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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
|
#!/usr/bin/env python3
# Copyright 2017 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Statically analyze stack usage of EC firmware.
Example:
extra/stack_analyzer/stack_analyzer.py \
--export_taskinfo ./build/elm/util/export_taskinfo.so \
--section RW \
./build/elm/RW/ec.RW.elf
"""
from __future__ import print_function
import argparse
import collections
import ctypes
import os
import re
import subprocess
import yaml
SECTION_RO = 'RO'
SECTION_RW = 'RW'
# Default size of extra stack frame needed by exception context switch.
# This value is for cortex-m with FPU enabled.
DEFAULT_EXCEPTION_FRAME_SIZE = 224
class StackAnalyzerError(Exception):
"""Exception class for stack analyzer utility."""
class TaskInfo(ctypes.Structure):
"""Taskinfo ctypes structure.
The structure definition is corresponding to the "struct taskinfo"
in "util/export_taskinfo.so.c".
"""
_fields_ = [('name', ctypes.c_char_p),
('routine', ctypes.c_char_p),
('stack_size', ctypes.c_uint32)]
class Task(object):
"""Task information.
Attributes:
name: Task name.
routine_name: Routine function name.
stack_max_size: Max stack size.
routine_address: Resolved routine address. None if it hasn't been resolved.
"""
def __init__(self, name, routine_name, stack_max_size, routine_address=None):
"""Constructor.
Args:
name: Task name.
routine_name: Routine function name.
stack_max_size: Max stack size.
routine_address: Resolved routine address.
"""
self.name = name
self.routine_name = routine_name
self.stack_max_size = stack_max_size
self.routine_address = routine_address
def __eq__(self, other):
"""Task equality.
Args:
other: The compared object.
Returns:
True if equal, False if not.
"""
if not isinstance(other, Task):
return False
return (self.name == other.name and
self.routine_name == other.routine_name and
self.stack_max_size == other.stack_max_size and
self.routine_address == other.routine_address)
class Symbol(object):
"""Symbol information.
Attributes:
address: Symbol address.
symtype: Symbol type, 'O' (data, object) or 'F' (function).
size: Symbol size.
name: Symbol name.
"""
def __init__(self, address, symtype, size, name):
"""Constructor.
Args:
address: Symbol address.
symtype: Symbol type.
size: Symbol size.
name: Symbol name.
"""
assert symtype in ['O', 'F']
self.address = address
self.symtype = symtype
self.size = size
self.name = name
def __eq__(self, other):
"""Symbol equality.
Args:
other: The compared object.
Returns:
True if equal, False if not.
"""
if not isinstance(other, Symbol):
return False
return (self.address == other.address and
self.symtype == other.symtype and
self.size == other.size and
self.name == other.name)
class Callsite(object):
"""Function callsite.
Attributes:
address: Address of callsite location. None if it is unknown.
target: Callee address. None if it is unknown.
is_tail: A bool indicates that it is a tailing call.
callee: Resolved callee function. None if it hasn't been resolved.
"""
def __init__(self, address, target, is_tail, callee=None):
"""Constructor.
Args:
address: Address of callsite location. None if it is unknown.
target: Callee address. None if it is unknown.
is_tail: A bool indicates that it is a tailing call. (function jump to
another function without restoring the stack frame)
callee: Resolved callee function.
"""
# It makes no sense that both address and target are unknown.
assert not (address is None and target is None)
self.address = address
self.target = target
self.is_tail = is_tail
self.callee = callee
def __eq__(self, other):
"""Callsite equality.
Args:
other: The compared object.
Returns:
True if equal, False if not.
"""
if not isinstance(other, Callsite):
return False
if not (self.address == other.address and
self.target == other.target and
self.is_tail == other.is_tail):
return False
if self.callee is None:
return other.callee is None
elif other.callee is None:
return False
# Assume the addresses of functions are unique.
return self.callee.address == other.callee.address
class Function(object):
"""Function.
Attributes:
address: Address of function.
name: Name of function from its symbol.
stack_frame: Size of stack frame.
callsites: Callsite list.
stack_max_usage: Max stack usage. None if it hasn't been analyzed.
stack_max_path: Max stack usage path. None if it hasn't been analyzed.
"""
def __init__(self, address, name, stack_frame, callsites):
"""Constructor.
Args:
address: Address of function.
name: Name of function from its symbol.
stack_frame: Size of stack frame.
callsites: Callsite list.
"""
self.address = address
self.name = name
self.stack_frame = stack_frame
self.callsites = callsites
self.stack_max_usage = None
self.stack_max_path = None
def __eq__(self, other):
"""Function equality.
Args:
other: The compared object.
Returns:
True if equal, False if not.
"""
if not isinstance(other, Function):
return False
if not (self.address == other.address and
self.name == other.name and
self.stack_frame == other.stack_frame and
self.callsites == other.callsites and
self.stack_max_usage == other.stack_max_usage):
return False
if self.stack_max_path is None:
return other.stack_max_path is None
elif other.stack_max_path is None:
return False
if len(self.stack_max_path) != len(other.stack_max_path):
return False
for self_func, other_func in zip(self.stack_max_path, other.stack_max_path):
# Assume the addresses of functions are unique.
if self_func.address != other_func.address:
return False
return True
def __hash__(self):
return id(self)
class AndesAnalyzer(object):
"""Disassembly analyzer for Andes architecture.
Public Methods:
AnalyzeFunction: Analyze stack frame and callsites of the function.
"""
GENERAL_PURPOSE_REGISTER_SIZE = 4
# Possible condition code suffixes.
CONDITION_CODES = [ 'eq', 'eqz', 'gez', 'gtz', 'lez', 'ltz', 'ne', 'nez',
'eqc', 'nec', 'nezs', 'nes', 'eqs']
CONDITION_CODES_RE = '({})'.format('|'.join(CONDITION_CODES))
IMM_ADDRESS_RE = r'([0-9A-Fa-f]+)\s+<([^>]+)>'
# Branch instructions.
JUMP_OPCODE_RE = re.compile(r'^(b{0}|j|jr|jr.|jrnez)(\d?|\d\d)$' \
.format(CONDITION_CODES_RE))
# Call instructions.
CALL_OPCODE_RE = re.compile \
(r'^(jal|jral|jral.|jralnez|beqzal|bltzal|bgezal)(\d)?$')
CALL_OPERAND_RE = re.compile(r'^{}$'.format(IMM_ADDRESS_RE))
# Ignore lp register because it's for return.
INDIRECT_CALL_OPERAND_RE = re.compile \
(r'^\$r\d{1,}$|\$fp$|\$gp$|\$ta$|\$sp$|\$pc$')
# TODO: Handle other kinds of store instructions.
PUSH_OPCODE_RE = re.compile(r'^push(\d{1,})$')
PUSH_OPERAND_RE = re.compile(r'^\$r\d{1,}, \#\d{1,} \! \{([^\]]+)\}')
SMW_OPCODE_RE = re.compile(r'^smw(\.\w\w|\.\w\w\w)$')
SMW_OPERAND_RE = re.compile(r'^(\$r\d{1,}|\$\wp), \[\$\wp\], '
r'(\$r\d{1,}|\$\wp), \#\d\w\d \! \{([^\]]+)\}')
OPERANDGROUP_RE = re.compile(r'^\$r\d{1,}\~\$r\d{1,}')
LWI_OPCODE_RE = re.compile(r'^lwi(\.\w\w)$')
LWI_PC_OPERAND_RE = re.compile(r'^\$pc, \[([^\]]+)\]')
# Example: "34280: 3f c8 0f ec addi.gp $fp, #0xfec"
# Assume there is always a "\t" after the hex data.
DISASM_REGEX_RE = re.compile(r'^(?P<address>[0-9A-Fa-f]+):\s+'
r'(?P<words>[0-9A-Fa-f ]+)'
r'\t\s*(?P<opcode>\S+)(\s+(?P<operand>[^;]*))?')
def ParseInstruction(self, line, function_end):
"""Parse the line of instruction.
