ldso.c 27 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Program to load an ELF binary on a linux system, and run it
  4. * after resolving ELF shared library symbols
  5. *
  6. * Copyright (C) 2000-2004 by Erik Andersen <andersen@codpoet.org>
  7. * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
  8. * David Engel, Hongjiu Lu and Mitch D'Souza
  9. *
  10. * Redistribution and use in source and binary forms, with or without
  11. * modification, are permitted provided that the following conditions
  12. * are met:
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. * 2. The name of the above contributors may not be
  16. * used to endorse or promote products derived from this software
  17. * without specific prior written permission.
  18. *
  19. * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  20. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22. * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  23. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29. * SUCH DAMAGE.
  30. */
  31. #include "ldso.h"
  32. #include "unsecvars.h"
  33. #define ALLOW_ZERO_PLTGOT
  34. /* Pull in the value of _dl_progname */
  35. #include "dl-progname.h"
  36. /* Global variables used within the shared library loader */
  37. char *_dl_library_path = 0; /* Where we look for libraries */
  38. char *_dl_preload = 0; /* Things to be loaded before the libs */
  39. char *_dl_ldsopath = 0; /* Location of the shared lib loader */
  40. int _dl_secure = 1; /* Are we dealing with setuid stuff? */
  41. int _dl_errno = 0; /* We can't use the real errno in ldso */
  42. size_t _dl_pagesize = 0; /* Store the page size for use later */
  43. struct r_debug *_dl_debug_addr = NULL; /* Used to communicate with the gdb debugger */
  44. void *(*_dl_malloc_function) (size_t size) = NULL;
  45. #ifdef __SUPPORT_LD_DEBUG__
  46. char *_dl_debug = 0;
  47. char *_dl_debug_symbols = 0;
  48. char *_dl_debug_move = 0;
  49. char *_dl_debug_reloc = 0;
  50. char *_dl_debug_detail = 0;
  51. char *_dl_debug_nofixups = 0;
  52. char *_dl_debug_bindings = 0;
  53. int _dl_debug_file = 2;
  54. #endif
  55. #include "dl-startup.c"
  56. /* Forward function declarations */
  57. static int _dl_suid_ok(void);
  58. /*
  59. * This stub function is used by some debuggers. The idea is that they
  60. * can set an internal breakpoint on it, so that we are notified when the
  61. * address mapping is changed in some way.
  62. */
  63. void _dl_debug_state(void)
  64. {
  65. }
  66. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  67. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  68. #if defined (__SUPPORT_LD_DEBUG__)
  69. static void debug_fini (int status, void *arg)
  70. {
  71. (void)status;
  72. _dl_dprintf(_dl_debug_file,"\ncalling fini: %s\n\n", (const char*)arg);
  73. }
  74. #endif
  75. void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
  76. Elf32_auxv_t auxvt[AT_EGID + 1], char **envp,
  77. char **argv)
  78. {
  79. ElfW(Phdr) *ppnt;
  80. Elf32_Dyn *dpnt;
  81. char *lpntstr;
  82. int i, nlist, goof = 0, unlazy = 0, trace_loaded_objects = 0;
  83. struct elf_resolve **init_fini_list;
  84. struct dyn_elf *rpnt;
  85. struct elf_resolve *tcurr;
  86. struct elf_resolve *tpnt1;
  87. struct elf_resolve app_tpnt_tmp;
  88. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  89. struct r_debug *debug_addr;
  90. unsigned long *lpnt;
  91. int (*_dl_atexit) (void *);
  92. unsigned long *_dl_envp; /* The environment address */
  93. ElfW(Addr) relro_addr = 0;
  94. size_t relro_size = 0;
  95. #if defined (__SUPPORT_LD_DEBUG__)
  96. int (*_dl_on_exit) (void (*FUNCTION)(int STATUS, void *ARG),void*);
  97. #endif
  98. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  99. /* Wahoo!!! */
  100. SEND_STDERR("Cool, we managed to make a function call.\n");
  101. #endif
  102. /* Store the page size for later use */
  103. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  104. /* Make it so _dl_malloc can use the page of memory we have already
  105. * allocated. We shouldn't need to grab any more memory. This must
  106. * be first since things like _dl_dprintf() use _dl_malloc()...
