aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/perf/util/symbol-elf.c
blob: 31cd59a2b66e6cc2223ad6fb18bfe90d40e9d4b2 (plain) (blame)
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
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
// SPDX-License-Identifier: GPL-2.0
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>

#include "dso.h"
#include "map.h"
#include "maps.h"
#include "symbol.h"
#include "symsrc.h"
#include "demangle-ocaml.h"
#include "demangle-java.h"
#include "demangle-rust.h"
#include "machine.h"
#include "vdso.h"
#include "debug.h"
#include "util/copyfile.h"
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/zalloc.h>
#include <symbol/kallsyms.h>
#include <internal/lib.h>

#ifndef EM_AARCH64
#define EM_AARCH64	183  /* ARM 64 bit */
#endif

#ifndef ELF32_ST_VISIBILITY
#define ELF32_ST_VISIBILITY(o)	((o) & 0x03)
#endif

/* For ELF64 the definitions are the same.  */
#ifndef ELF64_ST_VISIBILITY
#define ELF64_ST_VISIBILITY(o)	ELF32_ST_VISIBILITY (o)
#endif

/* How to extract information held in the st_other field.  */
#ifndef GELF_ST_VISIBILITY
#define GELF_ST_VISIBILITY(val)	ELF64_ST_VISIBILITY (val)
#endif

typedef Elf64_Nhdr GElf_Nhdr;

#ifndef DMGL_PARAMS
#define DMGL_NO_OPTS     0              /* For readability... */
#define DMGL_PARAMS      (1 << 0)       /* Include function args */
#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
#endif

#ifdef HAVE_LIBBFD_SUPPORT
#define PACKAGE 'perf'
#include <bfd.h>
#else
#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
extern char *cplus_demangle(const char *, int);

static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
{
	return cplus_demangle(c, i);
}
#else
#ifdef NO_DEMANGLE
static inline char *bfd_demangle(void __maybe_unused *v,
				 const char __maybe_unused *c,
				 int __maybe_unused i)
{
	return NULL;
}
#endif
#endif
#endif

#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
static int elf_getphdrnum(Elf *elf, size_t *dst)
{
	GElf_Ehdr gehdr;
	GElf_Ehdr *ehdr;

	ehdr = gelf_getehdr(elf, &gehdr);
	if (!ehdr)
		return -1;

	*dst = ehdr->e_phnum;

	return 0;
}
#endif

#ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
{
	pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
	return -1;
}
#endif

#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif

/**
 * elf_symtab__for_each_symbol - iterate thru all the symbols
 *
 * @syms: struct elf_symtab instance to iterate
 * @idx: uint32_t idx
 * @sym: GElf_Sym iterator
 */
#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
	for (idx = 0, gelf_getsym(syms, idx, &sym);\
	     idx < nr_syms; \
	     idx++, gelf_getsym(syms, idx, &sym))

static inline uint8_t elf_sym__type(const GElf_Sym *sym)
{
	return GELF_ST_TYPE(sym->st_info);
}

static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
{
	return GELF_ST_VISIBILITY(sym->st_other);
}

#ifndef STT_GNU_IFUNC
#define STT_GNU_IFUNC 10
#endif

static inline int elf_sym__is_function(const GElf_Sym *sym)
{
	return (elf_sym__type(sym) == STT_FUNC ||
		elf_sym__type(sym) == STT_GNU_IFUNC) &&
	       sym->st_name != 0 &&
	       sym->st_shndx != SHN_UNDEF;
}

static inline bool elf_sym__is_object(const GElf_Sym *sym)
{
	return elf_sym__type(sym) == STT_OBJECT &&
		sym->st_name != 0 &&
		sym->st_shndx != SHN_UNDEF;
}

static inline int elf_sym__is_label(const GElf_Sym *sym)
{
	return elf_sym__type(sym) == STT_NOTYPE &&
		sym->st_name != 0 &&
		sym->st_shndx != SHN_UNDEF &&
		sym->st_shndx != SHN_ABS &&
		elf_sym__visibility(sym) != STV_HIDDEN &&
		elf_sym__visibility(sym) != STV_INTERNAL;
}

static bool elf_sym__filter(GElf_Sym *sym)
{
	return elf_sym__is_function(sym) || elf_sym__is_object(sym);
}

static inline const char *elf_sym__name(const GElf_Sym *sym,
					const Elf_Data *symstrs)
{
	return symstrs->d_buf + sym->st_name;
}

static inline const char *elf_sec__name(const GElf_Shdr *shdr,
					const Elf_Data *secstrs)
{
	return secstrs->d_buf + shdr->sh_name;
}

static inline int elf_sec__is_text(const GElf_Shdr *shdr,
					const Elf_Data *secstrs)
{
	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
}

static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
				    const Elf_Data *secstrs)
{
	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
}

static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
{
	return elf_sec__is_text(shdr, secstrs) || 
	       elf_sec__is_data(shdr, secstrs);
}

static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
{
	Elf_Scn *sec = NULL;
	GElf_Shdr shdr;
	size_t cnt = 1;

	while ((sec = elf_nextscn(elf, sec)) != NULL) {
		gelf_getshdr(sec, &shdr);

		if ((addr >= shdr.sh_addr) &&
		    (addr < (shdr.sh_addr + shdr.sh_size)))
			return cnt;

		++cnt;
	}

	return -1;
}

Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
			     GElf_Shdr *shp, const char *name, size_t *idx)
{
	Elf_Scn *sec = NULL;
	size_t cnt = 1;

	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
		return NULL;

	while ((sec = elf_nextscn(elf, sec)) != NULL) {
		char *str;

		gelf_getshdr(sec, shp);
		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
		if (str && !strcmp(name, str)) {
			if (idx)
				*idx = cnt;
			return sec;
		}
		++cnt;
	}

	return NULL;
}

static bool want_demangle(bool is_kernel_sym)
{
	return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
}

static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
{
	int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
	char *demangled = NULL;

	/*
	 * We need to figure out if the object was created from C++ sources
	 * DWARF DW_compile_unit has this, but we don't always have access
	 * to it...
	 */
	if (!want_demangle(dso->kernel || kmodule))
	    return demangled;

	demangled = bfd_demangle(NULL, elf_name, demangle_flags);
	if (demangled == NULL) {
		demangled = ocaml_demangle_sym(elf_name);
		if (demangled == NULL) {
			demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
		}
	}
	else if (rust_is_mangled(demangled))
		/*
		    * Input to Rust demangling is the BFD-demangled
		    * name which it Rust-demangles in place.
		    */
		rust_demangle_sym(demangled);

	return demangled;
}

#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
	     idx < nr_entries; \
	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))

#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
	     idx < nr_entries; \
	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))

/*
 * We need to check if we have a .dynsym, so that we can handle the
 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 * .dynsym or .symtab).
 * And always look at the original dso, not at debuginfo packages, that
 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 */
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
{
	uint32_t nr_rel_entries, idx;
	GElf_Sym sym;
	u64 plt_offset, plt_header_size, plt_entry_size;
	GElf_Shdr shdr_plt;
	struct symbol *f;
	GElf_Shdr shdr_rel_plt, shdr_dynsym;
	Elf_Data *reldata, *syms, *symstrs;
	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
	size_t dynsym_idx;
	GElf_Ehdr ehdr;
	char sympltname[1024];
	Elf *elf;
	int nr = 0, symidx, err = 0;

	if (!ss->dynsym)
		return 0;

	elf = ss->elf;
	ehdr = ss->ehdr;

	scn_dynsym = ss->dynsym;
	shdr_dynsym = ss->dynshdr;
	dynsym_idx = ss->dynsym_idx;

	if (scn_dynsym == NULL)
		goto out_elf_end;

