-
Notifications
You must be signed in to change notification settings - Fork 3
/
dwarf_info.c
1652 lines (1395 loc) · 34.6 KB
/
dwarf_info.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* dwarf_info.c
*
* Copyright (C) 2011 NEC Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <elfutils/libdw.h>
#include <elfutils/libdwfl.h>
#include <dwarf.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include "common.h"
#include "print_info.h"
#include "dwarf_info.h"
/*
* Debugging information
*/
#define DEFAULT_DEBUGINFO_PATH "/usr/lib/debug"
struct dwarf_info {
unsigned int cmd; /* IN */
int fd_debuginfo; /* IN */
char *name_debuginfo; /* IN */
char *module_name; /* IN */
char *struct_name; /* IN */
char *symbol_name; /* IN */
char *member_name; /* IN */
char *enum_name; /* IN */
Elf *elfd; /* OUT */
Dwarf *dwarfd; /* OUT */
Dwfl *dwfl; /* OUT */
char *type_name; /* OUT */
long struct_size; /* OUT */
long member_offset; /* OUT */
long array_length; /* OUT */
long enum_number; /* OUT */
unsigned char type_flag; /* OUT */
char src_name[LEN_SRCFILE]; /* OUT */
Dwarf_Off die_offset; /* OUT */
};
static struct dwarf_info dwarf_info = {
.fd_debuginfo = -1,
};
/*
* Internal functions.
*/
static int
is_search_structure(int cmd)
{
if ((cmd == DWARF_INFO_GET_STRUCT_SIZE)
|| (cmd == DWARF_INFO_GET_MEMBER_OFFSET)
|| (cmd == DWARF_INFO_GET_MEMBER_TYPE)
|| (cmd == DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION)
|| (cmd == DWARF_INFO_GET_MEMBER_ARRAY_LENGTH))
return TRUE;
else
return FALSE;
}
static int
is_search_number(int cmd)
{
if (cmd == DWARF_INFO_GET_ENUM_NUMBER)
return TRUE;
else
return FALSE;
}
static int
is_search_symbol(int cmd)
{
if ((cmd == DWARF_INFO_GET_SYMBOL_ARRAY_LENGTH)
|| (cmd == DWARF_INFO_GET_SYMBOL_TYPE)
|| (cmd == DWARF_INFO_CHECK_SYMBOL_ARRAY_TYPE))
return TRUE;
else
return FALSE;
}
static int
is_search_typedef(int cmd)
{
if ((cmd == DWARF_INFO_GET_TYPEDEF_SIZE)
|| (cmd == DWARF_INFO_GET_TYPEDEF_SRCNAME))
return TRUE;
else
return FALSE;
}
static int
is_search_domain(int cmd)
{
if ((cmd == DWARF_INFO_GET_DOMAIN_STRUCT)
|| (cmd == DWARF_INFO_GET_DOMAIN_TYPEDEF)
|| (cmd == DWARF_INFO_GET_DOMAIN_ARRAY)
|| (cmd == DWARF_INFO_GET_DOMAIN_UNION)
|| (cmd == DWARF_INFO_GET_DOMAIN_ENUM)
|| (cmd == DWARF_INFO_GET_DOMAIN_REF)
|| (cmd == DWARF_INFO_GET_DOMAIN_STRING)
|| (cmd == DWARF_INFO_GET_DOMAIN_BASE))
return TRUE;
else
return FALSE;
}
static int
is_search_die(int cmd)
{
if (cmd == DWARF_INFO_GET_DIE)
return TRUE;
else
return FALSE;
}
static int
process_module (Dwfl_Module *dwflmod,
void **userdata __attribute__ ((unused)),
const char *name __attribute__ ((unused)),
Dwarf_Addr base __attribute__ ((unused)),
void *arg)
{
const char *fname, *mod_name, *debugfile;
Dwarf_Addr dwbias;
/* get a debug context descriptor.*/
dwarf_info.dwarfd = dwfl_module_getdwarf (dwflmod, &dwbias);
if (dwarf_info.dwarfd == NULL) {
ERRMSG("dwfl_module_getdwarf error.\n");
return DWARF_CB_ABORT;
}
dwarf_info.elfd = dwarf_getelf(dwarf_info.dwarfd);
mod_name = dwfl_module_info(dwflmod, NULL, NULL, NULL, NULL, NULL,
&fname, &debugfile);
if (!strcmp(dwarf_info.module_name, mod_name) &&
!dwarf_info.name_debuginfo && debugfile) {
/*
* Store the debuginfo filename. Next time we will
* open debuginfo file direclty instead of searching
* for it again.
