Loading...
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 2817 2818 2819 2820 2821 | /* Run time dynamic linker.
Copyright (C) 1995-2022 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
<https://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 <unsecvars.h>
#include <dl-cache.h>
#include <dl-osinfo.h>
#include <dl-procinfo.h>
#include <dl-prop.h>
#include <dl-vdso.h>
#include <dl-vdso-setup.h>
#include <tls.h>
#include <stap-probe.h>
#include <stackinfo.h>
#include <not-cancel.h>
#include <array_length.h>
#include <libc-early-init.h>
#include <dl-main.h>
#include <gnu/lib-names.h>
#include <dl-tunables.h>
#include <get-dynamic-info.h>
#include <dl-execve.h>
#include <dl-find_object.h>
#include <dl-audit-check.h>
#include <assert.h>
/* 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 RESOLVE_MAP(map, scope, sym, version, flags) map
#include "dynamic-link.h"
/* Must include after <dl-machine.h> for DT_MIPS definition. */
#include <dl-debug.h>
/* Only enables rtld profiling for architectures which provides non generic
hp-timing support. The generic support requires either syscall
(clock_gettime), which will incur in extra overhead on loading time.
Using vDSO is also an option, but it will require extra support on loader
to setup the vDSO pointer before its usage. */
#if HP_TIMING_INLINE
# define RLTD_TIMING_DECLARE(var, classifier,...) \
classifier hp_timing_t var __VA_ARGS__
# define RTLD_TIMING_VAR(var) RLTD_TIMING_DECLARE (var, )
# define RTLD_TIMING_SET(var, value) (var) = (value)
# define RTLD_TIMING_REF(var) &(var)
static inline void
rtld_timer_start (hp_timing_t *var)
{
HP_TIMING_NOW (*var);
}
static inline void
rtld_timer_stop (hp_timing_t *var, hp_timing_t start)
{
hp_timing_t stop;
HP_TIMING_NOW (stop);
HP_TIMING_DIFF (*var, start, stop);
}
static inline void
rtld_timer_accum (hp_timing_t *sum, hp_timing_t start)
{
hp_timing_t stop;
rtld_timer_stop (&stop, start);
HP_TIMING_ACCUM_NT(*sum, stop);
}
#else
# define RLTD_TIMING_DECLARE(var, classifier...)
# define RTLD_TIMING_SET(var, value)
# define RTLD_TIMING_VAR(var)
# define RTLD_TIMING_REF(var) 0
# define rtld_timer_start(var)
# define rtld_timer_stop(var, start)
# define rtld_timer_accum(sum, start)
#endif
/* 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 (const hp_timing_t *total_timep);
/* Creates an empty audit list. */
static void audit_list_init (struct audit_list *);
/* Add a string to the end of the audit list, for later parsing. Must
not be called after audit_list_next. */
static void audit_list_add_string (struct audit_list *, const char *);
/* Add the audit strings from the link map, found in the dynamic
segment at TG (either DT_AUDIT and DT_DEPAUDIT). Must be called
before audit_list_next. */
static void audit_list_add_dynamic_tag (struct audit_list *,
struct link_map *,
unsigned int tag);
/* Extract the next audit module from the audit list. Only modules
for which dso_name_valid_for_suid is true are returned. Must be
called after all the audit_list_add_string,
audit_list_add_dynamic_tags calls. */
static const char *audit_list_next (struct audit_list *);
/* Initialize *STATE with the defaults. */
static void dl_main_state_init (struct dl_main_state *state);
/* 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 (struct dl_main_state *state);
int _dl_argc attribute_relro attribute_hidden;
char **_dl_argv attribute_relro = NULL;
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;
#ifndef THREAD_SET_POINTER_GUARD
strong_alias (__pointer_chk_guard_local, __pointer_chk_guard)
#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';
}
static void
audit_list_init (struct audit_list *list)
{
list->length = 0;
list->current_index = 0;
list->current_tail = NULL;
}
static void
audit_list_add_string (struct audit_list *list, const char *string)
{
/* Empty strings do not load anything. */
if (*string == '\0')
return;
if (list->length == array_length (list->audit_strings))