	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
					  ".rela.plt", NULL);
	if (scn_plt_rel == NULL) {
		scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
						  ".rel.plt", NULL);
		if (scn_plt_rel == NULL)
			goto out_elf_end;
	}

	err = -1;

	if (shdr_rel_plt.sh_link != dynsym_idx)
		goto out_elf_end;

	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
		goto out_elf_end;

	/*
	 * Fetch the relocation section to find the idxes to the GOT
	 * and the symbols in the .dynsym they refer to.
	 */
	reldata = elf_getdata(scn_plt_rel, NULL);
	if (reldata == NULL)
		goto out_elf_end;

	syms = elf_getdata(scn_dynsym, NULL);
	if (syms == NULL)
		goto out_elf_end;

	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
	if (scn_symstrs == NULL)
		goto out_elf_end;

	symstrs = elf_getdata(scn_symstrs, NULL);
	if (symstrs == NULL)
		goto out_elf_end;

	if (symstrs->d_size == 0)
		goto out_elf_end;

	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
	plt_offset = shdr_plt.sh_offset;
	switch (ehdr.e_machine) {
		case EM_ARM:
			plt_header_size = 20;
			plt_entry_size = 12;
			break;

		case EM_AARCH64:
			plt_header_size = 32;
			plt_entry_size = 16;
			break;

		case EM_SPARC:
			plt_header_size = 48;
			plt_entry_size = 12;
			break;

		case EM_SPARCV9:
			plt_header_size = 128;
			plt_entry_size = 32;
			break;

		default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
			plt_header_size = shdr_plt.sh_entsize;
			plt_entry_size = shdr_plt.sh_entsize;
			break;
	}
	plt_offset += plt_header_size;

	if (shdr_rel_plt.sh_type == SHT_RELA) {
		GElf_Rela pos_mem, *pos;

		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
					   nr_rel_entries) {
			const char *elf_name = NULL;
			char *demangled = NULL;
			symidx = GELF_R_SYM(pos->r_info);
			gelf_getsym(syms, symidx, &sym);

			elf_name = elf_sym__name(&sym, symstrs);
			demangled = demangle_sym(dso, 0, elf_name);
			if (demangled != NULL)
				elf_name = demangled;
			snprintf(sympltname, sizeof(sympltname),
				 "%s@plt", elf_name);
			free(demangled);

			f = symbol__new(plt_offset, plt_entry_size,
					STB_GLOBAL, STT_FUNC, sympltname);
			if (!f)
				goto out_elf_end;

			plt_offset += plt_entry_size;
			symbols__insert(&dso->symbols, f);
			++nr;
		}
	} else if (shdr_rel_plt.sh_type == SHT_REL) {
		GElf_Rel pos_mem, *pos;
		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
					  nr_rel_entries) {
			const char *elf_name = NULL;
			char *demangled = NULL;
			symidx = GELF_R_SYM(pos->r_info);
			gelf_getsym(syms, symidx, &sym);

			elf_name = elf_sym__name(&sym, symstrs);
			demangled = demangle_sym(dso, 0, elf_name);
			if (demangled != NULL)
				elf_name = demangled;
			snprintf(sympltname, sizeof(sympltname),
				 "%s@plt", elf_name);
			free(demangled);

			f = symbol__new(plt_offset, plt_entry_size,
					STB_GLOBAL, STT_FUNC, sympltname);
			if (!f)
				goto out_elf_end;

			plt_offset += plt_entry_size;
			symbols__insert(&dso->symbols, f);
			++nr;
		}
	}

	err = 0;
out_elf_end:
	if (err == 0)
		return nr;
	pr_debug("%s: problems reading %s PLT info.\n",
		 __func__, dso->long_name);
	return 0;
}

char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
{
	return demangle_sym(dso, kmodule, elf_name);
}

/*
 * Align offset to 4 bytes as needed for note name and descriptor data.
 */
#define NOTE_ALIGN(n) (((n) + 3) & -4U)

static int elf_read_build_id(Elf *elf, void *bf, size_t size)
{
	int err = -1;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	Elf_Data *data;
	Elf_Scn *sec;
	Elf_Kind ek;
	void *ptr;

	if (size < BUILD_ID_SIZE)
		goto out;

	ek = elf_kind(elf);
	if (ek != ELF_K_ELF)
		goto out;

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		pr_err("%s: cannot get elf header.\n", __func__);
		goto out;
	}

	/*
	 * Check following sections for notes:
	 *   '.note.gnu.build-id'
	 *   '.notes'
	 *   '.note' (VDSO specific)
	 */
	do {
		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".note.gnu.build-id", NULL);
		if (sec)
			break;

		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".notes", NULL);
		if (sec)
			break;

		sec = elf_section_by_name(elf, &ehdr, &shdr,
					  ".note", NULL);
		if (sec)
			break;

		return err;

	} while (0);

	data = elf_getdata(sec, NULL);
	if (data == NULL)
		goto out;

	ptr = data->d_buf;
	while (ptr < (data->d_buf + data->d_size)) {
		GElf_Nhdr *nhdr = ptr;
		size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
		       descsz = NOTE_ALIGN(nhdr->n_descsz);
		const char *name;

		ptr += sizeof(*nhdr);
		name = ptr;
		ptr += namesz;
		if (nhdr->n_type == NT_GNU_BUILD_ID &&
		    nhdr->n_namesz == sizeof("GNU")) {
			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
				size_t sz = min(size, descsz);
				memcpy(bf, ptr, sz);
				memset(bf + sz, 0, size - sz);
				err = descsz;
				break;
			}
		}
		ptr += descsz;
	}

out:
	return err;
}

#ifdef HAVE_LIBBFD_BUILDID_SUPPORT

static int read_build_id(const char *filename, struct build_id *bid)
{
	size_t size = sizeof(bid->data);
	int err = -1;
	bfd *abfd;

	abfd = bfd_openr(filename, NULL);
	if (!abfd)
		return -1;

	if (!bfd_check_format(abfd, bfd_object)) {
		pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
		goto out_close;
	}

	if (!abfd->build_id || abfd->build_id->size > size)
		goto out_close;

	memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
	memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
	err = bid->size = abfd->build_id->size;

out_close:
	bfd_close(abfd);
	return err;
}

#else // HAVE_LIBBFD_BUILDID_SUPPORT

static int read_build_id(const char *filename, struct build_id *bid)
{
	size_t size = sizeof(bid->data);
	int fd, err = -1;
	Elf *elf;

	if (size < BUILD_ID_SIZE)
		goto out;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
		goto out_close;
	}

	err = elf_read_build_id(elf, bid->data, size);
	if (err > 0)
		bid->size = err;

	elf_end(elf);
out_close:
	close(fd);
out:
	return err;
}

#endif // HAVE_LIBBFD_BUILDID_SUPPORT

int filename__read_build_id(const char *filename, struct build_id *bid)
{
	struct kmod_path m = { .name = NULL, };
	char path[PATH_MAX];
	int err;

	if (!filename)
		return -EFAULT;

	err = kmod_path__parse(&m, filename);
	if (err)
		return -1;

	if (m.comp) {
		int error = 0, fd;

		fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
		if (fd < 0) {
			pr_debug("Failed to decompress (error %d) %s\n",
				 error, filename);
			return -1;
		}
		close(fd);
		filename = path;
	}

	err = read_build_id(filename, bid);

	if (m.comp)
		unlink(filename);
	return err;
}

int sysfs__read_build_id(const char *filename, struct build_id *bid)
{
	size_t size = sizeof(bid->data);
	int fd, err = -1;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	while (1) {
		char bf[BUFSIZ];
		GElf_Nhdr nhdr;
		size_t namesz, descsz;