Args:
line: Text of disassembly.
function_end: End address of the current function. None if unknown.
Returns:
(address, words, opcode, operand_text): The instruction address, words,
opcode, and the text of operands.
None if it isn't an instruction line.
"""
result = self.DISASM_REGEX_RE.match(line)
if result is None:
return None
address = int(result.group('address'), 16)
# Check if it's out of bound.
if function_end is not None and address >= function_end:
return None
opcode = result.group('opcode').strip()
operand_text = result.group('operand')
words = result.group('words')
if operand_text is None:
operand_text = ''
else:
operand_text = operand_text.strip()
return (address, words, opcode, operand_text)
def AnalyzeFunction(self, function_symbol, instructions):
stack_frame = 0
callsites = []
for address, words, opcode, operand_text in instructions:
is_jump_opcode = self.JUMP_OPCODE_RE.match(opcode) is not None
is_call_opcode = self.CALL_OPCODE_RE.match(opcode) is not None
if is_jump_opcode or is_call_opcode:
is_tail = is_jump_opcode
result = self.CALL_OPERAND_RE.match(operand_text)
if result is None:
if (self.INDIRECT_CALL_OPERAND_RE.match(operand_text) is not None):
# Found an indirect call.
callsites.append(Callsite(address, None, is_tail))
else:
target_address = int(result.group(1), 16)
# Filter out the in-function target (branches and in-function calls,
# which are actually branches).
if not (function_symbol.size > 0 and
function_symbol.address < target_address <
(function_symbol.address + function_symbol.size)):
# Maybe it is a callsite.
callsites.append(Callsite(address, target_address, is_tail))
elif self.LWI_OPCODE_RE.match(opcode) is not None:
result = self.LWI_PC_OPERAND_RE.match(operand_text)
if result is not None:
# Ignore "lwi $pc, [$sp], xx" because it's usually a return.
if result.group(1) != '$sp':
# Found an indirect call.
callsites.append(Callsite(address, None, True))
elif self.PUSH_OPCODE_RE.match(opcode) is not None:
# Example: fc 20 push25 $r8, #0 ! {$r6~$r8, $fp, $gp, $lp}
if self.PUSH_OPERAND_RE.match(operand_text) is not None:
# capture fc 20
imm5u = int(words.split(' ')[1], 16)
# sp = sp - (imm5u << 3)
imm8u = (imm5u<<3) & 0xff
stack_frame += imm8u
result = self.PUSH_OPERAND_RE.match(operand_text)
operandgroup_text = result.group(1)
# capture $rx~$ry
if self.OPERANDGROUP_RE.match(operandgroup_text) is not None:
# capture number & transfer string to integer
oprandgrouphead = operandgroup_text.split(',')[0]
rx=int(''.join(filter(str.isdigit, oprandgrouphead.split('~')[0])))
ry=int(''.join(filter(str.isdigit, oprandgrouphead.split('~')[1])))
stack_frame += ((len(operandgroup_text.split(','))+ry-rx) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
else:
stack_frame += (len(operandgroup_text.split(',')) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
elif self.SMW_OPCODE_RE.match(opcode) is not None:
# Example: smw.adm $r6, [$sp], $r10, #0x2 ! {$r6~$r10, $lp}
if self.SMW_OPERAND_RE.match(operand_text) is not None:
result = self.SMW_OPERAND_RE.match(operand_text)
operandgroup_text = result.group(3)
# capture $rx~$ry
if self.OPERANDGROUP_RE.match(operandgroup_text) is not None:
# capture number & transfer string to integer
oprandgrouphead = operandgroup_text.split(',')[0]
rx=int(''.join(filter(str.isdigit, oprandgrouphead.split('~')[0])))
ry=int(''.join(filter(str.isdigit, oprandgrouphead.split('~')[1])))
stack_frame += ((len(operandgroup_text.split(','))+ry-rx) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
else:
stack_frame += (len(operandgroup_text.split(',')) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
return (stack_frame, callsites)
class ArmAnalyzer(object):
"""Disassembly analyzer for ARM architecture.
Public Methods:
AnalyzeFunction: Analyze stack frame and callsites of the function.
"""
GENERAL_PURPOSE_REGISTER_SIZE = 4
# Possible condition code suffixes.
CONDITION_CODES = ['', 'eq', 'ne', 'cs', 'hs', 'cc', 'lo', 'mi', 'pl', 'vs',
'vc', 'hi', 'ls', 'ge', 'lt', 'gt', 'le']
CONDITION_CODES_RE = '({})'.format('|'.join(CONDITION_CODES))
# Assume there is no function name containing ">".
IMM_ADDRESS_RE = r'([0-9A-Fa-f]+)\s+<([^>]+)>'
# Fuzzy regular expressions for instruction and operand parsing.
# Branch instructions.
JUMP_OPCODE_RE = re.compile(
r'^(b{0}|bx{0})(\.\w)?$'.format(CONDITION_CODES_RE))
# Call instructions.
CALL_OPCODE_RE = re.compile(
r'^(bl{0}|blx{0})(\.\w)?$'.format(CONDITION_CODES_RE))
CALL_OPERAND_RE = re.compile(r'^{}$'.format(IMM_ADDRESS_RE))
CBZ_CBNZ_OPCODE_RE = re.compile(r'^(cbz|cbnz)(\.\w)?$')
# Example: "r0, 1009bcbe <host_cmd_motion_sense+0x1d2>"
CBZ_CBNZ_OPERAND_RE = re.compile(r'^[^,]+,\s+{}$'.format(IMM_ADDRESS_RE))
# Ignore lr register because it's for return.
INDIRECT_CALL_OPERAND_RE = re.compile(r'^r\d+|sb|sl|fp|ip|sp|pc$')
# TODO(cheyuw): Handle conditional versions of following
# instructions.
# TODO(cheyuw): Handle other kinds of pc modifying instructions (e.g. mov pc).
LDR_OPCODE_RE = re.compile(r'^ldr(\.\w)?$')
# Example: "pc, [sp], #4"
LDR_PC_OPERAND_RE = re.compile(r'^pc, \[([^\]]+)\]')
# TODO(cheyuw): Handle other kinds of stm instructions.
PUSH_OPCODE_RE = re.compile(r'^push$')
STM_OPCODE_RE = re.compile(r'^stmdb$')
# Stack subtraction instructions.
SUB_OPCODE_RE = re.compile(r'^sub(s|w)?(\.\w)?$')
SUB_OPERAND_RE = re.compile(r'^sp[^#]+#(\d+)')
# Example: "44d94: f893 0068 ldrb.w r0, [r3, #104] ; 0x68"
# Assume there is always a "\t" after the hex data.
DISASM_REGEX_RE = re.compile(r'^(?P<address>[0-9A-Fa-f]+):\s+[0-9A-Fa-f ]+'
r'\t\s*(?P<opcode>\S+)(\s+(?P<operand>[^;]*))?')
def ParseInstruction(self, line, function_end):
"""Parse the line of instruction.