*/
dwarf_info.name_debuginfo = strdup(debugfile);
}
return DWARF_CB_OK;
}
static int
dwfl_report_module_p(const char *modname, const char *filename)
{
if (filename && !strcmp(modname, dwarf_info.module_name))
return 1;
return 0;
}
static void
clean_dwfl_info(void)
{
if (dwarf_info.dwfl)
dwfl_end(dwarf_info.dwfl);
dwarf_info.dwfl = NULL;
dwarf_info.dwarfd = NULL;
dwarf_info.elfd = NULL;
}
/*
* Search module debuginfo.
* This function searches for module debuginfo in default debuginfo path for
* a given module in dwarf_info.module_name.
*
* On success, dwarf_info.name_debuginfo is set to absolute path of
* module debuginfo.
*/
static int
search_module_debuginfo(char *os_release)
{
Dwfl *dwfl = NULL;
static char *debuginfo_path = DEFAULT_DEBUGINFO_PATH;
static const Dwfl_Callbacks callbacks = {
.section_address = dwfl_offline_section_address,
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
};
/*
* Check if We already have debuginfo file name with us. If yes,
* then we don't need to proceed with search method.
*/
if (dwarf_info.name_debuginfo)
return TRUE;
if ((dwfl = dwfl_begin(&callbacks)) == NULL) {
ERRMSG("Can't create a handle for a new dwfl session.\n");
return FALSE;
}
/* Search for module debuginfo file. */
if (dwfl_linux_kernel_report_offline(dwfl,
os_release,
&dwfl_report_module_p)) {
ERRMSG("Can't get Module debuginfo for module '%s'\n",
dwarf_info.module_name);
dwfl_end(dwfl);
return FALSE;
}
dwfl_report_end(dwfl, NULL, NULL);
dwfl_getmodules(dwfl, &process_module, NULL, 0);
dwfl_end(dwfl);
clean_dwfl_info();
/* Return success if module debuginfo is found. */
if (dwarf_info.name_debuginfo)
return TRUE;
return FALSE;
}
static int
dwarf_no_debuginfo_found(Dwfl_Module *mod, void **userdata,
const char *modname, Dwarf_Addr base,
const char *file_name,
const char *debuglink_file, GElf_Word debuglink_crc,
char **debuginfo_file_name)
{
return -1;
}
/*
* Initialize the dwarf info.
* Linux kernel module debuginfo are of ET_REL (relocatable) type.
* This function uses dwfl API's to apply relocation before reading the
* dwarf information from module debuginfo.
* On success, this function sets the dwarf_info.elfd and dwarf_info.dwarfd
* after applying relocation to module debuginfo.
*/
static int
init_dwarf_info(void)
{
Dwfl *dwfl = NULL;
int dwfl_fd = -1;
static const Dwfl_Callbacks callbacks = {
.section_address = dwfl_offline_section_address,
/*
* By the time init_dwarf_info() function is called, we already
* know absolute path of debuginfo either resolved through
* search_module_debuginfo() call OR user specified vmlinux
* debuginfo through '-x' option. In which case .find_debuginfo
* callback is never invoked.
* But we can not deny a situation where user may pass invalid
* file name through '-x' option, where .find_debuginfo gets
* invoked to find a valid vmlinux debuginfo and hence we run
* into seg fault issue. Hence, set .find_debuginfo to a
* funtion pointer that returns -1 to avoid seg fault and let
* the makedumpfile throw error messages against the invalid
* vmlinux file input.
*/
.find_debuginfo = dwarf_no_debuginfo_found
};
dwarf_info.elfd = NULL;
dwarf_info.dwarfd = NULL;
/*
* We already know the absolute path of debuginfo file. Fail if we
* still don't have one. Ideally we should never be in this situation.
