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
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
|
/* Run time dynamic linker.
Copyright (C) 1995-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <ldsodefs.h>
#include <_itoa.h>
#include <entry.h>
#include <fpu_control.h>
#include <hp-timing.h>
#include <libc-lock.h>
#include "dynamic-link.h"
#include <dl-librecon.h>
#include <unsecvars.h>
#include <dl-cache.h>
#include <dl-osinfo.h>
#include <dl-procinfo.h>
#include <dl-prop.h>
#include <tls.h>
#include <stap-probe.h>
#include <stackinfo.h>
#include <not-cancel.h>
#include <assert.h>
/* Avoid PLT use for our local calls at startup. */
extern __typeof (__mempcpy) __mempcpy attribute_hidden;
/* GCC has mental blocks about _exit. */
extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden;
#define _exit exit_internal
/* Helper function to handle errors while resolving symbols. */
static void print_unresolved (int errcode, const char *objname,
const char *errsting);
/* Helper function to handle errors when a version is missing. */
static void print_missing_version (int errcode, const char *objname,
const char *errsting);
/* Print the various times we collected. */
static void print_statistics (hp_timing_t *total_timep);
/* Add audit objects. */
static void process_dl_audit (char *str);
/* This is a list of all the modes the dynamic loader can be in. */
enum mode { normal, list, verify, trace };
/* Process all environments variables the dynamic linker must recognize.
Since all of them start with `LD_' we are a bit smarter while finding
all the entries. */
static void process_envvars (enum mode *modep);
#ifdef DL_ARGV_NOT_RELRO
int _dl_argc attribute_hidden;
char **_dl_argv = NULL;
/* Nonzero if we were run directly. */
unsigned int _dl_skip_args attribute_hidden;
#else
int _dl_argc attribute_relro attribute_hidden;
char **_dl_argv attribute_relro = NULL;
unsigned int _dl_skip_args attribute_relro attribute_hidden;
#endif
rtld_hidden_data_def (_dl_argv)
#ifndef THREAD_SET_STACK_GUARD
/* Only exported for architectures that don't store the stack guard canary
in thread local area. */
uintptr_t __stack_chk_guard attribute_relro;
#endif
/* Only exported for architectures that don't store the pointer guard
value in thread local area. */
uintptr_t __pointer_chk_guard_local
attribute_relro attribute_hidden __attribute__ ((nocommon));
#ifndef THREAD_SET_POINTER_GUARD
strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
#endif
/* Length limits for names and paths, to protect the dynamic linker,
particularly when __libc_enable_secure is active. */
#ifdef NAME_MAX
# define SECURE_NAME_LIMIT NAME_MAX
#else
# define SECURE_NAME_LIMIT 255
#endif
#ifdef PATH_MAX
# define SECURE_PATH_LIMIT PATH_MAX
#else
# define SECURE_PATH_LIMIT 1024
#endif
/* Check that AT_SECURE=0, or that the passed name does not contain
directories and is not overly long. Reject empty names
unconditionally. */
static bool
dso_name_valid_for_suid (const char *p)
{
if (__glibc_unlikely (__libc_enable_secure))
{
/* Ignore pathnames with directories for AT_SECURE=1
programs, and also skip overlong names. */
size_t len = strlen (p);
if (len >= SECURE_NAME_LIMIT || memchr (p, '/', len) != NULL)
return false;
}
return *p != '\0';
}
/* LD_AUDIT variable contents. Must be processed before the
audit_list below. */
const char *audit_list_string;
/* Cyclic list of auditing DSOs. audit_list->next is the first
element. */
static struct audit_list
{
const char *name;
struct audit_list *next;
} *audit_list;
/* Iterator for audit_list_string followed by audit_list. */
struct audit_list_iter
{
/* Tail of audit_list_string still needing processing, or NULL. */
const char *audit_list_tail;
/* The list element returned in the previous iteration. NULL before
the first element. */
struct audit_list *previous;
/* Scratch buffer for returning a name which is part of
audit_list_string. */
char fname[SECURE_NAME_LIMIT];
};
/* Initialize an audit list iterator. */
static void
audit_list_iter_init (struct audit_list_iter *iter)
{
iter->audit_list_tail = audit_list_string;
iter->previous = NULL;
}
/* Iterate through both audit_list_string and audit_list. */
static const char *
audit_list_iter_next (struct audit_list_iter *iter)
{
if (iter->audit_list_tail != NULL)
{
/* First iterate over audit_list_string. */
while (*iter->audit_list_tail != '\0')
{
/* Split audit list at colon. */
size_t len = strcspn (iter->audit_list_tail, ":");
if (len > 0 && len < sizeof (iter->fname))
{
memcpy (iter->fname, iter->audit_list_tail, len);
iter->fname[len] = '\0';
}
else
/* Do not return this name to the caller. */
iter->fname[0] = '\0';
/* Skip over the substring and the following delimiter. */
iter->audit_list_tail += len;
if (*iter->audit_list_tail == ':')
++iter->audit_list_tail;
/* If the name is valid, return it. */
if (dso_name_valid_for_suid (iter->fname))
return iter->fname;
/* Otherwise, wrap around and try the next name. */
}
/* Fall through to the procesing of audit_list. */
}
if (iter->previous == NULL)
{
if (audit_list == NULL)
/* No pre-parsed audit list. */
return NULL;
/* Start of audit list. The first list element is at
audit_list->next (cyclic list). */
iter->previous = audit_list->next;
return iter->previous->name;
}
if (iter->previous == audit_list)
/* Cyclic list wrap-around. */
return NULL;
iter->previous = iter->previous->next;
return iter->previous->name;
}
#ifndef HAVE_INLINED_SYSCALLS
/* Set nonzero during loading and initialization of executable and
libraries, cleared before the executable's entry point runs. This
must not be initialized to nonzero, because the unused dynamic
linker loaded in for libc.so's "ld.so.1" dep will provide the
definition seen by libc.so's initializer; that value must be zero,
and will be since that dynamic linker's _dl_start and dl_main will
never be called. */
int _dl_starting_up = 0;
rtld_hidden_def (_dl_starting_up)
#endif
/* This is the structure which defines all variables global to ld.so
(except those which cannot be added for some reason). */
struct rtld_global _rtld_global =
{
/* Generally the default presumption without further information is an
* executable stack but this is not true for all platforms. */
._dl_stack_flags = DEFAULT_STACK_PERMS,
#ifdef _LIBC_REENTRANT
._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER,
#endif
._dl_nns = 1,
._dl_ns =
{
#ifdef _LIBC_REENTRANT
[LM_ID_BASE] = { ._ns_unique_sym_table
= { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } }
#endif
}
};
/* If we would use strong_alias here the compiler would see a
non-hidden definition. This would undo the effect of the previous
declaration. So spell out was strong_alias does plus add the
visibility attribute. */
extern struct rtld_global _rtld_local
__attribute__ ((alias ("_rtld_global"), visibility ("hidden")));
/* This variable is similar to _rtld_local, but all values are
read-only after relocation. */
struct rtld_global_ro _rtld_global_ro attribute_relro =
{
/* Get architecture specific initializer. */
#include <dl-procinfo.c>
#ifdef NEED_DL_SYSINFO
._dl_sysinfo = DL_SYSINFO_DEFAULT,
#endif
._dl_debug_fd = STDERR_FILENO,
._dl_use_load_bias = -2,
._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID,
#if !HAVE_TUNABLES
._dl_hwcap_mask = HWCAP_IMPORTANT,
#endif
._dl_lazy = 1,
._dl_fpu_control = _FPU_DEFAULT,
._dl_pagesize = EXEC_PAGESIZE,
._dl_inhibit_cache = 0,
/* Function pointers. */
._dl_debug_printf = _dl_debug_printf,
._dl_mcount = _dl_mcount,
._dl_lookup_symbol_x = _dl_lookup_symbol_x,
._dl_open = _dl_open,
._dl_close = _dl_close,
._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
#ifdef HAVE_DL_DISCOVER_OSVERSION
._dl_discover_osversion = _dl_discover_osversion
#endif
};
/* If we would use strong_alias here the compiler would see a
non-hidden definition. This would undo the effect of the previous
declaration. So spell out was strong_alias does plus add the
visibility attribute. */
extern struct rtld_global_ro _rtld_local_ro
__attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden")));
static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv);
/* These two variables cannot be moved into .data.rel.ro. */
static struct libname_list _dl_rtld_libname;
static struct libname_list _dl_rtld_libname2;
/* Variable for statistics. */
#ifndef HP_TIMING_NONAVAIL
static hp_timing_t relocate_time;
static hp_timing_t load_time attribute_relro;
static hp_timing_t start_time attribute_relro;
#endif
/* Additional definitions needed by TLS initialization. */
#ifdef TLS_INIT_HELPER
TLS_INIT_HELPER
#endif
/* Helper function for syscall implementation. */
#ifdef DL_SYSINFO_IMPLEMENTATION
DL_SYSINFO_IMPLEMENTATION
#endif
/* Before ld.so is relocated we must not access variables which need
relocations. This means variables which are exported. Variables
declared as static are fine. If we can mark a variable hidden this
is fine, too. The latter is important here. We can avoid setting
up a temporary link map for ld.so if we can mark _rtld_global as
hidden. */
#ifdef PI_STATIC_AND_HIDDEN
# define DONT_USE_BOOTSTRAP_MAP 1
#endif
#ifdef DONT_USE_BOOTSTRAP_MAP
static ElfW(Addr) _dl_start_final (void *arg);
#else
struct dl_start_final_info
{
struct link_map l;
#if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE
hp_timing_t start_time;
#endif
};
static ElfW(Addr) _dl_start_final (void *arg,
struct dl_start_final_info *info);
#endif
/* These defined magically in the linker script. */
extern char _begin[] attribute_hidden;
extern char _etext[] attribute_hidden;
extern char _end[] attribute_hidden;
#ifdef RTLD_START
