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e9174d1e | 1 | /* pecoff.c -- Get debug data from a PE/COFFF file for backtraces. |
ba9703b0 | 2 | Copyright (C) 2015-2020 Free Software Foundation, Inc. |
e9174d1e SL |
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 | ||
ba9703b0 | 136 | /* Names of sections, indexed by enum dwarf_section in internal.h. */ |
e9174d1e SL |
137 | |
138 | static const char * const debug_section_names[DEBUG_MAX] = | |
139 | { | |
140 | ".debug_info", | |
141 | ".debug_line", | |
142 | ".debug_abbrev", | |
143 | ".debug_ranges", | |
ba9703b0 XL |
144 | ".debug_str", |
145 | ".debug_addr", | |
146 | ".debug_str_offsets", | |
147 | ".debug_line_str", | |
148 | ".debug_rnglists" | |
e9174d1e SL |
149 | }; |
150 | ||
151 | /* Information we gather for the sections we care about. */ | |
152 | ||
153 | struct debug_section_info | |
154 | { | |
155 | /* Section file offset. */ | |
156 | off_t offset; | |
157 | /* Section size. */ | |
158 | size_t size; | |
e9174d1e SL |
159 | }; |
160 | ||
161 | /* Information we keep for an coff symbol. */ | |
162 | ||
163 | struct coff_symbol | |
164 | { | |
165 | /* The name of the symbol. */ | |
166 | const char *name; | |
167 | /* The address of the symbol. */ | |
168 | uintptr_t address; | |
169 | }; | |
170 | ||
171 | /* Information to pass to coff_syminfo. */ | |
172 | ||
173 | struct coff_syminfo_data | |
174 | { | |
175 | /* Symbols for the next module. */ | |
176 | struct coff_syminfo_data *next; | |
177 | /* The COFF symbols, sorted by address. */ | |
178 | struct coff_symbol *symbols; | |
179 | /* The number of symbols. */ | |
180 | size_t count; | |
181 | }; | |
182 | ||
183 | /* A dummy callback function used when we can't find any debug info. */ | |
184 | ||
185 | static int | |
186 | coff_nodebug (struct backtrace_state *state ATTRIBUTE_UNUSED, | |
187 | uintptr_t pc ATTRIBUTE_UNUSED, | |
188 | backtrace_full_callback callback ATTRIBUTE_UNUSED, | |
189 | backtrace_error_callback error_callback, void *data) | |
190 | { | |
191 | error_callback (data, "no debug info in PE/COFF executable", -1); | |
192 | return 0; | |
193 | } | |
194 | ||
195 | /* A dummy callback function used when we can't find a symbol | |
196 | table. */ | |
197 | ||
198 | static void | |
199 | coff_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED, | |
200 | uintptr_t addr ATTRIBUTE_UNUSED, | |
201 | backtrace_syminfo_callback callback ATTRIBUTE_UNUSED, | |
202 | backtrace_error_callback error_callback, void *data) | |
203 | { | |
204 | error_callback (data, "no symbol table in PE/COFF executable", -1); | |
205 | } | |
206 | ||
207 | /* Read a potentially unaligned 4 byte word at P, using native endianness. */ | |
208 | ||
209 | static uint32_t | |
210 | coff_read4 (const unsigned char *p) | |
211 | { | |
212 | uint32_t res; | |
213 | ||
214 | memcpy (&res, p, 4); | |
215 | return res; | |
216 | } | |
217 | ||
218 | /* Read a potentially unaligned 2 byte word at P, using native endianness. | |
219 | All 2 byte word in symbols are always aligned, but for coherency all | |
220 | fields are declared as char arrays. */ | |
221 | ||
222 | static uint16_t | |
223 | coff_read2 (const unsigned char *p) | |
224 | { | |
225 | uint16_t res; | |
226 | ||