Args:
line: Text of disassembly.
function_end: End address of the current function. None if unknown.
Returns:
(address, opcode, operand_text): The instruction address, opcode,
and the text of operands. None if it
isn't an instruction line.
"""
result = self.DISASM_REGEX_RE.match(line)
if result is None:
return None
address = int(result.group('address'), 16)
# Check if it's out of bound.
if function_end is not None and address >= function_end:
return None
opcode = result.group('opcode').strip()
operand_text = result.group('operand')
if operand_text is None:
operand_text = ''
else:
operand_text = operand_text.strip()
return (address, opcode, operand_text)
def AnalyzeFunction(self, function_symbol, instructions):
"""Analyze function, resolve the size of stack frame and callsites.
Args:
function_symbol: Function symbol.
instructions: Instruction list.
Returns:
(stack_frame, callsites): Size of stack frame, callsite list.
"""
stack_frame = 0
callsites = []
for address, opcode, operand_text in instructions:
is_jump_opcode = self.JUMP_OPCODE_RE.match(opcode) is not None
is_call_opcode = self.CALL_OPCODE_RE.match(opcode) is not None
is_cbz_cbnz_opcode = self.CBZ_CBNZ_OPCODE_RE.match(opcode) is not None
if is_jump_opcode or is_call_opcode or is_cbz_cbnz_opcode:
is_tail = is_jump_opcode or is_cbz_cbnz_opcode
if is_cbz_cbnz_opcode:
result = self.CBZ_CBNZ_OPERAND_RE.match(operand_text)
else:
result = self.CALL_OPERAND_RE.match(operand_text)
if result is None:
# Failed to match immediate address, maybe it is an indirect call.
# CBZ and CBNZ can't be indirect calls.
if (not is_cbz_cbnz_opcode and
self.INDIRECT_CALL_OPERAND_RE.match(operand_text) is not None):
# Found an indirect call.
callsites.append(Callsite(address, None, is_tail))
else:
target_address = int(result.group(1), 16)
# Filter out the in-function target (branches and in-function calls,
# which are actually branches).
if not (function_symbol.size > 0 and
function_symbol.address < target_address <
(function_symbol.address + function_symbol.size)):
# Maybe it is a callsite.
callsites.append(Callsite(address, target_address, is_tail))
elif self.LDR_OPCODE_RE.match(opcode) is not None:
result = self.LDR_PC_OPERAND_RE.match(operand_text)
if result is not None:
# Ignore "ldr pc, [sp], xx" because it's usually a return.
if result.group(1) != 'sp':
# Found an indirect call.
callsites.append(Callsite(address, None, True))
elif self.PUSH_OPCODE_RE.match(opcode) is not None:
# Example: "{r4, r5, r6, r7, lr}"
stack_frame += (len(operand_text.split(',')) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
elif self.SUB_OPCODE_RE.match(opcode) is not None:
result = self.SUB_OPERAND_RE.match(operand_text)
if result is not None:
stack_frame += int(result.group(1))
else:
# Unhandled stack register subtraction.
assert not operand_text.startswith('sp')
elif self.STM_OPCODE_RE.match(opcode) is not None:
if operand_text.startswith('sp!'):
# Subtract and writeback to stack register.
# Example: "sp!, {r4, r5, r6, r7, r8, r9, lr}"
# Get the text of pushed register list.
unused_sp, unused_sep, parameter_text = operand_text.partition(',')
stack_frame += (len(parameter_text.split(',')) *
self.GENERAL_PURPOSE_REGISTER_SIZE)
return (stack_frame, callsites)
class RiscvAnalyzer(object):
"""Disassembly analyzer for RISC-V architecture.
Public Methods:
AnalyzeFunction: Analyze stack frame and callsites of the function.
"""
# Possible condition code suffixes.
CONDITION_CODES = [ 'eqz', 'nez', 'lez', 'gez', 'ltz', 'gtz', 'gt', 'le',
'gtu', 'leu', 'eq', 'ne', 'ge', 'lt', 'ltu', 'geu']
CONDITION_CODES_RE = '({})'.format('|'.join(CONDITION_CODES))
# Branch instructions.
JUMP_OPCODE_RE = re.compile(r'^(b{0}|j|jr)$'.format(CONDITION_CODES_RE))
# Call instructions.
CALL_OPCODE_RE = re.compile(r'^(jal|jalr)$')
# Example: "j 8009b318 <set_state_prl_hr>" or
# "jal ra,800a4394 <power_get_signals>" or
# "bltu t0,t1,80080300 <data_loop>"
JUMP_ADDRESS_RE = r'((\w(\w|\d\d),){0,2})([0-9A-Fa-f]+)\s+<([^>]+)>'
CALL_OPERAND_RE = re.compile(r'^{}$'.format(JUMP_ADDRESS_RE))
# Capture address, Example: 800a4394
CAPTURE_ADDRESS = re.compile(r'[0-9A-Fa-f]{8}')
# Indirect jump, Example: jalr a5
INDIRECT_CALL_OPERAND_RE = re.compile(r'^t\d+|s\d+|a\d+$')
# Example: addi
ADDI_OPCODE_RE = re.compile(r'^addi$')
# Allocate stack instructions.
ADDI_OPERAND_RE = re.compile(r'^(sp,sp,-\d+)$')
# Example: "800804b6: 1101 addi sp,sp,-32"
DISASM_REGEX_RE = re.compile(r'^(?P<address>[0-9A-Fa-f]+):\s+[0-9A-Fa-f ]+'
r'\t\s*(?P<opcode>\S+)(\s+(?P<operand>[^;]*))?')
def ParseInstruction(self, line, function_end):
"""Parse the line of instruction.
Args:
line: Text of disassembly.
function_end: End address of the current function. None if unknown.
Returns:
(address, opcode, operand_text): The instruction address, opcode,
and the text of operands. None if it
isn't an instruction line.