RTLD_START
#else
# error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
#endif
/* This is the second half of _dl_start (below). It can be inlined safely
under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT
references. When the tools don't permit us to avoid using a GOT entry
for _dl_rtld_global (no attribute_hidden support), we must make sure
this function is not inlined (see below). */
#ifdef DONT_USE_BOOTSTRAP_MAP
static inline ElfW(Addr) __attribute__ ((always_inline))
_dl_start_final (void *arg)
#else
static ElfW(Addr) __attribute__ ((noinline))
_dl_start_final (void *arg, struct dl_start_final_info *info)
#endif
{
ElfW(Addr) start_addr;
if (HP_SMALL_TIMING_AVAIL)
{
/* If it hasn't happen yet record the startup time. */
if (! HP_TIMING_INLINE)
HP_TIMING_NOW (start_time);
#if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL
else
start_time = info->start_time;
#endif
}
/* Transfer data about ourselves to the permanent link_map structure. */
#ifndef DONT_USE_BOOTSTRAP_MAP
GL(dl_rtld_map).l_addr = info->l.l_addr;
GL(dl_rtld_map).l_ld = info->l.l_ld;
memcpy (GL(dl_rtld_map).l_info, info->l.l_info,
sizeof GL(dl_rtld_map).l_info);
GL(dl_rtld_map).l_mach = info->l.l_mach;
GL(dl_rtld_map).l_relocated = 1;
#endif
_dl_setup_hash (&GL(dl_rtld_map));
GL(dl_rtld_map).l_real = &GL(dl_rtld_map);
GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin;
GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end;
GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
/* Copy the TLS related data if necessary. */
#ifndef DONT_USE_BOOTSTRAP_MAP
# if NO_TLS_OFFSET != 0
GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
# endif
#endif
HP_TIMING_NOW (GL(dl_cpuclock_offset));
/* Initialize the stack end variable. */
__libc_stack_end = __builtin_frame_address (0);
/* Call the OS-dependent function to set up life so we can do things like
file access. It will call `dl_main' (below) to do all the real work
of the dynamic linker, and then unwind our frame and run the user
entry point on the same stack we entered on. */
start_addr = _dl_sysdep_start (arg, &dl_main);
#ifndef HP_TIMING_NONAVAIL
hp_timing_t rtld_total_time;
if (HP_SMALL_TIMING_AVAIL)
{
hp_timing_t end_time;
/* Get the current time. */
HP_TIMING_NOW (end_time);
/* Compute the difference. */
HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
}
#endif
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS))
{
#ifndef HP_TIMING_NONAVAIL
print_statistics (&rtld_total_time);
#else
print_statistics (NULL);
#endif
}
return start_addr;
}
static ElfW(Addr) __attribute_used__
_dl_start (void *arg)
{
#ifdef DONT_USE_BOOTSTRAP_MAP
# define bootstrap_map GL(dl_rtld_map)
#else
struct dl_start_final_info info;
# define bootstrap_map info.l
#endif
/* This #define produces dynamic linking inline functions for
bootstrap relocation instead of general-purpose relocation.
Since ld.so must not have any undefined symbols the result
is trivial: always the map of ld.so itself. */
#define RTLD_BOOTSTRAP
#define BOOTSTRAP_MAP (&bootstrap_map)
#define RESOLVE_MAP(sym, version, flags) BOOTSTRAP_MAP
#include "dynamic-link.h"
if (HP_TIMING_INLINE && HP_SMALL_TIMING_AVAIL)
#ifdef DONT_USE_BOOTSTRAP_MAP
HP_TIMING_NOW (start_time);
#else
HP_TIMING_NOW (info.start_time);
#endif
/* Partly clean the `bootstrap_map' structure up. Don't use
`memset' since it might not be built in or inlined and we cannot
make function calls at this point. Use '__builtin_memset' if we
know it is available. We do not have to clear the memory if we
do not have to use the temporary bootstrap_map. Global variables
are initialized to zero by default. */
#ifndef DONT_USE_BOOTSTRAP_MAP
# ifdef HAVE_BUILTIN_MEMSET
__builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
# else
for (size_t cnt = 0;
cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
++cnt)
bootstrap_map.l_info[cnt] = 0;
# endif
#endif
/* Figure out the run-time load address of the dynamic linker itself. */
bootstrap_map.l_addr = elf_machine_load_address ();
/* Read our own dynamic section and fill in the info array. */
bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
elf_get_dynamic_info (&bootstrap_map, NULL);
#if NO_TLS_OFFSET != 0
bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
#endif
#ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
#endif
if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)])
{
/* Relocate ourselves so we can do normal function calls and
data access using the global offset table. */
ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0, 0);
}
bootstrap_map.l_relocated = 1;
/* Please note that we don't allow profiling of this object and
therefore need not test whether we have to allocate the array
for the relocation results (as done in dl-reloc.c). */
/* Now life is sane; we can call functions and access global data.
Set up to use the operating system facilities, and find out from
the operating system's program loader where to find the program
header table in core. Put the rest of _dl_start into a separate
function, that way the compiler cannot put accesses to the GOT
before ELF_DYNAMIC_RELOCATE. */
{
#ifdef DONT_USE_BOOTSTRAP_MAP
ElfW(Addr) entry = _dl_start_final (arg);
#else
ElfW(Addr) entry = _dl_start_final (arg, &info);
#endif
#ifndef ELF_MACHINE_START_ADDRESS
# define ELF_MACHINE_START_ADDRESS(map, start) (start)
#endif
return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry);
}
}
/* Now life is peachy; we can do all normal operations.
On to the real work. */
/* Some helper functions. */
/* Arguments to relocate_doit. */
struct relocate_args
{
struct link_map *l;
int reloc_mode;
};
struct map_args
{
/* Argument to map_doit. */
const char *str;
struct link_map *loader;
int mode;
/* Return value of map_doit. */
struct link_map *map;
};
struct dlmopen_args
{
const char *fname;
struct link_map *map;
};
struct lookup_args
{
const char *name;
struct link_map *map;
void *result;
};
/* Arguments to version_check_doit. */
struct version_check_args
{
int doexit;
int dotrace;
};
static void
relocate_doit (void *a)
{
struct relocate_args *args = (struct relocate_args *) a;
_dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0);
}
static void
map_doit (void *a)
{
struct map_args *args = (struct map_args *) a;
int type = (args->mode == __RTLD_OPENEXEC) ? lt_executable : lt_library;
args->map = _dl_map_object (args->loader, args->str, type, 0,
args->mode, LM_ID_BASE);
}
static void
dlmopen_doit (void *a)
{
struct dlmopen_args *args = (struct dlmopen_args *) a;
args->map = _dl_open (args->fname,
(RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT
| __RTLD_SECURE),
dl_main, LM_ID_NEWLM, _dl_argc, _dl_argv,
__environ);
}
static void
lookup_doit (void *a)
{
struct lookup_args *args = (struct lookup_args *) a;
const ElfW(Sym) *ref = NULL;
args->result = NULL;
lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref,
args->map->l_local_scope, NULL, 0,
DL_LOOKUP_RETURN_NEWEST, NULL);
if (ref != NULL)
args->result = DL_SYMBOL_ADDRESS (l, ref);
}
static void
version_check_doit (void *a)
{
struct version_check_args *args = (struct version_check_args *) a;
if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1,
args->dotrace) && args->doexit)
/* We cannot start the application. Abort now. */
_exit (1);
}
static inline struct link_map *
find_needed (const char *name)
{
struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist;
unsigned int n = scope->r_nlist;
while (n-- > 0)
if (_dl_name_match_p (name, scope->r_list[n]))
return scope->r_list[n];
/* Should never happen. */
return NULL;
}
static int
match_version (const char *string, struct link_map *map)
{
const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
ElfW(Verdef) *def;
#define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
if (map->l_info[VERDEFTAG] == NULL)
/* The file has no symbol versioning. */
return 0;
def = (ElfW(Verdef) *) ((char *) map->l_addr
+ map->l_info[VERDEFTAG]->d_un.d_ptr);
while (1)
{
ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
/* Compare the version strings. */
if (strcmp (string, strtab + aux->vda_name) == 0)
/* Bingo! */
return 1;
/* If no more definitions we failed to find what we want. */
if (def->vd_next == 0)
break;
/* Next definition. */
def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
}
return 0;
}
static bool tls_init_tp_called;
static void *
init_tls (void)
{
/* Number of elements in the static TLS block. */
GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
/* Do not do this twice. The audit interface might have required
the DTV interfaces to be set up early. */
if (GL(dl_initial_dtv) != NULL)
return NULL;
/* Allocate the array which contains the information about the
dtv slots. We allocate a few entries more than needed to
avoid the need for reallocation. */
size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS;
/* Allocate. */
GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *)
calloc (sizeof (struct dtv_slotinfo_list)
+ nelem * sizeof (struct dtv_slotinfo), 1);
/* No need to check the return value. If memory allocation failed
the program would have been terminated. */
struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
GL(dl_tls_dtv_slotinfo_list)->len = nelem;
GL(dl_tls_dtv_slotinfo_list)->next = NULL;
/* Fill in the information from the loaded modules. No namespace
but the base one can be filled at this time. */
assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL);
int i = 0;
for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL;
l = l->l_next)
if (l->l_tls_blocksize != 0)
{
/* This is a module with TLS data. Store the map reference.