227 | memcpy (&res, p, sizeof (res)); | |
228 | return res; | |
229 | } | |
230 | ||
231 | /* Return the length (without the trailing 0) of a COFF short name. */ | |
232 | ||
233 | static size_t | |
234 | coff_short_name_len (const char *name) | |
235 | { | |
236 | int i; | |
237 | ||
238 | for (i = 0; i < 8; i++) | |
239 | if (name[i] == 0) | |
240 | return i; | |
241 | return 8; | |
242 | } | |
243 | ||
244 | /* Return true iff COFF short name CNAME is the same as NAME (a NUL-terminated | |
245 | string). */ | |
246 | ||
247 | static int | |
248 | coff_short_name_eq (const char *name, const char *cname) | |
249 | { | |
250 | int i; | |
251 | ||
252 | for (i = 0; i < 8; i++) | |
253 | { | |
254 | if (name[i] != cname[i]) | |
255 | return 0; | |
256 | if (name[i] == 0) | |
257 | return 1; | |
258 | } | |
259 | return name[8] == 0; | |
260 | } | |
261 | ||
262 | /* Return true iff NAME is the same as string at offset OFF. */ | |
263 | ||
264 | static int | |
265 | coff_long_name_eq (const char *name, unsigned int off, | |
266 | struct backtrace_view *str_view) | |
267 | { | |
268 | if (off >= str_view->len) | |
269 | return 0; | |
270 | return strcmp (name, (const char *)str_view->data + off) == 0; | |
271 | } | |
272 | ||
273 | /* Compare struct coff_symbol for qsort. */ | |
274 | ||
275 | static int | |
276 | coff_symbol_compare (const void *v1, const void *v2) | |
277 | { | |
278 | const struct coff_symbol *e1 = (const struct coff_symbol *) v1; | |
279 | const struct coff_symbol *e2 = (const struct coff_symbol *) v2; | |
280 | ||
281 | if (e1->address < e2->address) | |
282 | return -1; | |
283 | else if (e1->address > e2->address) | |
284 | return 1; | |
285 | else | |
286 | return 0; | |
287 | } | |
288 | ||
289 | /* Convert SYM to internal (and aligned) format ISYM, using string table | |
290 | from STRTAB and STRTAB_SIZE, and number of sections SECTS_NUM. | |
291 | Return -1 in case of error (invalid section number or string index). */ | |
292 | ||
293 | static int | |
294 | coff_expand_symbol (b_coff_internal_symbol *isym, | |
295 | const b_coff_external_symbol *sym, | |
296 | uint16_t sects_num, | |
297 | const unsigned char *strtab, size_t strtab_size) | |
298 | { | |
299 | isym->type = coff_read2 (sym->type); | |
300 | isym->sec = coff_read2 (sym->section_number); | |
301 | isym->sc = sym->storage_class; | |
302 | ||
303 | if (isym->sec > 0 && (uint16_t) isym->sec > sects_num) | |
304 | return -1; | |
305 | if (sym->name.short_name[0] != 0) | |
306 | isym->name = sym->name.short_name; | |
307 | else | |
308 | { | |
309 | uint32_t off = coff_read4 (sym->name.long_name.off); | |
310 | ||
311 | if (off >= strtab_size) | |
312 | return -1; | |
313 | isym->name = (const char *) strtab + off; | |
314 | } | |
315 | return 0; | |
316 | } | |
317 | ||
318 | /* Return true iff SYM is a defined symbol for a function. Data symbols | |
319 | aren't considered because they aren't easily identified (same type as | |
320 | section names, presence of symbols defined by the linker script). */ | |
321 | ||
322 | static int | |
323 | coff_is_function_symbol (const b_coff_internal_symbol *isym) | |
324 | { | |
325 | return (isym->type >> N_TBSHFT) == IMAGE_SYM_DTYPE_FUNCTION | |
326 | && isym->sec > 0; | |
327 | } | |
328 | ||