"""
result = self.DISASM_REGEX_RE.match(line)
if result is None:
return None
address = int(result.group('address'), 16)
# Check if it's out of bound.
if function_end is not None and address >= function_end:
return None
opcode = result.group('opcode').strip()
operand_text = result.group('operand')
if operand_text is None:
operand_text = ''
else:
operand_text = operand_text.strip()
return (address, opcode, operand_text)
def AnalyzeFunction(self, function_symbol, instructions):
stack_frame = 0
callsites = []
for address, opcode, operand_text in instructions:
is_jump_opcode = self.JUMP_OPCODE_RE.match(opcode) is not None
is_call_opcode = self.CALL_OPCODE_RE.match(opcode) is not None
if is_jump_opcode or is_call_opcode:
is_tail = is_jump_opcode
result = self.CALL_OPERAND_RE.match(operand_text)
if result is None:
if (self.INDIRECT_CALL_OPERAND_RE.match(operand_text) is not None):
# Found an indirect call.
callsites.append(Callsite(address, None, is_tail))
else:
# Capture address form operand_text and then convert to string
address_str = "".join(self.CAPTURE_ADDRESS.findall(operand_text))
# String to integer
target_address = int(address_str, 16)
# Filter out the in-function target (branches and in-function calls,
# which are actually branches).
if not (function_symbol.size > 0 and
function_symbol.address < target_address <
(function_symbol.address + function_symbol.size)):
# Maybe it is a callsite.
callsites.append(Callsite(address, target_address, is_tail))
elif self.ADDI_OPCODE_RE.match(opcode) is not None:
# Example: sp,sp,-32
if self.ADDI_OPERAND_RE.match(operand_text) is not None:
stack_frame += abs(int(operand_text.split(",")[2]))
return (stack_frame, callsites)
class StackAnalyzer(object):
"""Class to analyze stack usage.
Public Methods:
Analyze: Run the stack analysis.
"""
C_FUNCTION_NAME = r'_A-Za-z0-9'
# Assume there is no ":" in the path.
# Example: "driver/accel_kionix.c:321 (discriminator 3)"
ADDRTOLINE_RE = re.compile(
r'^(?P<path>[^:]+):(?P<linenum>\d+)(\s+\(discriminator\s+\d+\))?$')
# To eliminate the suffix appended by compilers, try to extract the
# C function name from the prefix of symbol name.
# Example: "SHA256_transform.constprop.28"
FUNCTION_PREFIX_NAME_RE = re.compile(
r'^(?P<name>[{0}]+)([^{0}].*)?$'.format(C_FUNCTION_NAME))
# Errors of annotation resolving.
ANNOTATION_ERROR_INVALID = 'invalid signature'
ANNOTATION_ERROR_NOTFOUND = 'function is not found'
ANNOTATION_ERROR_AMBIGUOUS = 'signature is ambiguous'
def __init__(self, options, symbols, rodata, tasklist, annotation):
"""Constructor.
Args:
options: Namespace from argparse.parse_args().
symbols: Symbol list.
rodata: Content of .rodata section (offset, data)
tasklist: Task list.
annotation: Annotation config.
"""
self.options = options
self.symbols = symbols
self.rodata_offset = rodata[0]
self.rodata = rodata[1]
self.tasklist = tasklist
self.annotation = annotation
self.address_to_line_cache = {}
def AddressToLine(self, address, resolve_inline=False):
"""Convert address to line.
Args:
address: Target address.
resolve_inline: Output the stack of inlining.
Returns:
lines: List of the corresponding lines.
Raises:
StackAnalyzerError: If addr2line is failed.
"""
cache_key = (address, resolve_inline)
if cache_key in self.address_to_line_cache:
return self.address_to_line_cache[cache_key]
try:
args = [self.options.addr2line,
'-f',
'-e',
self.options.elf_path,
'{:x}'.format(address)]
if resolve_inline:
args.append('-i')
line_text = subprocess.check_output(args, encoding='utf-8')
except subprocess.CalledProcessError:
raise StackAnalyzerError('addr2line failed to resolve lines.')
except OSError:
raise StackAnalyzerError('Failed to run addr2line.')
lines = [line.strip() for line in line_text.splitlines()]
# Assume the output has at least one pair like "function\nlocation\n", and
# they always show up in pairs.
# Example: "handle_request\n
# common/usb_pd_protocol.c:1191\n"
assert len(lines) >= 2 and len(lines) % 2 == 0
line_infos = []
for index in range(0, len(lines), 2):
(function_name, line_text) = lines[index:index + 2]
if line_text in ['??:0', ':?']:
line_infos.append(None)
else:
result = self.ADDRTOLINE_RE.match(line_text)
# Assume the output is always well-formed.
assert result is not None
line_infos.append((function_name.strip(),
os.path.realpath(result.group('path').strip()),
int(result.group('linenum'))))
self.address_to_line_cache[cache_key] = line_infos
return line_infos
def AnalyzeDisassembly(self, disasm_text):
"""Parse the disassembly text, analyze, and build a map of all functions.
Args:
disasm_text: Disassembly text.
Returns:
function_map: Dict of functions.
"""
disasm_lines = [line.strip() for line in disasm_text.splitlines()]
if 'nds' in disasm_lines[1]:
analyzer = AndesAnalyzer()
elif 'arm' in disasm_lines[1]:
analyzer = ArmAnalyzer()
elif 'riscv' in disasm_lines[1]:
analyzer = RiscvAnalyzer()
else:
raise StackAnalyzerError('Unsupported architecture.')
# Example: "08028c8c <motion_lid_calc>:"
function_signature_regex = re.compile(
r'^(?P<address>[0-9A-Fa-f]+)\s+<(?P<name>[^>]+)>:$')
def DetectFunctionHead(line):
"""Check if the line is a function head.
Args:
line: Text of disassembly.
Returns:
symbol: Function symbol. None if it isn't a function head.
"""
result = function_signature_regex.match(line)
if result is None:
return None
address = int(result.group('address'), 16)
symbol = symbol_map.get(address)
# Check if the function exists and matches.
if symbol is None or symbol.symtype != 'F':
return None
return symbol
# Build symbol map, indexed by symbol address.
symbol_map = {}
for symbol in self.symbols:
# If there are multiple symbols with same address, keeping any of them is
# good enough.
symbol_map[symbol.address] = symbol
# Parse the disassembly text. We update the variable "line" to next line
# when needed. There are two steps of parser:
#
# Step 1: Searching for the function head. Once reach the function head,
# move to the next line, which is the first line of function body.
#
# Step 2: Parsing each instruction line of function body. Once reach a
# non-instruction line, stop parsing and analyze the parsed instructions.
#
# Finally turn back to the step 1 without updating the line, because the
# current non-instruction line can be another function head.
function_map = {}
# The following three variables are the states of the parsing processing.
# They will be initialized properly during the state changes.
function_symbol = None
function_end = None
instructions = []
# Remove heading and tailing spaces for each line.
line_index = 0
while line_index < len(disasm_lines):
# Get the current line.
line = disasm_lines[line_index]
if function_symbol is None:
# Step 1: Search for the function head.
function_symbol = DetectFunctionHead(line)
if function_symbol is not None:
# Assume there is no empty function. If the function head is followed
# by EOF, it is an empty function.
assert line_index + 1 < len(disasm_lines)
# Found the function head, initialize and turn to the step 2.
instructions = []
# If symbol size exists, use it as a hint of function size.
if function_symbol.size > 0:
function_end = function_symbol.address + function_symbol.size
else:
function_end = None
else:
# Step 2: Parse the function body.
instruction = analyzer.ParseInstruction(line, function_end)
if instruction is not None:
instructions.append(instruction)
if instruction is None or line_index + 1 == len(disasm_lines):
# Either the invalid instruction or EOF indicates the end of the
# function, finalize the function analysis.
# Assume there is no empty function.
assert len(instructions) > 0
(stack_frame, callsites) = analyzer.AnalyzeFunction(function_symbol,
instructions)
# Assume the function addresses are unique in the disassembly.
assert function_symbol.address not in function_map
function_map[function_symbol.address] = Function(
function_symbol.address,
function_symbol.name,
stack_frame,
callsites)
# Initialize and turn back to the step 1.
function_symbol = None
# If the current line isn't an instruction, it can be another function
# head, skip moving to the next line.
if instruction is None:
continue
# Move to the next line.
line_index += 1
# Resolve callees of functions.
for function in function_map.values():
for callsite in function.callsites:
if callsite.target is not None:
# Remain the callee as None if we can't resolve it.
callsite.callee = function_map.get(callsite.target)
return function_map
def MapAnnotation(self, function_map, signature_set):
"""Map annotation signatures to functions.