The generation counter is zero. */
slotinfo[i].map = l;
/* slotinfo[i].gen = 0; */
++i;
}
assert (i == GL(dl_tls_max_dtv_idx));
/* Compute the TLS offsets for the various blocks. */
_dl_determine_tlsoffset ();
/* Construct the static TLS block and the dtv for the initial
thread. For some platforms this will include allocating memory
for the thread descriptor. The memory for the TLS block will
never be freed. It should be allocated accordingly. The dtv
array can be changed if dynamic loading requires it. */
void *tcbp = _dl_allocate_tls_storage ();
if (tcbp == NULL)
_dl_fatal_printf ("\
cannot allocate TLS data structures for initial thread\n");
/* Store for detection of the special case by __tls_get_addr
so it knows not to pass this dtv to the normal realloc. */
GL(dl_initial_dtv) = GET_DTV (tcbp);
/* And finally install it for the main thread. */
const char *lossage = TLS_INIT_TP (tcbp);
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
tls_init_tp_called = true;
return tcbp;
}
static unsigned int
do_preload (const char *fname, struct link_map *main_map, const char *where)
{
const char *objname;
const char *err_str = NULL;
struct map_args args;
bool malloced;
args.str = fname;
args.loader = main_map;
args.mode = __RTLD_SECURE;
unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
(void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args);
if (__glibc_unlikely (err_str != NULL))
{
_dl_error_printf ("\
ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n",
fname, where, err_str);
/* No need to call free, this is still before
the libc's malloc is used. */
}
else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded)
/* It is no duplicate. */
return 1;
/* Nothing loaded. */
return 0;
}
#if defined SHARED && defined _LIBC_REENTRANT \
&& defined __rtld_lock_default_lock_recursive
static void
rtld_lock_default_lock_recursive (void *lock)
{
__rtld_lock_default_lock_recursive (lock);
}
static void
rtld_lock_default_unlock_recursive (void *lock)
{
__rtld_lock_default_unlock_recursive (lock);
}
#endif
static void
security_init (void)
{
/* Set up the stack checker's canary. */
uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
#ifdef THREAD_SET_STACK_GUARD
THREAD_SET_STACK_GUARD (stack_chk_guard);
#else
__stack_chk_guard = stack_chk_guard;
#endif
/* Set up the pointer guard as well, if necessary. */
uintptr_t pointer_chk_guard
= _dl_setup_pointer_guard (_dl_random, stack_chk_guard);
#ifdef THREAD_SET_POINTER_GUARD
THREAD_SET_POINTER_GUARD (pointer_chk_guard);
#endif
__pointer_chk_guard_local = pointer_chk_guard;
/* We do not need the _dl_random value anymore. The less
information we leave behind, the better, so clear the
variable. */
_dl_random = NULL;
}
#include "setup-vdso.h"
/* The library search path. */
static const char *library_path attribute_relro;
/* The list preloaded objects. */
static const char *preloadlist attribute_relro;
/* Nonzero if information about versions has to be printed. */
static int version_info attribute_relro;
/* The LD_PRELOAD environment variable gives list of libraries
separated by white space or colons that are loaded before the
executable's dependencies and prepended to the global scope list.
(If the binary is running setuid all elements containing a '/' are
ignored since it is insecure.) Return the number of preloads
performed. */
unsigned int
handle_ld_preload (const char *preloadlist, struct link_map *main_map)
{
unsigned int npreloads = 0;
const char *p = preloadlist;
char fname[SECURE_PATH_LIMIT];
while (*p != '\0')
{
/* Split preload list at space/colon. */
size_t len = strcspn (p, " :");
if (len > 0 && len < sizeof (fname))
{
memcpy (fname, p, len);
fname[len] = '\0';
}
else
fname[0] = '\0';
/* Skip over the substring and the following delimiter. */
p += len;
if (*p != '\0')
++p;
if (dso_name_valid_for_suid (fname))
npreloads += do_preload (fname, main_map, "LD_PRELOAD");
}
return npreloads;
}
static void
dl_main (const ElfW(Phdr) *phdr,
ElfW(Word) phnum,
ElfW(Addr) *user_entry,
ElfW(auxv_t) *auxv)
{
const ElfW(Phdr) *ph;
enum mode mode;
struct link_map *main_map;
size_t file_size;
char *file;
bool has_interp = false;
unsigned int i;
bool prelinked = false;
bool rtld_is_main = false;
#ifndef HP_TIMING_NONAVAIL
hp_timing_t start;
hp_timing_t stop;
hp_timing_t diff;
#endif
void *tcbp = NULL;
GL(dl_init_static_tls) = &_dl_nothread_init_static_tls;
#if defined SHARED && defined _LIBC_REENTRANT \
&& defined __rtld_lock_default_lock_recursive
GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive;
GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
#endif
/* The explicit initialization here is cheaper than processing the reloc
in the _rtld_local definition's initializer. */
GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
/* Process the environment variable which control the behaviour. */
process_envvars (&mode);
#ifndef HAVE_INLINED_SYSCALLS
/* Set up a flag which tells we are just starting. */
_dl_starting_up = 1;
#endif
if (*user_entry == (ElfW(Addr)) ENTRY_POINT)
{
/* Ho ho. We are not the program interpreter! We are the program
itself! This means someone ran ld.so as a command. Well, that
might be convenient to do sometimes. We support it by
interpreting the args like this:
ld.so PROGRAM ARGS...
The first argument is the name of a file containing an ELF
executable we will load and run with the following arguments.
To simplify life here, PROGRAM is searched for using the
normal rules for shared objects, rather than $PATH or anything
like that. We just load it and use its entry point; we don't
pay attention to its PT_INTERP command (we are the interpreter
ourselves). This is an easy way to test a new ld.so before
installing it. */
rtld_is_main = true;
/* Note the place where the dynamic linker actually came from. */
GL(dl_rtld_map).l_name = rtld_progname;
while (_dl_argc > 1)
if (! strcmp (_dl_argv[1], "--list"))
{
mode = list;
GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */
++_dl_skip_args;
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--verify"))
{
mode = verify;
++_dl_skip_args;
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--inhibit-cache"))
{
GLRO(dl_inhibit_cache) = 1;
++_dl_skip_args;
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--library-path")
&& _dl_argc > 2)
{
library_path = _dl_argv[2];
_dl_skip_args += 2;
_dl_argc -= 2;
_dl_argv += 2;
}
else if (! strcmp (_dl_argv[1], "--inhibit-rpath")
&& _dl_argc > 2)
{
GLRO(dl_inhibit_rpath) = _dl_argv[2];
_dl_skip_args += 2;
_dl_argc -= 2;
_dl_argv += 2;
}
else if (! strcmp (_dl_argv[1], "--audit") && _dl_argc > 2)
{
process_dl_audit (_dl_argv[2]);
_dl_skip_args += 2;
_dl_argc -= 2;
_dl_argv += 2;
}
else
break;
/* If we have no further argument the program was called incorrectly.
Grant the user some education. */
if (_dl_argc < 2)
_dl_fatal_printf ("\
Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
You have invoked `ld.so', the helper program for shared library executables.\n\
This program usually lives in the file `/lib/ld.so', and special directives\n\
in executable files using ELF shared libraries tell the system's program\n\
loader to load the helper program from this file. This helper program loads\n\
the shared libraries needed by the program executable, prepares the program\n\
to run, and runs it. You may invoke this helper program directly from the\n\
command line to load and run an ELF executable file; this is like executing\n\
that file itself, but always uses this helper program from the file you\n\
specified, instead of the helper program file specified in the executable\n\
file you run. This is mostly of use for maintainers to test new versions\n\
of this helper program; chances are you did not intend to run this program.\n\
\n\
--list list all dependencies and how they are resolved\n\
--verify verify that given object really is a dynamically linked\n\
object we can handle\n\
--inhibit-cache Do not use " LD_SO_CACHE "\n\
--library-path PATH use given PATH instead of content of the environment\n\
variable LD_LIBRARY_PATH\n\
--inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\
in LIST\n\
--audit LIST use objects named in LIST as auditors\n");
++_dl_skip_args;
--_dl_argc;
++_dl_argv;
/* The initialization of _dl_stack_flags done below assumes the
executable's PT_GNU_STACK may have been honored by the kernel, and
so a PT_GNU_STACK with PF_X set means the stack started out with
execute permission. However, this is not really true if the
dynamic linker is the executable the kernel loaded. For this
case, we must reinitialize _dl_stack_flags to match the dynamic
linker itself. If the dynamic linker was built with a
PT_GNU_STACK, then the kernel may have loaded us with a
nonexecutable stack that we will have to make executable when we
load the program below unless it has a PT_GNU_STACK indicating
nonexecutable stack is ok. */
for (ph = phdr; ph < &phdr[phnum]; ++ph)
if (ph->p_type == PT_GNU_STACK)
{
GL(dl_stack_flags) = ph->p_flags;
break;
}
if (__builtin_expect (mode, normal) == verify)
{
const char *objname;
const char *err_str = NULL;
struct map_args args;
bool malloced;
args.str = rtld_progname;
args.loader = NULL;
args.mode = __RTLD_OPENEXEC;
(void) _dl_catch_error (&objname, &err_str, &malloced, map_doit,
&args);
if (__glibc_unlikely (err_str != NULL))
/* We don't free the returned string, the programs stops
anyway. */
_exit (EXIT_FAILURE);
}
else
{
HP_TIMING_NOW (start);
_dl_map_object (NULL, rtld_progname, lt_executable, 0,
__RTLD_OPENEXEC, LM_ID_BASE);
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (load_time, start, stop);
}
/* Now the map for the main executable is available. */
main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
if (__builtin_expect (mode, normal) == normal
&& GL(dl_rtld_map).l_info[DT_SONAME] != NULL
&& main_map->l_info[DT_SONAME] != NULL
&& strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val,
(const char *) D_PTR (main_map, l_info[DT_STRTAB])
+ main_map->l_info[DT_SONAME]->d_un.d_val) == 0)
_dl_fatal_printf ("loader cannot load itself\n");
phdr = main_map->l_phdr;
phnum = main_map->l_phnum;
/* We overwrite here a pointer to a malloc()ed string. But since
the malloc() implementation used at this point is the dummy
implementations which has no real free() function it does not
makes sense to free the old string first. */
main_map->l_name = (char *) "";
*user_entry = main_map->l_entry;
#ifdef HAVE_AUX_VECTOR
/* Adjust the on-stack auxiliary vector so that it looks like the
binary was executed directly. */
for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++)
switch (av->a_type)
{
case AT_PHDR:
av->a_un.a_val = (uintptr_t) phdr;
break;
case AT_PHNUM:
av->a_un.a_val = phnum;
break;
case AT_ENTRY:
av->a_un.a_val = *user_entry;
break;
case AT_EXECFN:
av->a_un.a_val = (uintptr_t) _dl_argv[0];
break;
}
#endif
}
else
{
/* Create a link_map for the executable itself.