329 | /* Initialize the symbol table info for coff_syminfo. */ | |
330 | ||
331 | static int | |
332 | coff_initialize_syminfo (struct backtrace_state *state, | |
333 | uintptr_t base_address, | |
334 | const b_coff_section_header *sects, size_t sects_num, | |
335 | const b_coff_external_symbol *syms, size_t syms_size, | |
336 | const unsigned char *strtab, size_t strtab_size, | |
337 | backtrace_error_callback error_callback, | |
338 | void *data, struct coff_syminfo_data *sdata) | |
339 | { | |
340 | size_t syms_count; | |
341 | char *coff_symstr; | |
342 | size_t coff_symstr_len; | |
343 | size_t coff_symbol_count; | |
344 | size_t coff_symbol_size; | |
345 | struct coff_symbol *coff_symbols; | |
346 | struct coff_symbol *coff_sym; | |
347 | char *coff_str; | |
348 | size_t i; | |
349 | ||
350 | syms_count = syms_size / SYM_SZ; | |
351 | ||
352 | /* We only care about function symbols. Count them. Also count size of | |
353 | strings for in-symbol names. */ | |
354 | coff_symbol_count = 0; | |
355 | coff_symstr_len = 0; | |
356 | for (i = 0; i < syms_count; ++i) | |
357 | { | |
358 | const b_coff_external_symbol *asym = &syms[i]; | |
359 | b_coff_internal_symbol isym; | |
360 | ||
361 | if (coff_expand_symbol (&isym, asym, sects_num, strtab, strtab_size) < 0) | |
362 | { | |
363 | error_callback (data, "invalid section or offset in coff symbol", 0); | |
364 | return 0; | |
365 | } | |
366 | if (coff_is_function_symbol (&isym)) | |
367 | { | |
368 | ++coff_symbol_count; | |
369 | if (asym->name.short_name[0] != 0) | |
370 | coff_symstr_len += coff_short_name_len (asym->name.short_name) + 1; | |
371 | } | |
372 | ||
373 | i += asym->number_of_aux_symbols; | |
374 | } | |
375 | ||
376 | coff_symbol_size = (coff_symbol_count + 1) * sizeof (struct coff_symbol); | |
377 | coff_symbols = ((struct coff_symbol *) | |
378 | backtrace_alloc (state, coff_symbol_size, error_callback, | |
379 | data)); | |
380 | if (coff_symbols == NULL) | |
381 | return 0; | |
382 | ||
383 | /* Allocate memory for symbols strings. */ | |
384 | if (coff_symstr_len > 0) | |
385 | { | |
386 | coff_symstr = ((char *) | |
387 | backtrace_alloc (state, coff_symstr_len, error_callback, | |
388 | data)); | |
389 | if (coff_symstr == NULL) | |
390 | { | |
391 | backtrace_free (state, coff_symbols, coff_symbol_size, | |
392 | error_callback, data); | |
393 | return 0; | |
394 | } | |
395 | } | |
396 | else | |
397 | coff_symstr = NULL; | |
398 | ||
399 | /* Copy symbols. */ | |
400 | coff_sym = coff_symbols; | |
401 | coff_str = coff_symstr; | |
402 | for (i = 0; i < syms_count; ++i) | |
403 | { | |
404 | const b_coff_external_symbol *asym = &syms[i]; | |
405 | b_coff_internal_symbol isym; | |
406 | ||
407 | if (coff_expand_symbol (&isym, asym, sects_num, strtab, strtab_size)) | |
408 | { | |
409 | /* Should not fail, as it was already tested in the previous | |
410 | loop. */ | |
411 | abort (); | |
412 | } | |
413 | if (coff_is_function_symbol (&isym)) | |
414 | { | |
415 | const char *name; | |
416 | int16_t secnum; | |
417 | ||
418 | if (asym->name.short_name[0] != 0) | |
419 | { | |
420 | size_t len = coff_short_name_len (isym.name); | |
421 | name = coff_str; | |
422 | memcpy (coff_str, isym.name, len); | |
423 | coff_str[len] = 0; | |
424 | coff_str += len + 1; | |
425 | } | |