		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
			break;

		namesz = NOTE_ALIGN(nhdr.n_namesz);
		descsz = NOTE_ALIGN(nhdr.n_descsz);
		if (nhdr.n_type == NT_GNU_BUILD_ID &&
		    nhdr.n_namesz == sizeof("GNU")) {
			if (read(fd, bf, namesz) != (ssize_t)namesz)
				break;
			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
				size_t sz = min(descsz, size);
				if (read(fd, bid->data, sz) == (ssize_t)sz) {
					memset(bid->data + sz, 0, size - sz);
					bid->size = sz;
					err = 0;
					break;
				}
			} else if (read(fd, bf, descsz) != (ssize_t)descsz)
				break;
		} else {
			int n = namesz + descsz;

			if (n > (int)sizeof(bf)) {
				n = sizeof(bf);
				pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
					 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
			}
			if (read(fd, bf, n) != n)
				break;
		}
	}
	close(fd);
out:
	return err;
}

#ifdef HAVE_LIBBFD_SUPPORT

int filename__read_debuglink(const char *filename, char *debuglink,
			     size_t size)
{
	int err = -1;
	asection *section;
	bfd *abfd;

	abfd = bfd_openr(filename, NULL);
	if (!abfd)
		return -1;

	if (!bfd_check_format(abfd, bfd_object)) {
		pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
		goto out_close;
	}

	section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
	if (!section)
		goto out_close;

	if (section->size > size)
		goto out_close;

	if (!bfd_get_section_contents(abfd, section, debuglink, 0,
				      section->size))
		goto out_close;

	err = 0;

out_close:
	bfd_close(abfd);
	return err;
}

#else

int filename__read_debuglink(const char *filename, char *debuglink,
			     size_t size)
{
	int fd, err = -1;
	Elf *elf;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	Elf_Data *data;
	Elf_Scn *sec;
	Elf_Kind ek;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		goto out;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
		goto out_close;
	}

	ek = elf_kind(elf);
	if (ek != ELF_K_ELF)
		goto out_elf_end;

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		pr_err("%s: cannot get elf header.\n", __func__);
		goto out_elf_end;
	}

	sec = elf_section_by_name(elf, &ehdr, &shdr,
				  ".gnu_debuglink", NULL);
	if (sec == NULL)
		goto out_elf_end;

	data = elf_getdata(sec, NULL);
	if (data == NULL)
		goto out_elf_end;

	/* the start of this section is a zero-terminated string */
	strncpy(debuglink, data->d_buf, size);

	err = 0;

out_elf_end:
	elf_end(elf);
out_close:
	close(fd);
out:
	return err;
}

#endif

static int dso__swap_init(struct dso *dso, unsigned char eidata)
{
	static unsigned int const endian = 1;

	dso->needs_swap = DSO_SWAP__NO;

	switch (eidata) {
	case ELFDATA2LSB:
		/* We are big endian, DSO is little endian. */
		if (*(unsigned char const *)&endian != 1)
			dso->needs_swap = DSO_SWAP__YES;
		break;

	case ELFDATA2MSB:
		/* We are little endian, DSO is big endian. */
		if (*(unsigned char const *)&endian != 0)
			dso->needs_swap = DSO_SWAP__YES;
		break;

	default:
		pr_err("unrecognized DSO data encoding %d\n", eidata);
		return -EINVAL;
	}

	return 0;
}

bool symsrc__possibly_runtime(struct symsrc *ss)
{
	return ss->dynsym || ss->opdsec;
}

bool symsrc__has_symtab(struct symsrc *ss)
{
	return ss->symtab != NULL;
}

void symsrc__destroy(struct symsrc *ss)
{
	zfree(&ss->name);
	elf_end(ss->elf);
	close(ss->fd);
}

bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
{
	/*
	 * Usually vmlinux is an ELF file with type ET_EXEC for most
	 * architectures; except Arm64 kernel is linked with option
	 * '-share', so need to check type ET_DYN.
	 */
	return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
	       ehdr.e_type == ET_DYN;
}

int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
		 enum dso_binary_type type)
{
	GElf_Ehdr ehdr;
	Elf *elf;
	int fd;

	if (dso__needs_decompress(dso)) {
		fd = dso__decompress_kmodule_fd(dso, name);
		if (fd < 0)
			return -1;

		type = dso->symtab_type;
	} else {
		fd = open(name, O_RDONLY);
		if (fd < 0) {
			dso->load_errno = errno;
			return -1;
		}
	}

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL) {
		pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
		dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
		goto out_close;
	}

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
		pr_debug("%s: cannot get elf header.\n", __func__);
		goto out_elf_end;
	}

	if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
		dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
		goto out_elf_end;
	}

	/* Always reject images with a mismatched build-id: */
	if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
		u8 build_id[BUILD_ID_SIZE];
		struct build_id bid;
		int size;

		size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
		if (size <= 0) {
			dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
			goto out_elf_end;
		}

		build_id__init(&bid, build_id, size);
		if (!dso__build_id_equal(dso, &bid)) {
			pr_debug("%s: build id mismatch for %s.\n", __func__, name);
			dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
			goto out_elf_end;
		}
	}

	ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);

	ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
			NULL);
	if (ss->symshdr.sh_type != SHT_SYMTAB)
		ss->symtab = NULL;

	ss->dynsym_idx = 0;
	ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
			&ss->dynsym_idx);
	if (ss->dynshdr.sh_type != SHT_DYNSYM)
		ss->dynsym = NULL;

	ss->opdidx = 0;
	ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
			&ss->opdidx);
	if (ss->opdshdr.sh_type != SHT_PROGBITS)
		ss->opdsec = NULL;

	if (dso->kernel == DSO_SPACE__USER)
		ss->adjust_symbols = true;
	else
		ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);

	ss->name   = strdup(name);
	if (!ss->name) {
		dso->load_errno = errno;
		goto out_elf_end;
	}

	ss->elf    = elf;
	ss->fd     = fd;
	ss->ehdr   = ehdr;
	ss->type   = type;

	return 0;

out_elf_end:
	elf_end(elf);
out_close:
	close(fd);
	return -1;
}

/**
 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
 * @kmap: kernel maps and relocation reference symbol
 *
 * This function returns %true if we are dealing with the kernel maps and the
 * relocation reference symbol has not yet been found.  Otherwise %false is
 * returned.
 */
static bool ref_reloc_sym_not_found(struct kmap *kmap)
{
	return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
	       !kmap->ref_reloc_sym->unrelocated_addr;
}

