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
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
|
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/wasm/wasm-code-manager.h"
#include <iomanip>
#include "src/base/iterator.h"
#include "src/base/macros.h"
#include "src/base/platform/platform.h"
#include "src/base/small-vector.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/macro-assembler-inl.h"
#include "src/codegen/macro-assembler.h"
#include "src/common/globals.h"
#include "src/diagnostics/disassembler.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/objects/objects-inl.h"
#include "src/snapshot/embedded/embedded-data.h"
#include "src/utils/ostreams.h"
#include "src/utils/vector.h"
#include "src/wasm/compilation-environment.h"
#include "src/wasm/function-compiler.h"
#include "src/wasm/jump-table-assembler.h"
#include "src/wasm/wasm-debug.h"
#include "src/wasm/wasm-import-wrapper-cache.h"
#include "src/wasm/wasm-module-sourcemap.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects-inl.h"
#include "src/wasm/wasm-objects.h"
#if defined(V8_OS_WIN64)
#include "src/diagnostics/unwinding-info-win64.h"
#endif // V8_OS_WIN64
#define TRACE_HEAP(...) \
do { \
if (FLAG_trace_wasm_native_heap) PrintF(__VA_ARGS__); \
} while (false)
namespace v8 {
namespace internal {
namespace wasm {
using trap_handler::ProtectedInstructionData;
base::AddressRegion DisjointAllocationPool::Merge(base::AddressRegion region) {
auto dest_it = regions_.begin();
auto dest_end = regions_.end();
// Skip over dest regions strictly before {region}.
while (dest_it != dest_end && dest_it->end() < region.begin()) ++dest_it;
// After last dest region: insert and done.
if (dest_it == dest_end) {
regions_.push_back(region);
return region;
}
// Adjacent (from below) to dest: merge and done.
if (dest_it->begin() == region.end()) {
base::AddressRegion merged_region{region.begin(),
region.size() + dest_it->size()};
DCHECK_EQ(merged_region.end(), dest_it->end());
*dest_it = merged_region;
return merged_region;
}
// Before dest: insert and done.
if (dest_it->begin() > region.end()) {
regions_.insert(dest_it, region);
return region;
}
// Src is adjacent from above. Merge and check whether the merged region is
// now adjacent to the next region.
DCHECK_EQ(dest_it->end(), region.begin());
dest_it->set_size(dest_it->size() + region.size());
DCHECK_EQ(dest_it->end(), region.end());
auto next_dest = dest_it;
++next_dest;
if (next_dest != dest_end && dest_it->end() == next_dest->begin()) {
dest_it->set_size(dest_it->size() + next_dest->size());
DCHECK_EQ(dest_it->end(), next_dest->end());
regions_.erase(next_dest);
}
return *dest_it;
}
base::AddressRegion DisjointAllocationPool::Allocate(size_t size) {
return AllocateInRegion(size,
{kNullAddress, std::numeric_limits<size_t>::max()});
}
base::AddressRegion DisjointAllocationPool::AllocateInRegion(
size_t size, base::AddressRegion region) {
for (auto it = regions_.begin(), end = regions_.end(); it != end; ++it) {
base::AddressRegion overlap = it->GetOverlap(region);
if (size > overlap.size()) continue;
base::AddressRegion ret{overlap.begin(), size};
if (size == it->size()) {
// We use the full region --> erase the region from {regions_}.
regions_.erase(it);
} else if (ret.begin() == it->begin()) {
// We return a region at the start --> shrink remaining region from front.
*it = base::AddressRegion{it->begin() + size, it->size() - size};
} else if (ret.end() == it->end()) {
// We return a region at the end --> shrink remaining region.
*it = base::AddressRegion{it->begin(), it->size() - size};
} else {
// We return something in the middle --> split the remaining region.
regions_.insert(
it, base::AddressRegion{it->begin(), ret.begin() - it->begin()});
*it = base::AddressRegion{ret.end(), it->end() - ret.end()};
}
return ret;
}
return {};
}
Address WasmCode::constant_pool() const {
if (FLAG_enable_embedded_constant_pool) {
if (constant_pool_offset_ < code_comments_offset_) {
return instruction_start() + constant_pool_offset_;
}
}
return kNullAddress;
}
Address WasmCode::handler_table() const {
return instruction_start() + handler_table_offset_;
}
int WasmCode::handler_table_size() const {
DCHECK_GE(constant_pool_offset_, handler_table_offset_);
return static_cast<int>(constant_pool_offset_ - handler_table_offset_);
}
Address WasmCode::code_comments() const {
return instruction_start() + code_comments_offset_;
}
int WasmCode::code_comments_size() const {
DCHECK_GE(unpadded_binary_size_, code_comments_offset_);
return static_cast<int>(unpadded_binary_size_ - code_comments_offset_);
}
std::unique_ptr<const byte[]> WasmCode::ConcatenateBytes(
std::initializer_list<Vector<const byte>> vectors) {
size_t total_size = 0;
for (auto& vec : vectors) total_size += vec.size();
// Use default-initialization (== no initialization).
std::unique_ptr<byte[]> result{new byte[total_size]};
byte* ptr = result.get();
for (auto& vec : vectors) {
if (vec.empty()) continue; // Avoid nullptr in {memcpy}.
memcpy(ptr, vec.begin(), vec.size());
ptr += vec.size();
}
return result;
}
void WasmCode::RegisterTrapHandlerData() {
DCHECK(!has_trap_handler_index());
if (kind() != WasmCode::kFunction) return;
if (protected_instructions_size_ == 0) return;
Address base = instruction_start();
size_t size = instructions().size();
auto protected_instruction_data = this->protected_instructions();
const int index =
RegisterHandlerData(base, size, protected_instruction_data.size(),
protected_instruction_data.begin());
// TODO(eholk): if index is negative, fail.
CHECK_LE(0, index);
set_trap_handler_index(index);
DCHECK(has_trap_handler_index());
}
bool WasmCode::ShouldBeLogged(Isolate* isolate) {
// The return value is cached in {WasmEngine::IsolateData::log_codes}. Ensure
// to call {WasmEngine::EnableCodeLogging} if this return value would change
// for any isolate. Otherwise we might lose code events.
return isolate->logger()->is_listening_to_code_events() ||
isolate->code_event_dispatcher()->IsListeningToCodeEvents() ||
isolate->is_profiling();
}
void WasmCode::LogCode(Isolate* isolate) const {
DCHECK(ShouldBeLogged(isolate));
if (IsAnonymous()) return;
ModuleWireBytes wire_bytes(native_module()->wire_bytes());
WireBytesRef name_ref = native_module()->module()->function_names.Lookup(
wire_bytes, index(), VectorOf(native_module()->module()->export_table));
WasmName name = wire_bytes.GetNameOrNull(name_ref);
const std::string& source_map_url = native_module()->module()->source_map_url;
auto load_wasm_source_map = isolate->wasm_load_source_map_callback();
auto source_map = native_module()->GetWasmSourceMap();
if (!source_map && !source_map_url.empty() && load_wasm_source_map) {
HandleScope scope(isolate);
v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
Local<v8::String> source_map_str =
load_wasm_source_map(v8_isolate, source_map_url.c_str());
native_module()->SetWasmSourceMap(
std::make_unique<WasmModuleSourceMap>(v8_isolate, source_map_str));
}
std::string name_buffer;
if (kind_ == kWasmToJsWrapper) {
name_buffer = "wasm-to-js:";
size_t prefix_len = name_buffer.size();
constexpr size_t kMaxSigLength = 128;
name_buffer.resize(prefix_len + kMaxSigLength);
const FunctionSig* sig = native_module()->module()->functions[index_].sig;
size_t sig_length =
PrintSignature(VectorOf(&name_buffer[prefix_len], kMaxSigLength), sig);
name_buffer.resize(prefix_len + sig_length);
// If the import has a name, also append that (separated by "-").
if (!name.empty()) {
name_buffer += '-';
name_buffer.append(name.begin(), name.size());
}
name = VectorOf(name_buffer);
} else if (name.empty()) {
name_buffer.resize(32);
name_buffer.resize(
SNPrintF(VectorOf(&name_buffer.front(), name_buffer.size()),
"wasm-function[%d]", index()));
name = VectorOf(name_buffer);
}
PROFILE(isolate,
CodeCreateEvent(CodeEventListener::FUNCTION_TAG, this, name));
if (!source_positions().empty()) {
LOG_CODE_EVENT(isolate, CodeLinePosInfoRecordEvent(instruction_start(),
source_positions()));
}
}
void WasmCode::Validate() const {
#ifdef DEBUG
// We expect certain relocation info modes to never appear in {WasmCode}
// objects or to be restricted to a small set of valid values. Hence the
// iteration below does not use a mask, but visits all relocation data.
for (RelocIterator it(instructions(), reloc_info(), constant_pool());
!it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
switch (mode) {
case RelocInfo::WASM_CALL: {
Address target = it.rinfo()->wasm_call_address();
WasmCode* code = native_module_->Lookup(target);
CHECK_NOT_NULL(code);
CHECK_EQ(WasmCode::kJumpTable, code->kind());
CHECK(code->contains(target));
break;
}
case RelocInfo::WASM_STUB_CALL: {
Address target = it.rinfo()->wasm_stub_call_address();
WasmCode* code = native_module_->Lookup(target);
CHECK_NOT_NULL(code);
CHECK_EQ(WasmCode::kJumpTable, code->kind());
CHECK(code->contains(target));
break;
}
case RelocInfo::INTERNAL_REFERENCE:
case RelocInfo::INTERNAL_REFERENCE_ENCODED: {
Address target = it.rinfo()->target_internal_reference();
CHECK(contains(target));
break;
}
case RelocInfo::EXTERNAL_REFERENCE:
case RelocInfo::CONST_POOL:
case RelocInfo::VENEER_POOL:
// These are OK to appear.
break;
default:
FATAL("Unexpected mode: %d", mode);
}
}
#endif
}
void WasmCode::MaybePrint(const char* name) const {
// Determines whether flags want this code to be printed.