426 | else | |
427 | name = isym.name; | |
428 | ||
429 | /* Strip leading '_'. */ | |
430 | if (name[0] == '_') | |
431 | name++; | |
432 | ||
433 | /* Symbol value is section relative, so we need to read the address | |
434 | of its section. */ | |
435 | secnum = coff_read2 (asym->section_number); | |
436 | ||
437 | coff_sym->name = name; | |
438 | coff_sym->address = (coff_read4 (asym->value) | |
439 | + sects[secnum - 1].virtual_address | |
440 | + base_address); | |
441 | coff_sym++; | |
442 | } | |
443 | ||
444 | i += asym->number_of_aux_symbols; | |
445 | } | |
446 | ||
447 | /* End of symbols marker. */ | |
448 | coff_sym->name = NULL; | |
449 | coff_sym->address = -1; | |
450 | ||
451 | backtrace_qsort (coff_symbols, coff_symbol_count, | |
452 | sizeof (struct coff_symbol), coff_symbol_compare); | |
453 | ||
454 | sdata->next = NULL; | |
455 | sdata->symbols = coff_symbols; | |
456 | sdata->count = coff_symbol_count; | |
457 | ||
458 | return 1; | |
459 | } | |
460 | ||
461 | /* Add EDATA to the list in STATE. */ | |
462 | ||
463 | static void | |
464 | coff_add_syminfo_data (struct backtrace_state *state, | |
465 | struct coff_syminfo_data *sdata) | |
466 | { | |
467 | if (!state->threaded) | |
468 | { | |
469 | struct coff_syminfo_data **pp; | |
470 | ||
471 | for (pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
472 | *pp != NULL; | |
473 | pp = &(*pp)->next) | |
474 | ; | |
475 | *pp = sdata; | |
476 | } | |
477 | else | |
478 | { | |
479 | while (1) | |
480 | { | |
481 | struct coff_syminfo_data **pp; | |
482 | ||
483 | pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
484 | ||
485 | while (1) | |
486 | { | |
487 | struct coff_syminfo_data *p; | |
488 | ||
489 | p = backtrace_atomic_load_pointer (pp); | |
490 | ||
491 | if (p == NULL) | |
492 | break; | |
493 | ||
494 | pp = &p->next; | |
495 | } | |
496 | ||
497 | if (__sync_bool_compare_and_swap (pp, NULL, sdata)) | |
498 | break; | |
499 | } | |
500 | } | |
501 | } | |
502 | ||
503 | /* Compare an ADDR against an elf_symbol for bsearch. We allocate one | |
504 | extra entry in the array so that this can look safely at the next | |
505 | entry. */ | |
506 | ||
507 | static int | |
508 | coff_symbol_search (const void *vkey, const void *ventry) | |
509 | { | |
510 | const uintptr_t *key = (const uintptr_t *) vkey; | |
511 | const struct coff_symbol *entry = (const struct coff_symbol *) ventry; | |
512 | uintptr_t addr; | |
513 | ||
514 | addr = *key; | |
515 | if (addr < entry->address) | |
516 | return -1; | |
517 | else if (addr >= entry[1].address) | |
518 | return 1; | |
519 | else | |
520 | return 0; | |
521 | } | |
522 | ||
523 | /* Return the symbol name and value for an ADDR. */ | |
524 | ||
525 | static void | |
526 | coff_syminfo (struct backtrace_state *state, uintptr_t addr, | |
527 | backtrace_syminfo_callback callback, | |
528 | backtrace_error_callback error_callback ATTRIBUTE_UNUSED, | |
529 | void *data) | |
530 | { | |
531 | struct coff_syminfo_data *sdata; | |
532 | struct coff_symbol *sym = NULL; | |
533 | ||
534 | if (!state->threaded) | |
535 | { | |
536 | for (sdata = (struct coff_syminfo_data *) state->syminfo_data; | |
537 | sdata != NULL; | |
538 | sdata = sdata->next) | |
539 | { | |
540 | sym = ((struct coff_symbol *) | |
