (const b_coff_optional_header *) sects_view.data; | |
689 | sects = (const b_coff_section_header *) | |
690 | (sects_view.data + fhdr.size_of_optional_header); | |
691 | ||
692 | if (fhdr.size_of_optional_header > sizeof (*opt_hdr)) | |
693 | { | |
694 | if (opt_hdr->magic == PE_MAGIC) | |
695 | image_base = opt_hdr->u.pe.image_base; | |
696 | else if (opt_hdr->magic == PEP_MAGIC) | |
697 | image_base = opt_hdr->u.pep.image_base; | |
698 | else | |
699 | { | |
700 | error_callback (data, "bad magic in PE optional header", 0); | |
701 | goto fail; | |
702 | } | |
703 | } | |
704 | else | |
705 | image_base = 0; | |
706 | ||
707 | /* Read the symbol table and the string table. */ | |
708 | ||
709 | if (fhdr.pointer_to_symbol_table == 0) | |
710 | { | |
711 | /* No symbol table, no string table. */ | |
712 | str_off = 0; | |
713 | str_size = 0; | |
714 | syms_num = 0; | |
715 | syms_size = 0; | |
716 | } | |
717 | else | |
718 | { | |
719 | /* Symbol table is followed by the string table. The string table | |
720 | starts with its length (on 4 bytes). | |
721 | Map the symbol table and the length of the string table. */ | |
722 | syms_off = fhdr.pointer_to_symbol_table; | |
723 | syms_size = syms_num * SYM_SZ; | |
724 | ||
725 | if (!backtrace_get_view (state, descriptor, syms_off, syms_size + 4, | |
726 | error_callback, data, &syms_view)) | |
727 | goto fail; | |
728 | syms_view_valid = 1; | |
729 | ||
730 | memcpy (&str_size, syms_view.data + syms_size, 4); | |
731 | ||
732 | str_off = syms_off + syms_size; | |
733 | ||
734 | if (str_size > 4) | |
735 | { | |
736 | /* Map string table (including the length word). */ | |
737 | ||
738 | if (!backtrace_get_view (state, descriptor, str_off, str_size, | |
739 | error_callback, data, &str_view)) | |
740 | goto fail; | |
741 | str_view_valid = 1; | |
742 | } | |
743 | } | |
744 | ||
745 | memset (sections, 0, sizeof sections); | |
746 | ||
747 | /* Look for the symbol table. */ | |
748 | for (i = 0; i < sects_num; ++i) | |
749 | { | |
750 | const b_coff_section_header *s = sects + i; | |
751 | unsigned int str_off; | |
752 | int j; | |
753 | ||
754 | if (s->name[0] == '/') | |
755 | { | |
756 | /* Extended section name. */ | |
757 | str_off = atoi (s->name + 1); | |
758 | } | |
759 | else | |
760 | str_off = 0; | |
761 | ||
762 | for (j = 0; j < (int) DEBUG_MAX; ++j) | |
763 | { | |
764 | const char *dbg_name = debug_section_names[j]; | |
765 | int match; | |
766 | ||
767 | if (str_off != 0) | |
768 | match = coff_long_name_eq (dbg_name, str_off, &str_view); | |
769 | else | |
770 | match = coff_short_name_eq (dbg_name, s->name); | |
771 | if (match) | |
772 | { | |
773 | sections[j].offset = s->pointer_to_raw_data; | |
774 | sections[j].size = s->virtual_size <= s->size_of_raw_data ? | |
775 | s->virtual_size : s->size_of_raw_data; | |
776 | break; | |
777 | } | |
778 | } | |
779 | } | |
780 | ||
781 | if (syms_num != 0) | |
782 | { | |
783 | struct coff_syminfo_data *sdata; | |
784 | ||
785 | sdata = ((struct coff_syminfo_data *) | |
786 | backtrace_alloc (state, sizeof *sdata, error_callback, data)); | |
787 | if (sdata == NULL) | |
788 | goto fail; | |
789 | ||
790 | if (!coff_initialize_syminfo (state, image_base, | |
791 | sects, sects_num, | |
792 | syms_view.data, syms_size, | |
793 | str_view.data, str_size, | |
794 | error_callback, data, sdata)) | |
795 | { | |
796 | backtrace_free (state, sdata, sizeof *sdata, error_callback, data); | |
797 | goto fail; | |
798 | } | |
799 | ||
800 | *found_sym = 1; | |
801 | ||
802 | coff_add_syminfo_data (state, sdata); | |
803 | } | |
804 | ||
805 | backtrace_release_view (state, §s_view, error_callback, data); | |
806 | sects_view_valid = 0; | |
807 | backtrace_release_view (state, &syms_view, error_callback, data); | |
808 | syms_view_valid = 0; | |
809 | ||
810 | /* Read all the debug sections in a single view, since they are | |
811 | probably adjacent in the file. We never release this view. */ | |
812 | ||
813 | min_offset = 0; | |
814 | max_offset = 0; | |
815 | for (i = 0; i < (int) DEBUG_MAX; ++i) | |