if ((FLAG_print_wasm_code && kind() == kFunction) ||
(FLAG_print_wasm_stub_code && kind() != kFunction) || FLAG_print_code) {
Print(name);
}
}
void WasmCode::Print(const char* name) const {
StdoutStream os;
os << "--- WebAssembly code ---\n";
Disassemble(name, os);
os << "--- End code ---\n";
}
void WasmCode::Disassemble(const char* name, std::ostream& os,
Address current_pc) const {
if (name) os << "name: " << name << "\n";
if (!IsAnonymous()) os << "index: " << index() << "\n";
os << "kind: " << GetWasmCodeKindAsString(kind_) << "\n";
os << "compiler: " << (is_liftoff() ? "Liftoff" : "TurboFan") << "\n";
size_t padding = instructions().size() - unpadded_binary_size_;
os << "Body (size = " << instructions().size() << " = "
<< unpadded_binary_size_ << " + " << padding << " padding)\n";
#ifdef ENABLE_DISASSEMBLER
int instruction_size = unpadded_binary_size_;
if (constant_pool_offset_ < instruction_size) {
instruction_size = constant_pool_offset_;
}
if (safepoint_table_offset_ && safepoint_table_offset_ < instruction_size) {
instruction_size = safepoint_table_offset_;
}
if (handler_table_offset_ < instruction_size) {
instruction_size = handler_table_offset_;
}
DCHECK_LT(0, instruction_size);
os << "Instructions (size = " << instruction_size << ")\n";
Disassembler::Decode(nullptr, &os, instructions().begin(),
instructions().begin() + instruction_size,
CodeReference(this), current_pc);
os << "\n";
if (handler_table_size() > 0) {
HandlerTable table(handler_table(), handler_table_size(),
HandlerTable::kReturnAddressBasedEncoding);
os << "Exception Handler Table (size = " << table.NumberOfReturnEntries()
<< "):\n";
table.HandlerTableReturnPrint(os);
os << "\n";
}
if (protected_instructions_size_ > 0) {
os << "Protected instructions:\n pc offset land pad\n";
for (auto& data : protected_instructions()) {
os << std::setw(10) << std::hex << data.instr_offset << std::setw(10)
<< std::hex << data.landing_offset << "\n";
}
os << "\n";
}
if (!source_positions().empty()) {
os << "Source positions:\n pc offset position\n";
for (SourcePositionTableIterator it(source_positions()); !it.done();
it.Advance()) {
os << std::setw(10) << std::hex << it.code_offset() << std::dec
<< std::setw(10) << it.source_position().ScriptOffset()
<< (it.is_statement() ? " statement" : "") << "\n";
}
os << "\n";
}
if (safepoint_table_offset_ > 0) {
SafepointTable table(instruction_start(), safepoint_table_offset_,
stack_slots_);
os << "Safepoints (size = " << table.size() << ")\n";
for (uint32_t i = 0; i < table.length(); i++) {
uintptr_t pc_offset = table.GetPcOffset(i);
os << reinterpret_cast<const void*>(instruction_start() + pc_offset);
os << std::setw(6) << std::hex << pc_offset << " " << std::dec;
table.PrintEntry(i, os);
os << " (sp -> fp)";
SafepointEntry entry = table.GetEntry(i);
if (entry.trampoline_pc() != -1) {
os << " trampoline: " << std::hex << entry.trampoline_pc() << std::dec;
}
if (entry.has_deoptimization_index()) {
os << " deopt: " << std::setw(6) << entry.deoptimization_index();
}
os << "\n";
}
os << "\n";
}
os << "RelocInfo (size = " << reloc_info().size() << ")\n";
for (RelocIterator it(instructions(), reloc_info(), constant_pool());
!it.done(); it.next()) {
it.rinfo()->Print(nullptr, os);
}
os << "\n";
if (code_comments_size() > 0) {
PrintCodeCommentsSection(os, code_comments(), code_comments_size());
}
#endif // ENABLE_DISASSEMBLER
}
const char* GetWasmCodeKindAsString(WasmCode::Kind kind) {
switch (kind) {
case WasmCode::kFunction:
return "wasm function";
case WasmCode::kWasmToCapiWrapper:
return "wasm-to-capi";
case WasmCode::kWasmToJsWrapper:
return "wasm-to-js";
case WasmCode::kInterpreterEntry:
return "interpreter entry";
case WasmCode::kJumpTable:
return "jump table";
}
return "unknown kind";
}
WasmCode::~WasmCode() {
if (has_trap_handler_index()) {
trap_handler::ReleaseHandlerData(trap_handler_index());
}
}
V8_WARN_UNUSED_RESULT bool WasmCode::DecRefOnPotentiallyDeadCode() {
if (native_module_->engine()->AddPotentiallyDeadCode(this)) {
// The code just became potentially dead. The ref count we wanted to
// decrement is now transferred to the set of potentially dead code, and
// will be decremented when the next GC is run.
return false;
}
// If we reach here, the code was already potentially dead. Decrement the ref
// count, and return true if it drops to zero.
return DecRefOnDeadCode();
}
// static
void WasmCode::DecrementRefCount(Vector<WasmCode* const> code_vec) {
// Decrement the ref counter of all given code objects. Keep the ones whose
// ref count drops to zero.
WasmEngine::DeadCodeMap dead_code;
WasmEngine* engine = nullptr;
for (WasmCode* code : code_vec) {
if (!code->DecRef()) continue; // Remaining references.
dead_code[code->native_module()].push_back(code);
if (!engine) engine = code->native_module()->engine();
DCHECK_EQ(engine, code->native_module()->engine());
}
DCHECK_EQ(dead_code.empty(), engine == nullptr);
if (engine) engine->FreeDeadCode(dead_code);
}
WasmCodeAllocator::OptionalLock::~OptionalLock() {
if (allocator_) allocator_->mutex_.Unlock();
}
void WasmCodeAllocator::OptionalLock::Lock(WasmCodeAllocator* allocator) {
DCHECK(!is_locked());
allocator_ = allocator;
allocator->mutex_.Lock();
}
WasmCodeAllocator::WasmCodeAllocator(WasmCodeManager* code_manager,
VirtualMemory code_space,
std::shared_ptr<Counters> async_counters)
: code_manager_(code_manager),
free_code_space_(code_space.region()),
async_counters_(std::move(async_counters)) {
owned_code_space_.reserve(4);
owned_code_space_.emplace_back(std::move(code_space));
async_counters_->wasm_module_num_code_spaces()->AddSample(1);
}
WasmCodeAllocator::~WasmCodeAllocator() {
code_manager_->FreeNativeModule(VectorOf(owned_code_space_),
committed_code_space());
}
void WasmCodeAllocator::Init(NativeModule* native_module) {
DCHECK_EQ(1, owned_code_space_.size());
native_module->AddCodeSpace(owned_code_space_[0].region(), {});
}
namespace {
// On Windows, we cannot commit a region that straddles different reservations
// of virtual memory. Because we bump-allocate, and because, if we need more
// memory, we append that memory at the end of the owned_code_space_ list, we
// traverse that list in reverse order to find the reservation(s) that guide how
// to chunk the region to commit.
#if V8_OS_WIN
constexpr bool kNeedsToSplitRangeByReservations = true;
#else
constexpr bool kNeedsToSplitRangeByReservations = false;
#endif
base::SmallVector<base::AddressRegion, 1> SplitRangeByReservationsIfNeeded(
base::AddressRegion range,
const std::vector<VirtualMemory>& owned_code_space) {
if (!kNeedsToSplitRangeByReservations) return {range};
base::SmallVector<base::AddressRegion, 1> split_ranges;
size_t missing_begin = range.begin();
size_t missing_end = range.end();
for (auto& vmem : base::Reversed(owned_code_space)) {
Address overlap_begin = std::max(missing_begin, vmem.address());
Address overlap_end = std::min(missing_end, vmem.end());
if (overlap_begin >= overlap_end) continue;
split_ranges.emplace_back(overlap_begin, overlap_end - overlap_begin);
// Opportunistically reduce the missing range. This might terminate the loop
// early.
if (missing_begin == overlap_begin) missing_begin = overlap_end;
if (missing_end == overlap_end) missing_end = overlap_begin;
if (missing_begin >= missing_end) break;
}
#ifdef ENABLE_SLOW_DCHECKS
// The returned vector should cover the full range.
size_t total_split_size = 0;
for (auto split : split_ranges) total_split_size += split.size();
DCHECK_EQ(range.size(), total_split_size);
#endif
return split_ranges;
}
int NumWasmFunctionsInFarJumpTable(uint32_t num_declared_functions) {
return NativeModule::kNeedsFarJumpsBetweenCodeSpaces
? static_cast<int>(num_declared_functions)
: 0;
}
// Returns an overapproximation of the code size overhead per new code space
// created by the jump tables.
size_t OverheadPerCodeSpace(uint32_t num_declared_functions) {
// Overhead for the jump table.
size_t overhead = RoundUp<kCodeAlignment>(
JumpTableAssembler::SizeForNumberOfSlots(num_declared_functions));
#if defined(V8_OS_WIN64)
// On Win64, we need to reserve some pages at the beginning of an executable
// space. See {AddCodeSpace}.
overhead += Heap::GetCodeRangeReservedAreaSize();
#endif // V8_OS_WIN64
// Overhead for the far jump table.
overhead +=
RoundUp<kCodeAlignment>(JumpTableAssembler::SizeForNumberOfFarJumpSlots(
WasmCode::kRuntimeStubCount,
NumWasmFunctionsInFarJumpTable(num_declared_functions)));
return overhead;
}
size_t ReservationSize(size_t code_size_estimate, int num_declared_functions,
size_t total_reserved) {
size_t overhead = OverheadPerCodeSpace(num_declared_functions);
// Reserve a power of two at least as big as any of
// a) needed size + overhead (this is the minimum needed)
// b) 2 * overhead (to not waste too much space by overhead)
// c) 1/4 of current total reservation size (to grow exponentially)
size_t reserve_size = base::bits::RoundUpToPowerOfTwo(
std::max(std::max(RoundUp<kCodeAlignment>(code_size_estimate) + overhead,
2 * overhead),
total_reserved / 4));
// Limit by the maximum supported code space size.