  107. */
  108. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  109. _dl_mmap_zero = 0;
  110. /* Now we have done the mandatory linking of some things. We are now
  111. * free to start using global variables, since these things have all
  112. * been fixed up by now. Still no function calls outside of this
  113. * library, since the dynamic resolver is not yet ready.
  114. */
  115. if (argv[0]) {
  116. _dl_progname = argv[0];
  117. }
  118. /* Start to build the tables of the modules that are required for
  119. * this beast to run. We start with the basic executable, and then
  120. * go from there. Eventually we will run across ourself, and we
  121. * will need to properly deal with that as well.
  122. */
  123. rpnt = NULL;
  124. if (_dl_getenv("LD_BIND_NOW", envp))
  125. unlazy = RTLD_NOW;
  126. /* At this point we are now free to examine the user application,
  127. * and figure out which libraries are supposed to be called. Until
  128. * we have this list, we will not be completely ready for dynamic
  129. * linking.
  130. */
  131. /* Find the runtime load address of the main executable. This may be
  132. * different from what the ELF header says for ET_DYN/PIE executables.
  133. */
  134. {
  135. int i;
  136. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  137. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  138. if (ppnt->p_type == PT_PHDR) {
  139. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  140. break;
  141. }
  142. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  143. if (app_tpnt->loadaddr) {
  144. SEND_STDERR("Position Independent Executable: app_tpnt->loadaddr=");
  145. SEND_ADDRESS_STDERR(app_tpnt->loadaddr, 1);
  146. }
  147. #endif
  148. }
  149. /*
  150. * This is used by gdb to locate the chain of shared libraries that are
  151. * currently loaded.
  152. */
  153. debug_addr = _dl_malloc(sizeof(struct r_debug));
  154. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  155. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  156. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  157. if (ppnt->p_type == PT_GNU_RELRO) {
  158. relro_addr = ppnt->p_vaddr;
  159. relro_size = ppnt->p_memsz;
  160. }
  161. if (ppnt->p_type == PT_DYNAMIC) {
  162. dpnt = (Elf32_Dyn *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  163. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr);
  164. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  165. /* Ugly, ugly. We need to call mprotect to change the
  166. * protection of the text pages so that we can do the
  167. * dynamic linking. We can set the protection back
  168. * again once we are done.
  169. */
  170. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  171. SEND_STDERR("calling mprotect on the application program\n");
  172. #endif
  173. /* Now cover the application program. */
  174. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  175. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  176. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  177. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  178. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  179. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  180. (unsigned long) ppnt->p_filesz,
  181. PROT_READ | PROT_WRITE | PROT_EXEC);
  182. }
  183. }
  184. #endif
  185. #ifndef ALLOW_ZERO_PLTGOT
  186. /* make sure it's really there. */
  187. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  188. continue;
  189. #endif
  190. /* OK, we have what we need - slip this one into the list. */
  191. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  192. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  193. _dl_loaded_modules->libtype = elf_executable;
  194. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  195. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  196. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  197. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  198. rpnt->dyn = _dl_loaded_modules;
  199. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  200. app_tpnt->usage_count++;
  201. app_tpnt->symbol_scope = _dl_symbol_tables;
  202. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT] + app_tpnt->loadaddr);
  203. #ifdef ALLOW_ZERO_PLTGOT
  204. if (lpnt)
  205. #endif
  206. INIT_GOT(lpnt, _dl_loaded_modules);
  207. }
  208. /* OK, fill this in - we did not have this before */
  209. if (ppnt->p_type == PT_INTERP) {
  210. int readsize = 0;
  211. char *pnt, *pnt1, buf[1024];
  212. tpnt->libname = _dl_strdup((char *) ppnt->p_offset +
  213. (auxvt[AT_PHDR].a_un.a_val & PAGE_ALIGN));
  214. /* Determine if the shared lib loader is a symlink */
  215. _dl_memset(buf, 0, sizeof(buf));
  216. readsize = _dl_readlink(tpnt->libname, buf, sizeof(buf));
  217. if (readsize > 0 && readsize < (int)(sizeof(buf)-1)) {
  218. pnt1 = _dl_strrchr(buf, '/');
  219. if (pnt1 && buf != pnt1) {
  220. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  221. _dl_dprintf(_dl_debug_file,
  222. "changing tpnt->libname from '%s' to '%s'\n",
  223. tpnt->libname, buf);
  224. #endif
  225. tpnt->libname = _dl_strdup(buf);
  226. }
  227. }
  228. /* Store the path where the shared lib loader was found
  229. * for later use
  230. */
  231. pnt = _dl_strdup(tpnt->libname);
  232. pnt1 = _dl_strrchr(pnt, '/');
  233. if (pnt != pnt1) {
  234. *pnt1 = '\0';
  235. _dl_ldsopath = pnt;
  236. } else {
  237. _dl_ldsopath = tpnt->libname;
  238. }
  239. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  240. _dl_dprintf(_dl_debug_file, "Lib Loader:\t(%x) %s\n",
  241. tpnt->loadaddr, tpnt->libname);
  242. #endif
  243. }
  244. }
  245. app_tpnt->relro_addr = relro_addr;
  246. app_tpnt->relro_size = relro_size;
  247. /* Now we need to figure out what kind of options are selected.