/**
 * ref_reloc - kernel relocation offset.
 * @kmap: kernel maps and relocation reference symbol
 *
 * This function returns the offset of kernel addresses as determined by using
 * the relocation reference symbol i.e. if the kernel has not been relocated
 * then the return value is zero.
 */
static u64 ref_reloc(struct kmap *kmap)
{
	if (kmap && kmap->ref_reloc_sym &&
	    kmap->ref_reloc_sym->unrelocated_addr)
		return kmap->ref_reloc_sym->addr -
		       kmap->ref_reloc_sym->unrelocated_addr;
	return 0;
}

void __weak arch__sym_update(struct symbol *s __maybe_unused,
		GElf_Sym *sym __maybe_unused) { }

static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
				      GElf_Sym *sym, GElf_Shdr *shdr,
				      struct maps *kmaps, struct kmap *kmap,
				      struct dso **curr_dsop, struct map **curr_mapp,
				      const char *section_name,
				      bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
{
	struct dso *curr_dso = *curr_dsop;
	struct map *curr_map;
	char dso_name[PATH_MAX];

	/* Adjust symbol to map to file offset */
	if (adjust_kernel_syms)
		sym->st_value -= shdr->sh_addr - shdr->sh_offset;

	if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
		return 0;

	if (strcmp(section_name, ".text") == 0) {
		/*
		 * The initial kernel mapping is based on
		 * kallsyms and identity maps.  Overwrite it to
		 * map to the kernel dso.
		 */
		if (*remap_kernel && dso->kernel && !kmodule) {
			*remap_kernel = false;
			map->start = shdr->sh_addr + ref_reloc(kmap);
			map->end = map->start + shdr->sh_size;
			map->pgoff = shdr->sh_offset;
			map->map_ip = map__map_ip;
			map->unmap_ip = map__unmap_ip;
			/* Ensure maps are correctly ordered */
			if (kmaps) {
				map__get(map);
				maps__remove(kmaps, map);
				maps__insert(kmaps, map);
				map__put(map);
			}
		}

		/*
		 * The initial module mapping is based on
		 * /proc/modules mapped to offset zero.
		 * Overwrite it to map to the module dso.
		 */
		if (*remap_kernel && kmodule) {
			*remap_kernel = false;
			map->pgoff = shdr->sh_offset;
		}

		*curr_mapp = map;
		*curr_dsop = dso;
		return 0;
	}

	if (!kmap)
		return 0;

	snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);

	curr_map = maps__find_by_name(kmaps, dso_name);
	if (curr_map == NULL) {
		u64 start = sym->st_value;

		if (kmodule)
			start += map->start + shdr->sh_offset;

		curr_dso = dso__new(dso_name);
		if (curr_dso == NULL)
			return -1;
		curr_dso->kernel = dso->kernel;
		curr_dso->long_name = dso->long_name;
		curr_dso->long_name_len = dso->long_name_len;
		curr_map = map__new2(start, curr_dso);
		dso__put(curr_dso);
		if (curr_map == NULL)
			return -1;

		if (curr_dso->kernel)
			map__kmap(curr_map)->kmaps = kmaps;

		if (adjust_kernel_syms) {
			curr_map->start  = shdr->sh_addr + ref_reloc(kmap);
			curr_map->end	 = curr_map->start + shdr->sh_size;
			curr_map->pgoff	 = shdr->sh_offset;
		} else {
			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
		}
		curr_dso->symtab_type = dso->symtab_type;
		maps__insert(kmaps, curr_map);
		/*
		 * Add it before we drop the reference to curr_map, i.e. while
		 * we still are sure to have a reference to this DSO via
		 * *curr_map->dso.
		 */
		dsos__add(&kmaps->machine->dsos, curr_dso);
		/* kmaps already got it */
		map__put(curr_map);
		dso__set_loaded(curr_dso);
		*curr_mapp = curr_map;
		*curr_dsop = curr_dso;
	} else
		*curr_dsop = curr_map->dso;

	return 0;
}

static int
dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
		       struct symsrc *runtime_ss, int kmodule, int dynsym)
{
	struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
	struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
	struct map *curr_map = map;
	struct dso *curr_dso = dso;
	Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym;
	uint32_t nr_syms;
	int err = -1;
	uint32_t idx;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	GElf_Shdr tshdr;
	Elf_Data *syms, *opddata = NULL;
	GElf_Sym sym;
	Elf_Scn *sec, *sec_strndx;
	Elf *elf;
	int nr = 0;
	bool remap_kernel = false, adjust_kernel_syms = false;

	if (kmap && !kmaps)
		return -1;

	elf = syms_ss->elf;
	ehdr = syms_ss->ehdr;
	if (dynsym) {
		sec  = syms_ss->dynsym;
		shdr = syms_ss->dynshdr;
	} else {
		sec =  syms_ss->symtab;
		shdr = syms_ss->symshdr;
	}

	if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
				".text", NULL))
		dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;

	if (runtime_ss->opdsec)
		opddata = elf_rawdata(runtime_ss->opdsec, NULL);

	syms = elf_getdata(sec, NULL);
	if (syms == NULL)
		goto out_elf_end;

	sec = elf_getscn(elf, shdr.sh_link);
	if (sec == NULL)
		goto out_elf_end;

	symstrs = elf_getdata(sec, NULL);
	if (symstrs == NULL)
		goto out_elf_end;

	sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
	if (sec_strndx == NULL)
		goto out_elf_end;

	secstrs_run = elf_getdata(sec_strndx, NULL);
	if (secstrs_run == NULL)
		goto out_elf_end;

	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
	if (sec_strndx == NULL)
		goto out_elf_end;

	secstrs_sym = elf_getdata(sec_strndx, NULL);
	if (secstrs_sym == NULL)
		goto out_elf_end;

	nr_syms = shdr.sh_size / shdr.sh_entsize;

	memset(&sym, 0, sizeof(sym));

	/*
	 * The kernel relocation symbol is needed in advance in order to adjust
	 * kernel maps correctly.
	 */
	if (ref_reloc_sym_not_found(kmap)) {
		elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
			const char *elf_name = elf_sym__name(&sym, symstrs);

			if (strcmp(elf_name, kmap->ref_reloc_sym->name))
				continue;
			kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
			map->reloc = kmap->ref_reloc_sym->addr -
				     kmap->ref_reloc_sym->unrelocated_addr;
			break;
		}
	}

	/*
	 * Handle any relocation of vdso necessary because older kernels
	 * attempted to prelink vdso to its virtual address.
	 */
	if (dso__is_vdso(dso))
		map->reloc = map->start - dso->text_offset;

	dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
	/*
	 * Initial kernel and module mappings do not map to the dso.
	 * Flag the fixups.
	 */
	if (dso->kernel) {
		remap_kernel = true;
		adjust_kernel_syms = dso->adjust_symbols;
	}
	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
		struct symbol *f;
		const char *elf_name = elf_sym__name(&sym, symstrs);
		char *demangled = NULL;
		int is_label = elf_sym__is_label(&sym);
		const char *section_name;
		bool used_opd = false;

		if (!is_label && !elf_sym__filter(&sym))
			continue;