541 | bsearch (&addr, sdata->symbols, sdata->count, | |
542 | sizeof (struct coff_symbol), coff_symbol_search)); | |
543 | if (sym != NULL) | |
544 | break; | |
545 | } | |
546 | } | |
547 | else | |
548 | { | |
549 | struct coff_syminfo_data **pp; | |
550 | ||
551 | pp = (struct coff_syminfo_data **) (void *) &state->syminfo_data; | |
552 | while (1) | |
553 | { | |
554 | sdata = backtrace_atomic_load_pointer (pp); | |
555 | if (sdata == NULL) | |
556 | break; | |
557 | ||
558 | sym = ((struct coff_symbol *) | |
559 | bsearch (&addr, sdata->symbols, sdata->count, | |
560 | sizeof (struct coff_symbol), coff_symbol_search)); | |
561 | if (sym != NULL) | |
562 | break; | |
563 | ||
564 | pp = &sdata->next; | |
565 | } | |
566 | } | |
567 | ||
568 | if (sym == NULL) | |
569 | callback (data, addr, NULL, 0, 0); | |
570 | else | |
571 | callback (data, addr, sym->name, sym->address, 0); | |
572 | } | |
573 | ||
574 | /* Add the backtrace data for one PE/COFF file. Returns 1 on success, | |
575 | 0 on failure (in both cases descriptor is closed). */ | |
576 | ||
577 | static int | |
578 | coff_add (struct backtrace_state *state, int descriptor, | |
579 | backtrace_error_callback error_callback, void *data, | |
580 | fileline *fileline_fn, int *found_sym, int *found_dwarf) | |
581 | { | |
582 | struct backtrace_view fhdr_view; | |
583 | off_t fhdr_off; | |
584 | int magic_ok; | |
585 | b_coff_file_header fhdr; | |
586 | off_t opt_sects_off; | |
587 | size_t opt_sects_size; | |
588 | unsigned int sects_num; | |
589 | struct backtrace_view sects_view; | |
590 | int sects_view_valid; | |
591 | const b_coff_optional_header *opt_hdr; | |
592 | const b_coff_section_header *sects; | |
593 | struct backtrace_view str_view; | |
594 | int str_view_valid; | |
9cc50fc6 | 595 | uint32_t str_size; |
e9174d1e | 596 | off_t str_off; |
32a655c1 SL |
597 | // NOTE: upstream doesn't have `{0}`, this is a fix for Rust issue #39468. |
598 | // If syms_view is not initialized, then `free(syms_view.base)` may segfault later. | |
599 | struct backtrace_view syms_view = {0}; | |
e9174d1e SL |
600 | off_t syms_off; |
601 | size_t syms_size; | |
602 | int syms_view_valid; | |
603 | unsigned int syms_num; | |
604 | unsigned int i; | |
605 | struct debug_section_info sections[DEBUG_MAX]; | |
606 | off_t min_offset; | |
607 | off_t max_offset; | |
608 | struct backtrace_view debug_view; | |
609 | int debug_view_valid; | |
610 | uintptr_t image_base; | |
ba9703b0 | 611 | struct dwarf_sections dwarf_sections; |
e9174d1e SL |
612 | |
613 | *found_sym = 0; | |
614 | *found_dwarf = 0; | |
615 | ||
616 | sects_view_valid = 0; | |
617 | syms_view_valid = 0; | |
618 | str_view_valid = 0; | |
619 | debug_view_valid = 0; | |
620 | ||
621 | /* Map the MS-DOS stub (if any) and extract file header offset. */ | |
622 | if (!backtrace_get_view (state, descriptor, 0, 0x40, error_callback, | |
623 | data, &fhdr_view)) | |
624 | goto fail; | |
625 | ||
626 | { | |
94b46f34 | 627 | const unsigned char *vptr = fhdr_view.data; |
e9174d1e SL |
628 | |
629 | if (vptr[0] == 'M' && vptr[1] == 'Z') | |
94b46f34 | 630 | fhdr_off = coff_read4 (vptr + 0x3c); |
e9174d1e SL |
631 | else |
632 | fhdr_off = 0; | |
633 | } | |
634 | ||
635 | backtrace_release_view (state, &fhdr_view, error_callback, data); | |