_dl_fatal_printf ("Fatal glibc error: Too many audit modules requested\n");
list->audit_strings[list->length++] = string;
/* Initialize processing of the first string for
audit_list_next. */
if (list->length == 1)
list->current_tail = string;
}
static void
audit_list_add_dynamic_tag (struct audit_list *list, struct link_map *main_map,
unsigned int tag)
{
ElfW(Dyn) *info = main_map->l_info[ADDRIDX (tag)];
const char *strtab = (const char *) D_PTR (main_map, l_info[DT_STRTAB]);
if (info != NULL)
audit_list_add_string (list, strtab + info->d_un.d_val);
}
static const char *
audit_list_next (struct audit_list *list)
{
if (list->current_tail == NULL)
return NULL;
while (true)
{
/* Advance to the next string in audit_strings if the current
string has been exhausted. */
while (*list->current_tail == '\0')
{
++list->current_index;
if (list->current_index == list->length)
{
list->current_tail = NULL;
return NULL;
}
list->current_tail = list->audit_strings[list->current_index];
}
/* Split the in-string audit list at the next colon colon. */
size_t len = strcspn (list->current_tail, ":");
if (len > 0 && len < sizeof (list->fname))
{
memcpy (list->fname, list->current_tail, len);
list->fname[len] = '\0';
}
else
/* Mark the name as unusable for dso_name_valid_for_suid. */
list->fname[0] = '\0';
/* Skip over the substring and the following delimiter. */
list->current_tail += len;
if (*list->current_tail == ':')
++list->current_tail;
/* If the name is valid, return it. */
if (dso_name_valid_for_suid (list->fname))
return list->fname;
/* Otherwise wrap around to find the next list element. . */
}
}
/* Count audit modules before they are loaded so GLRO(dl_naudit)
is not yet usable. */
static size_t
audit_list_count (struct audit_list *list)
{
/* Restore the audit_list iterator state at the end. */
const char *saved_tail = list->current_tail;
size_t naudit = 0;
assert (list->current_index == 0);
while (audit_list_next (list) != NULL)
naudit++;
list->current_tail = saved_tail;
list->current_index = 0;
return naudit;
}
static void
dl_main_state_init (struct dl_main_state *state)
{
audit_list_init (&state->audit_list);
state->library_path = NULL;
state->library_path_source = NULL;
state->preloadlist = NULL;
state->preloadarg = NULL;
state->glibc_hwcaps_prepend = NULL;
state->glibc_hwcaps_mask = NULL;
state->mode = rtld_mode_normal;
state->any_debug = false;
state->version_info = false;
}
#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 =
{
/* Get architecture specific initializer. */
#include <dl-procruntime.c>
/* 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,
._dl_load_tls_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 what 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,
#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_catch_error = _rtld_catch_error,
._dl_error_free = _dl_error_free,
._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
._dl_libc_freeres = __rtld_libc_freeres,
};
/* 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. */
RLTD_TIMING_DECLARE (relocate_time, static);
RLTD_TIMING_DECLARE (load_time, static, attribute_relro);
RLTD_TIMING_DECLARE (start_time, static, attribute_relro);
/* 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. */
#ifndef HIDDEN_VAR_NEEDS_DYNAMIC_RELOC
# 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;
RTLD_TIMING_VAR (start_time);
};
static ElfW(Addr) _dl_start_final (void *arg,
struct dl_start_final_info *info);
#endif
/* These are defined magically by the linker. */
extern const ElfW(Ehdr) __ehdr_start 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;
/* Do not use an initializer for these members because it would
intefere with __rtld_static_init. */
GLRO (dl_find_object) = &_dl_find_object;
/* If it hasn't happen yet record the startup time. */
rtld_timer_start (&start_time);
#if !defined DONT_USE_BOOTSTRAP_MAP
RTLD_TIMING_SET (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;