  248. * Note that for SUID programs we ignore the settings in
  249. * LD_LIBRARY_PATH.
  250. */
  251. if ((auxvt[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) ||
  252. (auxvt[AT_UID].a_un.a_val != -1 &&
  253. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  254. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  255. _dl_secure = 0;
  256. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  257. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  258. } else {
  259. static const char unsecure_envvars[] =
  260. #ifdef EXTRA_UNSECURE_ENVVARS
  261. EXTRA_UNSECURE_ENVVARS
  262. #endif
  263. UNSECURE_ENVVARS;
  264. const char *nextp;
  265. _dl_secure = 1;
  266. nextp = unsecure_envvars;
  267. do {
  268. _dl_unsetenv (nextp, envp);
  269. /* We could use rawmemchr but this need not be fast. */
  270. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  271. } while (*nextp != '\0');
  272. _dl_preload = NULL;
  273. _dl_library_path = NULL;
  274. }
  275. #ifdef __SUPPORT_LD_DEBUG__
  276. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  277. if (_dl_debug) {
  278. if (_dl_strstr(_dl_debug, "all")) {
  279. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  280. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  281. } else {
  282. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  283. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  284. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  285. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  286. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  287. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  288. }
  289. }
  290. {
  291. const char *dl_debug_output;
  292. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  293. if (dl_debug_output) {
  294. char tmp[22], *tmp1, *filename;
  295. int len1, len2;
  296. _dl_memset(tmp, 0, sizeof(tmp));
  297. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  298. len1 = _dl_strlen(dl_debug_output);
  299. len2 = _dl_strlen(tmp1);
  300. filename = _dl_malloc(len1+len2+2);
  301. if (filename) {
  302. _dl_strcpy (filename, dl_debug_output);
  303. filename[len1] = '.';
  304. _dl_strcpy (&filename[len1+1], tmp1);
  305. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  306. if (_dl_debug_file < 0) {
  307. _dl_debug_file = 2;
  308. _dl_dprintf (2, "can't open file: '%s'\n",filename);
  309. }
  310. }
  311. }
  312. }
  313. #endif
  314. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  315. trace_loaded_objects++;
  316. }
  317. #ifndef __LDSO_LDD_SUPPORT__
  318. if (trace_loaded_objects) {
  319. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  320. _dl_exit(1);
  321. }
  322. #endif
  323. /*
  324. * OK, fix one more thing - set up debug_addr so it will point
  325. * to our chain. Later we may need to fill in more fields, but this
  326. * should be enough for now.
  327. */
  328. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  329. debug_addr->r_version = 1;
  330. debug_addr->r_ldbase = load_addr;
  331. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  332. _dl_debug_addr = debug_addr;
  333. /* Notify the debugger we are in a consistant state */
  334. _dl_debug_addr->r_state = RT_CONSISTENT;
  335. _dl_debug_state();
  336. /* OK, we now have the application in the list, and we have some
  337. * basic stuff in place. Now search through the list for other shared
  338. * libraries that should be loaded, and insert them on the list in the
  339. * correct order.