		/* Reject ARM ELF "mapping symbols": these aren't unique and
		 * don't identify functions, so will confuse the profile
		 * output: */
		if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
			if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
			    && (elf_name[2] == '\0' || elf_name[2] == '.'))
				continue;
		}

		if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
			u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
			u64 *opd = opddata->d_buf + offset;
			sym.st_value = DSO__SWAP(dso, u64, *opd);
			sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
					sym.st_value);
			used_opd = true;
		}
		/*
		 * When loading symbols in a data mapping, ABS symbols (which
		 * has a value of SHN_ABS in its st_shndx) failed at
		 * elf_getscn().  And it marks the loading as a failure so
		 * already loaded symbols cannot be fixed up.
		 *
		 * I'm not sure what should be done. Just ignore them for now.
		 * - Namhyung Kim
		 */
		if (sym.st_shndx == SHN_ABS)
			continue;

		sec = elf_getscn(syms_ss->elf, sym.st_shndx);
		if (!sec)
			goto out_elf_end;

		gelf_getshdr(sec, &shdr);

		secstrs = secstrs_sym;

		/*
		 * We have to fallback to runtime when syms' section header has
		 * NOBITS set. NOBITS results in file offset (sh_offset) not
		 * being incremented. So sh_offset used below has different
		 * values for syms (invalid) and runtime (valid).
		 */
		if (shdr.sh_type == SHT_NOBITS) {
			sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
			if (!sec)
				goto out_elf_end;

			gelf_getshdr(sec, &shdr);
			secstrs = secstrs_run;
		}

		if (is_label && !elf_sec__filter(&shdr, secstrs))
			continue;

		section_name = elf_sec__name(&shdr, secstrs);

		/* On ARM, symbols for thumb functions have 1 added to
		 * the symbol address as a flag - remove it */
		if ((ehdr.e_machine == EM_ARM) &&
		    (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
		    (sym.st_value & 1))
			--sym.st_value;

		if (dso->kernel) {
			if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
						       section_name, adjust_kernel_syms, kmodule, &remap_kernel))
				goto out_elf_end;
		} else if ((used_opd && runtime_ss->adjust_symbols) ||
			   (!used_opd && syms_ss->adjust_symbols)) {
			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
				  (u64)sym.st_value, (u64)shdr.sh_addr,
				  (u64)shdr.sh_offset);
			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
		}

		demangled = demangle_sym(dso, kmodule, elf_name);
		if (demangled != NULL)
			elf_name = demangled;

		f = symbol__new(sym.st_value, sym.st_size,
				GELF_ST_BIND(sym.st_info),
				GELF_ST_TYPE(sym.st_info), elf_name);
		free(demangled);
		if (!f)
			goto out_elf_end;

		arch__sym_update(f, &sym);

		__symbols__insert(&curr_dso->symbols, f, dso->kernel);
		nr++;
	}

	/*
	 * For misannotated, zeroed, ASM function sizes.
	 */
	if (nr > 0) {
		symbols__fixup_end(&dso->symbols);
		symbols__fixup_duplicate(&dso->symbols);
		if (kmap) {
			/*
			 * We need to fixup this here too because we create new
			 * maps here, for things like vsyscall sections.
			 */
			maps__fixup_end(kmaps);
		}
	}
	err = nr;
out_elf_end:
	return err;
}

int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
		  struct symsrc *runtime_ss, int kmodule)
{
	int nr = 0;
	int err = -1;

	dso->symtab_type = syms_ss->type;
	dso->is_64_bit = syms_ss->is_64_bit;
	dso->rel = syms_ss->ehdr.e_type == ET_REL;

	/*
	 * Modules may already have symbols from kallsyms, but those symbols
	 * have the wrong values for the dso maps, so remove them.
	 */
	if (kmodule && syms_ss->symtab)
		symbols__delete(&dso->symbols);

	if (!syms_ss->symtab) {
		/*
		 * If the vmlinux is stripped, fail so we will fall back
		 * to using kallsyms. The vmlinux runtime symbols aren't
		 * of much use.
		 */
		if (dso->kernel)
			return err;
	} else  {
		err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
					     kmodule, 0);
		if (err < 0)
			return err;
		nr = err;
	}

	if (syms_ss->dynsym) {
		err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
					     kmodule, 1);
		if (err < 0)
			return err;
		err += nr;
	}

	return err;
}

static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
{
	GElf_Phdr phdr;
	size_t i, phdrnum;
	int err;
	u64 sz;

	if (elf_getphdrnum(elf, &phdrnum))
		return -1;

	for (i = 0; i < phdrnum; i++) {
		if (gelf_getphdr(elf, i, &phdr) == NULL)
			return -1;
		if (phdr.p_type != PT_LOAD)
			continue;
		if (exe) {
			if (!(phdr.p_flags & PF_X))
				continue;
		} else {
			if (!(phdr.p_flags & PF_R))
				continue;
		}
		sz = min(phdr.p_memsz, phdr.p_filesz);
		if (!sz)
			continue;
		err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
		if (err)
			return err;
	}
	return 0;
}

int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
		    bool *is_64_bit)
{
	int err;
	Elf *elf;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL)
		return -1;

	if (is_64_bit)
		*is_64_bit = (gelf_getclass(elf) == ELFCLASS64);

	err = elf_read_maps(elf, exe, mapfn, data);

	elf_end(elf);
	return err;
}

enum dso_type dso__type_fd(int fd)
{
	enum dso_type dso_type = DSO__TYPE_UNKNOWN;
	GElf_Ehdr ehdr;
	Elf_Kind ek;
	Elf *elf;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (elf == NULL)
		goto out;

	ek = elf_kind(elf);
	if (ek != ELF_K_ELF)
		goto out_end;

	if (gelf_getclass(elf) == ELFCLASS64) {
		dso_type = DSO__TYPE_64BIT;
		goto out_end;
	}

	if (gelf_getehdr(elf, &ehdr) == NULL)
		goto out_end;

	if (ehdr.e_machine == EM_X86_64)
		dso_type = DSO__TYPE_X32BIT;
	else
		dso_type = DSO__TYPE_32BIT;
out_end:
	elf_end(elf);
out:
	return dso_type;
}

static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
{
	ssize_t r;
	size_t n;
	int err = -1;
	char *buf = malloc(page_size);

	if (buf == NULL)
		return -1;

	if (lseek(to, to_offs, SEEK_SET) != to_offs)
		goto out;

	if (lseek(from, from_offs, SEEK_SET) != from_offs)
		goto out;

	while (len) {
		n = page_size;
		if (len < n)
			n = len;
		/* Use read because mmap won't work on proc files */
		r = read(from, buf, n);
		if (r < 0)
			goto out;
		if (!r)
			break;
		n = r;
		r = write(to, buf, n);
		if (r < 0)
			goto out;
		if ((size_t)r != n)
			goto out;
		len -= n;
	}

	err = 0;
out:
	free(buf);
	return err;
}

struct kcore {
	int fd;
	int elfclass;
	Elf *elf;
	GElf_Ehdr ehdr;
};

static int kcore__open(struct kcore *kcore, const char *filename)
{
	GElf_Ehdr *ehdr;

	kcore->fd = open(filename, O_RDONLY);
	if (kcore->fd == -1)
		return -1;

	kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
	if (!kcore->elf)
		goto out_close;

	kcore->elfclass = gelf_getclass(kcore->elf);
	if (kcore->elfclass == ELFCLASSNONE)
		goto out_end;

	ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
	if (!ehdr)
		goto out_end;

	return 0;

out_end:
	elf_end(kcore->elf);
out_close:
	close(kcore->fd);
	return -1;
}

static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
		       bool temp)
{
	kcore->elfclass = elfclass;

	if (temp)
		kcore->fd = mkstemp(filename);
	else
		kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
	if (kcore->fd == -1)
		return -1;

	kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
	if (!kcore->elf)
		goto out_close;

	if (!gelf_newehdr(kcore->elf, elfclass))
		goto out_end;

	memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));

	return 0;

out_end:
	elf_end(kcore->elf);
out_close:
	close(kcore->fd);
	unlink(filename);
	return -1;
}

static void kcore__close(struct kcore *kcore)
{
	elf_end(kcore->elf);
	close(kcore->fd);
}

static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
{
	GElf_Ehdr *ehdr = &to->ehdr;
	GElf_Ehdr *kehdr = &from->ehdr;

	memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
	ehdr->e_type      = kehdr->e_type;
	ehdr->e_machine   = kehdr->e_machine;
	ehdr->e_version   = kehdr->e_version;
	ehdr->e_entry     = 0;
	ehdr->e_shoff     = 0;
	ehdr->e_flags     = kehdr->e_flags;
	ehdr->e_phnum     = count;
	ehdr->e_shentsize = 0;
	ehdr->e_shnum     = 0;
	ehdr->e_shstrndx  = 0;

	if (from->elfclass == ELFCLASS32) {
		ehdr->e_phoff     = sizeof(Elf32_Ehdr);
		ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
		ehdr->e_phentsize = sizeof(Elf32_Phdr);
	} else {
		ehdr->e_phoff     = sizeof(Elf64_Ehdr);
		ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
		ehdr->e_phentsize = sizeof(Elf64_Phdr);
	}

	if (!gelf_update_ehdr(to->elf, ehdr))
		return -1;

	if (!gelf_newphdr(to->elf, count))
		return -1;

	return 0;
}

static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
			   u64 addr, u64 len)
{
	GElf_Phdr phdr = {
		.p_type		= PT_LOAD,
		.p_flags	= PF_R | PF_W | PF_X,
		.p_offset	= offset,
		.p_vaddr	= addr,
		.p_paddr	= 0,
		.p_filesz	= len,
		.p_memsz	= len,
		.p_align	= page_size,
	};

	if (!gelf_update_phdr(kcore->elf, idx, &phdr))
		return -1;

	return 0;
}

static off_t kcore__write(struct kcore *kcore)
{
	return elf_update(kcore->elf, ELF_C_WRITE);
}

struct phdr_data {
	off_t offset;
	off_t rel;
	u64 addr;
	u64 len;
	struct list_head node;
	struct phdr_data *remaps;
};

struct sym_data {
	u64 addr;
	struct list_head node;
};

struct kcore_copy_info {
	u64 stext;
	u64 etext;
	u64 first_symbol;
	u64 last_symbol;
	u64 first_module;
	u64 first_module_symbol;
	u64 last_module_symbol;
	size_t phnum;
	struct list_head phdrs;
	struct list_head syms;
};

#define kcore_copy__for_each_phdr(k, p) \
	list_for_each_entry((p), &(k)->phdrs, node)

static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
{
	struct phdr_data *p = zalloc(sizeof(*p));

	if (p) {
		p->addr   = addr;
		p->len    = len;
		p->offset = offset;
	}

	return p;
}

static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
						 u64 addr, u64 len,
						 off_t offset)
{
	struct phdr_data *p = phdr_data__new(addr, len, offset);

	if (p)
		list_add_tail(&p->node, &kci->phdrs);

	return p;
}

static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
{
	struct phdr_data *p, *tmp;

	list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
		list_del_init(&p->node);
		free(p);
	}
}

static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
					    u64 addr)
{
	struct sym_data *s = zalloc(sizeof(*s));

	if (s) {
		s->addr = addr;
		list_add_tail(&s->node, &kci->syms);
	}

	return s;
}

static void kcore_copy__free_syms(struct kcore_copy_info *kci)
{
	struct sym_data *s, *tmp;

	list_for_each_entry_safe(s, tmp, &kci->syms, node) {
		list_del_init(&s->node);
		free(s);
	}
}

static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
					u64 start)
{
	struct kcore_copy_info *kci = arg;

	if (!kallsyms__is_function(type))
		return 0;

	if (strchr(name, '[')) {
		if (!kci->first_module_symbol || start < kci->first_module_symbol)
			kci->first_module_symbol = start;
		if (start > kci->last_module_symbol)
			kci->last_module_symbol = start;
		return 0;
	}

	if (!kci->first_symbol || start < kci->first_symbol)
		kci->first_symbol = start;

	if (!kci->last_symbol || start > kci->last_symbol)
		kci->last_symbol = start;

	if (!strcmp(name, "_stext")) {
		kci->stext = start;
		return 0;
	}

	if (!strcmp(name, "_etext")) {
		kci->etext = start;
		return 0;
	}

	if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
		return -1;

	return 0;
}

static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
				      const char *dir)
{
	char kallsyms_filename[PATH_MAX];

	scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);

	if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
		return -1;

	if (kallsyms__parse(kallsyms_filename, kci,
			    kcore_copy__process_kallsyms) < 0)
		return -1;

	return 0;
}

static int kcore_copy__process_modules(void *arg,
				       const char *name __maybe_unused,
				       u64 start, u64 size __maybe_unused)
{
	struct kcore_copy_info *kci = arg;

	if (!kci->first_module || start < kci->first_module)
		kci->first_module = start;

	return 0;
}

static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
				     const char *dir)
{
	char modules_filename[PATH_MAX];

	scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);

	if (symbol__restricted_filename(modules_filename, "/proc/modules"))
		return -1;

	if (modules__parse(modules_filename, kci,
			   kcore_copy__process_modules) < 0)
		return -1;

	return 0;
}

static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
			   u64 pgoff, u64 s, u64 e)
{
	u64 len, offset;

	if (s < start || s >= end)
		return 0;

	offset = (s - start) + pgoff;
	len = e < end ? e - s : end - s;

	return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
}

static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
{
	struct kcore_copy_info *kci = data;
	u64 end = start + len;
	struct sym_data *sdat;

	if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
		return -1;

	if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
			    kci->last_module_symbol))
		return -1;

	list_for_each_entry(sdat, &kci->syms, node) {
		u64 s = round_down(sdat->addr, page_size);

		if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
			return -1;
	}

	return 0;
}

static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
{
	if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
		return -1;

	return 0;
}

static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
{
	struct phdr_data *p, *k = NULL;
	u64 kend;

	if (!kci->stext)
		return;

	/* Find phdr that corresponds to the kernel map (contains stext) */
	kcore_copy__for_each_phdr(kci, p) {
		u64 pend = p->addr + p->len - 1;

		if (p->addr <= kci->stext && pend >= kci->stext) {
			k = p;
			break;
		}
	}

	if (!k)
		return;

	kend = k->offset + k->len;