Args:
function_map: Function map.
signature_set: Set of annotation signatures.
Returns:
Map of signatures to functions, map of signatures which can't be resolved.
"""
# Build the symbol map indexed by symbol name. If there are multiple symbols
# with the same name, add them into a set. (e.g. symbols of static function
# with the same name)
symbol_map = collections.defaultdict(set)
for symbol in self.symbols:
if symbol.symtype == 'F':
# Function symbol.
result = self.FUNCTION_PREFIX_NAME_RE.match(symbol.name)
if result is not None:
function = function_map.get(symbol.address)
# Ignore the symbol not in disassembly.
if function is not None:
# If there are multiple symbol with the same name and point to the
# same function, the set will deduplicate them.
symbol_map[result.group('name').strip()].add(function)
# Build the signature map indexed by annotation signature.
signature_map = {}
sig_error_map = {}
symbol_path_map = {}
for sig in signature_set:
(name, path, _) = sig
functions = symbol_map.get(name)
if functions is None:
sig_error_map[sig] = self.ANNOTATION_ERROR_NOTFOUND
continue
if name not in symbol_path_map:
# Lazy symbol path resolving. Since the addr2line isn't fast, only
# resolve needed symbol paths.
group_map = collections.defaultdict(list)
for function in functions:
line_info = self.AddressToLine(function.address)[0]
if line_info is None:
continue
(_, symbol_path, _) = line_info
# Group the functions with the same symbol signature (symbol name +
# symbol path). Assume they are the same copies and do the same
# annotation operations of them because we don't know which copy is
# indicated by the users.
group_map[symbol_path].append(function)
symbol_path_map[name] = group_map
# Symbol matching.
function_group = None
group_map = symbol_path_map[name]
if len(group_map) > 0:
if path is None:
if len(group_map) > 1:
# There is ambiguity but the path isn't specified.
sig_error_map[sig] = self.ANNOTATION_ERROR_AMBIGUOUS
continue
# No path signature but all symbol signatures of functions are same.
# Assume they are the same functions, so there is no ambiguity.
(function_group,) = group_map.values()
else:
function_group = group_map.get(path)
if function_group is None:
sig_error_map[sig] = self.ANNOTATION_ERROR_NOTFOUND
continue
# The function_group is a list of all the same functions (according to
# our assumption) which should be annotated together.
signature_map[sig] = function_group
return (signature_map, sig_error_map)
def LoadAnnotation(self):
"""Load annotation rules.
Returns:
Map of add rules, set of remove rules, set of text signatures which can't
be parsed.
"""
# Assume there is no ":" in the path.
# Example: "get_range.lto.2501[driver/accel_kionix.c:327]"
annotation_signature_regex = re.compile(
r'^(?P<name>[^\[]+)(\[(?P<path>[^:]+)(:(?P<linenum>\d+))?\])?$')
def NormalizeSignature(signature_text):
"""Parse and normalize the annotation signature.
Args:
signature_text: Text of the annotation signature.
Returns:
(function name, path, line number) of the signature. The path and line
number can be None if not exist. None if failed to parse.
"""
result = annotation_signature_regex.match(signature_text.strip())
if result is None:
return None
name_result = self.FUNCTION_PREFIX_NAME_RE.match(
result.group('name').strip())
if name_result is None:
return None
path = result.group('path')
if path is not None:
path = os.path.realpath(path.strip())
linenum = result.group('linenum')
if linenum is not None:
linenum = int(linenum.strip())
return (name_result.group('name').strip(), path, linenum)
def ExpandArray(dic):
"""Parse and expand a symbol array
Args:
dic: Dictionary for the array annotation
Returns:
array of (symbol name, None, None).
"""
# TODO(drinkcat): This function is quite inefficient, as it goes through
# the symbol table multiple times.
begin_name = dic['name']
end_name = dic['name'] + "_end"
offset = dic['offset'] if 'offset' in dic else 0
stride = dic['stride']
begin_address = None
end_address = None
for symbol in self.symbols:
if (symbol.name == begin_name):
begin_address = symbol.address
if (symbol.name == end_name):
end_address = symbol.address
if (not begin_address or not end_address):
return None
output = []
# TODO(drinkcat): This is inefficient as we go from address to symbol
# object then to symbol name, and later on we'll go back from symbol name
# to symbol object.
for addr in range(begin_address+offset, end_address, stride):
# TODO(drinkcat): Not all architectures need to drop the first bit.
val = self.rodata[(addr-self.rodata_offset) // 4] & 0xfffffffe
name = None
for symbol in self.symbols:
if (symbol.address == val):
result = self.FUNCTION_PREFIX_NAME_RE.match(symbol.name)
name = result.group('name')
break
if not name:
raise StackAnalyzerError('Cannot find function for address %s.',
hex(val))
output.append((name, None, None))
return output
add_rules = collections.defaultdict(set)
remove_rules = list()
invalid_sigtxts = set()
if 'add' in self.annotation and self.annotation['add'] is not None:
for src_sigtxt, dst_sigtxts in self.annotation['add'].items():
src_sig = NormalizeSignature(src_sigtxt)
if src_sig is None:
invalid_sigtxts.add(src_sigtxt)
continue
for dst_sigtxt in dst_sigtxts:
if isinstance(dst_sigtxt, dict):
dst_sig = ExpandArray(dst_sigtxt)
if dst_sig is None:
invalid_sigtxts.add(str(dst_sigtxt))
else:
add_rules[src_sig].update(dst_sig)
else:
dst_sig = NormalizeSignature(dst_sigtxt)
if dst_sig is None:
invalid_sigtxts.add(dst_sigtxt)
else:
add_rules[src_sig].add(dst_sig)
if 'remove' in self.annotation and self.annotation['remove'] is not None:
for sigtxt_path in self.annotation['remove']:
if isinstance(sigtxt_path, str):
# The path has only one vertex.
sigtxt_path = [sigtxt_path]
if len(sigtxt_path) == 0:
continue
# Generate multiple remove paths from all the combinations of the
# signatures of each vertex.
sig_paths = [[]]
broken_flag = False
for sigtxt_node in sigtxt_path:
if isinstance(sigtxt_node, str):
# The vertex has only one signature.
sigtxt_set = {sigtxt_node}
elif isinstance(sigtxt_node, list):
# The vertex has multiple signatures.
sigtxt_set = set(sigtxt_node)
else:
# Assume the format of annotation is verified. There should be no
# invalid case.
assert False
sig_set = set()
for sigtxt in sigtxt_set:
sig = NormalizeSignature(sigtxt)
if sig is None:
invalid_sigtxts.add(sigtxt)
broken_flag = True
elif not broken_flag:
sig_set.add(sig)
if broken_flag:
continue
# Append each signature of the current node to the all previous
# remove paths.
sig_paths = [path + [sig] for path in sig_paths for sig in sig_set]
if not broken_flag:
# All signatures are normalized. The remove path has no error.
remove_rules.extend(sig_paths)
return (add_rules, remove_rules, invalid_sigtxts)
def ResolveAnnotation(self, function_map):
"""Resolve annotation.
