-
Notifications
You must be signed in to change notification settings - Fork 16
/
Copy pathmod.cpp
1386 lines (1087 loc) · 33.9 KB
/
mod.cpp
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
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "types.h"
#include "mod.h"
#include "elfio/elfio.hpp"
#include "elfio/elfio_dump.hpp"
#include "nx.h"
#include "utils.h"
using namespace ELFIO;
void mod_init(mod_context* ctx)
{
memset(ctx, 0, sizeof(mod_context));
}
void mod_set_header(mod_context* ctx, mod_header* header)
{
ctx->header = header;
}
void mod_set_name(mod_context* ctx, const char* name)
{
ctx->name = name;
}
void mod_set_buffer(mod_context* ctx, u8* buffer)
{
ctx->buffer = buffer;
}
void mod_set_size(mod_context* ctx, u64 size)
{
ctx->size = size;
}
void mod_set_discover(mod_context* ctx, int discover)
{
ctx->discover = discover;
}
void mod_set_meta(mod_context* ctx, mod_meta* meta)
{
ctx->meta = meta;
}
void mod_set_usersettings(mod_context* ctx, settings* usersettings)
{
ctx->usersettings = usersettings;
}
u64 eh_value_decode(mod_context* ctx, u8 encoding, const u8** stream, u64 hdr_offset)
{
const u8* start = *stream;
u64 pc_offset = start - ctx->buffer;
// DW_EH_PE_omit
if (encoding == 0xFF) return 0;
u8 application = encoding & 0xF0;
u8 format = encoding & 0x0F;
bool sign = false;
u64 value_unsigned = 0;
s64 value_signed = 0;
switch (format)
{
// DW_EH_PE_uleb128
case 0x1:
{
value_unsigned = getuleb128(stream);
break;
}
// DW_EH_PE_udata2
case 0x2:
{
value_unsigned = getle16(*stream);
*stream += sizeof(u16);
break;
}
// DW_EH_PE_udata4
case 0x3:
{
value_unsigned = getle32(*stream);
*stream += sizeof(u32);
break;
}
// DW_EH_PE_udata8
case 0x4:
{
value_unsigned = getle64(*stream);
*stream += sizeof(u64);
break;
}
// DW_EH_PE_sleb128
case 0x9:
{
sign = true;
value_signed = getsleb128(stream);
break;
}
// DW_EH_PE_sdata2
case 0xA:
{
sign = true;
value_signed = (s64)getle16(*stream);
*stream += sizeof(s16);
break;
}
// DW_EH_PE_sdata4
case 0xB:
{
sign = true;
value_signed = (s64)getle32(*stream);
*stream += sizeof(s32);
break;
}
// DW_EH_PE_sdata8
case 0xC:
{
sign = true;
value_signed = (s64)getle64(*stream);
*stream += sizeof(s64);
break;
}
}
u64 value = 0;
switch (application & 0x70)
{
// DW_EH_PE_absptr
case 0x00:
value = sign ? value_signed : value_unsigned;
break;
// DW_EH_PE_pcrel
case 0x10:
value = sign ? (s64)pc_offset + value_signed : pc_offset + value_unsigned;
break;
// DW_EH_PE_datarel
case 0x30:
value = sign ? (s64)hdr_offset + value_signed : hdr_offset + value_unsigned;
break;
}
// DW_EH_PE_indirect
if (application & 0x80)
value = getle64(ctx->buffer + value);
return value;
}
typedef struct {
u64 size;
u8 lpstart_encoding;
u8 types_encoding;
u8 cs_encoding;
u64 lpstart;
u64 types_offset;
u64 cs_size;
const u8* action_table;
const u8* types_table;
} lsda_data;
int eh_lsda_parse(mod_context* ctx, const u8* lsda, lsda_data* data)
{
const u8* start = lsda;
memset(data, 0, sizeof(lsda_data));
data->lpstart_encoding = *lsda++;
if (data->lpstart_encoding != 0xFF)
data->lpstart = getuleb128(&lsda);
data->types_encoding = *lsda++;
if (data->types_encoding != 0xFF)