	/* Find phdrs that remap the kernel */
	kcore_copy__for_each_phdr(kci, p) {
		u64 pend = p->offset + p->len;

		if (p == k)
			continue;

		if (p->offset >= k->offset && pend <= kend)
			p->remaps = k;
	}
}

static void kcore_copy__layout(struct kcore_copy_info *kci)
{
	struct phdr_data *p;
	off_t rel = 0;

	kcore_copy__find_remaps(kci);

	kcore_copy__for_each_phdr(kci, p) {
		if (!p->remaps) {
			p->rel = rel;
			rel += p->len;
		}
		kci->phnum += 1;
	}

	kcore_copy__for_each_phdr(kci, p) {
		struct phdr_data *k = p->remaps;

		if (k)
			p->rel = p->offset - k->offset + k->rel;
	}
}

static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
				 Elf *elf)
{
	if (kcore_copy__parse_kallsyms(kci, dir))
		return -1;

	if (kcore_copy__parse_modules(kci, dir))
		return -1;

	if (kci->stext)
		kci->stext = round_down(kci->stext, page_size);
	else
		kci->stext = round_down(kci->first_symbol, page_size);

	if (kci->etext) {
		kci->etext = round_up(kci->etext, page_size);
	} else if (kci->last_symbol) {
		kci->etext = round_up(kci->last_symbol, page_size);
		kci->etext += page_size;
	}

	if (kci->first_module_symbol &&
	    (!kci->first_module || kci->first_module_symbol < kci->first_module))
		kci->first_module = kci->first_module_symbol;

	kci->first_module = round_down(kci->first_module, page_size);

	if (kci->last_module_symbol) {
		kci->last_module_symbol = round_up(kci->last_module_symbol,
						   page_size);
		kci->last_module_symbol += page_size;
	}

	if (!kci->stext || !kci->etext)
		return -1;

	if (kci->first_module && !kci->last_module_symbol)
		return -1;

	if (kcore_copy__read_maps(kci, elf))
		return -1;

	kcore_copy__layout(kci);

	return 0;
}

static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
				 const char *name)
{
	char from_filename[PATH_MAX];
	char to_filename[PATH_MAX];

	scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
	scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);

	return copyfile_mode(from_filename, to_filename, 0400);
}

static int kcore_copy__unlink(const char *dir, const char *name)
{
	char filename[PATH_MAX];

	scnprintf(filename, PATH_MAX, "%s/%s", dir, name);

	return unlink(filename);
}

static int kcore_copy__compare_fds(int from, int to)
{
	char *buf_from;
	char *buf_to;
	ssize_t ret;
	size_t len;
	int err = -1;

	buf_from = malloc(page_size);
	buf_to = malloc(page_size);
	if (!buf_from || !buf_to)
		goto out;

	while (1) {
		/* Use read because mmap won't work on proc files */
		ret = read(from, buf_from, page_size);
		if (ret < 0)
			goto out;

		if (!ret)
			break;

		len = ret;

		if (readn(to, buf_to, len) != (int)len)
			goto out;

		if (memcmp(buf_from, buf_to, len))
			goto out;
	}

	err = 0;
out:
	free(buf_to);
	free(buf_from);
	return err;
}

static int kcore_copy__compare_files(const char *from_filename,
				     const char *to_filename)
{
	int from, to, err = -1;

	from = open(from_filename, O_RDONLY);
	if (from < 0)
		return -1;

	to = open(to_filename, O_RDONLY);
	if (to < 0)
		goto out_close_from;

	err = kcore_copy__compare_fds(from, to);

	close(to);
out_close_from:
	close(from);
	return err;
}

static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
				    const char *name)
{
	char from_filename[PATH_MAX];
	char to_filename[PATH_MAX];

	scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
	scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);

	return kcore_copy__compare_files(from_filename, to_filename);
}

/**
 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
 * @from_dir: from directory
 * @to_dir: to directory
 *
 * This function copies kallsyms, modules and kcore files from one directory to
 * another.  kallsyms and modules are copied entirely.  Only code segments are
 * copied from kcore.  It is assumed that two segments suffice: one for the
 * kernel proper and one for all the modules.  The code segments are determined
 * from kallsyms and modules files.  The kernel map starts at _stext or the
 * lowest function symbol, and ends at _etext or the highest function symbol.
 * The module map starts at the lowest module address and ends at the highest
 * module symbol.  Start addresses are rounded down to the nearest page.  End
 * addresses are rounded up to the nearest page.  An extra page is added to the
 * highest kernel symbol and highest module symbol to, hopefully, encompass that
 * symbol too.  Because it contains only code sections, the resulting kcore is
 * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
 * is not the same for the kernel map and the modules map.  That happens because
 * the data is copied adjacently whereas the original kcore has gaps.  Finally,
 * kallsyms and modules files are compared with their copies to check that
 * modules have not been loaded or unloaded while the copies were taking place.
 *
 * Return: %0 on success, %-1 on failure.
 */
int kcore_copy(const char *from_dir, const char *to_dir)
{
	struct kcore kcore;
	struct kcore extract;
	int idx = 0, err = -1;
	off_t offset, sz;
	struct kcore_copy_info kci = { .stext = 0, };
	char kcore_filename[PATH_MAX];
	char extract_filename[PATH_MAX];
	struct phdr_data *p;

	INIT_LIST_HEAD(&kci.phdrs);
	INIT_LIST_HEAD(&kci.syms);

	if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
		return -1;

	if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
		goto out_unlink_kallsyms;

	scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
	scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);

	if (kcore__open(&kcore, kcore_filename))
		goto out_unlink_modules;

	if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
		goto out_kcore_close;

	if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
		goto out_kcore_close;

	if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
		goto out_extract_close;

	offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
		 gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
	offset = round_up(offset, page_size);

	kcore_copy__for_each_phdr(&kci, p) {
		off_t offs = p->rel + offset;

		if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
			goto out_extract_close;
	}

	sz = kcore__write(&extract);
	if (sz < 0 || sz > offset)
		goto out_extract_close;

	kcore_copy__for_each_phdr(&kci, p) {
		off_t offs = p->rel + offset;

		if (p->remaps)
			continue;
		if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
			goto out_extract_close;
	}

	if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
		goto out_extract_close;

	if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
		goto out_extract_close;

	err = 0;

out_extract_close:
	kcore__close(&extract);
	if (err)
		unlink(extract_filename);
out_kcore_close:
	kcore__close(&kcore);
out_unlink_modules:
	if (err)
		kcore_copy__unlink(to_dir, "modules");
out_unlink_kallsyms:
	if (err)
		kcore_copy__unlink(to_dir, "kallsyms");

	kcore_copy__free_phdrs(&kci);
	kcore_copy__free_syms(&kci);

	return err;
}

int kcore_extract__create(struct kcore_extract *kce)
{
	struct kcore kcore;
	struct kcore extract;
	size_t count = 1;
	int idx = 0, err = -1;
	off_t offset = page_size, sz;

	if (kcore__open(&kcore, kce->kcore_filename))
		return -1;

	strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
	if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
		goto out_kcore_close;

	if (kcore__copy_hdr(&kcore, &extract, count))
		goto out_extract_close;

	if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
		goto out_extract_close;

	sz = kcore__write(&extract);
	if (sz < 0 || sz > offset)
		goto out_extract_close;

	if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
		goto out_extract_close;

	err = 0;

out_extract_close:
	kcore__close(&extract);
	if (err)
		unlink(kce->extract_filename);
out_kcore_close:
	kcore__close(&kcore);

	return err;
}

void kcore_extract__delete(struct kcore_extract *kce)
{
	unlink(kce->extract_filename);
}