636 | ||
637 | /* Map the coff file header. */ | |
638 | if (!backtrace_get_view (state, descriptor, fhdr_off, | |
639 | sizeof (b_coff_file_header) + 4, | |
640 | error_callback, data, &fhdr_view)) | |
641 | goto fail; | |
642 | ||
643 | if (fhdr_off != 0) | |
644 | { | |
645 | const char *magic = (const char *) fhdr_view.data; | |
646 | magic_ok = memcmp (magic, "PE\0", 4) == 0; | |
647 | fhdr_off += 4; | |
648 | ||
649 | memcpy (&fhdr, fhdr_view.data + 4, sizeof fhdr); | |
650 | } | |
651 | else | |
652 | { | |
653 | memcpy (&fhdr, fhdr_view.data, sizeof fhdr); | |
654 | /* TODO: test fhdr.machine for coff but non-PE platforms. */ | |
655 | magic_ok = 0; | |
656 | } | |
657 | backtrace_release_view (state, &fhdr_view, error_callback, data); | |
658 | ||
659 | if (!magic_ok) | |
660 | { | |
661 | error_callback (data, "executable file is not COFF", 0); | |
662 | goto fail; | |
663 | } | |
664 | ||
665 | sects_num = fhdr.number_of_sections; | |
666 | syms_num = fhdr.number_of_symbols; | |
667 | ||
668 | opt_sects_off = fhdr_off + sizeof (fhdr); | |
669 | opt_sects_size = (fhdr.size_of_optional_header | |
670 | + sects_num * sizeof (b_coff_section_header)); | |
671 | ||
672 | /* To translate PC to file/line when using DWARF, we need to find | |
673 | the .debug_info and .debug_line sections. */ | |
674 | ||
675 | /* Read the optional header and the section headers. */ | |
676 | ||
677 | if (!backtrace_get_view (state, descriptor, opt_sects_off, opt_sects_size, | |
678 | error_callback, data, §s_view)) | |
679 | goto fail; | |
680 | sects_view_valid = 1; | |
681 | opt_hdr = (const b_coff_optional_header *) sects_view.data; | |
682 | sects = (const b_coff_section_header *) | |
683 | (sects_view.data + fhdr.size_of_optional_header); | |
684 | ||
685 | if (fhdr.size_of_optional_header > sizeof (*opt_hdr)) | |
686 | { | |
687 | if (opt_hdr->magic == PE_MAGIC) | |
688 | image_base = opt_hdr->u.pe.image_base; | |
689 | else if (opt_hdr->magic == PEP_MAGIC) | |
690 | image_base = opt_hdr->u.pep.image_base; | |
691 | else | |
692 | { | |
693 | error_callback (data, "bad magic in PE optional header", 0); | |
694 | goto fail; | |
695 | } | |
696 | } | |
697 | else | |
698 | image_base = 0; | |
699 | ||
700 | /* Read the symbol table and the string table. */ | |
701 | ||
702 | if (fhdr.pointer_to_symbol_table == 0) | |
703 | { | |
704 | /* No symbol table, no string table. */ | |
705 | str_off = 0; | |
706 | str_size = 0; | |
707 | syms_num = 0; | |
708 | syms_size = 0; | |
709 | } | |
710 | else | |
711 | { | |
712 | /* Symbol table is followed by the string table. The string table | |
713 | starts with its length (on 4 bytes). | |
714 | Map the symbol table and the length of the string table. */ | |
715 | syms_off = fhdr.pointer_to_symbol_table; | |
716 | syms_size = syms_num * SYM_SZ; | |
717 | ||
718 | if (!backtrace_get_view (state, descriptor, syms_off, syms_size + 4, | |
719 | error_callback, data, &syms_view)) | |
720 | goto fail; | |
721 | syms_view_valid = 1; | |
722 | ||
94b46f34 | 723 | str_size = coff_read4 (syms_view.data + syms_size); |
e9174d1e SL |
724 | |
725 | str_off = syms_off + syms_size; | |
726 | ||
727 | if (str_size > 4) | |
728 | { | |
729 | /* Map string table (including the length word). */ | |