{
data->types_offset = getuleb128(&lsda);
data->types_table = lsda + data->types_offset;
}
data->cs_encoding = *lsda++;
if (data->cs_encoding != 0xFF)
data->cs_size = getuleb128(&lsda);
data->action_table = lsda + data->cs_size;
while (lsda < data->action_table)
{
u64 cs_start = eh_value_decode(ctx, data->cs_encoding, &lsda, 0);
u64 cs_len = eh_value_decode(ctx, data->cs_encoding, &lsda, 0);
u64 cs_lp = eh_value_decode(ctx, data->cs_encoding, &lsda, 0);
u64 cs_action = getuleb128(&lsda);
}
if (lsda != data->action_table)
return -1;
while (true)
{
s64 type_filter = getsleb128(&lsda);
s64 next_entry = getsleb128(&lsda);
if (next_entry == 0) break;
}
data->size = lsda - start;
if (data->types_table)
data->size = data->types_table - start;
return 0;
}
typedef struct {
u64 size;
u8 version;
bool aug_data_present;
bool eh_data_present;
const char* aug_string;
const u8* aug_data;
u64 aug_size;
u64 eh_data;
u64 return_register;
u64 code_factor;
u64 data_factor;
u8 lsda_encoding;
u8 fde_encoding;
u8 p_encoding;
u64 p_routine;
} cie_data;
typedef struct {
cie_data* cie;
u64 size;
u64 pc_begin;
u64 pc_range;
const char* aug_string;
const u8* aug_data;
u64 aug_size;
u64 lsda_address;
} fde_data;
int eh_frame_parse(mod_context* ctx, const u8* frame, u64 hdr_offset, cie_data* cie, fde_data* fde)
{
const u8* start = frame;
u32 size32 = getle32(frame);
if (size32 == 0) return 0;
frame += sizeof(size32);
u64 size = size32 + sizeof(size32);
// Uses extended size.
if (size32 == 0xFFFFFFFF)
{
size = getle64(frame) + sizeof(size32);
frame += sizeof(size);
}
u32 cie_id = getle32(frame);
frame += sizeof(cie_id);
// If zero, this entry is a CIE, otherwise this value is a pointer to the CIE.
if (cie_id == 0)
{
memset(cie, 0, sizeof(cie_data));
cie->size = size;
cie->version = *frame++;
cie->aug_string = (const char*)frame;
cie->aug_data_present = false;
cie->eh_data_present = false;
if (strlen((const char*)cie->aug_string) != 0)
{
if (strcmp((const char*)cie->aug_string, "eh") == 0)
cie->eh_data_present = true;
else if (*cie->aug_string == 'z')
cie->aug_data_present = true;
}
frame += strlen(cie->aug_string) + 1;
if (cie->eh_data_present)
{
cie->eh_data = getle64(frame);
frame += sizeof(u64);
}
cie->code_factor = getuleb128(&frame);
cie->data_factor = getsleb128(&frame);
cie->return_register = getuleb128(&frame);
if (cie->aug_data_present)
{
cie->aug_size = getuleb128(&frame);
cie->aug_data = frame;
const char* string_cursor = cie->aug_string;
const u8* data_cursor = cie->aug_data;
while (strlen(string_cursor) != 0)
{
switch (*string_cursor)
{
case 'L':
cie->lsda_encoding = *data_cursor++;
break;
case 'R':
cie->fde_encoding = *data_cursor++;
break;
case 'P':
cie->p_encoding = *data_cursor++;
cie->p_routine = eh_value_decode(ctx, cie->p_encoding, &data_cursor, hdr_offset);
break;
}
string_cursor++;
}
frame += cie->aug_size;
}
return 1;
}
// Process FDE.
else
{
memset(fde, 0, sizeof(fde_data));
fde->size = size;
// Read the CIE for this FDE.
const u8* cie_frame = start + sizeof(size32) - cie_id;
int res = eh_frame_parse(ctx, cie_frame, hdr_offset, cie, fde);
// CIE is not a CIE?