#ifdef HAVE_GELF_GETNOTE_SUPPORT

static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
{
	if (!base_off)
		return;

	if (tmp->bit32)
		tmp->addr.a32[SDT_NOTE_IDX_LOC] =
			tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
			tmp->addr.a32[SDT_NOTE_IDX_BASE];
	else
		tmp->addr.a64[SDT_NOTE_IDX_LOC] =
			tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
			tmp->addr.a64[SDT_NOTE_IDX_BASE];
}

static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
			      GElf_Addr base_off)
{
	if (!base_off)
		return;

	if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
		tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
	else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
		tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
}

/**
 * populate_sdt_note : Parse raw data and identify SDT note
 * @elf: elf of the opened file
 * @data: raw data of a section with description offset applied
 * @len: note description size
 * @type: type of the note
 * @sdt_notes: List to add the SDT note
 *
 * Responsible for parsing the @data in section .note.stapsdt in @elf and
 * if its an SDT note, it appends to @sdt_notes list.
 */
static int populate_sdt_note(Elf **elf, const char *data, size_t len,
			     struct list_head *sdt_notes)
{
	const char *provider, *name, *args;
	struct sdt_note *tmp = NULL;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;
	int ret = -EINVAL;

	union {
		Elf64_Addr a64[NR_ADDR];
		Elf32_Addr a32[NR_ADDR];
	} buf;

	Elf_Data dst = {
		.d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
		.d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
		.d_off = 0, .d_align = 0
	};
	Elf_Data src = {
		.d_buf = (void *) data, .d_type = ELF_T_ADDR,
		.d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
		.d_align = 0
	};

	tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
	if (!tmp) {
		ret = -ENOMEM;
		goto out_err;
	}

	INIT_LIST_HEAD(&tmp->note_list);

	if (len < dst.d_size + 3)
		goto out_free_note;

	/* Translation from file representation to memory representation */
	if (gelf_xlatetom(*elf, &dst, &src,
			  elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
		pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
		goto out_free_note;
	}

	/* Populate the fields of sdt_note */
	provider = data + dst.d_size;

	name = (const char *)memchr(provider, '\0', data + len - provider);
	if (name++ == NULL)
		goto out_free_note;

	tmp->provider = strdup(provider);
	if (!tmp->provider) {
		ret = -ENOMEM;
		goto out_free_note;
	}
	tmp->name = strdup(name);
	if (!tmp->name) {
		ret = -ENOMEM;
		goto out_free_prov;
	}

	args = memchr(name, '\0', data + len - name);

	/*
	 * There is no argument if:
	 * - We reached the end of the note;
	 * - There is not enough room to hold a potential string;
	 * - The argument string is empty or just contains ':'.
	 */
	if (args == NULL || data + len - args < 2 ||
		args[1] == ':' || args[1] == '\0')
		tmp->args = NULL;
	else {
		tmp->args = strdup(++args);
		if (!tmp->args) {
			ret = -ENOMEM;
			goto out_free_name;
		}
	}

	if (gelf_getclass(*elf) == ELFCLASS32) {
		memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
		tmp->bit32 = true;
	} else {
		memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
		tmp->bit32 = false;
	}

	if (!gelf_getehdr(*elf, &ehdr)) {
		pr_debug("%s : cannot get elf header.\n", __func__);
		ret = -EBADF;
		goto out_free_args;
	}

	/* Adjust the prelink effect :
	 * Find out the .stapsdt.base section.
	 * This scn will help us to handle prelinking (if present).
	 * Compare the retrieved file offset of the base section with the
	 * base address in the description of the SDT note. If its different,
	 * then accordingly, adjust the note location.
	 */
	if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
		sdt_adjust_loc(tmp, shdr.sh_offset);

	/* Adjust reference counter offset */
	if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
		sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);

	list_add_tail(&tmp->note_list, sdt_notes);
	return 0;

out_free_args:
	zfree(&tmp->args);
out_free_name:
	zfree(&tmp->name);
out_free_prov:
	zfree(&tmp->provider);
out_free_note:
	free(tmp);
out_err:
	return ret;
}

/**
 * construct_sdt_notes_list : constructs a list of SDT notes
 * @elf : elf to look into
 * @sdt_notes : empty list_head
 *
 * Scans the sections in 'elf' for the section
 * .note.stapsdt. It, then calls populate_sdt_note to find
 * out the SDT events and populates the 'sdt_notes'.
 */
static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
{
	GElf_Ehdr ehdr;
	Elf_Scn *scn = NULL;
	Elf_Data *data;
	GElf_Shdr shdr;
	size_t shstrndx, next;
	GElf_Nhdr nhdr;
	size_t name_off, desc_off, offset;
	int ret = 0;

	if (gelf_getehdr(elf, &ehdr) == NULL) {
		ret = -EBADF;
		goto out_ret;
	}
	if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
		ret = -EBADF;
		goto out_ret;
	}

	/* Look for the required section */
	scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
	if (!scn) {
		ret = -ENOENT;
		goto out_ret;
	}

	if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
		ret = -ENOENT;
		goto out_ret;
	}

	data = elf_getdata(scn, NULL);

	/* Get the SDT notes */
	for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
					      &desc_off)) > 0; offset = next) {
		if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
		    !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
			    sizeof(SDT_NOTE_NAME))) {
			/* Check the type of the note */
			if (nhdr.n_type != SDT_NOTE_TYPE)
				goto out_ret;

			ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
						nhdr.n_descsz, sdt_notes);
			if (ret < 0)
				goto out_ret;
		}
	}
	if (list_empty(sdt_notes))
		ret = -ENOENT;

out_ret:
	return ret;
}

/**
 * get_sdt_note_list : Wrapper to construct a list of sdt notes
 * @head : empty list_head
 * @target : file to find SDT notes from
 *
 * This opens the file, initializes
 * the ELF and then calls construct_sdt_notes_list.
 */
int get_sdt_note_list(struct list_head *head, const char *target)
{
	Elf *elf;
	int fd, ret;

	fd = open(target, O_RDONLY);
	if (fd < 0)
		return -EBADF;

	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
	if (!elf) {
		ret = -EBADF;
		goto out_close;
	}
	ret = construct_sdt_notes_list(elf, head);
	elf_end(elf);
out_close:
	close(fd);
	return ret;
}

/**
 * cleanup_sdt_note_list : free the sdt notes' list
 * @sdt_notes: sdt notes' list
 *
 * Free up the SDT notes in @sdt_notes.
 * Returns the number of SDT notes free'd.
 */
int cleanup_sdt_note_list(struct list_head *sdt_notes)
{
	struct sdt_note *tmp, *pos;
	int nr_free = 0;

	list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
		list_del_init(&pos->note_list);
		zfree(&pos->args);
		zfree(&pos->name);
		zfree(&pos->provider);
		free(pos);
		nr_free++;
	}
	return nr_free;
}

/**
 * sdt_notes__get_count: Counts the number of sdt events
 * @start: list_head to sdt_notes list
 *
 * Returns the number of SDT notes in a list
 */
int sdt_notes__get_count(struct list_head *start)
{
	struct sdt_note *sdt_ptr;
	int count = 0;

	list_for_each_entry(sdt_ptr, start, note_list)
		count++;
	return count;
}
#endif

void symbol__elf_init(void)
{
	elf_version(EV_CURRENT);
}