*/
if (!dwarf_info.name_debuginfo) {
ERRMSG("Can't find absolute path to debuginfo file.\n");
return FALSE;
}
if ((dwfl = dwfl_begin(&callbacks)) == NULL) {
ERRMSG("Can't create a handle for a new dwfl session.\n");
return FALSE;
}
/* Open the debuginfo file if it is not already open. */
if (dwarf_info.fd_debuginfo < 0)
dwarf_info.fd_debuginfo =
open(dwarf_info.name_debuginfo, O_RDONLY);
dwfl_fd = dup(dwarf_info.fd_debuginfo);
if (dwfl_fd < 0) {
ERRMSG("Failed to get a duplicate handle for"
" debuginfo.\n");
goto err_out;
}
/* Apply relocations. */
if (dwfl_report_offline(dwfl, dwarf_info.module_name,
dwarf_info.name_debuginfo, dwfl_fd) == NULL) {
ERRMSG("Failed reading %s: %s\n",
dwarf_info.name_debuginfo, dwfl_errmsg (-1));
/* dwfl_fd is consumed on success, not on failure */
close(dwfl_fd);
goto err_out;
}
dwfl_report_end(dwfl, NULL, NULL);
dwfl_getmodules(dwfl, &process_module, NULL, 0);
if (dwarf_info.elfd == NULL) {
ERRMSG("Can't get first elf header of %s.\n",
dwarf_info.name_debuginfo);
goto err_out;
}
if (dwarf_info.dwarfd == NULL) {
ERRMSG("Can't get debug context descriptor for %s.\n",
dwarf_info.name_debuginfo);
goto err_out;
}
dwarf_info.dwfl = dwfl;
return TRUE;
err_out:
if (dwfl)
dwfl_end(dwfl);
return FALSE;
}
static int
get_data_member_location(Dwarf_Die *die, long *offset)
{
size_t expcnt;
Dwarf_Attribute attr;
Dwarf_Op *expr;
if (dwarf_attr(die, DW_AT_data_member_location, &attr) == NULL)
return FALSE;
if (dwarf_getlocation(&attr, &expr, &expcnt) < 0)
return FALSE;
(*offset) = expr[0].number;
return TRUE;
}
static int
get_die_type(Dwarf_Die *die, Dwarf_Die *die_type)
{
Dwarf_Attribute attr;
if (dwarf_attr(die, DW_AT_type, &attr) == NULL)
return FALSE;
if (dwarf_formref_die(&attr, die_type) < 0) {
ERRMSG("Can't get CU die.\n");
return FALSE;
}
return TRUE;
}
static int
get_data_array_length(Dwarf_Die *die)
{
int tag;
Dwarf_Attribute attr;
Dwarf_Die die_type;
Dwarf_Word upper_bound;
if (!get_die_type(die, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
return FALSE;
}
tag = dwarf_tag(&die_type);
if (tag == DW_TAG_const_type) {
/* This array is of const type. Get the die type again */
if (!get_die_type(&die_type, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
return FALSE;
}
tag = dwarf_tag(&die_type);
}
if (tag != DW_TAG_array_type) {
/*
* This kernel doesn't have the member of array.
*/
return TRUE;
}
/*
* Get the demanded array length.
*/
dwarf_child(&die_type, &die_type);
do {
tag = dwarf_tag(&die_type);
if (tag == DW_TAG_subrange_type)
break;
} while (dwarf_siblingof(&die_type, &die_type));
if (tag != DW_TAG_subrange_type)
return FALSE;
if (dwarf_attr(&die_type, DW_AT_upper_bound, &attr) == NULL)
return FALSE;
if (dwarf_formudata(&attr, &upper_bound) < 0)
return FALSE;
if (upper_bound < 0)
return FALSE;
dwarf_info.array_length = upper_bound + 1;
return TRUE;
}
static int
check_array_type(Dwarf_Die *die)
{
int tag;
Dwarf_Die die_type;
if (!get_die_type(die, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
return FALSE;
}
tag = dwarf_tag(&die_type);
if (tag == DW_TAG_array_type)
dwarf_info.array_length = FOUND_ARRAY_TYPE;
return TRUE;
}
static int
get_dwarf_base_type(Dwarf_Die *die)
{
int tag;
const char *name;
while (get_die_type(die, die)) {
tag = dwarf_tag(die);
switch (tag) {
case DW_TAG_array_type:
dwarf_info.type_flag |= TYPE_ARRAY;
break;
case DW_TAG_pointer_type:
dwarf_info.type_flag |= TYPE_PTR;
break;
case DW_TAG_structure_type:
dwarf_info.type_flag |= TYPE_STRUCT;
break;
case DW_TAG_base_type:
dwarf_info.type_flag |= TYPE_BASE;
break;
}
}
name = dwarf_diename(die);
if (name)
dwarf_info.type_name = strdup(name);
else if (dwarf_info.type_flag == TYPE_PTR)
dwarf_info.type_name = strdup("void");
dwarf_info.struct_size = dwarf_bytesize(die);
return TRUE;
}
/*
* Get the die, given the offset
*/
static int
get_die_from_offset(Dwarf_Off offset, Dwarf_Die *die)
{
if (!init_dwarf_info())
return FALSE;
if ((!offset) || (!die))
return FALSE;
if (!dwarf_offdie(dwarf_info.dwarfd, offset, die)) {
return FALSE;
}
return TRUE;
}
/*
* Function for searching struct page.union.struct.mapping.