Args:
function_map: Function map.
Returns:
Set of added call edges, list of remove paths, set of eliminated
callsite addresses, set of annotation signatures which can't be resolved.
"""
def StringifySignature(signature):
"""Stringify the tupled signature.
Args:
signature: Tupled signature.
Returns:
Signature string.
"""
(name, path, linenum) = signature
bracket_text = ''
if path is not None:
path = os.path.relpath(path)
if linenum is None:
bracket_text = '[{}]'.format(path)
else:
bracket_text = '[{}:{}]'.format(path, linenum)
return name + bracket_text
(add_rules, remove_rules, invalid_sigtxts) = self.LoadAnnotation()
signature_set = set()
for src_sig, dst_sigs in add_rules.items():
signature_set.add(src_sig)
signature_set.update(dst_sigs)
for remove_sigs in remove_rules:
signature_set.update(remove_sigs)
# Map signatures to functions.
(signature_map, sig_error_map) = self.MapAnnotation(function_map,
signature_set)
# Build the indirect callsite map indexed by callsite signature.
indirect_map = collections.defaultdict(set)
for function in function_map.values():
for callsite in function.callsites:
if callsite.target is not None:
continue
# Found an indirect callsite.
line_info = self.AddressToLine(callsite.address)[0]
if line_info is None:
continue
(name, path, linenum) = line_info
result = self.FUNCTION_PREFIX_NAME_RE.match(name)
if result is None:
continue
indirect_map[(result.group('name').strip(), path, linenum)].add(
(function, callsite.address))
# Generate the annotation sets.
add_set = set()
remove_list = list()
eliminated_addrs = set()
for src_sig, dst_sigs in add_rules.items():
src_funcs = set(signature_map.get(src_sig, []))
# Try to match the source signature to the indirect callsites. Even if it
# can't be found in disassembly.
indirect_calls = indirect_map.get(src_sig)
if indirect_calls is not None:
for function, callsite_address in indirect_calls:
# Add the caller of the indirect callsite to the source functions.
src_funcs.add(function)
# Assume each callsite can be represented by a unique address.
eliminated_addrs.add(callsite_address)
if src_sig in sig_error_map:
# Assume the error is always the not found error. Since the signature
# found in indirect callsite map must be a full signature, it can't
# happen the ambiguous error.
assert sig_error_map[src_sig] == self.ANNOTATION_ERROR_NOTFOUND
# Found in inline stack, remove the not found error.
del sig_error_map[src_sig]
for dst_sig in dst_sigs:
dst_funcs = signature_map.get(dst_sig)
if dst_funcs is None:
continue
# Duplicate the call edge for all the same source and destination
# functions.
for src_func in src_funcs:
for dst_func in dst_funcs:
add_set.add((src_func, dst_func))
for remove_sigs in remove_rules:
# Since each signature can be mapped to multiple functions, generate
# multiple remove paths from all the combinations of these functions.
remove_paths = [[]]
skip_flag = False
for remove_sig in remove_sigs:
# Transform each signature to the corresponding functions.
remove_funcs = signature_map.get(remove_sig)
if remove_funcs is None:
# There is an unresolved signature in the remove path. Ignore the
# whole broken remove path.
skip_flag = True
break
else:
# Append each function of the current signature to the all previous
# remove paths.
remove_paths = [p + [f] for p in remove_paths for f in remove_funcs]
if skip_flag:
# Ignore the broken remove path.
continue
for remove_path in remove_paths:
# Deduplicate the remove paths.
if remove_path not in remove_list:
remove_list.append(remove_path)
# Format the error messages.
failed_sigtxts = set()
for sigtxt in invalid_sigtxts:
failed_sigtxts.add((sigtxt, self.ANNOTATION_ERROR_INVALID))
for sig, error in sig_error_map.items():
failed_sigtxts.add((StringifySignature(sig), error))
return (add_set, remove_list, eliminated_addrs, failed_sigtxts)
def PreprocessAnnotation(self, function_map, add_set, remove_list,
eliminated_addrs):
"""Preprocess the annotation and callgraph.
Add the missing call edges, and delete simple remove paths (the paths have
one or two vertices) from the function_map.
Eliminate the annotated indirect callsites.
Return the remaining remove list.
Args:
function_map: Function map.
add_set: Set of missing call edges.
remove_list: List of remove paths.
eliminated_addrs: Set of eliminated callsite addresses.
Returns:
List of remaining remove paths.
"""
def CheckEdge(path):
"""Check if all edges of the path are on the callgraph.
Args:
path: Path.
Returns:
True or False.
"""
for index in range(len(path) - 1):
if (path[index], path[index + 1]) not in edge_set:
return False
return True
for src_func, dst_func in add_set:
# TODO(cheyuw): Support tailing call annotation.
src_func.callsites.append(
Callsite(None, dst_func.address, False, dst_func))
# Delete simple remove paths.
remove_simple = set(tuple(p) for p in remove_list if len(p) <= 2)
edge_set = set()
for function in function_map.values():
cleaned_callsites = []
for callsite in function.callsites:
if ((callsite.callee,) in remove_simple or
(function, callsite.callee) in remove_simple):
continue
if callsite.target is None and callsite.address in eliminated_addrs:
continue
cleaned_callsites.append(callsite)
if callsite.callee is not None:
edge_set.add((function, callsite.callee))
function.callsites = cleaned_callsites
return [p for p in remove_list if len(p) >= 3 and CheckEdge(p)]
def AnalyzeCallGraph(self, function_map, remove_list):
"""Analyze callgraph.
It will update the max stack size and path for each function.
Args:
function_map: Function map.
remove_list: List of remove paths.
Returns:
List of function cycles.
"""
def Traverse(curr_state):
"""Traverse the callgraph and calculate the max stack usages of functions.
Args:
curr_state: Current state.
Returns:
SCC lowest link.