if (res != 1) return -1;
fde->cie = cie;
fde->pc_begin = eh_value_decode(ctx, cie->fde_encoding, &frame, hdr_offset);
fde->pc_range = eh_value_decode(ctx, cie->fde_encoding, &frame, hdr_offset);
if (cie->aug_data_present)
{
fde->aug_size = getuleb128(&frame);
fde->aug_data = frame;
const char* string_cursor = cie->aug_string;
const u8* data_cursor = fde->aug_data;
while (strlen(string_cursor) != 0)
{
switch (*string_cursor)
{
case 'L':
fde->lsda_address = eh_value_decode(ctx, cie->lsda_encoding, &data_cursor, hdr_offset);
break;
}
string_cursor++;
}
frame += fde->aug_size;
}
return 2;
}
}
int dt_get(dynamic_section_accessor dynamic, Elf_Xword tag, Elf_Xword* value)
{
for (int i = 0; i < dynamic.get_entries_num(); ++i)
{
Elf_Xword _tag = 0;
Elf_Xword _value = 0;
std::string _str;
dynamic.get_entry(i, _tag, _value, _str);
if (tag == _tag)
{
*value = _value;
return 0;
}
}
return -1;
}
void mod_convert_elf(mod_context* ctx)
{
elfio* elf = (elfio*)ctx->elf;
mod_header* header = ctx->header;
// This converts the module (NSO/NRO) back to an ELF, in order to aid reverse engineering.
// Note that the original conversion to NSO/NRO is lossy - ELF segment/section headers are lost.
// Despite this, we are able to recover a vast majority of the sections produced by the official toolchain
// thanks to the module header and the .dynamic section.
elf->create(ELFCLASS64, ELFDATA2LSB);
elf->set_os_abi(ELFOSABI_NONE);
elf->set_type(ET_DYN);
elf->set_machine(EM_AARCH64);
elf->set_entry(0);
u64 base = 0;
s32 mod_offset = ctx->meta->mod_offset + (s32)getle32(header->mod_object);
mod_object* obj = (mod_object*)(ctx->buffer + mod_offset);
base = getle64(obj->base);
segment* text_seg = elf->segments.add();
{
text_seg->set_type(PT_LOAD);
text_seg->set_flags(PF_R | PF_X);
text_seg->set_align(0x10000);
text_seg->set_virtual_address(base + ctx->meta->text_offset);
text_seg->set_physical_address(ctx->meta->text_offset);
text_seg->set_memory_size(ctx->meta->text_size);
text_seg->set_file_size(ctx->meta->text_size);
}
segment* ro_seg = elf->segments.add();
{
ro_seg->set_type(PT_LOAD);
ro_seg->set_flags(PF_R);
ro_seg->set_align(0x10000);
ro_seg->set_virtual_address(base + ctx->meta->ro_offset);
ro_seg->set_physical_address(ctx->meta->ro_offset);
ro_seg->set_memory_size(ctx->meta->ro_size);
ro_seg->set_file_size(ctx->meta->ro_size);
}
segment* data_seg = elf->segments.add();
{
data_seg->set_type(PT_LOAD);
data_seg->set_flags(PF_R | PF_W);
data_seg->set_align(0x10000);
data_seg->set_virtual_address(base + ctx->meta->data_offset);
data_seg->set_physical_address(ctx->meta->data_offset);
data_seg->set_memory_size(ctx->meta->data_size);
data_seg->set_file_size(ctx->meta->data_size);
}
segment* bss_seg = elf->segments.add();
{
bss_seg->set_type(PT_LOAD);
bss_seg->set_flags(PF_R | PF_W);
bss_seg->set_align(0x10000);
bss_seg->set_virtual_address(base + ctx->meta->data_offset + ctx->meta->data_size);
bss_seg->set_physical_address(ctx->meta->data_offset + ctx->meta->data_size);
bss_seg->set_memory_size(ctx->meta->bss_size);
bss_seg->set_file_size(0);
}
segment* dynamic_seg = elf->segments.add();
{
dynamic_seg->set_type(PT_DYNAMIC);