GL(dl_rtld_map).l_ld_readonly = info->l.l_ld_readonly;
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)) &__ehdr_start;
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
/* 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);
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS))
{
RTLD_TIMING_VAR (rtld_total_time);
rtld_timer_stop (&rtld_total_time, start_time);
print_statistics (RTLD_TIMING_REF(rtld_total_time));
}
#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, start_addr);
}
#ifdef DONT_USE_BOOTSTRAP_MAP
# define bootstrap_map GL(dl_rtld_map)
#else
# define bootstrap_map info.l
#endif
static ElfW(Addr) __attribute_used__
_dl_start (void *arg)
{
#ifdef DONT_USE_BOOTSTRAP_MAP
rtld_timer_start (&start_time);
#else
struct dl_start_final_info info;
rtld_timer_start (&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 ();
bootstrap_map.l_ld_readonly = DL_RO_DYN_SECTION;
elf_get_dynamic_info (&bootstrap_map, true, false);
#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, bootstrap_map.l_info);
#endif
if (bootstrap_map.l_addr)
{
/* Relocate ourselves so we can do normal function calls and
data access using the global offset table. */
ELF_DYNAMIC_RELOCATE (&bootstrap_map, NULL, 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. */
__rtld_malloc_init_stubs ();
#ifdef DONT_USE_BOOTSTRAP_MAP
return _dl_start_final (arg);
#else
return _dl_start_final (arg, &info);
#endif
}
/* 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 (size_t naudit)
{
/* 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));
/* Calculate the size of the static TLS surplus. */
_dl_tls_static_surplus_init (naudit);
/* 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 ();
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;
}
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 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. Ditto for --preload command argument. */
unsigned int
handle_preload_list (const char *preloadlist, struct link_map *main_map,
const char *where)
{
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, where);
}
return npreloads;
}
/* Called if the audit DSO cannot be used: if it does not have the
appropriate interfaces, or it expects a more recent version library
version than what the dynamic linker provides. */
static void
unload_audit_module (struct link_map *map, int original_tls_idx)
{
#ifndef NDEBUG
Lmid_t ns = map->l_ns;
#endif
_dl_close (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) = original_tls_idx;
}
/* Called to print an error message if loading of an audit module
failed. */
static void
report_audit_module_load_error (const char *name, const char *err_str,
bool malloced)
{
_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);
}
/* Load one audit module. */
static void
load_audit_module (const char *name, struct audit_ifaces **last_audit)
{
int original_tls_idx = GL(dl_tls_max_dtv_idx);
struct dlmopen_args dlmargs;
dlmargs.fname = name;
dlmargs.map = NULL;
const char *objname;
const char *err_str = NULL;
bool malloced;
_dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, &dlmargs);
if (__glibc_unlikely (err_str != NULL))
{
report_audit_module_load_error (name, err_str, malloced);
return;
}
struct lookup_args largs;
largs.name = "la_version";
largs.map = dlmargs.map;
_dl_catch_error (&objname, &err_str, &malloced, lookup_doit, &largs);
if (__glibc_likely (err_str != NULL))
{
unload_audit_module (dlmargs.map, original_tls_idx);
report_audit_module_load_error (name, err_str, malloced);
return;
}
unsigned int (*laversion) (unsigned int) = largs.result;
/* A null symbol indicates that something is very wrong with the
loaded object because defined symbols are supposed to have a
valid, non-null address. */
assert (laversion != NULL);
unsigned int lav = laversion (LAV_CURRENT);
if (lav == 0)
{
/* Only print an error message if debugging because this can
happen deliberately. */