  340. */
  341. _dl_map_cache();
  342. if (_dl_preload) {
  343. char c, *str, *str2;
  344. str = _dl_preload;
  345. while (*str == ':' || *str == ' ' || *str == '\t')
  346. str++;
  347. while (*str) {
  348. str2 = str;
  349. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  350. str2++;
  351. c = *str2;
  352. *str2 = '\0';
  353. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  354. if ((tpnt1 = _dl_check_if_named_library_is_loaded(str, trace_loaded_objects))) {
  355. tpnt1->usage_count++;
  356. goto next_lib;
  357. }
  358. #if defined (__SUPPORT_LD_DEBUG__)
  359. if(_dl_debug)
  360. _dl_dprintf(_dl_debug_file,
  361. "\tfile='%s'; needed by '%s'\n",
  362. str, _dl_progname);
  363. #endif
  364. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  365. if (!tpnt1) {
  366. #ifdef __LDSO_LDD_SUPPORT__
  367. if (trace_loaded_objects)
  368. _dl_dprintf(1, "\t%s => not found\n", str);
  369. else
  370. #endif
  371. {
  372. _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
  373. _dl_exit(15);
  374. }
  375. } else {
  376. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  377. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  378. _dl_dprintf(_dl_debug_file,
  379. "Loading:\t(%x) %s\n",
  380. tpnt1->loadaddr,
  381. tpnt1->libname);
  382. #endif
  383. #ifdef __LDSO_LDD_SUPPORT__
  384. if (trace_loaded_objects &&
  385. tpnt1->usage_count == 1) {
  386. /* This is a real hack to make
  387. * ldd not print the library
  388. * itself when run on a
  389. * library.
  390. */
  391. if (_dl_strcmp(_dl_progname, str) != 0)
  392. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  393. (unsigned)tpnt1->loadaddr);
  394. }
  395. #endif
  396. }
  397. }
  398. next_lib:
  399. *str2 = c;
  400. str = str2;
  401. while (*str == ':' || *str == ' ' || *str == '\t')
  402. str++;
  403. }
  404. }
  405. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  406. do {
  407. struct stat st;
  408. char *preload;
  409. int fd;
  410. char c, *cp, *cp2;
  411. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  412. break;
  413. }
  414. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  415. _dl_dprintf(2, "%s: can't open file '%s'\n",
  416. _dl_progname, LDSO_PRELOAD);
  417. break;
  418. }
  419. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  420. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  421. _dl_close(fd);
  422. if (preload == (caddr_t) -1) {
  423. _dl_dprintf(2, "%s: can't map file '%s'\n",
  424. _dl_progname, LDSO_PRELOAD);
  425. break;
  426. }
  427. /* convert all separators and comments to spaces */
  428. for (cp = preload; *cp; /*nada */ ) {
  429. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  430. *cp++ = ' ';
  431. } else if (*cp == '#') {
  432. do {
  433. *cp++ = ' ';
  434. } while (*cp != '\n' && *cp != '\0');
  435. } else {
  436. cp++;
  437. }
  438. }
  439. /* find start of first library */
  440. for (cp = preload; *cp && *cp == ' '; cp++)
  441. /*nada */ ;
  442. while (*cp) {
  443. /* find end of library */
  444. for (cp2 = cp; *cp && *cp != ' '; cp++)
  445. /*nada */ ;
  446. c = *cp;
  447. *cp = '\0';
  448. if ((tpnt1 = _dl_check_if_named_library_is_loaded(cp2, trace_loaded_objects))) {
  449. tpnt1->usage_count++;
  450. goto next_lib2;
  451. }
  452. #if defined (__SUPPORT_LD_DEBUG__)
  453. if(_dl_debug)
  454. _dl_dprintf(_dl_debug_file,
  455. "\tfile='%s'; needed by '%s'\n",
  456. cp2, _dl_progname);
  457. #endif
  458. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  459. if (!tpnt1) {
  460. #ifdef __LDSO_LDD_SUPPORT__
  461. if (trace_loaded_objects)
  462. _dl_dprintf(1, "\t%s => not found\n", cp2);
  463. else
  464. #endif
  465. {
  466. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
  467. _dl_exit(15);
  468. }
  469. } else {
  470. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  471. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  472. _dl_dprintf(_dl_debug_file,
  473. "Loading:\t(%x) %s\n",
  474. tpnt1->loadaddr, tpnt1->libname);
  475. #endif