dynamic_seg->set_flags(PF_R | PF_W);
dynamic_seg->set_align(4);
dynamic_seg->set_virtual_address(base + ctx->meta->mod_offset + (s32)getle32(header->dynamic));
dynamic_seg->set_physical_address(ctx->meta->mod_offset + (s32)getle32(header->dynamic));
dynamic_seg->set_overlay(data_seg->get_index());
}
section* text_sec = elf->sections.add(".text");
{
text_sec->set_type(SHT_PROGBITS);
text_sec->set_flags(SHF_ALLOC | SHF_EXECINSTR);
text_sec->set_address(base + ctx->meta->text_offset);
text_sec->set_addr_align(4);
}
section* ro_sec = elf->sections.add(".rodata");
{
ro_sec->set_type(SHT_PROGBITS);
ro_sec->set_flags(SHF_ALLOC);
ro_sec->set_address(base + ctx->meta->ro_offset);
ro_sec->set_addr_align(4);
}
section* data_sec = elf->sections.add(".data");
{
data_sec->set_type(SHT_PROGBITS);
data_sec->set_flags(SHF_ALLOC | SHF_WRITE);
data_sec->set_address(base + ctx->meta->data_offset);
data_sec->set_addr_align(4);
}
section* bss_sec = elf->sections.add(".bss");
{
bss_sec->set_type(SHT_NOBITS);
bss_sec->set_flags(SHF_ALLOC | SHF_WRITE);
bss_sec->set_address(base + ctx->meta->data_offset + ctx->meta->data_size);
bss_sec->set_addr_align(4);
}
section* strtab_sec = elf->sections.add(".dynstr");
{
strtab_sec->set_type(SHT_STRTAB);
strtab_sec->set_flags(SHF_ALLOC);
strtab_sec->set_overlay(ro_sec->get_index());
strtab_sec->set_addr_align(1);
}
section* symtab_sec = elf->sections.add(".dynsym");
{
symtab_sec->set_type(SHT_DYNSYM);
symtab_sec->set_flags(SHF_ALLOC);
symtab_sec->set_entry_size(elf->get_default_entry_size(SHT_SYMTAB));
symtab_sec->set_link(strtab_sec->get_index());
symtab_sec->set_overlay(ro_sec->get_index());
symtab_sec->set_addr_align(8);
}
section* dynamic_sec = elf->sections.add(".dynamic");
{
dynamic_sec->set_type(SHT_DYNAMIC);
dynamic_sec->set_flags(SHF_ALLOC | SHF_WRITE);
dynamic_sec->set_link(strtab_sec->get_index());
dynamic_sec->set_overlay(data_sec->get_index());
dynamic_sec->set_entry_size(elf->get_default_entry_size(SHT_DYNAMIC));
// We don't have the true size for the .dynamic section, but it will always end on a DT_NULL.
u32 dynamic_size = 0;
u8* dynamic_buffer = ctx->dynamic;
while (true)
{
u64 tag = getle64(dynamic_buffer);
dynamic_size += elf->get_default_entry_size(SHT_DYNAMIC);
if (tag == DT_NULL) break;
dynamic_buffer += elf->get_default_entry_size(SHT_DYNAMIC);
}
// Set the actual data so that accessors work.
dynamic_sec->set_data((const char*)ctx->dynamic, dynamic_size);
dynamic_sec->set_address(base + ctx->meta->mod_offset + (s32)getle32(header->dynamic));
dynamic_seg->set_memory_size(dynamic_size);
dynamic_seg->set_file_size(dynamic_size);
dynamic_sec->set_addr_align(8);
dynamic_seg->add_section_index(dynamic_sec->get_index(), dynamic_sec->get_addr_align());
}
section* hash_sec = elf->sections.add(".hash");
{
hash_sec->set_type(SHT_HASH);
hash_sec->set_flags(SHF_ALLOC);
hash_sec->set_entry_size(sizeof(u32));
hash_sec->set_link(symtab_sec->get_index());
hash_sec->set_overlay(ro_sec->get_index());
hash_sec->set_addr_align(8);
}
section* got_sec = elf->sections.add(".got");
{
got_sec->set_type(SHT_PROGBITS);
got_sec->set_flags(SHF_ALLOC | SHF_WRITE);
got_sec->set_entry_size(sizeof(u64));