if (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
_dl_debug_printf ("\
file=%s [%lu]; audit interface function la_version returned zero; ignored.\n",
dlmargs.map->l_name, dlmargs.map->l_ns);
unload_audit_module (dlmargs.map, original_tls_idx);
return;
}
if (!_dl_audit_check_version (lav))
{
_dl_debug_printf ("\
ERROR: audit interface '%s' requires version %d (maximum supported version %d); ignored.\n",
name, lav, LAV_CURRENT);
unload_audit_module (dlmargs.map, original_tls_idx);
return;
}
enum { naudit_ifaces = 8 };
union
{
struct audit_ifaces ifaces;
void (*fptr[naudit_ifaces]) (void);
} *newp = malloc (sizeof (*newp));
if (newp == NULL)
_dl_fatal_printf ("Out of memory while loading audit modules\n");
/* 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"
LA_SYMBIND "\0"
#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;
_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;
else
newp->fptr[cnt] = NULL;
++cnt;
cp = 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;
/* The dynamic linker link map is statically allocated, so the
cookie in _dl_new_object has not happened. */
link_map_audit_state (&GL (dl_rtld_map), GLRO (dl_naudit))->cookie
= (intptr_t) &GL (dl_rtld_map);
++GLRO(dl_naudit);
/* Mark the DSO as being used for auditing. */
dlmargs.map->l_auditing = 1;
}
/* Load all audit modules. */
static void
load_audit_modules (struct link_map *main_map, struct audit_list *audit_list)
{
struct audit_ifaces *last_audit = NULL;
while (true)
{
const char *name = audit_list_next (audit_list);
if (name == NULL)
break;
load_audit_module (name, &last_audit);
}
/* Notify audit modules of the initially loaded modules (the main
program and the dynamic linker itself). */
if (GLRO(dl_naudit) > 0)
{
_dl_audit_objopen (main_map, LM_ID_BASE);
_dl_audit_objopen (&GL(dl_rtld_map), LM_ID_BASE);
}
}
/* Check if the executable is not actualy dynamically linked, and
invoke it directly in that case. */
static void
rtld_chain_load (struct link_map *main_map, char *argv0)
{
/* The dynamic loader run against itself. */
const char *rtld_soname
= ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB])
+ GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val);
if (main_map->l_info[DT_SONAME] != NULL
&& strcmp (rtld_soname,
((const char *) D_PTR (main_map, l_info[DT_STRTAB])
+ main_map->l_info[DT_SONAME]->d_un.d_val)) == 0)
_dl_fatal_printf ("%s: loader cannot load itself\n", rtld_soname);
/* With DT_NEEDED dependencies, the executable is dynamically
linked. */
if (__glibc_unlikely (main_map->l_info[DT_NEEDED] != NULL))
return;
/* If the executable has program interpreter, it is dynamically
linked. */
for (size_t i = 0; i < main_map->l_phnum; ++i)
if (main_map->l_phdr[i].p_type == PT_INTERP)
return;
const char *pathname = _dl_argv[0];
if (argv0 != NULL)
_dl_argv[0] = argv0;
int errcode = __rtld_execve (pathname, _dl_argv, _environ);
const char *errname = strerrorname_np (errcode);
if (errname != NULL)
_dl_fatal_printf("%s: cannot execute %s: %s\n",
rtld_soname, pathname, errname);
else
_dl_fatal_printf("%s: cannot execute %s: %d\n",
rtld_soname, pathname, errcode);
}
/* Called to complete the initialization of the link map for the main
executable. Returns true if there is a PT_INTERP segment. */
static bool
rtld_setup_main_map (struct link_map *main_map)
{
/* This have already been filled in right after _dl_new_object, or
as part of _dl_map_object. */
const ElfW(Phdr) *phdr = main_map->l_phdr;
ElfW(Word) phnum = main_map->l_phnum;
bool has_interp = false;
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;
main_map->l_contiguous = 1;
/* A PT_LOAD segment at an unexpected address will clear the
l_contiguous flag. The ELF specification says that PT_LOAD
segments need to be sorted in in increasing order, but perhaps
not all executables follow this requirement. Having l_contiguous
equal to 1 is just an optimization, so the code below does not
try to sort the segments in case they are unordered.