return std::min(kMaxWasmCodeSpaceSize, reserve_size);
}
} // namespace
Vector<byte> WasmCodeAllocator::AllocateForCode(NativeModule* native_module,
size_t size) {
return AllocateForCodeInRegion(
native_module, size, {kNullAddress, std::numeric_limits<size_t>::max()},
WasmCodeAllocator::OptionalLock{});
}
Vector<byte> WasmCodeAllocator::AllocateForCodeInRegion(
NativeModule* native_module, size_t size, base::AddressRegion region,
const WasmCodeAllocator::OptionalLock& optional_lock) {
OptionalLock new_lock;
if (!optional_lock.is_locked()) new_lock.Lock(this);
const auto& locked_lock =
optional_lock.is_locked() ? optional_lock : new_lock;
DCHECK(locked_lock.is_locked());
DCHECK_EQ(code_manager_, native_module->engine()->code_manager());
DCHECK_LT(0, size);
v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
size = RoundUp<kCodeAlignment>(size);
base::AddressRegion code_space =
free_code_space_.AllocateInRegion(size, region);
if (code_space.is_empty()) {
if (region.size() < std::numeric_limits<size_t>::max()) {
V8::FatalProcessOutOfMemory(nullptr, "wasm code reservation in region");
UNREACHABLE();
}
Address hint = owned_code_space_.empty() ? kNullAddress
: owned_code_space_.back().end();
size_t total_reserved = 0;
for (auto& vmem : owned_code_space_) total_reserved += vmem.size();
size_t reserve_size = ReservationSize(
size, native_module->module()->num_declared_functions, total_reserved);
VirtualMemory new_mem =
code_manager_->TryAllocate(reserve_size, reinterpret_cast<void*>(hint));
if (!new_mem.IsReserved()) {
V8::FatalProcessOutOfMemory(nullptr, "wasm code reservation");
UNREACHABLE();
}
base::AddressRegion new_region = new_mem.region();
code_manager_->AssignRange(new_region, native_module);
free_code_space_.Merge(new_region);
owned_code_space_.emplace_back(std::move(new_mem));
native_module->AddCodeSpace(new_region, locked_lock);
code_space = free_code_space_.Allocate(size);
DCHECK(!code_space.is_empty());
async_counters_->wasm_module_num_code_spaces()->AddSample(
static_cast<int>(owned_code_space_.size()));
}
const Address commit_page_size = page_allocator->CommitPageSize();
Address commit_start = RoundUp(code_space.begin(), commit_page_size);
Address commit_end = RoundUp(code_space.end(), commit_page_size);
// {commit_start} will be either code_space.start or the start of the next
// page. {commit_end} will be the start of the page after the one in which
// the allocation ends.
// We start from an aligned start, and we know we allocated vmem in
// page multiples.
// We just need to commit what's not committed. The page in which we
// start is already committed (or we start at the beginning of a page).
// The end needs to be committed all through the end of the page.
if (commit_start < commit_end) {
committed_code_space_.fetch_add(commit_end - commit_start);
// Committed code cannot grow bigger than maximum code space size.
DCHECK_LE(committed_code_space_.load(), kMaxWasmCodeMemory);
for (base::AddressRegion split_range : SplitRangeByReservationsIfNeeded(
{commit_start, commit_end - commit_start}, owned_code_space_)) {
if (!code_manager_->Commit(split_range)) {
V8::FatalProcessOutOfMemory(nullptr, "wasm code commit");
UNREACHABLE();
}
}
}
DCHECK(IsAligned(code_space.begin(), kCodeAlignment));
allocated_code_space_.Merge(code_space);
generated_code_size_.fetch_add(code_space.size(), std::memory_order_relaxed);
TRACE_HEAP("Code alloc for %p: 0x%" PRIxPTR ",+%zu\n", this,
code_space.begin(), size);
return {reinterpret_cast<byte*>(code_space.begin()), code_space.size()};
}
bool WasmCodeAllocator::SetExecutable(bool executable) {
base::MutexGuard lock(&mutex_);
if (is_executable_ == executable) return true;
TRACE_HEAP("Setting module %p as executable: %d.\n", this, executable);
v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
if (FLAG_wasm_write_protect_code_memory) {
PageAllocator::Permission permission =
executable ? PageAllocator::kReadExecute : PageAllocator::kReadWrite;
#if V8_OS_WIN
// On windows, we need to switch permissions per separate virtual memory
// reservation.
// For now, in that case, we commit at reserved memory granularity.
// Technically, that may be a waste, because we may reserve more than we
// use. On 32-bit though, the scarce resource is the address space -
// committed or not.
for (auto& vmem : owned_code_space_) {
if (!SetPermissions(page_allocator, vmem.address(), vmem.size(),
permission)) {
return false;
}
TRACE_HEAP("Set %p:%p to executable:%d\n", vmem.address(), vmem.end(),
executable);
}
#else // V8_OS_WIN
size_t commit_page_size = page_allocator->CommitPageSize();
for (auto& region : allocated_code_space_.regions()) {
// allocated_code_space_ is fine-grained, so we need to
// page-align it.
size_t region_size = RoundUp(region.size(), commit_page_size);
if (!SetPermissions(page_allocator, region.begin(), region_size,
permission)) {
return false;
}
TRACE_HEAP("Set 0x%" PRIxPTR ":0x%" PRIxPTR " to executable:%d\n",
region.begin(), region.end(), executable);
}
#endif // V8_OS_WIN
}
is_executable_ = executable;
return true;
}
void WasmCodeAllocator::FreeCode(Vector<WasmCode* const> codes) {
// Zap code area and collect freed code regions.
DisjointAllocationPool freed_regions;
size_t code_size = 0;
for (WasmCode* code : codes) {
ZapCode(code->instruction_start(), code->instructions().size());
FlushInstructionCache(code->instruction_start(),
code->instructions().size());
code_size += code->instructions().size();
freed_regions.Merge(base::AddressRegion{code->instruction_start(),
code->instructions().size()});
}
freed_code_size_.fetch_add(code_size);
// Merge {freed_regions} into {freed_code_space_} and discard full pages.
base::MutexGuard guard(&mutex_);
PageAllocator* allocator = GetPlatformPageAllocator();
size_t commit_page_size = allocator->CommitPageSize();
for (auto region : freed_regions.regions()) {
auto merged_region = freed_code_space_.Merge(region);
Address discard_start =
std::max(RoundUp(merged_region.begin(), commit_page_size),
RoundDown(region.begin(), commit_page_size));
Address discard_end =
std::min(RoundDown(merged_region.end(), commit_page_size),
RoundUp(region.end(), commit_page_size));
if (discard_start >= discard_end) continue;
size_t discard_size = discard_end - discard_start;
size_t old_committed = committed_code_space_.fetch_sub(discard_size);
DCHECK_GE(old_committed, discard_size);
USE(old_committed);
for (base::AddressRegion split_range : SplitRangeByReservationsIfNeeded(
{discard_start, discard_size}, owned_code_space_)) {
code_manager_->Decommit(split_range);
}
}
}
size_t WasmCodeAllocator::GetNumCodeSpaces() const {
base::MutexGuard lock(&mutex_);
return owned_code_space_.size();
}
NativeModule::NativeModule(WasmEngine* engine, const WasmFeatures& enabled,
VirtualMemory code_space,
std::shared_ptr<const WasmModule> module,
std::shared_ptr<Counters> async_counters,
std::shared_ptr<NativeModule>* shared_this)
: code_allocator_(engine->code_manager(), std::move(code_space),
async_counters),
enabled_features_(enabled),
module_(std::move(module)),
import_wrapper_cache_(std::unique_ptr<WasmImportWrapperCache>(
new WasmImportWrapperCache())),
engine_(engine),
use_trap_handler_(trap_handler::IsTrapHandlerEnabled() ? kUseTrapHandler
: kNoTrapHandler) {
// We receive a pointer to an empty {std::shared_ptr}, and install ourselve
// there.
DCHECK_NOT_NULL(shared_this);
DCHECK_NULL(*shared_this);
shared_this->reset(this);
compilation_state_ =
CompilationState::New(*shared_this, std::move(async_counters));
DCHECK_NOT_NULL(module_);
if (module_->num_declared_functions > 0) {
code_table_ =
std::make_unique<WasmCode*[]>(module_->num_declared_functions);
}
code_allocator_.Init(this);
}
void NativeModule::ReserveCodeTableForTesting(uint32_t max_functions) {
WasmCodeRefScope code_ref_scope;
DCHECK_LE(module_->num_declared_functions, max_functions);
auto new_table = std::make_unique<WasmCode*[]>(max_functions);
if (module_->num_declared_functions > 0) {
memcpy(new_table.get(), code_table_.get(),
module_->num_declared_functions * sizeof(WasmCode*));
}
code_table_ = std::move(new_table);
base::AddressRegion single_code_space_region;
{
base::MutexGuard guard(&allocation_mutex_);
CHECK_EQ(1, code_space_data_.size());
single_code_space_region = code_space_data_[0].region;
}
// Re-allocate jump table.
main_jump_table_ = CreateEmptyJumpTableInRegion(
JumpTableAssembler::SizeForNumberOfSlots(max_functions),
single_code_space_region, WasmCodeAllocator::OptionalLock{});
base::MutexGuard guard(&allocation_mutex_);
code_space_data_[0].jump_table = main_jump_table_;
}
void NativeModule::LogWasmCodes(Isolate* isolate) {
if (!WasmCode::ShouldBeLogged(isolate)) return;
// TODO(titzer): we skip the logging of the import wrappers
// here, but they should be included somehow.
int start = module()->num_imported_functions;
int end = start + module()->num_declared_functions;
WasmCodeRefScope code_ref_scope;
for (int func_index = start; func_index < end; ++func_index) {
if (WasmCode* code = GetCode(func_index)) code->LogCode(isolate);
}
}
CompilationEnv NativeModule::CreateCompilationEnv() const {
// Protect concurrent accesses to {tier_down_}.