This will be what dlopen on "" returns. */
main_map = _dl_new_object ((char *) "", "", lt_executable, NULL,
__RTLD_OPENEXEC, LM_ID_BASE);
assert (main_map != NULL);
main_map->l_phdr = phdr;
main_map->l_phnum = phnum;
main_map->l_entry = *user_entry;
/* Even though the link map is not yet fully initialized we can add
it to the map list since there are no possible users running yet. */
_dl_add_to_namespace_list (main_map, LM_ID_BASE);
assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded);
/* At this point we are in a bit of trouble. We would have to
fill in the values for l_dev and l_ino. But in general we
do not know where the file is. We also do not handle AT_EXECFD
even if it would be passed up.
We leave the values here defined to 0. This is normally no
problem as the program code itself is normally no shared
object and therefore cannot be loaded dynamically. Nothing
prevent the use of dynamic binaries and in these situations
we might get problems. We might not be able to find out
whether the object is already loaded. But since there is no
easy way out and because the dynamic binary must also not
have an SONAME we ignore this program for now. If it becomes
a problem we can force people using SONAMEs. */
/* We delay initializing the path structure until we got the dynamic
information for the program. */
}
main_map->l_map_end = 0;
main_map->l_text_end = 0;
/* Perhaps the executable has no PT_LOAD header entries at all. */
main_map->l_map_start = ~0;
/* And it was opened directly. */
++main_map->l_direct_opencount;
/* Scan the program header table for the dynamic section. */
for (ph = phdr; ph < &phdr[phnum]; ++ph)
switch (ph->p_type)
{
case PT_PHDR:
/* Find out the load address. */
main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr;
break;
case PT_DYNAMIC:
/* This tells us where to find the dynamic section,
which tells us everything we need to do. */
main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr;
break;
case PT_INTERP:
/* This "interpreter segment" was used by the program loader to
find the program interpreter, which is this program itself, the
dynamic linker. We note what name finds us, so that a future
dlopen call or DT_NEEDED entry, for something that wants to link
against the dynamic linker as a shared library, will know that
the shared object is already loaded. */
_dl_rtld_libname.name = ((const char *) main_map->l_addr
+ ph->p_vaddr);
/* _dl_rtld_libname.next = NULL; Already zero. */
GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
/* Ordinarilly, we would get additional names for the loader from
our DT_SONAME. This can't happen if we were actually linked as
a static executable (detect this case when we have no DYNAMIC).
If so, assume the filename component of the interpreter path to
be our SONAME, and add it to our name list. */
if (GL(dl_rtld_map).l_ld == NULL)
{
const char *p = NULL;
const char *cp = _dl_rtld_libname.name;
/* Find the filename part of the path. */
while (*cp != '\0')
if (*cp++ == '/')
p = cp;
if (p != NULL)
{
_dl_rtld_libname2.name = p;
/* _dl_rtld_libname2.next = NULL; Already zero. */
_dl_rtld_libname.next = &_dl_rtld_libname2;
}
}
has_interp = true;
break;
case PT_LOAD:
{
ElfW(Addr) mapstart;
ElfW(Addr) allocend;
/* Remember where the main program starts in memory. */
mapstart = (main_map->l_addr
+ (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
if (main_map->l_map_start > mapstart)
main_map->l_map_start = mapstart;
/* Also where it ends. */
allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz;
if (main_map->l_map_end < allocend)
main_map->l_map_end = allocend;
if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end)
main_map->l_text_end = allocend;
}
break;
case PT_TLS:
if (ph->p_memsz > 0)
{
/* Note that in the case the dynamic linker we duplicate work
here since we read the PT_TLS entry already in
_dl_start_final. But the result is repeatable so do not
check for this special but unimportant case. */
main_map->l_tls_blocksize = ph->p_memsz;
main_map->l_tls_align = ph->p_align;
if (ph->p_align == 0)
main_map->l_tls_firstbyte_offset = 0;
else
main_map->l_tls_firstbyte_offset = (ph->p_vaddr
& (ph->p_align - 1));
main_map->l_tls_initimage_size = ph->p_filesz;
main_map->l_tls_initimage = (void *) ph->p_vaddr;
/* This image gets the ID one. */
GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1;
}
break;
case PT_GNU_STACK:
GL(dl_stack_flags) = ph->p_flags;
break;
case PT_GNU_RELRO:
main_map->l_relro_addr = ph->p_vaddr;
main_map->l_relro_size = ph->p_memsz;
break;
case PT_NOTE:
if (_rtld_process_pt_note (main_map, ph))
_dl_error_printf ("\
ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
break;
}
/* Adjust the address of the TLS initialization image in case
the executable is actually an ET_DYN object. */
if (main_map->l_tls_initimage != NULL)
main_map->l_tls_initimage
= (char *) main_map->l_tls_initimage + main_map->l_addr;
if (! main_map->l_map_end)
main_map->l_map_end = ~0;
if (! main_map->l_text_end)
main_map->l_text_end = ~0;
if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name)
{
/* We were invoked directly, so the program might not have a
PT_INTERP. */
_dl_rtld_libname.name = GL(dl_rtld_map).l_name;
/* _dl_rtld_libname.next = NULL; Already zero. */
GL(dl_rtld_map).l_libname = &_dl_rtld_libname;
}
else
assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */
/* If the current libname is different from the SONAME, add the
latter as well. */
if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL
&& strcmp (GL(dl_rtld_map).l_libname->name,
(const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0)
{
static struct libname_list newname;
newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr);
newname.next = NULL;
newname.dont_free = 1;
assert (GL(dl_rtld_map).l_libname->next == NULL);
GL(dl_rtld_map).l_libname->next = &newname;
}
/* The ld.so must be relocated since otherwise loading audit modules
will fail since they reuse the very same ld.so. */
assert (GL(dl_rtld_map).l_relocated);
if (! rtld_is_main)
{
/* Extract the contents of the dynamic section for easy access. */
elf_get_dynamic_info (main_map, NULL);
/* Set up our cache of pointers into the hash table. */
_dl_setup_hash (main_map);
}
if (__builtin_expect (mode, normal) == verify)
{
/* We were called just to verify that this is a dynamic
executable using us as the program interpreter. Exit with an
error if we were not able to load the binary or no interpreter
is specified (i.e., this is no dynamically linked binary. */
if (main_map->l_ld == NULL)
_exit (1);
/* We allow here some platform specific code. */
#ifdef DISTINGUISH_LIB_VERSIONS
DISTINGUISH_LIB_VERSIONS;
#endif
_exit (has_interp ? 0 : 2);
}
struct link_map **first_preload = &GL(dl_rtld_map).l_next;
/* Set up the data structures for the system-supplied DSO early,
so they can influence _dl_init_paths. */
setup_vdso (main_map, &first_preload);
#ifdef DL_SYSDEP_OSCHECK
DL_SYSDEP_OSCHECK (_dl_fatal_printf);
#endif
/* Initialize the data structures for the search paths for shared
objects. */
_dl_init_paths (library_path);
/* Initialize _r_debug. */
struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr,
LM_ID_BASE);
r->r_state = RT_CONSISTENT;
/* Put the link_map for ourselves on the chain so it can be found by
name. Note that at this point the global chain of link maps contains
exactly one element, which is pointed to by dl_loaded. */
if (! GL(dl_rtld_map).l_name)
/* If not invoked directly, the dynamic linker shared object file was
found by the PT_INTERP name. */
GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name;
GL(dl_rtld_map).l_type = lt_library;
main_map->l_next = &GL(dl_rtld_map);
GL(dl_rtld_map).l_prev = main_map;
++GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
++GL(dl_load_adds);
/* If LD_USE_LOAD_BIAS env variable has not been seen, default
to not using bias for non-prelinked PIEs and libraries
and using it for executables or prelinked PIEs or libraries. */
if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
/* Set up the program header information for the dynamic linker
itself. It is needed in the dl_iterate_phdr callbacks. */
const ElfW(Ehdr) *rtld_ehdr;
/* Starting from binutils-2.23, the linker will define the magic symbol
__ehdr_start to point to our own ELF header if it is visible in a
segment that also includes the phdrs. If that's not available, we use
the old method that assumes the beginning of the file is part of the
lowest-addressed PT_LOAD segment. */
#ifdef HAVE_EHDR_START
extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
rtld_ehdr = &__ehdr_start;
#else
rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
#endif
assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr);
assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr)));
const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff;
GL(dl_rtld_map).l_phdr = rtld_phdr;
GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
/* PT_GNU_RELRO is usually the last phdr. */
size_t cnt = rtld_ehdr->e_phnum;
while (cnt-- > 0)
if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
{
GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
break;
}
/* Add the dynamic linker to the TLS list if it also uses TLS. */
if (GL(dl_rtld_map).l_tls_blocksize != 0)
/* Assign a module ID. Do this before loading any audit modules. */
GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
/* If we have auditing DSOs to load, do it now. */
bool need_security_init = true;
if (__glibc_unlikely (audit_list != NULL)
|| __glibc_unlikely (audit_list_string != NULL))
{
struct audit_ifaces *last_audit = NULL;
struct audit_list_iter al_iter;
audit_list_iter_init (&al_iter);
/* Since we start using the auditing DSOs right away we need to
initialize the data structures now. */
tcbp = init_tls ();
/* Initialize security features. We need to do it this early
since otherwise the constructors of the audit libraries will
use different values (especially the pointer guard) and will
fail later on. */
security_init ();
need_security_init = false;
while (true)
{
const char *name = audit_list_iter_next (&al_iter);
if (name == NULL)
break;
int tls_idx = GL(dl_tls_max_dtv_idx);
/* Now it is time to determine the layout of the static TLS
block and allocate it for the initial thread. Note that we
always allocate the static block, we never defer it even if
no DF_STATIC_TLS bit is set. The reason is that we know
glibc will use the static model. */
struct dlmopen_args dlmargs;
dlmargs.fname = name;
dlmargs.map = NULL;
const char *objname;
const char *err_str = NULL;
bool malloced;
(void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
&dlmargs);
if (__glibc_unlikely (err_str != NULL))
{
not_loaded:
_dl_error_printf ("\
ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
name, err_str);
if (malloced)
free ((char *) err_str);
}
else
{
struct lookup_args largs;
largs.name = "la_version";
largs.map = dlmargs.map;
/* Check whether the interface version matches. */
(void) _dl_catch_error (&objname, &err_str, &malloced,
lookup_doit, &largs);
unsigned int (*laversion) (unsigned int);
unsigned int lav;
if (err_str != NULL)
goto not_loaded;
if ((laversion = largs.result) != NULL
&& (lav = laversion (LAV_CURRENT)) > 0
&& lav <= LAV_CURRENT)
{
/* Allocate structure for the callback function pointers.