There is one corner case in which l_contiguous is not set to 1,
but where it could be set: If a PIE (ET_DYN) binary is loaded by
glibc itself (not the kernel), it is always contiguous due to the
way the glibc loader works. However, the kernel loader may still
create holes in this case, and the code here still uses 0
conservatively for the glibc-loaded case, too. */
ElfW(Addr) expected_load_address = 0;
/* Scan the program header table for the dynamic section. */
for (const ElfW(Phdr) *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;
main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0;
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;
if (main_map->l_contiguous && expected_load_address != 0
&& expected_load_address != mapstart)
main_map->l_contiguous = 0;
/* 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;
/* The next expected address is the page following this load
segment. */
expected_load_address = ((allocend + GLRO(dl_pagesize) - 1)
& ~(GLRO(dl_pagesize) - 1));
}
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;
}
/* Process program headers again, but scan them backwards so
that PT_NOTE can be skipped if PT_GNU_PROPERTY exits. */
for (const ElfW(Phdr) *ph = &phdr[phnum]; ph != phdr; --ph)
switch (ph[-1].p_type)
{
case PT_NOTE:
_dl_process_pt_note (main_map, -1, &ph[-1]);
break;
case PT_GNU_PROPERTY:
_dl_process_pt_gnu_property (main_map, -1, &ph[-1]);
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? */
return has_interp;
}
/* Adjusts the contents of the stack and related globals for the user
entry point. The ld.so processed skip_args arguments and bumped
_dl_argv and _dl_argc accordingly. Those arguments are removed from
argv here. */
static void
_dl_start_args_adjust (int skip_args)
{
void **sp = (void **) (_dl_argv - skip_args - 1);
void **p = sp + skip_args;
if (skip_args == 0)
return;
/* Sanity check. */
intptr_t argc __attribute__ ((unused)) = (intptr_t) sp[0] - skip_args;
assert (argc == _dl_argc);
/* Adjust argc on stack. */
sp[0] = (void *) (intptr_t) _dl_argc;
/* Update globals in rtld. */
_dl_argv -= skip_args;
_environ -= skip_args;
/* Shuffle argv down. */
do
*++sp = *++p;
while (*p != NULL);
assert (_environ == (char **) (sp + 1));
/* Shuffle envp down. */
do
*++sp = *++p;
while (*p != NULL);
#ifdef HAVE_AUX_VECTOR
void **auxv = (void **) GLRO(dl_auxv) - skip_args;
GLRO(dl_auxv) = (ElfW(auxv_t) *) auxv; /* Aliasing violation. */
assert (auxv == sp + 1);
/* Shuffle auxv down. */
ElfW(auxv_t) ax;
char *oldp = (char *) (p + 1);
char *newp = (char *) (sp + 1);
do
{
memcpy (&ax, oldp, sizeof (ax));
memcpy (newp, &ax, sizeof (ax));
oldp += sizeof (ax);
newp += sizeof (ax);
}
while (ax.a_type != AT_NULL);
#endif
}
static void
dl_main (const ElfW(Phdr) *phdr,
ElfW(Word) phnum,
ElfW(Addr) *user_entry,
ElfW(auxv_t) *auxv)
{
struct link_map *main_map;
size_t file_size;
char *file;
unsigned int i;
bool rtld_is_main = false;
void *tcbp = NULL;
struct dl_main_state state;
dl_main_state_init (&state);
__tls_pre_init_tp ();
#if !PTHREAD_IN_LIBC
/* 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;
#endif
/* Process the environment variable which control the behaviour. */
process_envvars (&state);
#ifndef HAVE_INLINED_SYSCALLS
/* Set up a flag which tells we are just starting. */
_dl_starting_up = 1;
#endif
const char *ld_so_name = _dl_argv[0];
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;
char *argv0 = NULL;
char **orig_argv = _dl_argv;
/* 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"))
{
if (state.mode != rtld_mode_help)
{
state.mode = rtld_mode_list;
/* This means do no dependency analysis. */
GLRO(dl_lazy) = -1;
}
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--verify"))
{
if (state.mode != rtld_mode_help)
state.mode = rtld_mode_verify;
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--inhibit-cache"))
{
GLRO(dl_inhibit_cache) = 1;
--_dl_argc;
++_dl_argv;
}
else if (! strcmp (_dl_argv[1], "--library-path")
&& _dl_argc > 2)
{
state.library_path = _dl_argv[2];
state.library_path_source = "--library-path";