got_sec->set_overlay(data_sec->get_index());
got_sec->set_addr_align(8);
}
section* plt_sec = elf->sections.add(".plt");
{
plt_sec->set_type(SHT_PROGBITS);
plt_sec->set_flags(SHF_ALLOC | SHF_EXECINSTR);
plt_sec->set_entry_size(4 * sizeof(u32));
plt_sec->set_overlay(text_sec->get_index());
plt_sec->set_addr_align(4);
}
dynamic_section_accessor dynamic(*elf, dynamic_sec);
section* gnuhash_sec = NULL;
section* reldyn_sec = NULL;
section* relplt_sec = NULL;
section* initarray_sec = NULL;
section* finiarray_sec = NULL;
section* preinitarray_sec = NULL;
Elf_Xword plt_rel = 0;
Elf_Xword plt_entry = 0;
Elf_Xword dt_value = 0;
if (!dt_get(dynamic, DT_PLTREL, &plt_rel))
{
if (plt_rel == DT_REL)
{
plt_entry = elf->get_default_entry_size(SHT_REL);
if (base == 0)
{
reldyn_sec = elf->sections.add(".rel.dyn");
reldyn_sec->set_type(SHT_REL);
reldyn_sec->set_entry_size(plt_entry);
relplt_sec = elf->sections.add(".rel.plt");
relplt_sec->set_type(SHT_REL);
relplt_sec->set_entry_size(plt_entry);
}
}
else if (plt_rel == DT_RELA)
{
plt_entry = elf->get_default_entry_size(SHT_RELA);
if (base == 0)
{
reldyn_sec = elf->sections.add(".rela.dyn");
reldyn_sec->set_type(SHT_RELA);
reldyn_sec->set_entry_size(plt_entry);
relplt_sec = elf->sections.add(".rela.plt");
relplt_sec->set_type(SHT_RELA);
relplt_sec->set_entry_size(plt_entry);
}
}
if (base == 0)
{
reldyn_sec->set_flags(SHF_ALLOC);
reldyn_sec->set_link(symtab_sec->get_index());
reldyn_sec->set_overlay(ro_sec->get_index());
reldyn_sec->set_addr_align(8);
relplt_sec->set_flags(SHF_ALLOC | SHF_INFO_LINK);
relplt_sec->set_info(got_sec->get_index());
relplt_sec->set_link(symtab_sec->get_index());
relplt_sec->set_overlay(ro_sec->get_index());
relplt_sec->set_addr_align(8);
}
}
if (!dt_get(dynamic, DT_GNU_HASH, &dt_value))
{
gnuhash_sec = elf->sections.add(".gnu.hash");
gnuhash_sec->set_type(SHT_GNU_HASH);
gnuhash_sec->set_flags(SHF_ALLOC);
gnuhash_sec->set_link(symtab_sec->get_index());
gnuhash_sec->set_overlay(ro_sec->get_index());
gnuhash_sec->set_addr_align(8);
}
if (!dt_get(dynamic, DT_INIT_ARRAY, &dt_value))
{
initarray_sec = elf->sections.add(".init_array");
initarray_sec->set_type(SHT_INIT_ARRAY);
initarray_sec->set_flags(SHF_ALLOC | SHF_WRITE);
initarray_sec->set_overlay(data_sec->get_index());
initarray_sec->set_addr_align(8);
initarray_sec->set_address(base + dt_value);
}
if (!dt_get(dynamic, DT_FINI_ARRAY, &dt_value))
{
finiarray_sec = elf->sections.add(".fini_array");
finiarray_sec->set_type(SHT_FINI_ARRAY);
finiarray_sec->set_flags(SHF_ALLOC | SHF_WRITE);
finiarray_sec->set_overlay(data_sec->get_index());
finiarray_sec->set_addr_align(8);
finiarray_sec->set_address(base + dt_value);
}
if (!dt_get(dynamic, DT_PREINIT_ARRAY, &dt_value))
{
preinitarray_sec = elf->sections.add(".preinit_array");
preinitarray_sec->set_type(SHT_PREINIT_ARRAY);
preinitarray_sec->set_flags(SHF_ALLOC | SHF_WRITE);
preinitarray_sec->set_overlay(data_sec->get_index());
preinitarray_sec->set_addr_align(8);
preinitarray_sec->set_address(base + dt_value);
}
if (!dt_get(dynamic, DT_STRTAB, &dt_value))
strtab_sec->set_address(base + dt_value);
if (!dt_get(dynamic, DT_STRSZ, &dt_value))
strtab_sec->set_size(dt_value);