  476. #ifdef __LDSO_LDD_SUPPORT__
  477. if (trace_loaded_objects &&
  478. tpnt1->usage_count == 1) {
  479. _dl_dprintf(1, "\t%s => %s (%x)\n",
  480. cp2, tpnt1->libname,
  481. (unsigned)tpnt1->loadaddr);
  482. }
  483. #endif
  484. }
  485. next_lib2:
  486. /* find start of next library */
  487. *cp = c;
  488. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  489. /*nada */ ;
  490. }
  491. _dl_munmap(preload, st.st_size + 1);
  492. } while (0);
  493. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  494. nlist = 0;
  495. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  496. Elf32_Dyn *dpnt;
  497. nlist++;
  498. for (dpnt = (Elf32_Dyn *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  499. if (dpnt->d_tag == DT_NEEDED) {
  500. char *name;
  501. struct init_fini_list *tmp;
  502. lpntstr = (char*) (tcurr->loadaddr + tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
  503. name = _dl_get_last_path_component(lpntstr);
  504. if ((tpnt1 = _dl_check_if_named_library_is_loaded(name, trace_loaded_objects))) {
  505. tpnt1->usage_count++;
  506. }
  507. #if defined (__SUPPORT_LD_DEBUG__)
  508. if(_dl_debug)
  509. _dl_dprintf(_dl_debug_file,
  510. "\tfile='%s'; needed by '%s'\n",
  511. lpntstr, _dl_progname);
  512. #endif
  513. if (!tpnt1) {
  514. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  515. #ifdef __LDSO_LDD_SUPPORT__
  516. if (trace_loaded_objects) {
  517. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  518. continue;
  519. } else
  520. #endif
  521. {
  522. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  523. _dl_exit(16);
  524. }
  525. }
  526. }
  527. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  528. tmp->tpnt = tpnt1;
  529. tmp->next = tcurr->init_fini;
  530. tcurr->init_fini = tmp;
  531. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  532. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  533. _dl_dprintf(_dl_debug_file,
  534. "Loading:\t(%x) %s\n",
  535. tpnt1->loadaddr, tpnt1->libname);
  536. #endif
  537. #ifdef __LDSO_LDD_SUPPORT__
  538. if (trace_loaded_objects &&
  539. tpnt1->usage_count == 1) {
  540. _dl_dprintf(1, "\t%s => %s (%x)\n",
  541. lpntstr, tpnt1->libname,
  542. (unsigned)tpnt1->loadaddr);
  543. }
  544. #endif
  545. }
  546. }
  547. }
  548. _dl_unmap_cache();
  549. --nlist; /* Exclude the application. */
  550. /* As long as atexit() is used to run the FINI functions, we can use
  551. * alloca here. The use of atexit() should go away at some time as that
  552. * will make Valgring happy.
  553. */
  554. init_fini_list = alloca(nlist * sizeof(struct elf_resolve *));
  555. i = 0;
  556. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  557. init_fini_list[i++] = tcurr;
  558. }
  559. /* Sort the INIT/FINI list in dependency order. */
  560. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  561. int j, k;
  562. for (j = 0; init_fini_list[j] != tcurr; ++j)
  563. /* Empty */;
  564. for (k = j + 1; k < nlist; ++k) {
  565. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  566. for (; runp; runp = runp->next) {
  567. if (runp->tpnt == tcurr) {
  568. struct elf_resolve *here = init_fini_list[k];
  569. #ifdef __SUPPORT_LD_DEBUG__
  570. if(_dl_debug)
  571. _dl_dprintf(2, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
  572. #endif
  573. for (i = (k - j); i; --i)
  574. init_fini_list[i+j] = init_fini_list[i+j-1];
  575. init_fini_list[j] = here;
  576. ++j;
  577. break;
  578. }
  579. }
  580. }
  581. }
  582. #ifdef __SUPPORT_LD_DEBUG__
  583. if(_dl_debug) {
  584. _dl_dprintf(2, "\nINIT/FINI order and dependencies:\n");
  585. for (i = 0; i < nlist; i++) {
  586. struct init_fini_list *tmp;
  587. _dl_dprintf(2, "lib: %s has deps:\n",
  588. init_fini_list[i]->libname);
  589. tmp = init_fini_list[i]->init_fini;
  590. for (; tmp; tmp = tmp->next)
  591. _dl_dprintf(2, " %s ", tmp->tpnt->libname);
  592. _dl_dprintf(2, "\n");
  593. }
  594. }
  595. #endif
  596. /*
  597. * If the program interpreter is not in the module chain, add it.