base::MutexGuard guard(&allocation_mutex_);
return {module(), use_trap_handler_, kRuntimeExceptionSupport,
enabled_features_, kNoLowerSimd, tier_down_};
}
WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
// For off-heap builtins, we create a copy of the off-heap instruction stream
// instead of the on-heap code object containing the trampoline. Ensure that
// we do not apply the on-heap reloc info to the off-heap instructions.
const size_t relocation_size =
code->is_off_heap_trampoline() ? 0 : code->relocation_size();
OwnedVector<byte> reloc_info;
if (relocation_size > 0) {
reloc_info = OwnedVector<byte>::New(relocation_size);
memcpy(reloc_info.start(), code->relocation_start(), relocation_size);
}
Handle<ByteArray> source_pos_table(code->SourcePositionTable(),
code->GetIsolate());
OwnedVector<byte> source_pos =
OwnedVector<byte>::New(source_pos_table->length());
if (source_pos_table->length() > 0) {
source_pos_table->copy_out(0, source_pos.start(),
source_pos_table->length());
}
Vector<const byte> instructions(
reinterpret_cast<byte*>(code->InstructionStart()),
static_cast<size_t>(code->InstructionSize()));
const int stack_slots = code->has_safepoint_info() ? code->stack_slots() : 0;
// TODO(jgruber,v8:8758): Remove this translation. It exists only because
// Code objects contains real offsets but WasmCode expects an offset of 0 to
// mean 'empty'.
const int safepoint_table_offset =
code->has_safepoint_table() ? code->safepoint_table_offset() : 0;
const int handler_table_offset = code->handler_table_offset();
const int constant_pool_offset = code->constant_pool_offset();
const int code_comments_offset = code->code_comments_offset();
Vector<uint8_t> dst_code_bytes =
code_allocator_.AllocateForCode(this, instructions.size());
memcpy(dst_code_bytes.begin(), instructions.begin(), instructions.size());
// Apply the relocation delta by iterating over the RelocInfo.
intptr_t delta = reinterpret_cast<Address>(dst_code_bytes.begin()) -
code->InstructionStart();
int mode_mask =
RelocInfo::kApplyMask | RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
auto jump_tables_ref =
FindJumpTablesForRegion(base::AddressRegionOf(dst_code_bytes));
Address dst_code_addr = reinterpret_cast<Address>(dst_code_bytes.begin());
Address constant_pool_start = dst_code_addr + constant_pool_offset;
RelocIterator orig_it(*code, mode_mask);
for (RelocIterator it(dst_code_bytes, reloc_info.as_vector(),
constant_pool_start, mode_mask);
!it.done(); it.next(), orig_it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsWasmStubCall(mode)) {
uint32_t stub_call_tag = orig_it.rinfo()->wasm_call_tag();
DCHECK_LT(stub_call_tag, WasmCode::kRuntimeStubCount);
Address entry = GetNearRuntimeStubEntry(
static_cast<WasmCode::RuntimeStubId>(stub_call_tag), jump_tables_ref);
it.rinfo()->set_wasm_stub_call_address(entry, SKIP_ICACHE_FLUSH);
} else {
it.rinfo()->apply(delta);
}
}
// Flush the i-cache after relocation.
FlushInstructionCache(dst_code_bytes.begin(), dst_code_bytes.size());
std::unique_ptr<WasmCode> new_code{
new WasmCode{this, // native_module
kAnonymousFuncIndex, // index
dst_code_bytes, // instructions
stack_slots, // stack_slots
0, // tagged_parameter_slots
safepoint_table_offset, // safepoint_table_offset
handler_table_offset, // handler_table_offset
constant_pool_offset, // constant_pool_offset
code_comments_offset, // code_comments_offset
instructions.length(), // unpadded_binary_size
{}, // protected_instructions
reloc_info.as_vector(), // reloc_info
source_pos.as_vector(), // source positions
WasmCode::kFunction, // kind
ExecutionTier::kNone}}; // tier
new_code->MaybePrint(nullptr);
new_code->Validate();
return PublishCode(std::move(new_code));
}
void NativeModule::UseLazyStub(uint32_t func_index) {
DCHECK_LE(module_->num_imported_functions, func_index);
DCHECK_LT(func_index,
module_->num_imported_functions + module_->num_declared_functions);
if (!lazy_compile_table_) {
uint32_t num_slots = module_->num_declared_functions;
WasmCodeRefScope code_ref_scope;
base::AddressRegion single_code_space_region;
{
base::MutexGuard guard(&allocation_mutex_);
DCHECK_EQ(1, code_space_data_.size());
single_code_space_region = code_space_data_[0].region;
}
lazy_compile_table_ = CreateEmptyJumpTableInRegion(
JumpTableAssembler::SizeForNumberOfLazyFunctions(num_slots),
single_code_space_region, WasmCodeAllocator::OptionalLock{});
JumpTableAssembler::GenerateLazyCompileTable(
lazy_compile_table_->instruction_start(), num_slots,
module_->num_imported_functions,
GetNearRuntimeStubEntry(WasmCode::kWasmCompileLazy,
FindJumpTablesForRegion(base::AddressRegionOf(
lazy_compile_table_->instructions()))));
}
// Add jump table entry for jump to the lazy compile stub.
uint32_t slot_index = declared_function_index(module(), func_index);
DCHECK_NULL(code_table_[slot_index]);
Address lazy_compile_target =
lazy_compile_table_->instruction_start() +
JumpTableAssembler::LazyCompileSlotIndexToOffset(slot_index);
base::MutexGuard guard(&allocation_mutex_);
PatchJumpTablesLocked(slot_index, lazy_compile_target);
}
std::unique_ptr<WasmCode> NativeModule::AddCode(
int index, const CodeDesc& desc, int stack_slots,
int tagged_parameter_slots, Vector<const byte> protected_instructions_data,
Vector<const byte> source_position_table, WasmCode::Kind kind,
ExecutionTier tier) {
Vector<byte> code_space =
code_allocator_.AllocateForCode(this, desc.instr_size);
auto jump_table_ref =
FindJumpTablesForRegion(base::AddressRegionOf(code_space));
return AddCodeWithCodeSpace(index, desc, stack_slots, tagged_parameter_slots,
protected_instructions_data,
source_position_table, kind, tier, code_space,
jump_table_ref);
}
std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
int index, const CodeDesc& desc, int stack_slots,
int tagged_parameter_slots, Vector<const byte> protected_instructions_data,
Vector<const byte> source_position_table, WasmCode::Kind kind,
ExecutionTier tier, Vector<uint8_t> dst_code_bytes,
const JumpTablesRef& jump_tables) {
Vector<byte> reloc_info{desc.buffer + desc.buffer_size - desc.reloc_size,
static_cast<size_t>(desc.reloc_size)};
// TODO(jgruber,v8:8758): Remove this translation. It exists only because
// CodeDesc contains real offsets but WasmCode expects an offset of 0 to mean
// 'empty'.
const int safepoint_table_offset =
desc.safepoint_table_size == 0 ? 0 : desc.safepoint_table_offset;
const int handler_table_offset = desc.handler_table_offset;
const int constant_pool_offset = desc.constant_pool_offset;
const int code_comments_offset = desc.code_comments_offset;
const int instr_size = desc.instr_size;
memcpy(dst_code_bytes.begin(), desc.buffer,
static_cast<size_t>(desc.instr_size));
// Apply the relocation delta by iterating over the RelocInfo.
intptr_t delta = dst_code_bytes.begin() - desc.buffer;
int mode_mask = RelocInfo::kApplyMask |
RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
Address code_start = reinterpret_cast<Address>(dst_code_bytes.begin());
Address constant_pool_start = code_start + constant_pool_offset;
for (RelocIterator it(dst_code_bytes, reloc_info, constant_pool_start,
mode_mask);
!it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsWasmCall(mode)) {
uint32_t call_tag = it.rinfo()->wasm_call_tag();
Address target = GetNearCallTargetForFunction(call_tag, jump_tables);
it.rinfo()->set_wasm_call_address(target, SKIP_ICACHE_FLUSH);
} else if (RelocInfo::IsWasmStubCall(mode)) {
uint32_t stub_call_tag = it.rinfo()->wasm_call_tag();
DCHECK_LT(stub_call_tag, WasmCode::kRuntimeStubCount);
Address entry = GetNearRuntimeStubEntry(
static_cast<WasmCode::RuntimeStubId>(stub_call_tag), jump_tables);
it.rinfo()->set_wasm_stub_call_address(entry, SKIP_ICACHE_FLUSH);
} else {
it.rinfo()->apply(delta);
}
}
// Flush the i-cache after relocation.
FlushInstructionCache(dst_code_bytes.begin(), dst_code_bytes.size());
std::unique_ptr<WasmCode> code{new WasmCode{
this, index, dst_code_bytes, stack_slots, tagged_parameter_slots,
safepoint_table_offset, handler_table_offset, constant_pool_offset,
code_comments_offset, instr_size, protected_instructions_data, reloc_info,
source_position_table, kind, tier}};
code->MaybePrint();
code->Validate();
return code;
}
WasmCode* NativeModule::PublishCode(std::unique_ptr<WasmCode> code) {
base::MutexGuard lock(&allocation_mutex_);
return PublishCodeLocked(std::move(code));
}
WasmCode::Kind GetCodeKind(const WasmCompilationResult& result) {
switch (result.kind) {
case WasmCompilationResult::kWasmToJsWrapper:
return WasmCode::Kind::kWasmToJsWrapper;
case WasmCompilationResult::kInterpreterEntry:
return WasmCode::Kind::kInterpreterEntry;
case WasmCompilationResult::kFunction:
return WasmCode::Kind::kFunction;
default:
UNREACHABLE();
}
}
WasmCode* NativeModule::PublishCodeLocked(std::unique_ptr<WasmCode> code) {
// The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
DCHECK(!allocation_mutex_.TryLock());
if (!code->IsAnonymous() &&
code->index() >= module_->num_imported_functions) {
DCHECK_LT(code->index(), num_functions());
code->RegisterTrapHandlerData();
// Assume an order of execution tiers that represents the quality of their
// generated code.
static_assert(ExecutionTier::kNone < ExecutionTier::kInterpreter &&
ExecutionTier::kInterpreter < ExecutionTier::kLiftoff &&
ExecutionTier::kLiftoff < ExecutionTier::kTurbofan,
"Assume an order on execution tiers");
// Unless tier down to Liftoff: update code table but avoid to fall back to
// less optimized code. We use the new code if it was compiled with a higher
// tier.
uint32_t slot_idx = declared_function_index(module(), code->index());
WasmCode* prior_code = code_table_[slot_idx];
// TODO(clemensb): Revisit this logic once tier down is fully working.
const bool prefer_liftoff = tier_down_ || debug_info_;
const bool update_code_table =
prefer_liftoff ? !prior_code || code->tier() == ExecutionTier::kLiftoff
: !prior_code || prior_code->tier() < code->tier();
if (update_code_table) {
code_table_[slot_idx] = code.get();
if (prior_code) {
WasmCodeRefScope::AddRef(prior_code);
// The code is added to the current {WasmCodeRefScope}, hence the ref
// count cannot drop to zero here.