This call can never fail. */
union
{
struct audit_ifaces ifaces;
#define naudit_ifaces 8
void (*fptr[naudit_ifaces]) (void);
} *newp = malloc (sizeof (*newp));
/* Names of the auditing interfaces. All in one
long string. */
static const char audit_iface_names[] =
"la_activity\0"
"la_objsearch\0"
"la_objopen\0"
"la_preinit\0"
#if __ELF_NATIVE_CLASS == 32
"la_symbind32\0"
#elif __ELF_NATIVE_CLASS == 64
"la_symbind64\0"
#else
# error "__ELF_NATIVE_CLASS must be defined"
#endif
#define STRING(s) __STRING (s)
"la_" STRING (ARCH_LA_PLTENTER) "\0"
"la_" STRING (ARCH_LA_PLTEXIT) "\0"
"la_objclose\0";
unsigned int cnt = 0;
const char *cp = audit_iface_names;
do
{
largs.name = cp;
(void) _dl_catch_error (&objname, &err_str, &malloced,
lookup_doit, &largs);
/* Store the pointer. */
if (err_str == NULL && largs.result != NULL)
{
newp->fptr[cnt] = largs.result;
/* The dynamic linker link map is statically
allocated, initialize the data now. */
GL(dl_rtld_map).l_audit[cnt].cookie
= (intptr_t) &GL(dl_rtld_map);
}
else
newp->fptr[cnt] = NULL;
++cnt;
cp = (char *) rawmemchr (cp, '\0') + 1;
}
while (*cp != '\0');
assert (cnt == naudit_ifaces);
/* Now append the new auditing interface to the list. */
newp->ifaces.next = NULL;
if (last_audit == NULL)
last_audit = GLRO(dl_audit) = &newp->ifaces;
else
last_audit = last_audit->next = &newp->ifaces;
++GLRO(dl_naudit);
/* Mark the DSO as being used for auditing. */
dlmargs.map->l_auditing = 1;
}
else
{
/* We cannot use the DSO, it does not have the
appropriate interfaces or it expects something
more recent. */
#ifndef NDEBUG
Lmid_t ns = dlmargs.map->l_ns;
#endif
_dl_close (dlmargs.map);
/* Make sure the namespace has been cleared entirely. */
assert (GL(dl_ns)[ns]._ns_loaded == NULL);
assert (GL(dl_ns)[ns]._ns_nloaded == 0);
GL(dl_tls_max_dtv_idx) = tls_idx;
if (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
{
_dl_debug_printf ("\
\nfile=%s cannot be loaded as audit interface; ignored.\n", name);
if (laversion == NULL)
_dl_debug_printf (
" la_version function not found.\n");
else
{
if (lav == 0)
_dl_debug_printf (
" auditor requested to be ignored (returned version of 0).\n");
else
_dl_debug_printf (
" auditor disabled since expected version %d is greater than "
"supported version %d.\n",
lav, LAV_CURRENT);
}
}
}
}
}
/* If we have any auditing modules, announce that we already
have two objects loaded. */
if (__glibc_unlikely (GLRO(dl_naudit) > 0))
{
struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
for (unsigned int outer = 0; outer < 2; ++outer)
{
struct audit_ifaces *afct = GLRO(dl_audit);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
if (afct->objopen != NULL)
{
ls[outer]->l_audit[cnt].bindflags
= afct->objopen (ls[outer], LM_ID_BASE,
&ls[outer]->l_audit[cnt].cookie);
ls[outer]->l_audit_any_plt
|= ls[outer]->l_audit[cnt].bindflags != 0;
}
afct = afct->next;
}
}
}
}
/* Keep track of the currently loaded modules to count how many
non-audit modules which use TLS are loaded. */
size_t count_modids = _dl_count_modids ();
/* Set up debugging before the debugger is notified for the first time. */
#ifdef ELF_MACHINE_DEBUG_SETUP
/* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
ELF_MACHINE_DEBUG_SETUP (main_map, r);
ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r);
#else
if (main_map->l_info[DT_DEBUG] != NULL)
/* There is a DT_DEBUG entry in the dynamic section. Fill it in
with the run-time address of the r_debug structure */
main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
/* Fill in the pointer in the dynamic linker's own dynamic section, in
case you run gdb on the dynamic linker directly. */
if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL)
GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
#endif
/* We start adding objects. */
r->r_state = RT_ADD;
_dl_debug_state ();
LIBC_PROBE (init_start, 2, LM_ID_BASE, r);
/* Auditing checkpoint: we are ready to signal that the initial map
is being constructed. */
if (__glibc_unlikely (GLRO(dl_naudit) > 0))
{
struct audit_ifaces *afct = GLRO(dl_audit);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
if (afct->activity != NULL)
afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
afct = afct->next;
}
}
/* We have two ways to specify objects to preload: via environment
variable and via the file /etc/ld.so.preload. The latter can also
be used when security is enabled. */
assert (*first_preload == NULL);
struct link_map **preloads = NULL;
unsigned int npreloads = 0;
if (__glibc_unlikely (preloadlist != NULL))
{
HP_TIMING_NOW (start);
npreloads += handle_ld_preload (preloadlist, main_map);
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (diff, start, stop);
HP_TIMING_ACCUM_NT (load_time, diff);
}
/* There usually is no ld.so.preload file, it should only be used
for emergencies and testing. So the open call etc should usually
fail. Using access() on a non-existing file is faster than using
open(). So we do this first. If it succeeds we do almost twice
the work but this does not matter, since it is not for production
use. */
static const char preload_file[] = "/etc/ld.so.preload";
if (__glibc_unlikely (__access (preload_file, R_OK) == 0))
{
/* Read the contents of the file. */
file = _dl_sysdep_read_whole_file (preload_file, &file_size,
PROT_READ | PROT_WRITE);
if (__glibc_unlikely (file != MAP_FAILED))
{
/* Parse the file. It contains names of libraries to be loaded,
separated by white spaces or `:'. It may also contain
comments introduced by `#'. */
char *problem;
char *runp;
size_t rest;
/* Eliminate comments. */
runp = file;
rest = file_size;
while (rest > 0)
{
char *comment = memchr (runp, '#', rest);
if (comment == NULL)
break;
rest -= comment - runp;
do
*comment = ' ';
while (--rest > 0 && *++comment != '\n');
}
/* We have one problematic case: if we have a name at the end of
the file without a trailing terminating characters, we cannot
place the \0. Handle the case separately. */
if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t'
&& file[file_size - 1] != '\n' && file[file_size - 1] != ':')
{
problem = &file[file_size];
while (problem > file && problem[-1] != ' '
&& problem[-1] != '\t'
&& problem[-1] != '\n' && problem[-1] != ':')
--problem;
if (problem > file)
problem[-1] = '\0';
}
else
{
problem = NULL;
file[file_size - 1] = '\0';
}
HP_TIMING_NOW (start);
if (file != problem)
{
char *p;
runp = file;
while ((p = strsep (&runp, ": \t\n")) != NULL)
if (p[0] != '\0')
npreloads += do_preload (p, main_map, preload_file);
}
if (problem != NULL)
{
char *p = strndupa (problem, file_size - (problem - file));
npreloads += do_preload (p, main_map, preload_file);
}
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (diff, start, stop);
HP_TIMING_ACCUM_NT (load_time, diff);
/* We don't need the file anymore. */
__munmap (file, file_size);
}
}
if (__glibc_unlikely (*first_preload != NULL))
{
/* Set up PRELOADS with a vector of the preloaded libraries. */
struct link_map *l = *first_preload;
preloads = __alloca (npreloads * sizeof preloads[0]);
i = 0;
do
{
preloads[i++] = l;
l = l->l_next;
} while (l);
assert (i == npreloads);
}
/* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD
specified some libraries to load, these are inserted before the actual
dependencies in the executable's searchlist for symbol resolution. */
HP_TIMING_NOW (start);
_dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0);
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (diff, start, stop);
HP_TIMING_ACCUM_NT (load_time, diff);
/* Mark all objects as being in the global scope. */
for (i = main_map->l_searchlist.r_nlist; i > 0; )
main_map->l_searchlist.r_list[--i]->l_global = 1;
/* Remove _dl_rtld_map from the chain. */
GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next;
if (GL(dl_rtld_map).l_next != NULL)
GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev;
for (i = 1; i < main_map->l_searchlist.r_nlist; ++i)
if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map))
break;
bool rtld_multiple_ref = false;
if (__glibc_likely (i < main_map->l_searchlist.r_nlist))
{
/* Some DT_NEEDED entry referred to the interpreter object itself, so
put it back in the list of visible objects. We insert it into the
chain in symbol search order because gdb uses the chain's order as
its symbol search order. */
rtld_multiple_ref = true;
GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1];
if (__builtin_expect (mode, normal) == normal)
{
GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist
? main_map->l_searchlist.r_list[i + 1]
: NULL);
#ifdef NEED_DL_SYSINFO_DSO
if (GLRO(dl_sysinfo_map) != NULL
&& GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map)
&& GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map))
GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map);
#endif
}
else
/* In trace mode there might be an invisible object (which we
could not find) after the previous one in the search list.