_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_argc -= 2;
_dl_argv += 2;
}
else if (! strcmp (_dl_argv[1], "--audit") && _dl_argc > 2)
{
audit_list_add_string (&state.audit_list, _dl_argv[2]);
_dl_argc -= 2;
_dl_argv += 2;
}
else if (! strcmp (_dl_argv[1], "--preload") && _dl_argc > 2)
{
state.preloadarg = _dl_argv[2];
_dl_argc -= 2;
_dl_argv += 2;
}
else if (! strcmp (_dl_argv[1], "--argv0") && _dl_argc > 2)
{
argv0 = _dl_argv[2];
_dl_argc -= 2;
_dl_argv += 2;
}
else if (strcmp (_dl_argv[1], "--glibc-hwcaps-prepend") == 0
&& _dl_argc > 2)
{
state.glibc_hwcaps_prepend = _dl_argv[2];
_dl_argc -= 2;
_dl_argv += 2;
}
else if (strcmp (_dl_argv[1], "--glibc-hwcaps-mask") == 0
&& _dl_argc > 2)
{
state.glibc_hwcaps_mask = _dl_argv[2];
_dl_argc -= 2;
_dl_argv += 2;
}
#if HAVE_TUNABLES
else if (! strcmp (_dl_argv[1], "--list-tunables"))
{
state.mode = rtld_mode_list_tunables;
--_dl_argc;
++_dl_argv;
}
#endif
else if (! strcmp (_dl_argv[1], "--list-diagnostics"))
{
state.mode = rtld_mode_list_diagnostics;
--_dl_argc;
++_dl_argv;
}
else if (strcmp (_dl_argv[1], "--help") == 0)
{
state.mode = rtld_mode_help;
--_dl_argc;
++_dl_argv;
}
else if (strcmp (_dl_argv[1], "--version") == 0)
_dl_version ();
else if (_dl_argv[1][0] == '-' && _dl_argv[1][1] == '-')
{
if (_dl_argv[1][1] == '\0')
/* End of option list. */
break;
else
/* Unrecognized option. */
_dl_usage (ld_so_name, _dl_argv[1]);
}
else
break;
#if HAVE_TUNABLES
if (__glibc_unlikely (state.mode == rtld_mode_list_tunables))
{
__tunables_print ();
_exit (0);
}
#endif
if (state.mode == rtld_mode_list_diagnostics)
_dl_print_diagnostics (_environ);
/* If we have no further argument the program was called incorrectly.
Grant the user some education. */
if (_dl_argc < 2)
{
if (state.mode == rtld_mode_help)
/* --help without an executable is not an error. */
_dl_help (ld_so_name, &state);
else
_dl_usage (ld_so_name, NULL);
}
--_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 (const ElfW(Phdr) *ph = phdr; ph < &phdr[phnum]; ++ph)
if (ph->p_type == PT_GNU_STACK)
{
GL(dl_stack_flags) = ph->p_flags;
break;
}
if (__glibc_unlikely (state.mode == rtld_mode_verify
|| state.mode == rtld_mode_help))
{
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. */
if (state.mode == rtld_mode_help)
/* Mask the failure to load the main object. The help
message contains less information in this case. */
_dl_help (ld_so_name, &state);
else
_exit (EXIT_FAILURE);
}
}
else
{
RTLD_TIMING_VAR (start);
rtld_timer_start (&start);
_dl_map_object (NULL, rtld_progname, lt_executable, 0,
__RTLD_OPENEXEC, LM_ID_BASE);
rtld_timer_stop (&load_time, start);
}
/* Now the map for the main executable is available. */
main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
if (__glibc_likely (state.mode == rtld_mode_normal))
rtld_chain_load (main_map, argv0);
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;
/* Set bit indicating this is the main program map. */
main_map->l_main_map = 1;
#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
/* Set the argv[0] string now that we've processed the executable. */
if (argv0 != NULL)
_dl_argv[0] = argv0;
/* Adjust arguments for the application entry point. */
_dl_start_args_adjust (_dl_argv - orig_argv);
}
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. */
}
bool has_interp = rtld_setup_main_map (main_map);
/* 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, false, false);
/* If the main map is libc.so, update the base namespace to
refer to this map. If libc.so is loaded later, this happens
in _dl_map_object_from_fd. */
if (main_map->l_info[DT_SONAME] != NULL
&& (strcmp (((const char *) D_PTR (main_map, l_info[DT_STRTAB])
+ main_map->l_info[DT_SONAME]->d_un.d_val), LIBC_SO)
== 0))
GL(dl_ns)[LM_ID_BASE].libc_map = main_map;
/* Set up our cache of pointers into the hash table. */
_dl_setup_hash (main_map);
}
if (__glibc_unlikely (state.mode == rtld_mode_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);
_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);
/* With vDSO setup we can initialize the function pointers. */