if (!dt_get(dynamic, DT_SYMTAB, &dt_value))
symtab_sec->set_address(base + dt_value);
if (!dt_get(dynamic, DT_HASH, &dt_value))
{
u32 nbucket = getle32(ctx->buffer + dt_value);
u32 nchain = getle32(ctx->buffer + dt_value + sizeof(nbucket));
symtab_sec->set_size(nchain * symtab_sec->get_entry_size());
hash_sec->set_address(base + dt_value);
hash_sec->set_size(sizeof(nbucket) + sizeof(nchain) + (nbucket * sizeof(u32)) + (nchain * sizeof(u32)));
}
if (!dt_get(dynamic, DT_PLTGOT, &dt_value))
got_sec->set_address(base + dt_value);
u32 plt_prologue_size = 8 * sizeof(u32);
if (!dt_get(dynamic, DT_GNU_HASH, &dt_value))
{
gnuhash_sec->set_address(base + dt_value);
u32 dynsymcount = symtab_sec->get_size() / symtab_sec->get_entry_size();
u32 nbuckets = getle32(ctx->buffer + dt_value);
u32 symndx = getle32(ctx->buffer + dt_value + sizeof(nbuckets));
u32 maskwords = getle32(ctx->buffer + dt_value + sizeof(nbuckets) + sizeof(symndx));
u32 header_size = sizeof(nbuckets) + sizeof(symndx) + sizeof(maskwords) + sizeof(u32);
u32 bloom_filter_size = sizeof(u64) * maskwords;
u32 buckets_size = sizeof(u32) * nbuckets;
u32 values_size = sizeof(u32) * (dynsymcount - symndx);
gnuhash_sec->set_size(header_size + bloom_filter_size + buckets_size + values_size);
}
u64 relplt_start = 0;
u64 relplt_size = 0;
u64 reldyn_start = 0;
u64 reldyn_size = 0;
if (!dt_get(dynamic, DT_JMPREL, &dt_value))
relplt_start = base + dt_value;
if(base == 0) relplt_sec->set_address(relplt_start);
s64 plt_start = 0;
s64 plt_search = ctx->meta->text_offset;
while (plt_search < ctx->meta->data_offset)
{
u8* code = ctx->buffer + plt_search;
u32 buffer[] = { 0xA9BF7BF0, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xD61F0220, 0xD503201F, 0xD503201F, 0xD503201F };
int buffer_words = buffer_words = sizeof(buffer) / sizeof(u32);
bool fail = false;
for (int i = 0; i < buffer_words; i++)
{
if (buffer[i] == 0xFFFFFFFF)
{
code += sizeof(u32);
continue;
}
if (getle32(code) != buffer[i]) fail = true;
code += sizeof(u32);
}
if (!fail)
{
plt_start = plt_search;
break;
}
plt_search += sizeof(u32);
}
if (!dt_get(dynamic, DT_PLTRELSZ, &dt_value))
{
relplt_size = dt_value;
if(base == 0) relplt_sec->set_size(dt_value);
u32 entries = dt_value / plt_entry;
plt_sec->set_size((entries * plt_sec->get_entry_size()) + plt_prologue_size);
plt_sec->set_address(base + plt_start);
}
if (!dt_get(dynamic, DT_REL, &dt_value) || !dt_get(dynamic, DT_RELA, &dt_value))
reldyn_start = base + dt_value;
if (base == 0) reldyn_sec->set_address(reldyn_start);
if (!dt_get(dynamic, DT_RELSZ, &dt_value) || !dt_get(dynamic, DT_RELASZ, &dt_value))
reldyn_size = dt_value;
if (base == 0) reldyn_sec->set_size(reldyn_size);
if (!dt_get(dynamic, DT_INIT_ARRAYSZ, &dt_value))
initarray_sec->set_size(dt_value);
if (!dt_get(dynamic, DT_FINI_ARRAYSZ, &dt_value))
finiarray_sec->set_size(dt_value);
if (!dt_get(dynamic, DT_PREINIT_ARRAYSZ, &dt_value))
preinitarray_sec->set_size(dt_value);
struct {
u8* rel;
u64 rel_size;
} rel_sections[] = {
{ ctx->buffer + relplt_start - base, relplt_size },
{ ctx->buffer + reldyn_start - base, reldyn_size },
{ NULL, 0 },
};
u64 max = 0;
// Glorious hack to find the end of .got.