"""
scc_index = scc_index_counter[0]
scc_index_counter[0] += 1
scc_index_map[curr_state] = scc_index
scc_lowlink = scc_index
scc_stack.append(curr_state)
# Push the current state in the stack. We can use a set to maintain this
# because the stacked states are unique; otherwise we will find a cycle
# first.
stacked_states.add(curr_state)
(curr_address, curr_positions) = curr_state
curr_func = function_map[curr_address]
invalid_flag = False
new_positions = list(curr_positions)
for index, position in enumerate(curr_positions):
remove_path = remove_list[index]
# The position of each remove path in the state is the length of the
# longest matching path between the prefix of the remove path and the
# suffix of the current traversing path. We maintain this length when
# appending the next callee to the traversing path. And it can be used
# to check if the remove path appears in the traversing path.
# TODO(cheyuw): Implement KMP algorithm to match remove paths
# efficiently.
if remove_path[position] is curr_func:
# Matches the current function, extend the length.
new_positions[index] = position + 1
if new_positions[index] == len(remove_path):
# The length of the longest matching path is equal to the length of
# the remove path, which means the suffix of the current traversing
# path matches the remove path.
invalid_flag = True
break
else:
# We can't get the new longest matching path by extending the previous
# one directly. Fallback to search the new longest matching path.
# If we can't find any matching path in the following search, reset
# the matching length to 0.
new_positions[index] = 0
# We want to find the new longest matching prefix of remove path with
# the suffix of the current traversing path. Because the new longest
# matching path won't be longer than the prevous one now, and part of
# the suffix matches the prefix of remove path, we can get the needed
# suffix from the previous matching prefix of the invalid path.
suffix = remove_path[:position] + [curr_func]
for offset in range(1, len(suffix)):
length = position - offset
if remove_path[:length] == suffix[offset:]:
new_positions[index] = length
break
new_positions = tuple(new_positions)
# If the current suffix is invalid, set the max stack usage to 0.
max_stack_usage = 0
max_callee_state = None
self_loop = False
if not invalid_flag:
# Max stack usage is at least equal to the stack frame.
max_stack_usage = curr_func.stack_frame
for callsite in curr_func.callsites:
callee = callsite.callee
if callee is None:
continue
callee_state = (callee.address, new_positions)
if callee_state not in scc_index_map:
# Unvisited state.
scc_lowlink = min(scc_lowlink, Traverse(callee_state))
elif callee_state in stacked_states:
# The state is shown in the stack. There is a cycle.
sub_stack_usage = 0
scc_lowlink = min(scc_lowlink, scc_index_map[callee_state])
if callee_state == curr_state:
self_loop = True
done_result = done_states.get(callee_state)
if done_result is not None:
# Already done this state and use its result. If the state reaches a
# cycle, reusing the result will cause inaccuracy (the stack usage
# of cycle depends on where the entrance is). But it's fine since we
# can't get accurate stack usage under this situation, and we rely
# on user-provided annotations to break the cycle, after which the
# result will be accurate again.
(sub_stack_usage, _) = done_result
if callsite.is_tail:
# For tailing call, since the callee reuses the stack frame of the
# caller, choose the larger one directly.
stack_usage = max(curr_func.stack_frame, sub_stack_usage)
else:
stack_usage = curr_func.stack_frame + sub_stack_usage
if stack_usage > max_stack_usage:
max_stack_usage = stack_usage
max_callee_state = callee_state
if scc_lowlink == scc_index:
group = []
while scc_stack[-1] != curr_state:
scc_state = scc_stack.pop()
stacked_states.remove(scc_state)
group.append(scc_state)
scc_stack.pop()
stacked_states.remove(curr_state)
# If the cycle is not empty, record it.
if len(group) > 0 or self_loop:
group.append(curr_state)
cycle_groups.append(group)
# Store the done result.
done_states[curr_state] = (max_stack_usage, max_callee_state)
if curr_positions == initial_positions:
# If the current state is initial state, we traversed the callgraph by
# using the current function as start point. Update the stack usage of
# the function.
# If the function matches a single vertex remove path, this will set its
# max stack usage to 0, which is not expected (we still calculate its
# max stack usage, but prevent any function from calling it). However,
# all the single vertex remove paths have been preprocessed and removed.
curr_func.stack_max_usage = max_stack_usage
# Reconstruct the max stack path by traversing the state transitions.
max_stack_path = [curr_func]
callee_state = max_callee_state
while callee_state is not None:
# The first element of state tuple is function address.
max_stack_path.append(function_map[callee_state[0]])
done_result = done_states.get(callee_state)
# All of the descendants should be done.
assert done_result is not None
(_, callee_state) = done_result
curr_func.stack_max_path = max_stack_path
return scc_lowlink
# The state is the concatenation of the current function address and the
# state of matching position.
initial_positions = (0,) * len(remove_list)
done_states = {}
stacked_states = set()
scc_index_counter = [0]
scc_index_map = {}
scc_stack = []
cycle_groups = []
for function in function_map.values():
if function.stack_max_usage is None:
Traverse((function.address, initial_positions))
cycle_functions = []
for group in cycle_groups:
cycle = set(function_map[state[0]] for state in group)
if cycle not in cycle_functions:
cycle_functions.append(cycle)
return cycle_functions
def Analyze(self):
"""Run the stack analysis.
Raises:
StackAnalyzerError: If disassembly fails.
"""
def OutputInlineStack(address, prefix=''):
"""Output beautiful inline stack.
Args:
address: Address.
prefix: Prefix of each line.
Returns:
Key for sorting, output text
"""
line_infos = self.AddressToLine(address, True)
if line_infos[0] is None:
order_key = (None, None)
else:
(_, path, linenum) = line_infos[0]
order_key = (linenum, path)
line_texts = []
for line_info in reversed(line_infos):
if line_info is None:
(function_name, path, linenum) = ('??', '??', 0)
else:
(function_name, path, linenum) = line_info
line_texts.append('{}[{}:{}]'.format(function_name,
os.path.relpath(path),
linenum))
output = '{}-> {} {:x}\n'.format(prefix, line_texts[0], address)
for depth, line_text in enumerate(line_texts[1:]):
output += '{} {}- {}\n'.format(prefix, ' ' * depth, line_text)
# Remove the last newline character.
return (order_key, output.rstrip('\n'))
# Analyze disassembly.
try:
disasm_text = subprocess.check_output([self.options.objdump,
'-d',
self.options.elf_path],
encoding='utf-8')
except subprocess.CalledProcessError:
raise StackAnalyzerError('objdump failed to disassemble.')
except OSError:
raise StackAnalyzerError('Failed to run objdump.')
function_map = self.AnalyzeDisassembly(disasm_text)
result = self.ResolveAnnotation(function_map)
(add_set, remove_list, eliminated_addrs, failed_sigtxts) = result
remove_list = self.PreprocessAnnotation(function_map,
add_set,
remove_list,
eliminated_addrs)
cycle_functions = self.AnalyzeCallGraph(function_map, remove_list)
# Print the results of task-aware stack analysis.
extra_stack_frame = self.annotation.get('exception_frame_size',
DEFAULT_EXCEPTION_FRAME_SIZE)
for task in self.tasklist:
routine_func = function_map[task.routine_address]
print('Task: {}, Max size: {} ({} + {}), Allocated size: {}'.format(
task.name,
routine_func.stack_max_usage + extra_stack_frame,
routine_func.stack_max_usage,
extra_stack_frame,
task.stack_max_size))
print('Call Trace:')