setup_vdso_pointers ();
/* Initialize the data structures for the search paths for shared
objects. */
call_init_paths (&state);
/* Initialize _r_debug_extended. */
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);
/* 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. */
/* 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 = &__ehdr_start;
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. */
_dl_assign_tls_modid (&GL(dl_rtld_map));
audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_AUDIT);
audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_DEPAUDIT);
/* At this point, all data has been obtained that is included in the
--help output. */
if (__glibc_unlikely (state.mode == rtld_mode_help))
_dl_help (ld_so_name, &state);
/* If we have auditing DSOs to load, do it now. */
bool need_security_init = true;
if (state.audit_list.length > 0)
{
size_t naudit = audit_list_count (&state.audit_list);
/* Since we start using the auditing DSOs right away we need to
initialize the data structures now. */
tcbp = init_tls (naudit);
/* 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;
load_audit_modules (main_map, &state.audit_list);
/* The count based on audit strings may overestimate the number
of audit modules that got loaded, but not underestimate. */
assert (GLRO(dl_naudit) <= naudit);
}
/* 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. */
elf_setup_debug_entry (main_map, r);
/* 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. */
_dl_audit_activity_map (main_map, LA_ACT_ADD);
/* 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 (state.preloadlist != NULL))
{
RTLD_TIMING_VAR (start);
rtld_timer_start (&start);
npreloads += handle_preload_list (state.preloadlist, main_map,
"LD_PRELOAD");
rtld_timer_accum (&load_time, start);
}
if (__glibc_unlikely (state.preloadarg != NULL))
{
RTLD_TIMING_VAR (start);
rtld_timer_start (&start);
npreloads += handle_preload_list (state.preloadarg, main_map,
"--preload");
rtld_timer_accum (&load_time, start);
}
/* 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';
}
RTLD_TIMING_VAR (start);
rtld_timer_start (&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);
}
rtld_timer_accum (&load_time, start);
/* 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);
}
#ifdef NEED_DL_SYSINFO_DSO
/* Now that the audit modules are opened, call la_objopen for the vDSO. */
if (GLRO(dl_sysinfo_map) != NULL)
_dl_audit_objopen (GLRO(dl_sysinfo_map), LM_ID_BASE);
#endif
/* 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. */
{
RTLD_TIMING_VAR (start);
rtld_timer_start (&start);
_dl_map_object_deps (main_map, preloads, npreloads,
state.mode == rtld_mode_trace, 0);
rtld_timer_accum (&load_time, start);
}
/* 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 (__glibc_likely (state.mode == rtld_mode_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 = state.mode == rtld_mode_normal;
args.dotrace = state.mode == rtld_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 (0);
if (__glibc_likely (need_security_init))
/* Initialize security features. But only if we have not done it
earlier. */
security_init ();
if (__glibc_unlikely (state.mode != rtld_mode_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_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 = state.mode_trace_program ? main_map : 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
_dl_printf ("\t%s => %s (0x%0*Zx)\n",
DSO_FILENAME (l->l_libname->name),
DSO_FILENAME (l->l_name),
(int) sizeof l->l_map_start * 2,
(size_t) l->l_map_start);
}
}
if (__glibc_unlikely (state.mode != rtld_mode_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);
}
}
}
#define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED))
if (state.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);
}
/* 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]);
/* 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;
/* If we are profiling we also must do lazy reloaction. */
GLRO(dl_lazy) |= consider_profiling;
RTLD_TIMING_VAR (start);
rtld_timer_start (&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, true);