CHECK(!prior_code->DecRef());
}
}
// Populate optimized code to the jump table unless there is an active
// redirection to the interpreter that should be preserved.
DCHECK_NOT_NULL(main_jump_table_);
bool update_jump_table =
update_code_table && !has_interpreter_redirection(code->index());
// Ensure that interpreter entries always populate to the jump table.
if (code->kind_ == WasmCode::Kind::kInterpreterEntry) {
SetInterpreterRedirection(code->index());
update_jump_table = true;
}
if (update_jump_table) {
PatchJumpTablesLocked(slot_idx, code->instruction_start());
}
}
WasmCodeRefScope::AddRef(code.get());
WasmCode* result = code.get();
owned_code_.emplace(result->instruction_start(), std::move(code));
return result;
}
WasmCode* NativeModule::AddDeserializedCode(
int index, Vector<const byte> instructions, int stack_slots,
int tagged_parameter_slots, int safepoint_table_offset,
int handler_table_offset, int constant_pool_offset,
int code_comments_offset, int unpadded_binary_size,
Vector<const byte> protected_instructions_data,
Vector<const byte> reloc_info, Vector<const byte> source_position_table,
WasmCode::Kind kind, ExecutionTier tier) {
Vector<uint8_t> dst_code_bytes =
code_allocator_.AllocateForCode(this, instructions.size());
memcpy(dst_code_bytes.begin(), instructions.begin(), instructions.size());
std::unique_ptr<WasmCode> code{new WasmCode{
this, index, dst_code_bytes, stack_slots, tagged_parameter_slots,
safepoint_table_offset, handler_table_offset, constant_pool_offset,
code_comments_offset, unpadded_binary_size, protected_instructions_data,
reloc_info, source_position_table, kind, tier}};
// Note: we do not flush the i-cache here, since the code needs to be
// relocated anyway. The caller is responsible for flushing the i-cache later.
return PublishCode(std::move(code));
}
std::vector<WasmCode*> NativeModule::SnapshotCodeTable() const {
base::MutexGuard lock(&allocation_mutex_);
WasmCode** start = code_table_.get();
WasmCode** end = start + module_->num_declared_functions;
return std::vector<WasmCode*>{start, end};
}
WasmCode* NativeModule::GetCode(uint32_t index) const {
base::MutexGuard guard(&allocation_mutex_);
WasmCode* code = code_table_[declared_function_index(module(), index)];
if (code) WasmCodeRefScope::AddRef(code);
return code;
}
bool NativeModule::HasCode(uint32_t index) const {
base::MutexGuard guard(&allocation_mutex_);
return code_table_[declared_function_index(module(), index)] != nullptr;
}
bool NativeModule::HasCodeWithTier(uint32_t index, ExecutionTier tier) const {
base::MutexGuard guard(&allocation_mutex_);
return code_table_[declared_function_index(module(), index)] != nullptr &&
code_table_[declared_function_index(module(), index)]->tier() == tier;
}
void NativeModule::SetWasmSourceMap(
std::unique_ptr<WasmModuleSourceMap> source_map) {
source_map_ = std::move(source_map);
}
WasmModuleSourceMap* NativeModule::GetWasmSourceMap() const {
return source_map_.get();
}
WasmCode* NativeModule::CreateEmptyJumpTableInRegion(
int jump_table_size, base::AddressRegion region,
const WasmCodeAllocator::OptionalLock& allocator_lock) {
// Only call this if we really need a jump table.
DCHECK_LT(0, jump_table_size);
Vector<uint8_t> code_space = code_allocator_.AllocateForCodeInRegion(
this, jump_table_size, region, allocator_lock);
DCHECK(!code_space.empty());
ZapCode(reinterpret_cast<Address>(code_space.begin()), code_space.size());
std::unique_ptr<WasmCode> code{
new WasmCode{this, // native_module
kAnonymousFuncIndex, // index
code_space, // instructions
0, // stack_slots
0, // tagged_parameter_slots
0, // safepoint_table_offset
jump_table_size, // handler_table_offset
jump_table_size, // constant_pool_offset
jump_table_size, // code_comments_offset
jump_table_size, // unpadded_binary_size
{}, // protected_instructions
{}, // reloc_info
{}, // source_pos
WasmCode::kJumpTable, // kind
ExecutionTier::kNone}}; // tier
return PublishCode(std::move(code));
}
void NativeModule::PatchJumpTablesLocked(uint32_t slot_index, Address target) {
// The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
DCHECK(!allocation_mutex_.TryLock());
for (auto& code_space_data : code_space_data_) {
DCHECK_IMPLIES(code_space_data.jump_table, code_space_data.far_jump_table);
if (!code_space_data.jump_table) continue;
PatchJumpTableLocked(code_space_data, slot_index, target);
}
}
void NativeModule::PatchJumpTableLocked(const CodeSpaceData& code_space_data,
uint32_t slot_index, Address target) {
// The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
DCHECK(!allocation_mutex_.TryLock());
DCHECK_NOT_NULL(code_space_data.jump_table);
DCHECK_NOT_NULL(code_space_data.far_jump_table);
DCHECK_LT(slot_index, module_->num_declared_functions);
Address jump_table_slot =
code_space_data.jump_table->instruction_start() +
JumpTableAssembler::JumpSlotIndexToOffset(slot_index);
uint32_t far_jump_table_offset = JumpTableAssembler::FarJumpSlotIndexToOffset(
WasmCode::kRuntimeStubCount + slot_index);
// Only pass the far jump table start if the far jump table actually has a
// slot for this function index (i.e. does not only contain runtime stubs).
bool has_far_jump_slot =
far_jump_table_offset <
code_space_data.far_jump_table->instructions().size();
Address far_jump_table_start =
code_space_data.far_jump_table->instruction_start();
Address far_jump_table_slot =
has_far_jump_slot ? far_jump_table_start + far_jump_table_offset
: kNullAddress;
JumpTableAssembler::PatchJumpTableSlot(jump_table_slot, far_jump_table_slot,
target);
}
void NativeModule::AddCodeSpace(
base::AddressRegion region,
const WasmCodeAllocator::OptionalLock& allocator_lock) {
// Each code space must be at least twice as large as the overhead per code
// space. Otherwise, we are wasting too much memory.
DCHECK_GE(region.size(),
2 * OverheadPerCodeSpace(module()->num_declared_functions));
#if defined(V8_OS_WIN64)
// On some platforms, specifically Win64, we need to reserve some pages at
// the beginning of an executable space.
// See src/heap/spaces.cc, MemoryAllocator::InitializeCodePageAllocator() and
// https://cs.chromium.org/chromium/src/components/crash/content/app/crashpad_win.cc?rcl=fd680447881449fba2edcf0589320e7253719212&l=204
// for details.
if (engine_->code_manager()
->CanRegisterUnwindInfoForNonABICompliantCodeRange()) {
size_t size = Heap::GetCodeRangeReservedAreaSize();
DCHECK_LT(0, size);
Vector<byte> padding = code_allocator_.AllocateForCodeInRegion(
this, size, region, allocator_lock);
CHECK_EQ(reinterpret_cast<Address>(padding.begin()), region.begin());
win64_unwindinfo::RegisterNonABICompliantCodeRange(
reinterpret_cast<void*>(region.begin()), region.size());
}
#endif // V8_OS_WIN64
WasmCodeRefScope code_ref_scope;
WasmCode* jump_table = nullptr;
WasmCode* far_jump_table = nullptr;
const uint32_t num_wasm_functions = module_->num_declared_functions;
const bool is_first_code_space = code_space_data_.empty();
// We always need a far jump table, because it contains the runtime stubs.
const bool needs_far_jump_table = !FindJumpTablesForRegion(region).is_valid();
const bool needs_jump_table = num_wasm_functions > 0 && needs_far_jump_table;
if (needs_jump_table) {
jump_table = CreateEmptyJumpTableInRegion(
JumpTableAssembler::SizeForNumberOfSlots(num_wasm_functions), region,
allocator_lock);
CHECK(region.contains(jump_table->instruction_start()));
}
if (needs_far_jump_table) {
int num_function_slots = NumWasmFunctionsInFarJumpTable(num_wasm_functions);
far_jump_table = CreateEmptyJumpTableInRegion(
JumpTableAssembler::SizeForNumberOfFarJumpSlots(
WasmCode::kRuntimeStubCount,
NumWasmFunctionsInFarJumpTable(num_function_slots)),
region, allocator_lock);
CHECK(region.contains(far_jump_table->instruction_start()));
EmbeddedData embedded_data = EmbeddedData::FromBlob();
#define RUNTIME_STUB(Name) Builtins::k##Name,
#define RUNTIME_STUB_TRAP(Name) RUNTIME_STUB(ThrowWasm##Name)
Builtins::Name stub_names[WasmCode::kRuntimeStubCount] = {
WASM_RUNTIME_STUB_LIST(RUNTIME_STUB, RUNTIME_STUB_TRAP)};
#undef RUNTIME_STUB
#undef RUNTIME_STUB_TRAP
Address builtin_addresses[WasmCode::kRuntimeStubCount];
for (int i = 0; i < WasmCode::kRuntimeStubCount; ++i) {
Builtins::Name builtin = stub_names[i];
CHECK(embedded_data.ContainsBuiltin(builtin));
builtin_addresses[i] = embedded_data.InstructionStartOfBuiltin(builtin);
}
JumpTableAssembler::GenerateFarJumpTable(
far_jump_table->instruction_start(), builtin_addresses,
WasmCode::kRuntimeStubCount, num_function_slots);
}
if (is_first_code_space) {
// This can be updated and accessed without locks, since the addition of the
// first code space happens during initialization of the {NativeModule},
// where no concurrent accesses are possible.