730 | ||
731 | if (!backtrace_get_view (state, descriptor, str_off, str_size, | |
732 | error_callback, data, &str_view)) | |
733 | goto fail; | |
734 | str_view_valid = 1; | |
735 | } | |
736 | } | |
737 | ||
738 | memset (sections, 0, sizeof sections); | |
739 | ||
740 | /* Look for the symbol table. */ | |
741 | for (i = 0; i < sects_num; ++i) | |
742 | { | |
743 | const b_coff_section_header *s = sects + i; | |
744 | unsigned int str_off; | |
745 | int j; | |
746 | ||
747 | if (s->name[0] == '/') | |
748 | { | |
749 | /* Extended section name. */ | |
750 | str_off = atoi (s->name + 1); | |
751 | } | |
752 | else | |
753 | str_off = 0; | |
754 | ||
755 | for (j = 0; j < (int) DEBUG_MAX; ++j) | |
756 | { | |
757 | const char *dbg_name = debug_section_names[j]; | |
758 | int match; | |
759 | ||
760 | if (str_off != 0) | |
761 | match = coff_long_name_eq (dbg_name, str_off, &str_view); | |
762 | else | |
763 | match = coff_short_name_eq (dbg_name, s->name); | |
764 | if (match) | |
765 | { | |
766 | sections[j].offset = s->pointer_to_raw_data; | |
767 | sections[j].size = s->virtual_size <= s->size_of_raw_data ? | |
768 | s->virtual_size : s->size_of_raw_data; | |
769 | break; | |
770 | } | |
771 | } | |
772 | } | |
773 | ||
774 | if (syms_num != 0) | |
775 | { | |
776 | struct coff_syminfo_data *sdata; | |
777 | ||
778 | sdata = ((struct coff_syminfo_data *) | |
779 | backtrace_alloc (state, sizeof *sdata, error_callback, data)); | |
780 | if (sdata == NULL) | |
781 | goto fail; | |
782 | ||
783 | if (!coff_initialize_syminfo (state, image_base, | |
784 | sects, sects_num, | |
785 | syms_view.data, syms_size, | |
786 | str_view.data, str_size, | |
787 | error_callback, data, sdata)) | |
788 | { | |
789 | backtrace_free (state, sdata, sizeof *sdata, error_callback, data); | |
790 | goto fail; | |
791 | } | |
792 | ||
793 | *found_sym = 1; | |
794 | ||
795 | coff_add_syminfo_data (state, sdata); | |
796 | } | |
797 | ||
798 | backtrace_release_view (state, §s_view, error_callback, data); | |
799 | sects_view_valid = 0; | |
94b46f34 XL |
800 | if (syms_view_valid) |
801 | { | |
802 | backtrace_release_view (state, &syms_view, error_callback, data); | |
803 | syms_view_valid = 0; | |
804 | } | |
e9174d1e SL |
805 | |
806 | /* Read all the debug sections in a single view, since they are | |
807 | probably adjacent in the file. We never release this view. */ | |
808 | ||
809 | min_offset = 0; | |
810 | max_offset = 0; | |
811 | for (i = 0; i < (int) DEBUG_MAX; ++i) | |
812 | { | |
813 | off_t end; | |
814 | ||
815 | if (sections[i].size == 0) | |
816 | continue; | |
817 | if (min_offset == 0 || sections[i].offset < min_offset) | |
818 | min_offset = sections[i].offset; | |
819 | end = sections[i].offset + sections[i].size; | |
820 | if (end > max_offset) | |
821 | max_offset = end; | |
822 | } | |
823 | if (min_offset == 0 || max_offset == 0) | |
824 | { | |
825 | if (!backtrace_close (descriptor, error_callback, data)) | |
826 | goto fail; | |
827 | *fileline_fn = coff_nodebug; | |
828 | return 1; | |
829 | } | |
830 | ||
831 | if (!backtrace_get_view (state, descriptor, min_offset, | |
832 | max_offset - min_offset, | |
833 | error_callback, data, &debug_view)) | |
834 | goto fail; | |
835 | debug_view_valid = 1; | |