for (int i = 0; rel_sections[i].rel != NULL; i++)
{
while (rel_sections[i].rel_size != 0)
{
Elf64_Rela* rel64 = (Elf64_Rela*)rel_sections[i].rel;
u64 offset = getle64((u8*)&rel64->r_offset);
if (offset > max) max = offset;
if (plt_rel == DT_REL)
{
rel_sections[i].rel += sizeof(Elf64_Rel);
rel_sections[i].rel_size -= sizeof(Elf64_Rel);
}
else
{
rel_sections[i].rel += sizeof(Elf64_Rela);
rel_sections[i].rel_size -= sizeof(Elf64_Rela);
}
}
}
max += sizeof(u64);
got_sec->set_size(max - (got_sec->get_address() - base));
if (base == 0)
{
reldyn_sec->set_data((const char*)ctx->buffer + reldyn_start - base, reldyn_size);
relplt_sec->set_data((const char*)ctx->buffer + relplt_start - base, relplt_size);
}
u8* dyn = ctx->buffer + dynamic_sec->get_address() - base;
u64 dyn_size = dynamic_sec->get_size();
while (dyn_size != 0)
{
u64 tag = 0;
u64 value = 0;
tag = getle64(dyn);
dyn += sizeof(u64);
dyn_size -= sizeof(u64);
value = getle64(dyn);
switch (tag)
{
case DT_INIT:
case DT_FINI:
case DT_INIT_ARRAY:
case DT_FINI_ARRAY:
case DT_PREINIT_ARRAY:
case DT_HASH:
case DT_GNU_HASH:
case DT_STRTAB:
case DT_SYMTAB:
case DT_PLTGOT:
case DT_JMPREL:
case DT_REL:
case DT_RELA:
case DT_VERDEF:
case DT_VERSYM:
value += base;
break;
default: break;
}
putle64(dyn, value);
dyn += sizeof(u64);
dyn_size -= sizeof(u64);
}
dynamic_sec->set_data((const char*)ctx->buffer + dynamic_sec->get_address() - base, dynamic_sec->get_size());
// Fix up symbol section indices.
u8* sym = ctx->buffer + symtab_sec->get_address() - base;
u64 sym_size = symtab_sec->get_size();
int sym_index = 0;
int sym_non_local = -1;
while (sym_size != 0)
{
Elf64_Sym* sym64 = (Elf64_Sym*)sym;
u64 value = getle64((u8*)&sym64->st_value);
u16 index = getle16((u8*)&sym64->st_shndx);
if (ELF_ST_BIND(sym64->st_info) != STB_LOCAL && sym_non_local == -1)
sym_non_local = sym_index;
if (index != 0)
{
if (value >= ctx->meta->text_offset && value <= ctx->meta->text_offset + ctx->meta->text_size)
putle16((u8*)&sym64->st_shndx, text_sec->get_index());
else if (value >= ctx->meta->ro_offset && value <= ctx->meta->ro_offset + ctx->meta->ro_size)
putle16((u8*)&sym64->st_shndx, ro_sec->get_index());
else if (value >= ctx->meta->data_offset && value <= ctx->meta->data_offset + ctx->meta->data_size)
putle16((u8*)&sym64->st_shndx, data_sec->get_index());
else if (value >= ctx->meta->data_offset + ctx->meta->data_size && value <= ctx->meta->data_offset + ctx->meta->data_size + ctx->meta->bss_size)
putle16((u8*)&sym64->st_shndx, bss_sec->get_index());
}
if (value != 0 && value < base)
{
value += base;
putle64((u8*)&sym64->st_value, value);
}
sym += sizeof(Elf64_Sym);
sym_size -= sizeof(Elf64_Sym);
sym_index++;
}
symtab_sec->set_info(sym_non_local);
// Set the actual data so that accessors work.
strtab_sec->set_data((const char*)ctx->buffer + strtab_sec->get_address() - base, strtab_sec->get_size());
symtab_sec->set_data((const char*)ctx->buffer + symtab_sec->get_address() - base, symtab_sec->get_size());
symbol_section_accessor symtab(*elf, symtab_sec);
section* framehdr_sec = NULL;
section* frame_sec = NULL;
section* except_sec = NULL;
section* exidx_sec = NULL;
section* extab_sec = NULL;
framehdr_sec = elf->sections.add(".eh_frame_hdr");
{
framehdr_sec->set_type(SHT_PROGBITS);
framehdr_sec->set_flags(SHF_ALLOC);
framehdr_sec->set_address(base + ctx->meta->mod_offset + (s32)getle32(header->unwind_start));
framehdr_sec->set_size((s32)getle32(header->unwind_end) - (s32)getle32(header->unwind_start));
framehdr_sec->set_overlay(ro_sec->get_index());
framehdr_sec->set_addr_align(4);
}
bool fail = false;
const u8* framehdr = ctx->buffer + framehdr_sec->get_address() - base;
u8 version = *framehdr++;
u8 eh_frame_ptr_enc = *framehdr++;
u8 fde_count_enc = *framehdr++;
u8 table_enc = *framehdr++;
if (version != 1 || eh_frame_ptr_enc == 0xFF)
fail = true;
u8* frame = NULL;
if (!fail)
{
u64 out = eh_value_decode(ctx, eh_frame_ptr_enc, &framehdr, framehdr_sec->get_address() - base);