main_jump_table_ = jump_table;
main_far_jump_table_ = far_jump_table;
}
base::MutexGuard guard(&allocation_mutex_);
code_space_data_.push_back(CodeSpaceData{region, jump_table, far_jump_table});
if (jump_table && !is_first_code_space) {
// Patch the new jump table(s) with existing functions. If this is the first
// code space, there cannot be any functions that have been compiled yet.
const CodeSpaceData& new_code_space_data = code_space_data_.back();
for (uint32_t slot_index = 0; slot_index < num_wasm_functions;
++slot_index) {
if (code_table_[slot_index]) {
PatchJumpTableLocked(new_code_space_data, slot_index,
code_table_[slot_index]->instruction_start());
} else if (lazy_compile_table_) {
Address lazy_compile_target =
lazy_compile_table_->instruction_start() +
JumpTableAssembler::LazyCompileSlotIndexToOffset(slot_index);
PatchJumpTableLocked(new_code_space_data, slot_index,
lazy_compile_target);
}
}
}
}
namespace {
class NativeModuleWireBytesStorage final : public WireBytesStorage {
public:
explicit NativeModuleWireBytesStorage(
std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes)
: wire_bytes_(std::move(wire_bytes)) {}
Vector<const uint8_t> GetCode(WireBytesRef ref) const final {
return wire_bytes_->as_vector().SubVector(ref.offset(), ref.end_offset());
}
private:
const std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes_;
};
} // namespace
void NativeModule::SetWireBytes(OwnedVector<const uint8_t> wire_bytes) {
auto shared_wire_bytes =
std::make_shared<OwnedVector<const uint8_t>>(std::move(wire_bytes));
wire_bytes_ = shared_wire_bytes;
if (!shared_wire_bytes->empty()) {
compilation_state_->SetWireBytesStorage(
std::make_shared<NativeModuleWireBytesStorage>(
std::move(shared_wire_bytes)));
}
}
WasmCode* NativeModule::Lookup(Address pc) const {
base::MutexGuard lock(&allocation_mutex_);
auto iter = owned_code_.upper_bound(pc);
if (iter == owned_code_.begin()) return nullptr;
--iter;
WasmCode* candidate = iter->second.get();
DCHECK_EQ(candidate->instruction_start(), iter->first);
if (!candidate->contains(pc)) return nullptr;
WasmCodeRefScope::AddRef(candidate);
return candidate;
}
uint32_t NativeModule::GetJumpTableOffset(uint32_t func_index) const {
uint32_t slot_idx = declared_function_index(module(), func_index);
return JumpTableAssembler::JumpSlotIndexToOffset(slot_idx);
}
Address NativeModule::GetCallTargetForFunction(uint32_t func_index) const {
// Return the jump table slot for that function index.
DCHECK_NOT_NULL(main_jump_table_);
uint32_t slot_offset = GetJumpTableOffset(func_index);
DCHECK_LT(slot_offset, main_jump_table_->instructions().size());
return main_jump_table_->instruction_start() + slot_offset;
}
NativeModule::JumpTablesRef NativeModule::FindJumpTablesForRegion(
base::AddressRegion code_region) const {
auto jump_table_usable = [code_region](const WasmCode* jump_table) {
Address table_start = jump_table->instruction_start();
Address table_end = table_start + jump_table->instructions().size();
// Compute the maximum distance from anywhere in the code region to anywhere
// in the jump table, avoiding any underflow.
size_t max_distance = std::max(
code_region.end() > table_start ? code_region.end() - table_start : 0,
table_end > code_region.begin() ? table_end - code_region.begin() : 0);
return max_distance < kMaxWasmCodeSpaceSize;
};
// Fast path: Try to use {main_jump_table_} and {main_far_jump_table_}.
// Access to these fields is possible without locking, since these fields are
// initialized on construction of the {NativeModule}.
if (main_far_jump_table_ && jump_table_usable(main_far_jump_table_) &&
(main_jump_table_ == nullptr || jump_table_usable(main_jump_table_))) {
return {
main_jump_table_ ? main_jump_table_->instruction_start() : kNullAddress,
main_far_jump_table_->instruction_start()};
}
// Otherwise, take the mutex and look for another suitable jump table.
base::MutexGuard guard(&allocation_mutex_);
for (auto& code_space_data : code_space_data_) {
DCHECK_IMPLIES(code_space_data.jump_table, code_space_data.far_jump_table);
if (!code_space_data.far_jump_table) continue;
// Only return these jump tables if they are reachable from the whole
// {code_region}.
if (kNeedsFarJumpsBetweenCodeSpaces &&
(!jump_table_usable(code_space_data.far_jump_table) ||
(code_space_data.jump_table &&
!jump_table_usable(code_space_data.jump_table)))) {
continue;
}
return {code_space_data.jump_table
? code_space_data.jump_table->instruction_start()
: kNullAddress,
code_space_data.far_jump_table->instruction_start()};
}
return {};
}
Address NativeModule::GetNearCallTargetForFunction(
uint32_t func_index, const JumpTablesRef& jump_tables) const {
DCHECK(jump_tables.is_valid());
uint32_t slot_offset = GetJumpTableOffset(func_index);
return jump_tables.jump_table_start + slot_offset;
}
Address NativeModule::GetNearRuntimeStubEntry(
WasmCode::RuntimeStubId index, const JumpTablesRef& jump_tables) const {
DCHECK(jump_tables.is_valid());
auto offset = JumpTableAssembler::FarJumpSlotIndexToOffset(index);
return jump_tables.far_jump_table_start + offset;
}
uint32_t NativeModule::GetFunctionIndexFromJumpTableSlot(
Address slot_address) const {
WasmCodeRefScope code_refs;
WasmCode* code = Lookup(slot_address);
DCHECK_NOT_NULL(code);
DCHECK_EQ(WasmCode::kJumpTable, code->kind());
uint32_t slot_offset =
static_cast<uint32_t>(slot_address - code->instruction_start());
uint32_t slot_idx = JumpTableAssembler::SlotOffsetToIndex(slot_offset);
DCHECK_LT(slot_idx, module_->num_declared_functions);
DCHECK_EQ(slot_address,
code->instruction_start() +
JumpTableAssembler::JumpSlotIndexToOffset(slot_idx));
return module_->num_imported_functions + slot_idx;
}
WasmCode::RuntimeStubId NativeModule::GetRuntimeStubId(Address target) const {
base::MutexGuard guard(&allocation_mutex_);
for (auto& code_space_data : code_space_data_) {
if (code_space_data.far_jump_table->contains(target)) {
uint32_t offset = static_cast<uint32_t>(
target - code_space_data.far_jump_table->instruction_start());
uint32_t index = JumpTableAssembler::FarJumpSlotOffsetToIndex(offset);
if (index >= WasmCode::kRuntimeStubCount) continue;
if (JumpTableAssembler::FarJumpSlotIndexToOffset(index) != offset) {
continue;
}
return static_cast<WasmCode::RuntimeStubId>(index);
}
}
// Invalid address.
return WasmCode::kRuntimeStubCount;
}
const char* NativeModule::GetRuntimeStubName(Address target) const {
WasmCode::RuntimeStubId stub_id = GetRuntimeStubId(target);
#define RUNTIME_STUB_NAME(Name) #Name,
#define RUNTIME_STUB_NAME_TRAP(Name) "ThrowWasm" #Name,
constexpr const char* runtime_stub_names[] = {WASM_RUNTIME_STUB_LIST(
RUNTIME_STUB_NAME, RUNTIME_STUB_NAME_TRAP) "<unknown>"};
#undef RUNTIME_STUB_NAME
#undef RUNTIME_STUB_NAME_TRAP
STATIC_ASSERT(arraysize(runtime_stub_names) ==
WasmCode::kRuntimeStubCount + 1);
DCHECK_GT(arraysize(runtime_stub_names), stub_id);
return runtime_stub_names[stub_id];
}
NativeModule::~NativeModule() {
TRACE_HEAP("Deleting native module: %p\n", this);
// Cancel all background compilation before resetting any field of the
// NativeModule or freeing anything.
compilation_state_->AbortCompilation();
engine_->FreeNativeModule(this);
// Free the import wrapper cache before releasing the {WasmCode} objects in
// {owned_code_}. The destructor of {WasmImportWrapperCache} still needs to
// decrease reference counts on the {WasmCode} objects.
import_wrapper_cache_.reset();
}
WasmCodeManager::WasmCodeManager(size_t max_committed)
: max_committed_code_space_(max_committed),
critical_committed_code_space_(max_committed / 2) {
DCHECK_LE(max_committed, kMaxWasmCodeMemory);
}
#if defined(V8_OS_WIN64)
bool WasmCodeManager::CanRegisterUnwindInfoForNonABICompliantCodeRange() const {
return win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
FLAG_win64_unwinding_info;
}
#endif // V8_OS_WIN64
bool WasmCodeManager::Commit(base::AddressRegion region) {
// TODO(v8:8462): Remove eager commit once perf supports remapping.
if (FLAG_perf_prof) return true;
DCHECK(IsAligned(region.begin(), CommitPageSize()));
DCHECK(IsAligned(region.size(), CommitPageSize()));
// Reserve the size. Use CAS loop to avoid overflow on
// {total_committed_code_space_}.