*/
static int
is_container(Dwarf_Die *die)
{
if (dwarf_tag(die) == DW_TAG_structure_type)
return TRUE;
if (dwarf_info.cmd != DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION
&& dwarf_tag(die) == DW_TAG_union_type)
return TRUE;
return FALSE;
}
static void
adjust_member_offset(Dwarf_Die *die)
{
long offset;
if (dwarf_info.member_offset == NOT_FOUND_STRUCTURE)
return;
if (!get_data_member_location(die, &offset))
return;
dwarf_info.member_offset += offset;
}
static int
search_member(Dwarf_Die *die)
{
int tag;
long offset;
const char *name;
Dwarf_Die child, *walker, die_type;
if (dwarf_child(die, &child) != 0)
return FALSE;
walker = &child;
do {
tag = dwarf_tag(walker);
name = dwarf_diename(walker);
if (tag != DW_TAG_member)
continue;
/*
* Descend into structures/unions and search for member
* there.
*/
if ((!name) || (strcmp(name, dwarf_info.member_name) != 0)) {
if (!get_die_type(walker, &die_type))
continue;
if (is_container(&die_type))
if (search_member(&die_type)) {
adjust_member_offset(walker);
return TRUE;
}
}
switch (dwarf_info.cmd) {
case DWARF_INFO_GET_MEMBER_TYPE:
if ((!name) || strcmp(name, dwarf_info.member_name))
continue;
/*
* Get the member offset.
*/
if (!get_dwarf_base_type(walker))
continue;
return TRUE;
case DWARF_INFO_GET_MEMBER_OFFSET:
if ((!name) || strcmp(name, dwarf_info.member_name))
continue;
/*
* Get the member offset.
*/
if (dwarf_tag(die) == DW_TAG_union_type)
offset = 0;
else if (!get_data_member_location(walker, &offset))
continue;
dwarf_info.member_offset = offset;
return TRUE;
case DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION:
if (!get_die_type(walker, &die_type))
continue;
if (dwarf_tag(&die_type) != DW_TAG_union_type)
continue;
/*
* Get the member offset.
*/
if (!get_data_member_location(walker, &offset))
continue;
dwarf_info.member_offset = offset;
return TRUE;
case DWARF_INFO_GET_MEMBER_ARRAY_LENGTH:
if ((!name) || strcmp(name, dwarf_info.member_name))
continue;
/*
* Get the member length.
*/
if (!get_data_array_length(walker))
continue;
return TRUE;
}
} while (!dwarf_siblingof(walker, walker));
/*
* Return even if not found.
*/
return FALSE;
}
static void
search_structure(Dwarf_Die *die, int *found)
{
int tag;
const char *name;
Dwarf_Die die_type;
/*
* If we get to here then we don't have any more
* children, check to see if this is a relevant tag
*/
do {
tag = dwarf_tag(die);
name = dwarf_diename(die);
if ((!name) || strcmp(name, dwarf_info.struct_name))
continue;
if (tag == DW_TAG_typedef) {
if (!get_die_type(die, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
break;
}
/* Resolve typedefs of typedefs. */
while ((tag = dwarf_tag(&die_type)) == DW_TAG_typedef) {
if (!get_die_type(&die_type, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
return;
}
}
if (tag != DW_TAG_structure_type)
continue;
die = &die_type;
} else if (tag != DW_TAG_structure_type) {
continue;
}
/*
* Skip if DW_AT_byte_size is not included.