836 | ||
837 | /* We've read all we need from the executable. */ | |
838 | if (!backtrace_close (descriptor, error_callback, data)) | |
839 | goto fail; | |
840 | descriptor = -1; | |
841 | ||
842 | for (i = 0; i < (int) DEBUG_MAX; ++i) | |
843 | { | |
ba9703b0 XL |
844 | size_t size = sections[i].size; |
845 | dwarf_sections.size[i] = size; | |
846 | if (size == 0) | |
847 | dwarf_sections.data[i] = NULL; | |
e9174d1e | 848 | else |
ba9703b0 XL |
849 | dwarf_sections.data[i] = ((const unsigned char *) debug_view.data |
850 | + (sections[i].offset - min_offset)); | |
e9174d1e SL |
851 | } |
852 | ||
ba9703b0 XL |
853 | if (!backtrace_dwarf_add (state, /* base_address */ 0, &dwarf_sections, |
854 | 0, /* FIXME: is_bigendian */ | |
855 | NULL, /* altlink */ | |
856 | error_callback, data, fileline_fn, | |
857 | NULL /* returned fileline_entry */)) | |
e9174d1e SL |
858 | goto fail; |
859 | ||
860 | *found_dwarf = 1; | |
861 | ||
862 | return 1; | |
863 | ||
864 | fail: | |
865 | if (sects_view_valid) | |
866 | backtrace_release_view (state, §s_view, error_callback, data); | |
867 | if (str_view_valid) | |
868 | backtrace_release_view (state, &str_view, error_callback, data); | |
869 | if (syms_view_valid) | |
870 | backtrace_release_view (state, &syms_view, error_callback, data); | |
871 | if (debug_view_valid) | |
872 | backtrace_release_view (state, &debug_view, error_callback, data); | |
873 | if (descriptor != -1) | |
874 | backtrace_close (descriptor, error_callback, data); | |
875 | return 0; | |
876 | } | |
877 | ||
878 | /* Initialize the backtrace data we need from an ELF executable. At | |
879 | the ELF level, all we need to do is find the debug info | |
880 | sections. */ | |
881 | ||
882 | int | |
94b46f34 XL |
883 | backtrace_initialize (struct backtrace_state *state, |
884 | const char *filename ATTRIBUTE_UNUSED, int descriptor, | |
e9174d1e SL |
885 | backtrace_error_callback error_callback, |
886 | void *data, fileline *fileline_fn) | |
887 | { | |
888 | int ret; | |
889 | int found_sym; | |
890 | int found_dwarf; | |
891 | fileline coff_fileline_fn; | |
892 | ||
893 | ret = coff_add (state, descriptor, error_callback, data, | |
894 | &coff_fileline_fn, &found_sym, &found_dwarf); | |
895 | if (!ret) | |
896 | return 0; | |
897 | ||
898 | if (!state->threaded) | |
899 | { | |
900 | if (found_sym) | |
901 | state->syminfo_fn = coff_syminfo; | |
902 | else if (state->syminfo_fn == NULL) | |
903 | state->syminfo_fn = coff_nosyms; | |
904 | } | |
905 | else | |
906 | { | |
907 | if (found_sym) | |
908 | backtrace_atomic_store_pointer (&state->syminfo_fn, coff_syminfo); | |
909 | else | |
ba9703b0 XL |
910 | (void) __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, |
911 | coff_nosyms); | |
e9174d1e SL |
912 | } |
913 | ||
914 | if (!state->threaded) | |
915 | { | |
916 | if (state->fileline_fn == NULL || state->fileline_fn == coff_nodebug) | |
917 | *fileline_fn = coff_fileline_fn; | |
918 | } | |
919 | else | |
920 | { | |
921 | fileline current_fn; | |
922 | ||
923 | current_fn = backtrace_atomic_load_pointer (&state->fileline_fn); | |
924 | if (current_fn == NULL || current_fn == coff_nodebug) | |
925 | *fileline_fn = coff_fileline_fn; | |
926 | } | |
927 | ||
928 | return 1; | |
929 | } |