max_stack_path = routine_func.stack_max_path
# Assume the routine function is resolved.
assert max_stack_path is not None
for depth, curr_func in enumerate(max_stack_path):
line_info = self.AddressToLine(curr_func.address)[0]
if line_info is None:
(path, linenum) = ('??', 0)
else:
(_, path, linenum) = line_info
print(' {} ({}) [{}:{}] {:x}'.format(curr_func.name,
curr_func.stack_frame,
os.path.relpath(path),
linenum,
curr_func.address))
if depth + 1 < len(max_stack_path):
succ_func = max_stack_path[depth + 1]
text_list = []
for callsite in curr_func.callsites:
if callsite.callee is succ_func:
indent_prefix = ' '
if callsite.address is None:
order_text = (None, '{}-> [annotation]'.format(indent_prefix))
else:
order_text = OutputInlineStack(callsite.address, indent_prefix)
text_list.append(order_text)
for _, text in sorted(text_list, key=lambda item: item[0]):
print(text)
print('Unresolved indirect callsites:')
for function in function_map.values():
indirect_callsites = []
for callsite in function.callsites:
if callsite.target is None:
indirect_callsites.append(callsite.address)
if len(indirect_callsites) > 0:
print(' In function {}:'.format(function.name))
text_list = []
for address in indirect_callsites:
text_list.append(OutputInlineStack(address, ' '))
for _, text in sorted(text_list, key=lambda item: item[0]):
print(text)
print('Unresolved annotation signatures:')
for sigtxt, error in failed_sigtxts:
print(' {}: {}'.format(sigtxt, error))
if len(cycle_functions) > 0:
print('There are cycles in the following function sets:')
for functions in cycle_functions:
print('[{}]'.format(', '.join(function.name for function in functions)))
def ParseArgs():
"""Parse commandline arguments.
Returns:
options: Namespace from argparse.parse_args().
"""
parser = argparse.ArgumentParser(description="EC firmware stack analyzer.")
parser.add_argument('elf_path', help="the path of EC firmware ELF")
parser.add_argument('--export_taskinfo', required=True,
help="the path of export_taskinfo.so utility")
parser.add_argument('--section', required=True, help='the section.',
choices=[SECTION_RO, SECTION_RW])
parser.add_argument('--objdump', default='objdump',
help='the path of objdump')
parser.add_argument('--addr2line', default='addr2line',
help='the path of addr2line')
parser.add_argument('--annotation', default=None,
help='the path of annotation file')
# TODO(cheyuw): Add an option for dumping stack usage of all functions.
return parser.parse_args()
def ParseSymbolText(symbol_text):
"""Parse the content of the symbol text.
Args:
symbol_text: Text of the symbols.
Returns:
symbols: Symbol list.
"""
# Example: "10093064 g F .text 0000015c .hidden hook_task"
symbol_regex = re.compile(r'^(?P<address>[0-9A-Fa-f]+)\s+[lwg]\s+'
r'((?P<type>[OF])\s+)?\S+\s+'
r'(?P<size>[0-9A-Fa-f]+)\s+'
r'(\S+\s+)?(?P<name>\S+)$')
symbols = []
for line in symbol_text.splitlines():
line = line.strip()
result = symbol_regex.match(line)
if result is not None:
address = int(result.group('address'), 16)
symtype = result.group('type')
if symtype is None:
symtype = 'O'
size = int(result.group('size'), 16)
name = result.group('name')
symbols.append(Symbol(address, symtype, size, name))
return symbols
def ParseRoDataText(rodata_text):
"""Parse the content of rodata
Args:
symbol_text: Text of the rodata dump.
Returns:
symbols: Symbol list.
"""
# Examples: 8018ab0 00040048 00010000 10020000 4b8e0108 ...H........K...
# 100a7294 00000000 00000000 01000000 ............
base_offset = None
offset = None
rodata = []
for line in rodata_text.splitlines():
line = line.strip()
space = line.find(' ')
if space < 0:
continue
try:
address = int(line[0:space], 16)
except ValueError:
continue
if not base_offset:
base_offset = address
offset = address
elif address != offset:
raise StackAnalyzerError('objdump of rodata not contiguous.')
for i in range(0, 4):
num = line[(space + 1 + i*9):(space + 9 + i*9)]
if len(num.strip()) > 0:
val = int(num, 16)
else:
val = 0
# TODO(drinkcat): Not all platforms are necessarily big-endian
rodata.append((val & 0x000000ff) << 24 |
(val & 0x0000ff00) << 8 |
(val & 0x00ff0000) >> 8 |
(val & 0xff000000) >> 24)
offset = offset + 4*4
return (base_offset, rodata)
def LoadTasklist(section, export_taskinfo, symbols):
"""Load the task information.
Args:
section: Section (RO | RW).
export_taskinfo: Handle of export_taskinfo.so.
symbols: Symbol list.
Returns:
tasklist: Task list.
"""
TaskInfoPointer = ctypes.POINTER(TaskInfo)
taskinfos = TaskInfoPointer()
if section == SECTION_RO:
get_taskinfos_func = export_taskinfo.get_ro_taskinfos
else:
get_taskinfos_func = export_taskinfo.get_rw_taskinfos
taskinfo_num = get_taskinfos_func(ctypes.pointer(taskinfos))
tasklist = []
for index in range(taskinfo_num):
taskinfo = taskinfos[index]
tasklist.append(Task(taskinfo.name.decode('utf-8'),
taskinfo.routine.decode('utf-8'),
taskinfo.stack_size))
# Resolve routine address for each task. It's more efficient to resolve all
# routine addresses of tasks together.
routine_map = dict((task.routine_name, None) for task in tasklist)
for symbol in symbols:
# Resolve task routine address.
if symbol.name in routine_map:
# Assume the symbol of routine is unique.
assert routine_map[symbol.name] is None
routine_map[symbol.name] = symbol.address
for task in tasklist:
address = routine_map[task.routine_name]
# Assume we have resolved all routine addresses.
assert address is not None
task.routine_address = address
return tasklist
def main():
"""Main function."""
try:
options = ParseArgs()
# Load annotation config.
if options.annotation is None:
annotation = {}
elif not os.path.exists(options.annotation):
print('Warning: Annotation file {} does not exist.'
.format(options.annotation))
annotation = {}
else:
try:
with open(options.annotation, 'r') as annotation_file:
annotation = yaml.safe_load(annotation_file)
except yaml.YAMLError:
raise StackAnalyzerError('Failed to parse annotation file {}.'
.format(options.annotation))
except IOError:
raise StackAnalyzerError('Failed to open annotation file {}.'
.format(options.annotation))
# TODO(cheyuw): Do complete annotation format verification.
if not isinstance(annotation, dict):
raise StackAnalyzerError('Invalid annotation file {}.'
.format(options.annotation))
# Generate and parse the symbols.
try:
symbol_text = subprocess.check_output([options.objdump,
'-t',
options.elf_path],
encoding='utf-8')
rodata_text = subprocess.check_output([options.objdump,
'-s',
'-j', '.rodata',
options.elf_path],
encoding='utf-8')
except subprocess.CalledProcessError:
raise StackAnalyzerError('objdump failed to dump symbol table or rodata.')
except OSError:
raise StackAnalyzerError('Failed to run objdump.')
symbols = ParseSymbolText(symbol_text)
rodata = ParseRoDataText(rodata_text)
# Load the tasklist.
try:
export_taskinfo = ctypes.CDLL(options.export_taskinfo)
except OSError:
raise StackAnalyzerError('Failed to load export_taskinfo.')
tasklist = LoadTasklist(options.section, export_taskinfo, symbols)
analyzer = StackAnalyzer(options, symbols, rodata, tasklist, annotation)
analyzer.Analyze()
except StackAnalyzerError as e:
print('Error: {}'.format(e))
if __name__ == '__main__':
main()
|