size_t old_value = total_committed_code_space_.load();
while (true) {
DCHECK_GE(max_committed_code_space_, old_value);
if (region.size() > max_committed_code_space_ - old_value) return false;
if (total_committed_code_space_.compare_exchange_weak(
old_value, old_value + region.size())) {
break;
}
}
PageAllocator::Permission permission = FLAG_wasm_write_protect_code_memory
? PageAllocator::kReadWrite
: PageAllocator::kReadWriteExecute;
bool ret = SetPermissions(GetPlatformPageAllocator(), region.begin(),
region.size(), permission);
TRACE_HEAP("Setting rw permissions for 0x%" PRIxPTR ":0x%" PRIxPTR "\n",
region.begin(), region.end());
if (!ret) {
// Highly unlikely.
total_committed_code_space_.fetch_sub(region.size());
return false;
}
return true;
}
void WasmCodeManager::Decommit(base::AddressRegion region) {
// TODO(v8:8462): Remove this once perf supports remapping.
if (FLAG_perf_prof) return;
PageAllocator* allocator = GetPlatformPageAllocator();
DCHECK(IsAligned(region.begin(), allocator->CommitPageSize()));
DCHECK(IsAligned(region.size(), allocator->CommitPageSize()));
size_t old_committed = total_committed_code_space_.fetch_sub(region.size());
DCHECK_LE(region.size(), old_committed);
USE(old_committed);
TRACE_HEAP("Discarding system pages 0x%" PRIxPTR ":0x%" PRIxPTR "\n",
region.begin(), region.end());
CHECK(allocator->SetPermissions(reinterpret_cast<void*>(region.begin()),
region.size(), PageAllocator::kNoAccess));
}
void WasmCodeManager::AssignRange(base::AddressRegion region,
NativeModule* native_module) {
base::MutexGuard lock(&native_modules_mutex_);
lookup_map_.insert(std::make_pair(
region.begin(), std::make_pair(region.end(), native_module)));
}
VirtualMemory WasmCodeManager::TryAllocate(size_t size, void* hint) {
v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
DCHECK_GT(size, 0);
size_t allocate_page_size = page_allocator->AllocatePageSize();
size = RoundUp(size, allocate_page_size);
if (!BackingStore::ReserveAddressSpace(size)) return {};
if (hint == nullptr) hint = page_allocator->GetRandomMmapAddr();
VirtualMemory mem(page_allocator, size, hint, allocate_page_size);
if (!mem.IsReserved()) {
BackingStore::ReleaseReservation(size);
return {};
}
TRACE_HEAP("VMem alloc: 0x%" PRIxPTR ":0x%" PRIxPTR " (%zu)\n", mem.address(),
mem.end(), mem.size());
// TODO(v8:8462): Remove eager commit once perf supports remapping.
if (FLAG_perf_prof) {
SetPermissions(GetPlatformPageAllocator(), mem.address(), mem.size(),
PageAllocator::kReadWriteExecute);
}
return mem;
}
namespace {
// The numbers here are rough estimates, used to calculate the size of the
// initial code reservation and for estimating the amount of external memory
// reported to the GC.
// They do not need to be accurate. Choosing them too small will result in
// separate code spaces being allocated (compile time and runtime overhead),
// choosing them too large results in over-reservation (virtual address space
// only).
// The current numbers have been determined on 2019-11-11 by clemensb@, based
// on one small and one large module compiled from C++ by Emscripten. If in
// doubt, they where chosen slightly larger than required, as over-reservation
// is not a big issue currently.
// Numbers will change when Liftoff or TurboFan evolve, other toolchains are
// used to produce the wasm code, or characteristics of wasm modules on the
// web change. They might require occasional tuning.
// This patch might help to find reasonable numbers for any future adaptation:
// https://crrev.com/c/1910945
#if V8_TARGET_ARCH_X64
constexpr size_t kTurbofanFunctionOverhead = 20;
constexpr size_t kTurbofanCodeSizeMultiplier = 3;
constexpr size_t kLiftoffFunctionOverhead = 60;
constexpr size_t kLiftoffCodeSizeMultiplier = 4;
constexpr size_t kImportSize = 350;
#elif V8_TARGET_ARCH_IA32
constexpr size_t kTurbofanFunctionOverhead = 20;
constexpr size_t kTurbofanCodeSizeMultiplier = 4;
constexpr size_t kLiftoffFunctionOverhead = 60;
constexpr size_t kLiftoffCodeSizeMultiplier = 5;
constexpr size_t kImportSize = 480;
#elif V8_TARGET_ARCH_ARM
constexpr size_t kTurbofanFunctionOverhead = 40;
constexpr size_t kTurbofanCodeSizeMultiplier = 4;
constexpr size_t kLiftoffFunctionOverhead = 108;
constexpr size_t kLiftoffCodeSizeMultiplier = 7;
constexpr size_t kImportSize = 750;
#elif V8_TARGET_ARCH_ARM64
constexpr size_t kTurbofanFunctionOverhead = 60;
constexpr size_t kTurbofanCodeSizeMultiplier = 4;
constexpr size_t kLiftoffFunctionOverhead = 80;
constexpr size_t kLiftoffCodeSizeMultiplier = 7;
constexpr size_t kImportSize = 750;
#else
// Other platforms should add their own estimates if needed. Numbers below are
// the minimum of other architectures.
constexpr size_t kTurbofanFunctionOverhead = 20;
constexpr size_t kTurbofanCodeSizeMultiplier = 3;
constexpr size_t kLiftoffFunctionOverhead = 60;
constexpr size_t kLiftoffCodeSizeMultiplier = 4;
constexpr size_t kImportSize = 350;
#endif
} // namespace
// static
size_t WasmCodeManager::EstimateLiftoffCodeSize(int body_size) {
return kLiftoffFunctionOverhead + kCodeAlignment / 2 +
body_size * kLiftoffCodeSizeMultiplier;
}
// static
size_t WasmCodeManager::EstimateNativeModuleCodeSize(const WasmModule* module,
bool include_liftoff) {
int num_functions = static_cast<int>(module->num_declared_functions);
int num_imported_functions = static_cast<int>(module->num_imported_functions);
int code_section_length = 0;
if (num_functions > 0) {
DCHECK_EQ(module->functions.size(), num_imported_functions + num_functions);
auto* first_fn = &module->functions[module->num_imported_functions];
auto* last_fn = &module->functions.back();
code_section_length =
static_cast<int>(last_fn->code.end_offset() - first_fn->code.offset());
}
return EstimateNativeModuleCodeSize(num_functions, num_imported_functions,
code_section_length, include_liftoff);
}
// static
size_t WasmCodeManager::EstimateNativeModuleCodeSize(int num_functions,
int num_imported_functions,
int code_section_length,
bool include_liftoff) {
const size_t overhead_per_function =
kTurbofanFunctionOverhead + kCodeAlignment / 2 +
(include_liftoff ? kLiftoffFunctionOverhead + kCodeAlignment / 2 : 0);
const size_t overhead_per_code_byte =
kTurbofanCodeSizeMultiplier +
(include_liftoff ? kLiftoffCodeSizeMultiplier : 0);
const size_t jump_table_size = RoundUp<kCodeAlignment>(
JumpTableAssembler::SizeForNumberOfSlots(num_functions));
const size_t far_jump_table_size =
RoundUp<kCodeAlignment>(JumpTableAssembler::SizeForNumberOfFarJumpSlots(
WasmCode::kRuntimeStubCount,
NumWasmFunctionsInFarJumpTable(num_functions)));
return jump_table_size // jump table
+ far_jump_table_size // far jump table
+ overhead_per_function * num_functions // per function
+ overhead_per_code_byte * code_section_length // per code byte
+ kImportSize * num_imported_functions; // per import
}
// static
size_t WasmCodeManager::EstimateNativeModuleMetaDataSize(
const WasmModule* module) {
size_t wasm_module_estimate = EstimateStoredSize(module);
uint32_t num_wasm_functions = module->num_declared_functions;
// TODO(wasm): Include wire bytes size.
size_t native_module_estimate =
sizeof(NativeModule) + /* NativeModule struct */
(sizeof(WasmCode*) * num_wasm_functions) + /* code table size */
(sizeof(WasmCode) * num_wasm_functions); /* code object size */
return wasm_module_estimate + native_module_estimate;
}
std::shared_ptr<NativeModule> WasmCodeManager::NewNativeModule(
WasmEngine* engine, Isolate* isolate, const WasmFeatures& enabled,
size_t code_size_estimate, std::shared_ptr<const WasmModule> module) {
DCHECK_EQ(this, isolate->wasm_engine()->code_manager());
if (total_committed_code_space_.load() >
critical_committed_code_space_.load()) {
(reinterpret_cast<v8::Isolate*>(isolate))
->MemoryPressureNotification(MemoryPressureLevel::kCritical);
size_t committed = total_committed_code_space_.load();
DCHECK_GE(max_committed_code_space_, committed);
critical_committed_code_space_.store(
committed + (max_committed_code_space_ - committed) / 2);
}
// If we cannot add code space later, reserve enough address space up front.
size_t code_vmem_size =
ReservationSize(code_size_estimate, module->num_declared_functions, 0);
// The '--wasm-max-code-space-reservation' testing flag can be used to reduce
// the maximum size of the initial code space reservation (in MB).
if (FLAG_wasm_max_initial_code_space_reservation > 0) {
size_t flag_max_bytes =
static_cast<size_t>(FLAG_wasm_max_initial_code_space_reservation) * MB;
if (flag_max_bytes < code_vmem_size) code_vmem_size = flag_max_bytes;
}
// Try up to two times; getting rid of dead JSArrayBuffer allocations might
// require two GCs because the first GC maybe incremental and may have
// floating garbage.
static constexpr int kAllocationRetries = 2;
VirtualMemory code_space;
for (int retries = 0;; ++retries) {
code_space = TryAllocate(code_vmem_size);
if (code_space.IsReserved()) break;
if (retries == kAllocationRetries) {
V8::FatalProcessOutOfMemory(isolate, "NewNativeModule");
UNREACHABLE();
}
// Run one GC, then try the allocation again.
isolate->heap()->MemoryPressureNotification(MemoryPressureLevel::kCritical,
true);
}
Address start = code_space.address();
size_t size = code_space.size();
Address end = code_space.end();
std::shared_ptr<NativeModule> ret;
new NativeModule(engine, enabled, std::move(code_space), std::move(module),
isolate->async_counters(), &ret);
// The constructor initialized the shared_ptr.