In this case it doesn't matter much where we put the
interpreter object, so we just initialize the list pointer so
that the assertion below holds. */
GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next;
assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next);
GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map);
if (GL(dl_rtld_map).l_next != NULL)
{
assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev);
GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map);
}
}
/* Now let us see whether all libraries are available in the
versions we need. */
{
struct version_check_args args;
args.doexit = mode == normal;
args.dotrace = mode == trace;
_dl_receive_error (print_missing_version, version_check_doit, &args);
}
/* We do not initialize any of the TLS functionality unless any of the
initial modules uses TLS. This makes dynamic loading of modules with
TLS impossible, but to support it requires either eagerly doing setup
now or lazily doing it later. Doing it now makes us incompatible with
an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
used. Trying to do it lazily is too hairy to try when there could be
multiple threads (from a non-TLS-using libpthread). */
bool was_tls_init_tp_called = tls_init_tp_called;
if (tcbp == NULL)
tcbp = init_tls ();
if (__glibc_likely (need_security_init))
/* Initialize security features. But only if we have not done it
earlier. */
security_init ();
if (__builtin_expect (mode, normal) != normal)
{
/* We were run just to list the shared libraries. It is
important that we do this before real relocation, because the
functions we call below for output may no longer work properly
after relocation. */
struct link_map *l;
if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
{
struct r_scope_elem *scope = &main_map->l_searchlist;
for (i = 0; i < scope->r_nlist; i++)
{
l = scope->r_list [i];
if (l->l_faked)
{
_dl_printf ("\t%s => not found\n", l->l_libname->name);
continue;
}
if (_dl_name_match_p (GLRO(dl_trace_prelink), l))
GLRO(dl_trace_prelink_map) = l;
_dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)",
DSO_FILENAME (l->l_libname->name),
DSO_FILENAME (l->l_name),
(int) sizeof l->l_map_start * 2,
(size_t) l->l_map_start,
(int) sizeof l->l_addr * 2,
(size_t) l->l_addr);
if (l->l_tls_modid)
_dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid,
(int) sizeof l->l_tls_offset * 2,
(size_t) l->l_tls_offset);
else
_dl_printf ("\n");
}
}
else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
{
/* Look through the dependencies of the main executable
and determine which of them is not actually
required. */
struct link_map *l = main_map;
/* Relocate the main executable. */
struct relocate_args args = { .l = l,
.reloc_mode = ((GLRO(dl_lazy)
? RTLD_LAZY : 0)
| __RTLD_NOIFUNC) };
_dl_receive_error (print_unresolved, relocate_doit, &args);
/* This loop depends on the dependencies of the executable to
correspond in number and order to the DT_NEEDED entries. */
ElfW(Dyn) *dyn = main_map->l_ld;
bool first = true;
while (dyn->d_tag != DT_NULL)
{
if (dyn->d_tag == DT_NEEDED)
{
l = l->l_next;
#ifdef NEED_DL_SYSINFO_DSO
/* Skip the VDSO since it's not part of the list
of objects we brought in via DT_NEEDED entries. */
if (l == GLRO(dl_sysinfo_map))
l = l->l_next;
#endif
if (!l->l_used)
{
if (first)
{
_dl_printf ("Unused direct dependencies:\n");
first = false;
}
_dl_printf ("\t%s\n", l->l_name);
}
}
++dyn;
}
_exit (first != true);
}
else if (! main_map->l_info[DT_NEEDED])
_dl_printf ("\tstatically linked\n");
else
{
for (l = main_map->l_next; l; l = l->l_next)
if (l->l_faked)
/* The library was not found. */
_dl_printf ("\t%s => not found\n", l->l_libname->name);
else if (strcmp (l->l_libname->name, l->l_name) == 0)
_dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name,
(int) sizeof l->l_map_start * 2,
(size_t) l->l_map_start);
else
_dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name,
l->l_name, (int) sizeof l->l_map_start * 2,
(size_t) l->l_map_start);
}
if (__builtin_expect (mode, trace) != trace)
for (i = 1; i < (unsigned int) _dl_argc; ++i)
{
const ElfW(Sym) *ref = NULL;
ElfW(Addr) loadbase;
lookup_t result;
result = _dl_lookup_symbol_x (_dl_argv[i], main_map,
&ref, main_map->l_scope,
NULL, ELF_RTYPE_CLASS_PLT,
DL_LOOKUP_ADD_DEPENDENCY, NULL);
loadbase = LOOKUP_VALUE_ADDRESS (result, false);
_dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n",
_dl_argv[i],
(int) sizeof ref->st_value * 2,
(size_t) ref->st_value,
(int) sizeof loadbase * 2, (size_t) loadbase);
}
else
{
/* If LD_WARN is set, warn about undefined symbols. */
if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose))
{
/* We have to do symbol dependency testing. */
struct relocate_args args;
unsigned int i;
args.reloc_mode = ((GLRO(dl_lazy) ? RTLD_LAZY : 0)
| __RTLD_NOIFUNC);
i = main_map->l_searchlist.r_nlist;
while (i-- > 0)
{
struct link_map *l = main_map->l_initfini[i];
if (l != &GL(dl_rtld_map) && ! l->l_faked)
{
args.l = l;
_dl_receive_error (print_unresolved, relocate_doit,
&args);
}
}
if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
&& rtld_multiple_ref)
{
/* Mark the link map as not yet relocated again. */
GL(dl_rtld_map).l_relocated = 0;
_dl_relocate_object (&GL(dl_rtld_map),
main_map->l_scope, __RTLD_NOIFUNC, 0);
}
}
#define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
if (version_info)
{
/* Print more information. This means here, print information
about the versions needed. */
int first = 1;
struct link_map *map;
for (map = main_map; map != NULL; map = map->l_next)
{
const char *strtab;
ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG];
ElfW(Verneed) *ent;
if (dyn == NULL)
continue;
strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
if (first)
{
_dl_printf ("\n\tVersion information:\n");
first = 0;
}
_dl_printf ("\t%s:\n", DSO_FILENAME (map->l_name));
while (1)
{
ElfW(Vernaux) *aux;
struct link_map *needed;
needed = find_needed (strtab + ent->vn_file);
aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
while (1)
{
const char *fname = NULL;
if (needed != NULL
&& match_version (strtab + aux->vna_name,
needed))
fname = needed->l_name;
_dl_printf ("\t\t%s (%s) %s=> %s\n",
strtab + ent->vn_file,
strtab + aux->vna_name,
aux->vna_flags & VER_FLG_WEAK
? "[WEAK] " : "",
fname ?: "not found");
if (aux->vna_next == 0)
/* No more symbols. */
break;
/* Next symbol. */
aux = (ElfW(Vernaux) *) ((char *) aux
+ aux->vna_next);
}
if (ent->vn_next == 0)
/* No more dependencies. */
break;
/* Next dependency. */
ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
}
}
}
}
_exit (0);
}
if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]
&& ! __builtin_expect (GLRO(dl_profile) != NULL, 0)
&& ! __builtin_expect (GLRO(dl_dynamic_weak), 0))
{
ElfW(Lib) *liblist, *liblistend;
struct link_map **r_list, **r_listend, *l;
const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]);
assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL);
liblist = (ElfW(Lib) *)
main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr;
liblistend = (ElfW(Lib) *)
((char *) liblist +
main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val);
r_list = main_map->l_searchlist.r_list;
r_listend = r_list + main_map->l_searchlist.r_nlist;
for (; r_list < r_listend && liblist < liblistend; r_list++)
{
l = *r_list;
if (l == main_map)
continue;
/* If the library is not mapped where it should, fail. */
if (l->l_addr)
break;
/* Next, check if checksum matches. */
if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL
|| l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val
!= liblist->l_checksum)
break;
if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL
|| l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val
!= liblist->l_time_stamp)
break;
if (! _dl_name_match_p (strtab + liblist->l_name, l))
break;
++liblist;
}
if (r_list == r_listend && liblist == liblistend)
prelinked = true;
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
_dl_debug_printf ("\nprelink checking: %s\n",
prelinked ? "ok" : "failed");
}
/* Now set up the variable which helps the assembler startup code. */
GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist;
/* Save the information about the original global scope list since
we need it in the memory handling later. */
GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
/* Remember the last search directory added at startup, now that
malloc will no longer be the one from dl-minimal.c. As a side
effect, this marks ld.so as initialized, so that the rtld_active
function returns true from now on. */
GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
/* Print scope information. */
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES))
{
_dl_debug_printf ("\nInitial object scopes\n");
for (struct link_map *l = main_map; l != NULL; l = l->l_next)
_dl_show_scope (l, 0);
}
_rtld_main_check (main_map, _dl_argv[0]);
if (prelinked)
{
if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL)
{
ElfW(Rela) *conflict, *conflictend;
#ifndef HP_TIMING_NONAVAIL
hp_timing_t start;
hp_timing_t stop;
#endif
HP_TIMING_NOW (start);
assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL);
conflict = (ElfW(Rela) *)
main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr;
conflictend = (ElfW(Rela) *)
((char *) conflict
+ main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val);
_dl_resolve_conflicts (main_map, conflict, conflictend);