  598. * This will be required for dlopen to be able to access the internal
  599. * functions in the dynamic linker and to relocate the interpreter
  600. * again once all libs are loaded.
  601. */
  602. if (tpnt) {
  603. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_ptr;
  604. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  605. int j;
  606. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  607. tpnt->dynamic_info,
  608. (unsigned long)tpnt->dynamic_addr,
  609. 0);
  610. tpnt->n_phent = epnt->e_phnum;
  611. tpnt->ppnt = myppnt;
  612. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  613. if (myppnt->p_type == PT_GNU_RELRO) {
  614. tpnt->relro_addr = myppnt->p_vaddr;
  615. tpnt->relro_size = myppnt->p_memsz;
  616. break;
  617. }
  618. }
  619. tpnt->libtype = program_interpreter;
  620. tpnt->usage_count++;
  621. tpnt->symbol_scope = _dl_symbol_tables;
  622. if (rpnt) {
  623. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  624. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  625. rpnt->next->prev = rpnt;
  626. rpnt = rpnt->next;
  627. } else {
  628. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  629. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  630. }
  631. rpnt->dyn = tpnt;
  632. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  633. #ifdef RERELOCATE_LDSO
  634. /* Only rerelocate functions for now. */
  635. tpnt->init_flag = RELOCS_DONE;
  636. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT] + load_addr);
  637. # ifdef ALLOW_ZERO_PLTGOT
  638. if (tpnt->dynamic_info[DT_PLTGOT])
  639. # endif
  640. INIT_GOT(lpnt, tpnt);
  641. #else
  642. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  643. #endif
  644. tpnt = NULL;
  645. }
  646. #ifdef __LDSO_LDD_SUPPORT__
  647. /* End of the line for ldd.... */
  648. if (trace_loaded_objects) {
  649. _dl_dprintf(1, "\t%s => %s (%x)\n",
  650. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  651. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  652. _dl_exit(0);
  653. }
  654. #endif
  655. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  656. _dl_dprintf(_dl_debug_file, "Beginning relocation fixups\n");
  657. #endif
  658. #ifdef __mips__
  659. /*
  660. * Relocation of the GOT entries for MIPS have to be done
  661. * after all the libraries have been loaded.
  662. */
  663. _dl_perform_mips_global_got_relocations(_dl_loaded_modules);
  664. #endif
  665. /*
  666. * OK, now all of the kids are tucked into bed in their proper
  667. * addresses. Now we go through and look for REL and RELA records that
  668. * indicate fixups to the GOT tables. We need to do this in reverse
  669. * order so that COPY directives work correctly.
  670. */
  671. if (_dl_symbol_tables)
  672. goof += _dl_fixup(_dl_symbol_tables, unlazy);
  673. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  674. if (tpnt->relro_size)
  675. _dl_protect_relro (tpnt);
  676. }
  677. /* OK, at this point things are pretty much ready to run. Now we need
  678. * to touch up a few items that are required, and then we can let the
  679. * user application have at it. Note that the dynamic linker itself
  680. * is not guaranteed to be fully dynamicly linked if we are using
  681. * ld.so.1, so we have to look up each symbol individually.
  682. */
  683. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, 0);
  684. if (_dl_envp)
  685. *_dl_envp = (unsigned long) envp;
  686. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  687. {
  688. unsigned int j;
  689. ElfW(Phdr) *myppnt;
  690. /* We had to set the protections of all pages to R/W for
  691. * dynamic linking. Set text pages back to R/O.