*/
dwarf_info.struct_size = dwarf_bytesize(die);
if (dwarf_info.struct_size > 0)
break;
} while (!dwarf_siblingof(die, die));
if (dwarf_info.struct_size <= 0) {
/*
* Not found the demanded structure.
*/
return;
}
/*
* Found the demanded structure.
*/
*found = TRUE;
switch (dwarf_info.cmd) {
case DWARF_INFO_GET_STRUCT_SIZE:
break;
case DWARF_INFO_GET_MEMBER_TYPE:
case DWARF_INFO_GET_MEMBER_OFFSET:
case DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION:
case DWARF_INFO_GET_MEMBER_ARRAY_LENGTH:
search_member(die);
break;
}
}
static void
search_number(Dwarf_Die *die, int *found)
{
int tag, bytesize;
Dwarf_Word const_value;
Dwarf_Attribute attr;
Dwarf_Die child, *walker;
const char *name;
do {
tag = dwarf_tag(die);
if (tag != DW_TAG_enumeration_type)
continue;
if (dwarf_info.cmd == DWARF_INFO_GET_ENUMERATION_TYPE_SIZE) {
name = dwarf_diename(die);
if (!name || strcmp(name, dwarf_info.struct_name))
continue;
if ((bytesize = dwarf_bytesize(die)) <= 0)
continue;
*found = TRUE;
dwarf_info.struct_size = bytesize;
return;
}
if (dwarf_child(die, &child) != 0)
continue;
walker = &child;
do {
tag = dwarf_tag(walker);
name = dwarf_diename(walker);
if ((tag != DW_TAG_enumerator) || (!name)
|| strcmp(name, dwarf_info.enum_name))
continue;
if (!dwarf_attr(walker, DW_AT_const_value, &attr))
continue;
if (dwarf_formudata(&attr, &const_value) < 0)
continue;
*found = TRUE;
dwarf_info.enum_number = (long)const_value;
} while (!dwarf_siblingof(walker, walker));
} while (!dwarf_siblingof(die, die));
}
static void
search_typedef(Dwarf_Die *die, int *found)
{
int tag = 0;
char *src_name = NULL;
const char *name;
Dwarf_Die die_type;
/*
* If we get to here then we don't have any more
* children, check to see if this is a relevant tag
*/
do {
tag = dwarf_tag(die);
name = dwarf_diename(die);
if ((tag != DW_TAG_typedef) || (!name)
|| strcmp(name, dwarf_info.struct_name))
continue;
if (dwarf_info.cmd == DWARF_INFO_GET_TYPEDEF_SIZE) {
if (!get_die_type(die, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
break;
}
/* Resolve typedefs of typedefs. */
while ((tag = dwarf_tag(&die_type)) == DW_TAG_typedef) {
if (!get_die_type(&die_type, &die_type)) {
ERRMSG("Can't get CU die of DW_AT_type.\n");
return;
}
}
dwarf_info.struct_size = dwarf_bytesize(&die_type);
if (dwarf_info.struct_size <= 0)
continue;
*found = TRUE;
break;
} else if (dwarf_info.cmd == DWARF_INFO_GET_TYPEDEF_SRCNAME) {
src_name = (char *)dwarf_decl_file(die);
if (!src_name)
continue;
*found = TRUE;
strncpy(dwarf_info.src_name, src_name, LEN_SRCFILE-1);
dwarf_info.src_name[LEN_SRCFILE-1] = '\0';
break;
}
} while (!dwarf_siblingof(die, die));
}
static void
search_symbol(Dwarf_Die *die, int *found)
{
int tag;
const char *name;
/*
* If we get to here then we don't have any more
* children, check to see if this is a relevant tag
*/
do {
tag = dwarf_tag(die);
name = dwarf_diename(die);
if ((tag == DW_TAG_variable) && (name)
&& !strcmp(name, dwarf_info.symbol_name))
break;
} while (!dwarf_siblingof(die, die));
if ((tag != DW_TAG_variable) || (!name)
|| strcmp(name, dwarf_info.symbol_name)) {
/*
* Not found the demanded symbol.
*/
return;
}
/*
* Found the demanded symbol.