DCHECK_NOT_NULL(ret);
TRACE_HEAP("New NativeModule %p: Mem: %" PRIuPTR ",+%zu\n", ret.get(), start,
size);
base::MutexGuard lock(&native_modules_mutex_);
lookup_map_.insert(std::make_pair(start, std::make_pair(end, ret.get())));
return ret;
}
void NativeModule::SampleCodeSize(
Counters* counters, NativeModule::CodeSamplingTime sampling_time) const {
size_t code_size = sampling_time == kSampling
? code_allocator_.committed_code_space()
: code_allocator_.generated_code_size();
int code_size_mb = static_cast<int>(code_size / MB);
Histogram* histogram = nullptr;
switch (sampling_time) {
case kAfterBaseline:
histogram = counters->wasm_module_code_size_mb_after_baseline();
break;
case kAfterTopTier:
histogram = counters->wasm_module_code_size_mb_after_top_tier();
break;
case kSampling: {
histogram = counters->wasm_module_code_size_mb();
// If this is a wasm module of >= 2MB, also sample the freed code size,
// absolute and relative. Code GC does not happen on asm.js modules, and
// small modules will never trigger GC anyway.
size_t generated_size = code_allocator_.generated_code_size();
if (generated_size >= 2 * MB && module()->origin == kWasmOrigin) {
size_t freed_size = code_allocator_.freed_code_size();
DCHECK_LE(freed_size, generated_size);
int freed_percent = static_cast<int>(100 * freed_size / generated_size);
counters->wasm_module_freed_code_size_percent()->AddSample(
freed_percent);
}
break;
}
}
histogram->AddSample(code_size_mb);
}
WasmCode* NativeModule::AddCompiledCode(WasmCompilationResult result) {
return AddCompiledCode({&result, 1})[0];
}
std::vector<WasmCode*> NativeModule::AddCompiledCode(
Vector<WasmCompilationResult> results) {
DCHECK(!results.empty());
// First, allocate code space for all the results.
size_t total_code_space = 0;
for (auto& result : results) {
DCHECK(result.succeeded());
total_code_space += RoundUp<kCodeAlignment>(result.code_desc.instr_size);
}
Vector<byte> code_space =
code_allocator_.AllocateForCode(this, total_code_space);
// Lookup the jump tables to use once, then use for all code objects.
auto jump_tables = FindJumpTablesForRegion(base::AddressRegionOf(code_space));
std::vector<std::unique_ptr<WasmCode>> generated_code;
generated_code.reserve(results.size());
// Now copy the generated code into the code space and relocate it.
for (auto& result : results) {
DCHECK_EQ(result.code_desc.buffer, result.instr_buffer.get());
size_t code_size = RoundUp<kCodeAlignment>(result.code_desc.instr_size);
Vector<byte> this_code_space = code_space.SubVector(0, code_size);
code_space += code_size;
generated_code.emplace_back(AddCodeWithCodeSpace(
result.func_index, result.code_desc, result.frame_slot_count,
result.tagged_parameter_slots,
result.protected_instructions_data.as_vector(),
result.source_positions.as_vector(), GetCodeKind(result),
result.result_tier, this_code_space, jump_tables));
}
DCHECK_EQ(0, code_space.size());
// Under the {allocation_mutex_}, publish the code. The published code is put
// into the top-most surrounding {WasmCodeRefScope} by {PublishCodeLocked}.
std::vector<WasmCode*> code_vector;
code_vector.reserve(results.size());
{
base::MutexGuard lock(&allocation_mutex_);
for (auto& result : generated_code)
code_vector.push_back(PublishCodeLocked(std::move(result)));
}
return code_vector;
}
bool NativeModule::IsRedirectedToInterpreter(uint32_t func_index) {
base::MutexGuard lock(&allocation_mutex_);
return has_interpreter_redirection(func_index);
}
bool NativeModule::SetTieredDown() {
// Do not tier down asm.js.
if (module()->origin != kWasmOrigin) return false;
base::MutexGuard lock(&allocation_mutex_);
if (tier_down_) return true;
tier_down_ = true;
return false;
}
bool NativeModule::IsTieredDown() {
base::MutexGuard lock(&allocation_mutex_);
return tier_down_;
}
void NativeModule::TierDown(Isolate* isolate) {
// Do not tier down asm.js.
if (module()->origin != kWasmOrigin) return;
// Set the flag. Return if it is already set.
if (SetTieredDown()) return;
// Tier down all functions.
isolate->wasm_engine()->RecompileAllFunctions(isolate, this,
ExecutionTier::kLiftoff);
}
void NativeModule::TierUp(Isolate* isolate) {
// Do not tier up asm.js.
if (module()->origin != kWasmOrigin) return;
// Set the flag.
{
base::MutexGuard lock(&allocation_mutex_);
tier_down_ = false;
}
// Tier up all functions.
isolate->wasm_engine()->RecompileAllFunctions(isolate, this,
ExecutionTier::kTurbofan);
}
void NativeModule::FreeCode(Vector<WasmCode* const> codes) {
// Free the code space.
code_allocator_.FreeCode(codes);
base::MutexGuard guard(&allocation_mutex_);
// Remove debug side tables for all removed code objects.
if (debug_info_) debug_info_->RemoveDebugSideTables(codes);
// Free the {WasmCode} objects. This will also unregister trap handler data.
for (WasmCode* code : codes) {
DCHECK_EQ(1, owned_code_.count(code->instruction_start()));
owned_code_.erase(code->instruction_start());
}
}
size_t NativeModule::GetNumberOfCodeSpacesForTesting() const {
return code_allocator_.GetNumCodeSpaces();
}
DebugInfo* NativeModule::GetDebugInfo() {
base::MutexGuard guard(&allocation_mutex_);
if (!debug_info_) debug_info_ = std::make_unique<DebugInfo>(this);
return debug_info_.get();
}
void WasmCodeManager::FreeNativeModule(Vector<VirtualMemory> owned_code_space,
size_t committed_size) {
base::MutexGuard lock(&native_modules_mutex_);
for (auto& code_space : owned_code_space) {
DCHECK(code_space.IsReserved());
TRACE_HEAP("VMem Release: 0x%" PRIxPTR ":0x%" PRIxPTR " (%zu)\n",
code_space.address(), code_space.end(), code_space.size());
#if defined(V8_OS_WIN64)
if (CanRegisterUnwindInfoForNonABICompliantCodeRange()) {
win64_unwindinfo::UnregisterNonABICompliantCodeRange(
reinterpret_cast<void*>(code_space.address()));
}
#endif // V8_OS_WIN64
lookup_map_.erase(code_space.address());
BackingStore::ReleaseReservation(code_space.size());
code_space.Free();
DCHECK(!code_space.IsReserved());
}
DCHECK(IsAligned(committed_size, CommitPageSize()));
// TODO(v8:8462): Remove this once perf supports remapping.
if (!FLAG_perf_prof) {
size_t old_committed =
total_committed_code_space_.fetch_sub(committed_size);
DCHECK_LE(committed_size, old_committed);
USE(old_committed);
}
}
NativeModule* WasmCodeManager::LookupNativeModule(Address pc) const {
base::MutexGuard lock(&native_modules_mutex_);
if (lookup_map_.empty()) return nullptr;
auto iter = lookup_map_.upper_bound(pc);
if (iter == lookup_map_.begin()) return nullptr;
--iter;
Address region_start = iter->first;
Address region_end = iter->second.first;
NativeModule* candidate = iter->second.second;
DCHECK_NOT_NULL(candidate);
return region_start <= pc && pc < region_end ? candidate : nullptr;
}
WasmCode* WasmCodeManager::LookupCode(Address pc) const {
NativeModule* candidate = LookupNativeModule(pc);
return candidate ? candidate->Lookup(pc) : nullptr;
}
// TODO(v8:7424): Code protection scopes are not yet supported with shared code
// enabled and need to be revisited.
NativeModuleModificationScope::NativeModuleModificationScope(
NativeModule* native_module)
: native_module_(native_module) {
if (FLAG_wasm_write_protect_code_memory && native_module_ &&
(native_module_->modification_scope_depth_++) == 0) {
bool success = native_module_->SetExecutable(false);
CHECK(success);
}
}
NativeModuleModificationScope::~NativeModuleModificationScope() {
if (FLAG_wasm_write_protect_code_memory && native_module_ &&
(native_module_->modification_scope_depth_--) == 1) {
bool success = native_module_->SetExecutable(true);
CHECK(success);
}
}
namespace {
thread_local WasmCodeRefScope* current_code_refs_scope = nullptr;
} // namespace
WasmCodeRefScope::WasmCodeRefScope()
: previous_scope_(current_code_refs_scope) {
current_code_refs_scope = this;
}
WasmCodeRefScope::~WasmCodeRefScope() {
DCHECK_EQ(this, current_code_refs_scope);
current_code_refs_scope = previous_scope_;
std::vector<WasmCode*> code_ptrs;
code_ptrs.reserve(code_ptrs_.size());
code_ptrs.assign(code_ptrs_.begin(), code_ptrs_.end());
WasmCode::DecrementRefCount(VectorOf(code_ptrs));
}
// static
void WasmCodeRefScope::AddRef(WasmCode* code) {
DCHECK_NOT_NULL(code);
WasmCodeRefScope* current_scope = current_code_refs_scope;
DCHECK_NOT_NULL(current_scope);
auto entry = current_scope->code_ptrs_.insert(code);
// If we added a new entry, increment the ref counter.
if (entry.second) code->IncRef();
}
} // namespace wasm
} // namespace internal
} // namespace v8
#undef TRACE_HEAP
|