  692. */
  693. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  694. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  695. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  696. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  697. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  698. }
  699. }
  700. }
  701. }
  702. #endif
  703. _dl_atexit = (int (*)(void *)) (intptr_t) _dl_find_hash("atexit", _dl_symbol_tables, ELF_RTYPE_CLASS_PLT);
  704. #if defined (__SUPPORT_LD_DEBUG__)
  705. _dl_on_exit = (int (*)(void (*)(int, void *),void*))
  706. (intptr_t) _dl_find_hash("on_exit", _dl_symbol_tables, ELF_RTYPE_CLASS_PLT);
  707. #endif
  708. /* Notify the debugger we have added some objects. */
  709. _dl_debug_addr->r_state = RT_ADD;
  710. _dl_debug_state();
  711. for (i = nlist; i; --i) {
  712. tpnt = init_fini_list[i-1];
  713. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  714. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  715. continue;
  716. tpnt->init_flag |= INIT_FUNCS_CALLED;
  717. if (tpnt->dynamic_info[DT_INIT]) {
  718. void (*dl_elf_func) (void);
  719. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  720. #if defined (__SUPPORT_LD_DEBUG__)
  721. if(_dl_debug)
  722. _dl_dprintf(_dl_debug_file,
  723. "\ncalling init: %s\n\n",
  724. tpnt->libname);
  725. #endif
  726. (*dl_elf_func) ();
  727. }
  728. tpnt->init_flag |= FINI_FUNCS_CALLED;
  729. if (_dl_atexit && tpnt->dynamic_info[DT_FINI]) {
  730. void (*dl_elf_func) (void);
  731. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  732. (*_dl_atexit) (dl_elf_func);
  733. #if defined (__SUPPORT_LD_DEBUG__)
  734. if(_dl_debug && _dl_on_exit) {
  735. (*_dl_on_exit)(debug_fini, tpnt->libname);
  736. }
  737. #endif
  738. }
  739. #if defined (__SUPPORT_LD_DEBUG__)
  740. else {
  741. if (!_dl_atexit)
  742. _dl_dprintf(_dl_debug_file, "%s: The address of atexit () is 0x0.\n", tpnt->libname);
  743. }
  744. #endif
  745. }
  746. /* Notify the debugger that all objects are now mapped in. */
  747. _dl_debug_addr->r_state = RT_CONSISTENT;
  748. _dl_debug_state();
  749. /* Find the real malloc function and make ldso functions use that from now on */
  750. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc", _dl_symbol_tables, ELF_RTYPE_CLASS_PLT);
  751. }
  752. char *_dl_getenv(const char *symbol, char **envp)
  753. {
  754. char *pnt;
  755. const char *pnt1;
  756. while ((pnt = *envp++)) {
  757. pnt1 = symbol;
  758. while (*pnt && *pnt == *pnt1)
  759. pnt1++, pnt++;
  760. if (!*pnt || *pnt != '=' || *pnt1)
  761. continue;
  762. return pnt + 1;
  763. }
  764. return 0;
  765. }
  766. void _dl_unsetenv(const char *symbol, char **envp)
  767. {
  768. char *pnt;
  769. const char *pnt1;
  770. char **newenvp = envp;
  771. for (pnt = *envp; pnt; pnt = *++envp) {
  772. pnt1 = symbol;
  773. while (*pnt && *pnt == *pnt1)
  774. pnt1++, pnt++;
  775. if (!*pnt || *pnt != '=' || *pnt1)
  776. *newenvp++ = *envp;
  777. }
  778. *newenvp++ = *envp;
  779. return;
  780. }
  781. static int _dl_suid_ok(void)
  782. {
  783. __kernel_uid_t uid, euid;
  784. __kernel_gid_t gid, egid;
  785. uid = _dl_getuid();
  786. euid = _dl_geteuid();
  787. gid = _dl_getgid();
  788. egid = _dl_getegid();
  789. if(uid == euid && gid == egid) {
  790. return 1;
  791. }
  792. return 0;
  793. }
  794. void *_dl_malloc(int size)
  795. {
  796. void *retval;
  797. #if 0
  798. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  799. _dl_dprintf(2, "malloc: request for %d bytes\n", size);
  800. #endif
  801. #endif
  802. if (_dl_malloc_function)
  803. return (*_dl_malloc_function) (size);
  804. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  805. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  806. _dl_dprintf(2, "malloc: mmapping more memory\n");
  807. #endif
  808. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  809. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  810. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  811. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  812. _dl_exit(20);
  813. }
  814. }
  815. retval = _dl_malloc_addr;
  816. _dl_malloc_addr += size;
  817. /*
  818. * Align memory to 4 byte boundary. Some platforms require this,
  819. * others simply get better performance.
  820. */
  821. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  822. return retval;
  823. }
  824. #include "dl-hash.c"
  825. #include "dl-elf.c"