816 | { | |
817 | off_t end; | |
818 | ||
819 | if (sections[i].size == 0) | |
820 | continue; | |
821 | if (min_offset == 0 || sections[i].offset < min_offset) | |
822 | min_offset = sections[i].offset; | |
823 | end = sections[i].offset + sections[i].size; | |
824 | if (end > max_offset) | |
825 | max_offset = end; | |
826 | } | |
827 | if (min_offset == 0 || max_offset == 0) | |
828 | { | |
829 | if (!backtrace_close (descriptor, error_callback, data)) | |
830 | goto fail; | |
831 | *fileline_fn = coff_nodebug; | |
832 | return 1; | |
833 | } | |
834 | ||
835 | if (!backtrace_get_view (state, descriptor, min_offset, | |
836 | max_offset - min_offset, | |
837 | error_callback, data, &debug_view)) | |
838 | goto fail; | |
839 | debug_view_valid = 1; | |
840 | ||
841 | /* We've read all we need from the executable. */ | |
842 | if (!backtrace_close (descriptor, error_callback, data)) | |
843 | goto fail; | |
844 | descriptor = -1; | |
845 | ||
846 | for (i = 0; i < (int) DEBUG_MAX; ++i) | |
847 | { | |
848 | if (sections[i].size == 0) | |
849 | sections[i].data = NULL; | |
850 | else | |
851 | sections[i].data = ((const unsigned char *) debug_view.data | |
852 | + (sections[i].offset - min_offset)); | |
853 | } | |
854 | ||
855 | if (!backtrace_dwarf_add (state, /* base_address */ 0, | |
856 | sections[DEBUG_INFO].data, | |
857 | sections[DEBUG_INFO].size, | |
858 | sections[DEBUG_LINE].data, | |
859 | sections[DEBUG_LINE].size, | |
860 | sections[DEBUG_ABBREV].data, | |
861 | sections[DEBUG_ABBREV].size, | |
862 | sections[DEBUG_RANGES].data, | |
863 | sections[DEBUG_RANGES].size, | |
864 | sections[DEBUG_STR].data, | |
865 | sections[DEBUG_STR].size, | |
866 | 0, /* FIXME */ | |
867 | error_callback, data, fileline_fn)) | |
868 | goto fail; | |
869 | ||
870 | *found_dwarf = 1; | |
871 | ||
872 | return 1; | |
873 | ||
874 | fail: | |
875 | if (sects_view_valid) | |
876 | backtrace_release_view (state, §s_view, error_callback, data); | |
877 | if (str_view_valid) | |
878 | backtrace_release_view (state, &str_view, error_callback, data); | |
879 | if (syms_view_valid) | |
880 | backtrace_release_view (state, &syms_view, error_callback, data); | |
881 | if (debug_view_valid) | |
882 | backtrace_release_view (state, &debug_view, error_callback, data); | |
883 | if (descriptor != -1) | |
884 | backtrace_close (descriptor, error_callback, data); | |
885 | return 0; | |
886 | } | |
887 | ||
888 | /* Initialize the backtrace data we need from an ELF executable. At | |
889 | the ELF level, all we need to do is find the debug info | |
890 | sections. */ | |
891 | ||
892 | int | |
893 | backtrace_initialize (struct backtrace_state *state, int descriptor, | |
894 | backtrace_error_callback error_callback, | |
895 | void *data, fileline *fileline_fn) | |
896 | { | |
897 | int ret; | |
898 | int found_sym; | |
899 | int found_dwarf; | |
900 | fileline coff_fileline_fn; | |
901 | ||
902 | ret = coff_add (state, descriptor, error_callback, data, | |
903 | &coff_fileline_fn, &found_sym, &found_dwarf); | |
904 | if (!ret) | |
905 | return 0; | |
906 | ||
907 | if (!state->threaded) | |
908 | { | |
909 | if (found_sym) | |
910 | state->syminfo_fn = coff_syminfo; | |
911 | else if (state->syminfo_fn == NULL) | |
912 | state->syminfo_fn = coff_nosyms; | |
913 | } | |
914 | else | |
915 | { | |
916 | if (found_sym) | |
917 | backtrace_atomic_store_pointer (&state->syminfo_fn, coff_syminfo); | |
918 | else | |
919 | __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, coff_nosyms); | |
920 | } | |
921 | ||
922 | if (!state->threaded) | |
923 | { | |
924 | if (state->fileline_fn == NULL || state->fileline_fn == coff_nodebug) | |
925 | *fileline_fn = coff_fileline_fn; | |
926 | } | |
927 | else | |
928 | { | |
929 | fileline current_fn; | |
930 | ||
931 | current_fn = backtrace_atomic_load_pointer (&state->fileline_fn); | |
932 | if (current_fn == NULL || current_fn == coff_nodebug) | |
933 | *fileline_fn = coff_fileline_fn; | |
934 | } | |
935 | ||
936 | return 1; | |
937 | } |