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (relocate_time, start, stop);
}
/* Mark all the objects so we know they have been already relocated. */
for (struct link_map *l = main_map; l != NULL; l = l->l_next)
{
l->l_relocated = 1;
if (l->l_relro_size)
_dl_protect_relro (l);
/* Add object to slot information data if necessasy. */
if (l->l_tls_blocksize != 0 && tls_init_tp_called)
_dl_add_to_slotinfo (l);
}
}
else
{
/* Now we have all the objects loaded. Relocate them all except for
the dynamic linker itself. We do this in reverse order so that copy
relocs of earlier objects overwrite the data written by later
objects. We do not re-relocate the dynamic linker itself in this
loop because that could result in the GOT entries for functions we
call being changed, and that would break us. It is safe to relocate
the dynamic linker out of order because it has no copy relocs (we
know that because it is self-contained). */
int consider_profiling = GLRO(dl_profile) != NULL;
#ifndef HP_TIMING_NONAVAIL
hp_timing_t start;
hp_timing_t stop;
#endif
/* If we are profiling we also must do lazy reloaction. */
GLRO(dl_lazy) |= consider_profiling;
HP_TIMING_NOW (start);
unsigned i = main_map->l_searchlist.r_nlist;
while (i-- > 0)
{
struct link_map *l = main_map->l_initfini[i];
/* While we are at it, help the memory handling a bit. We have to
mark some data structures as allocated with the fake malloc()
implementation in ld.so. */
struct libname_list *lnp = l->l_libname->next;
while (__builtin_expect (lnp != NULL, 0))
{
lnp->dont_free = 1;
lnp = lnp->next;
}
/* Also allocated with the fake malloc(). */
l->l_free_initfini = 0;
if (l != &GL(dl_rtld_map))
_dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,
consider_profiling);
/* Add object to slot information data if necessasy. */
if (l->l_tls_blocksize != 0 && tls_init_tp_called)
_dl_add_to_slotinfo (l);
}
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (relocate_time, start, stop);
/* Now enable profiling if needed. Like the previous call,
this has to go here because the calls it makes should use the
rtld versions of the functions (particularly calloc()), but it
needs to have _dl_profile_map set up by the relocator. */
if (__glibc_unlikely (GL(dl_profile_map) != NULL))
/* We must prepare the profiling. */
_dl_start_profile ();
}
if ((!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0)
|| count_modids != _dl_count_modids ())
++GL(dl_tls_generation);
/* Now that we have completed relocation, the initializer data
for the TLS blocks has its final values and we can copy them
into the main thread's TLS area, which we allocated above.
Note: thread-local variables must only be accessed after completing
the next step. */
_dl_allocate_tls_init (tcbp);
/* And finally install it for the main thread. */
if (! tls_init_tp_called)
{
const char *lossage = TLS_INIT_TP (tcbp);
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
lossage);
}
/* Make sure no new search directories have been added. */
assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
if (! prelinked && rtld_multiple_ref)
{
/* There was an explicit ref to the dynamic linker as a shared lib.
Re-relocate ourselves with user-controlled symbol definitions.
We must do this after TLS initialization in case after this
re-relocation, we might call a user-supplied function
(e.g. calloc from _dl_relocate_object) that uses TLS data. */
#ifndef HP_TIMING_NONAVAIL
hp_timing_t start;
hp_timing_t stop;
hp_timing_t add;
#endif
HP_TIMING_NOW (start);
/* Mark the link map as not yet relocated again. */
GL(dl_rtld_map).l_relocated = 0;
_dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0);
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (add, start, stop);
HP_TIMING_ACCUM_NT (relocate_time, add);
}
/* Do any necessary cleanups for the startup OS interface code.
We do these now so that no calls are made after rtld re-relocation
which might be resolved to different functions than we expect.
We cannot do this before relocating the other objects because
_dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
_dl_sysdep_start_cleanup ();
#ifdef SHARED
/* Auditing checkpoint: we have added all objects. */
if (__glibc_unlikely (GLRO(dl_naudit) > 0))
{
struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
/* Do not call the functions for any auditing object. */
if (head->l_auditing == 0)
{
struct audit_ifaces *afct = GLRO(dl_audit);
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
{
if (afct->activity != NULL)
afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
afct = afct->next;
}
}
}
#endif
/* Notify the debugger all new objects are now ready to go. We must re-get
the address since by now the variable might be in another object. */
r = _dl_debug_initialize (0, LM_ID_BASE);
r->r_state = RT_CONSISTENT;
_dl_debug_state ();
LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
#if defined USE_LDCONFIG && !defined MAP_COPY
/* We must munmap() the cache file. */
_dl_unload_cache ();
#endif
/* Once we return, _dl_sysdep_start will invoke
the DT_INIT functions and then *USER_ENTRY. */
}
/* This is a little helper function for resolving symbols while
tracing the binary. */
static void
print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
const char *errstring)
{
if (objname[0] == '\0')
objname = RTLD_PROGNAME;
_dl_error_printf ("%s (%s)\n", errstring, objname);
}
/* This is a little helper function for resolving symbols while
tracing the binary. */
static void
print_missing_version (int errcode __attribute__ ((unused)),
const char *objname, const char *errstring)
{
_dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME,
objname, errstring);
}
/* Nonzero if any of the debugging options is enabled. */
static int any_debug attribute_relro;
/* Process the string given as the parameter which explains which debugging
options are enabled. */
static void
process_dl_debug (const char *dl_debug)
{
/* When adding new entries make sure that the maximal length of a name
is correctly handled in the LD_DEBUG_HELP code below. */
static const struct
{
unsigned char len;
const char name[10];
const char helptext[41];
unsigned short int mask;
} debopts[] =
{
#define LEN_AND_STR(str) sizeof (str) - 1, str
{ LEN_AND_STR ("libs"), "display library search paths",
DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("reloc"), "display relocation processing",
DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("files"), "display progress for input file",
DL_DEBUG_FILES | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("symbols"), "display symbol table processing",
DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("bindings"), "display information about symbol binding",
DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("versions"), "display version dependencies",
DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS },
{ LEN_AND_STR ("scopes"), "display scope information",
DL_DEBUG_SCOPES },
{ LEN_AND_STR ("all"), "all previous options combined",
DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS
| DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS
| DL_DEBUG_SCOPES },
{ LEN_AND_STR ("statistics"), "display relocation statistics",
DL_DEBUG_STATISTICS },
{ LEN_AND_STR ("unused"), "determined unused DSOs",
DL_DEBUG_UNUSED },
{ LEN_AND_STR ("help"), "display this help message and exit",
DL_DEBUG_HELP },
};
#define ndebopts (sizeof (debopts) / sizeof (debopts[0]))
/* Skip separating white spaces and commas. */
while (*dl_debug != '\0')
{
if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':')
{
size_t cnt;
size_t len = 1;
while (dl_debug[len] != '\0' && dl_debug[len] != ' '
&& dl_debug[len] != ',' && dl_debug[len] != ':')
++len;
for (cnt = 0; cnt < ndebopts; ++cnt)
if (debopts[cnt].len == len
&& memcmp (dl_debug, debopts[cnt].name, len) == 0)
{
GLRO(dl_debug_mask) |= debopts[cnt].mask;
any_debug = 1;
break;
}
if (cnt == ndebopts)
{
/* Display a warning and skip everything until next
separator. */
char *copy = strndupa (dl_debug, len);
_dl_error_printf ("\
warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy);
}
dl_debug += len;
continue;
}
++dl_debug;
}
if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)
{
/* In order to get an accurate picture of whether a particular
DT_NEEDED entry is actually used we have to process both
the PLT and non-PLT relocation entries. */
GLRO(dl_lazy) = 0;
}
if (GLRO(dl_debug_mask) & DL_DEBUG_HELP)
{
size_t cnt;
_dl_printf ("\
Valid options for the LD_DEBUG environment variable are:\n\n");
for (cnt = 0; cnt < ndebopts; ++cnt)
_dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name,
" " + debopts[cnt].len - 3,
debopts[cnt].helptext);
_dl_printf ("\n\
To direct the debugging output into a file instead of standard output\n\
a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");
_exit (0);
}
}
static void
process_dl_audit (char *str)
{
/* The parameter is a colon separated list of DSO names. */
char *p;
while ((p = (strsep) (&str, ":")) != NULL)
if (dso_name_valid_for_suid (p))
{
/* This is using the local malloc, not the system malloc. The
memory can never be freed. */
struct audit_list *newp = malloc (sizeof (*newp));
newp->name = p;
if (audit_list == NULL)
audit_list = newp->next = newp;
else
{
newp->next = audit_list->next;
audit_list = audit_list->next = newp;
}
}
}
/* Process all environments variables the dynamic linker must recognize.