*/
*found = TRUE;
switch (dwarf_info.cmd) {
case DWARF_INFO_GET_SYMBOL_ARRAY_LENGTH:
get_data_array_length(die);
break;
case DWARF_INFO_CHECK_SYMBOL_ARRAY_TYPE:
check_array_type(die);
break;
case DWARF_INFO_GET_SYMBOL_TYPE:
get_dwarf_base_type(die);
break;
}
}
static void
search_domain(Dwarf_Die *die, int *found)
{
int tag;
const char *name;
short flag = 0;
Dwarf_Die die_type;
do {
tag = dwarf_tag(die);
name = dwarf_diename(die);
/*
* Descend into members and search for the
* needed domain there.
*/
if ((!name) || strcmp(name, dwarf_info.symbol_name)) {
if (!get_die_type(die, &die_type))
continue;
if (is_container(&die_type)) {
Dwarf_Die child;
if (dwarf_child(&die_type, &child) != 0)
continue;
search_domain(&child, found);
if (*found)
return;
}
}
if ((!name) || strcmp(name, dwarf_info.symbol_name))
continue;
switch (dwarf_info.cmd) {
case DWARF_INFO_GET_DOMAIN_STRUCT:
if (tag == DW_TAG_structure_type)
flag = 1;
break;
case DWARF_INFO_GET_DOMAIN_UNION:
if (tag == DW_TAG_union_type)
flag = 1;
break;
case DWARF_INFO_GET_DOMAIN_TYPEDEF:
if (tag == DW_TAG_typedef)
flag = 1;
break;
/* TODO
* Implement functionality for the rest of the domains
*/
}
if (!flag)
continue;
dwarf_info.struct_size = dwarf_bytesize(die);
if (dwarf_info.struct_size > 0) {
if (found)
*found = TRUE;
dwarf_info.die_offset = dwarf_dieoffset(die);
break;
}
} while (!dwarf_siblingof(die, die));
}
static void
search_die(Dwarf_Die *die, int *found)
{
const char *name;
do {
name = dwarf_diename(die);
if ((!name) || strcmp(name, dwarf_info.symbol_name))
continue;
if (found)
*found = TRUE;
dwarf_info.die_offset = dwarf_dieoffset(die);
return;
} while (!dwarf_siblingof(die, die));
}
static void
search_die_tree(Dwarf_Die *die, int *found)
{
Dwarf_Die child;
/*
* start by looking at the children
*/
if (dwarf_child(die, &child) == 0)
search_die_tree(&child, found);
if (*found)
return;
if (is_search_structure(dwarf_info.cmd))
search_structure(die, found);
else if (is_search_number(dwarf_info.cmd))
search_number(die, found);
else if (is_search_symbol(dwarf_info.cmd))
search_symbol(die, found);
else if (is_search_typedef(dwarf_info.cmd))
search_typedef(die, found);
else if (is_search_domain(dwarf_info.cmd))
search_domain(die, found);
else if (is_search_die(dwarf_info.cmd))
search_die(die, found);
}
static int
get_debug_info(void)
{
int found = FALSE;
char *name = NULL;
size_t shstrndx, header_size;
uint8_t address_size, offset_size;
Dwarf *dwarfd = NULL;
Elf *elfd = NULL;
Dwarf_Off off = 0, next_off = 0, abbrev_offset = 0;
Elf_Scn *scn = NULL;
GElf_Shdr scnhdr_mem, *scnhdr = NULL;
Dwarf_Die cu_die;
int ret = FALSE;
if (!init_dwarf_info())
return FALSE;
elfd = dwarf_info.elfd;
dwarfd = dwarf_info.dwarfd;
if (elf_getshdrstrndx(elfd, &shstrndx) < 0) {
ERRMSG("Can't get the section index of the string table.\n");
goto out;
}
/*
* Search for ".debug_info" section.
*/
while ((scn = elf_nextscn(elfd, scn)) != NULL) {
scnhdr = gelf_getshdr(scn, &scnhdr_mem);
name = elf_strptr(elfd, shstrndx, scnhdr->sh_name);
if (!strcmp(name, ".debug_info"))
break;
}
if (strcmp(name, ".debug_info")) {
ERRMSG("Can't get .debug_info section.\n");
goto out;
}
/*