}
}
rtld_timer_stop (&relocate_time, start);
/* 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, false);
/* 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);
__tls_init_tp ();
}
/* Make sure no new search directories have been added. */
assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));
if (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. */
/* Set up the object lookup structures. */
_dl_find_object_init ();
/* The malloc implementation has been relocated, so resolving
its symbols (and potentially calling IFUNC resolvers) is safe
at this point. */
__rtld_malloc_init_real (main_map);
/* Likewise for the locking implementation. */
__rtld_mutex_init ();
RTLD_TIMING_VAR (start);
rtld_timer_start (&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);
rtld_timer_accum (&relocate_time, start);
}
/* Relocation is complete. Perform early libc initialization. This
is the initial libc, even if audit modules have been loaded with
other libcs. */
_dl_call_libc_early_init (GL(dl_ns)[LM_ID_BASE].libc_map, true);
/* 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. */
_dl_audit_activity_nsid (LM_ID_BASE, LA_ACT_CONSISTENT);
#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_update (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);
}
/* Process the string given as the parameter which explains which debugging
options are enabled. */
static void
process_dl_debug (struct dl_main_state *state, 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;
state->any_debug = true;
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_envvars (struct dl_main_state *state)
{
char **runp = _environ;
char *envline;
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 (state, &envline[6]);
break;
}
if (memcmp (envline, "AUDIT", 5) == 0)
audit_list_add_string (&state->audit_list, &envline[6]);
break;
case 7:
/* Print information about versions. */
if (memcmp (envline, "VERBOSE", 7) == 0)
{
state->version_info = envline[8] != '\0';
break;
}
/* List of objects to be preloaded. */
if (memcmp (envline, "PRELOAD", 7) == 0)
{
state->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)
{
state->library_path = &envline[13];
state->library_path_source = "LD_LIBRARY_PATH";
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 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 20:
/* The mode of the dynamic linker can be set. */
if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
{
state->mode = rtld_mode_trace;
state->mode_trace_program
= _dl_strtoul (&envline[21], NULL) > 1;
}
break;
}
}
/* Extra security for SUID binaries. Remove all dangerous environment
variables. */
if (__glibc_unlikely (__libc_enable_secure))
{
const char *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 (state->mode != rtld_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 (state->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;
}
}
#if HP_TIMING_INLINE
static void
print_statistics_item (const char *title, hp_timing_t time,
hp_timing_t total)
{
char cycles[HP_TIMING_PRINT_SIZE];
HP_TIMING_PRINT (cycles, sizeof (cycles), time);
char relative[3 * sizeof (hp_timing_t) + 2];
char *cp = _itoa ((1000ULL * time) / total, relative + sizeof (relative),
10, 0);
/* Sets the decimal point. */
char *wp = relative;
switch (relative + sizeof (relative) - cp)
{
case 3:
*wp++ = *cp++;
/* Fall through. */
case 2:
*wp++ = *cp++;
/* Fall through. */
case 1:
*wp++ = '.';
*wp++ = *cp++;
}
*wp = '\0';
_dl_debug_printf ("%s: %s cycles (%s%%)\n", title, cycles, relative);
}
#endif
/* Print the various times we collected. */
static void
__attribute ((noinline))
print_statistics (const hp_timing_t *rtld_total_timep)
{
#if HP_TIMING_INLINE
{
char cycles[HP_TIMING_PRINT_SIZE];
HP_TIMING_PRINT (cycles, sizeof (cycles), *rtld_total_timep);
_dl_debug_printf ("\nruntime linker statistics:\n"
" total startup time in dynamic loader: %s cycles\n",
cycles);
print_statistics_item (" time needed for relocation",
relocate_time, *rtld_total_timep);
}
#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; |