Since all of them start with `LD_' we are a bit smarter while finding
all the entries. */
extern char **_environ attribute_hidden;
static void
process_envvars (enum mode *modep)
{
char **runp = _environ;
char *envline;
enum mode mode = normal;
char *debug_output = NULL;
/* This is the default place for profiling data file. */
GLRO(dl_profile_output)
= &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0];
while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
{
size_t len = 0;
while (envline[len] != '\0' && envline[len] != '=')
++len;
if (envline[len] != '=')
/* This is a "LD_" variable at the end of the string without
a '=' character. Ignore it since otherwise we will access
invalid memory below. */
continue;
switch (len)
{
case 4:
/* Warning level, verbose or not. */
if (memcmp (envline, "WARN", 4) == 0)
GLRO(dl_verbose) = envline[5] != '\0';
break;
case 5:
/* Debugging of the dynamic linker? */
if (memcmp (envline, "DEBUG", 5) == 0)
{
process_dl_debug (&envline[6]);
break;
}
if (memcmp (envline, "AUDIT", 5) == 0)
audit_list_string = &envline[6];
break;
case 7:
/* Print information about versions. */
if (memcmp (envline, "VERBOSE", 7) == 0)
{
version_info = envline[8] != '\0';
break;
}
/* List of objects to be preloaded. */
if (memcmp (envline, "PRELOAD", 7) == 0)
{
preloadlist = &envline[8];
break;
}
/* Which shared object shall be profiled. */
if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0')
GLRO(dl_profile) = &envline[8];
break;
case 8:
/* Do we bind early? */
if (memcmp (envline, "BIND_NOW", 8) == 0)
{
GLRO(dl_lazy) = envline[9] == '\0';
break;
}
if (memcmp (envline, "BIND_NOT", 8) == 0)
GLRO(dl_bind_not) = envline[9] != '\0';
break;
case 9:
/* Test whether we want to see the content of the auxiliary
array passed up from the kernel. */
if (!__libc_enable_secure
&& memcmp (envline, "SHOW_AUXV", 9) == 0)
_dl_show_auxv ();
break;
#if !HAVE_TUNABLES
case 10:
/* Mask for the important hardware capabilities. */
if (!__libc_enable_secure
&& memcmp (envline, "HWCAP_MASK", 10) == 0)
GLRO(dl_hwcap_mask) = _dl_strtoul (&envline[11], NULL);
break;
#endif
case 11:
/* Path where the binary is found. */
if (!__libc_enable_secure
&& memcmp (envline, "ORIGIN_PATH", 11) == 0)
GLRO(dl_origin_path) = &envline[12];
break;
case 12:
/* The library search path. */
if (!__libc_enable_secure
&& memcmp (envline, "LIBRARY_PATH", 12) == 0)
{
library_path = &envline[13];
break;
}
/* Where to place the profiling data file. */
if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
{
debug_output = &envline[13];
break;
}
if (!__libc_enable_secure
&& memcmp (envline, "DYNAMIC_WEAK", 12) == 0)
GLRO(dl_dynamic_weak) = 1;
break;
case 13:
/* We might have some extra environment variable with length 13
to handle. */
#ifdef EXTRA_LD_ENVVARS_13
EXTRA_LD_ENVVARS_13
#endif
if (!__libc_enable_secure
&& memcmp (envline, "USE_LOAD_BIAS", 13) == 0)
{
GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0;
break;
}
break;
case 14:
/* Where to place the profiling data file. */
if (!__libc_enable_secure
&& memcmp (envline, "PROFILE_OUTPUT", 14) == 0
&& envline[15] != '\0')
GLRO(dl_profile_output) = &envline[15];
break;
case 16:
/* The mode of the dynamic linker can be set. */
if (memcmp (envline, "TRACE_PRELINKING", 16) == 0)
{
mode = trace;
GLRO(dl_verbose) = 1;
GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK;
GLRO(dl_trace_prelink) = &envline[17];
}
break;
case 20:
/* The mode of the dynamic linker can be set. */
if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
mode = trace;
break;
/* We might have some extra environment variable to handle. This
is tricky due to the pre-processing of the length of the name
in the switch statement here. The code here assumes that added
environment variables have a different length. */
#ifdef EXTRA_LD_ENVVARS
EXTRA_LD_ENVVARS
#endif
}
}
/* The caller wants this information. */
*modep = mode;
/* Extra security for SUID binaries. Remove all dangerous environment
variables. */
if (__builtin_expect (__libc_enable_secure, 0))
{
static const char unsecure_envvars[] =
#ifdef EXTRA_UNSECURE_ENVVARS
EXTRA_UNSECURE_ENVVARS
#endif
UNSECURE_ENVVARS;
const char *nextp;
nextp = unsecure_envvars;
do
{
unsetenv (nextp);
/* We could use rawmemchr but this need not be fast. */
nextp = (char *) (strchr) (nextp, '\0') + 1;
}
while (*nextp != '\0');
if (__access ("/etc/suid-debug", F_OK) != 0)
{
#if !HAVE_TUNABLES
unsetenv ("MALLOC_CHECK_");
#endif
GLRO(dl_debug_mask) = 0;
}
if (mode != normal)
_exit (5);
}
/* If we have to run the dynamic linker in debugging mode and the
LD_DEBUG_OUTPUT environment variable is given, we write the debug
messages to this file. */
else if (any_debug && debug_output != NULL)
{
const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
size_t name_len = strlen (debug_output);
char buf[name_len + 12];
char *startp;
buf[name_len + 11] = '\0';
startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0);
*--startp = '.';
startp = memcpy (startp - name_len, debug_output, name_len);
GLRO(dl_debug_fd) = __open64_nocancel (startp, flags, DEFFILEMODE);
if (GLRO(dl_debug_fd) == -1)
/* We use standard output if opening the file failed. */
GLRO(dl_debug_fd) = STDOUT_FILENO;
}
}
/* Print the various times we collected. */
static void
__attribute ((noinline))
print_statistics (hp_timing_t *rtld_total_timep)
{
#ifndef HP_TIMING_NONAVAIL
char buf[200];
char *cp;
char *wp;
/* Total time rtld used. */
if (HP_SMALL_TIMING_AVAIL)
{
HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep);
_dl_debug_printf ("\nruntime linker statistics:\n"
" total startup time in dynamic loader: %s\n", buf);
/* Print relocation statistics. */
char pbuf[30];
HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep,
pbuf + sizeof (pbuf), 10, 0);
wp = pbuf;
switch (pbuf + sizeof (pbuf) - cp)
{
case 3:
*wp++ = *cp++;
case 2:
*wp++ = *cp++;
case 1:
*wp++ = '.';
*wp++ = *cp++;
}
*wp = '\0';
_dl_debug_printf ("\
time needed for relocation: %s (%s%%)\n", buf, pbuf);
}
#endif
unsigned long int num_relative_relocations = 0;
for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
{
if (GL(dl_ns)[ns]._ns_loaded == NULL)
continue;
struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
for (unsigned int i = 0; i < scope->r_nlist; i++)
{
struct link_map *l = scope->r_list [i];
if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
num_relative_relocations
+= l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
#ifndef ELF_MACHINE_REL_RELATIVE
/* Relative relocations are processed on these architectures if
library is loaded to different address than p_vaddr or
if not prelinked. */
if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)])
&& l->l_info[VERSYMIDX (DT_RELACOUNT)])
#else
/* On e.g. IA-64 or Alpha, relative relocations are processed
only if library is loaded to different address than p_vaddr. */
if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
#endif
num_relative_relocations
+= l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
}
}
_dl_debug_printf (" number of relocations: %lu\n"
" number of relocations from cache: %lu\n"
" number of relative relocations: %lu\n",
GL(dl_num_relocations),
GL(dl_num_cache_relocations),
num_relative_relocations);
#ifndef HP_TIMING_NONAVAIL
/* Time spend while loading the object and the dependencies. */
if (HP_SMALL_TIMING_AVAIL)
{
char pbuf[30];
HP_TIMING_PRINT (buf, sizeof (buf), load_time);
cp = _itoa ((1000ULL * load_time) / *rtld_total_timep,
pbuf + sizeof (pbuf), 10, 0);
wp = pbuf;
switch (pbuf + sizeof (pbuf) - cp)
{
case 3:
*wp++ = *cp++;
case 2:
*wp++ = *cp++;
case 1:
*wp++ = '.';
*wp++ = *cp++;
}
*wp = '\0';
_dl_debug_printf ("\
time needed to load objects: %s (%s%%)\n",
buf, pbuf);
}
#endif
}
|