ldso.c 26 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) 2005 by Joakim Tjernlund
  7. * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
  8. * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
  9. * David Engel, Hongjiu Lu and Mitch D'Souza
  10. *
  11. * Redistribution and use in source and binary forms, with or without
  12. * modification, are permitted provided that the following conditions
  13. * are met:
  14. * 1. Redistributions of source code must retain the above copyright
  15. * notice, this list of conditions and the following disclaimer.
  16. * 2. The name of the above contributors may not be
  17. * used to endorse or promote products derived from this software
  18. * without specific prior written permission.
  19. *
  20. * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  21. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23. * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  24. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30. * SUCH DAMAGE.
  31. */
  32. #include "ldso.h"
  33. #include "unsecvars.h"
  34. #define ALLOW_ZERO_PLTGOT
  35. /* Pull in the value of _dl_progname */
  36. #include "dl-progname.h"
  37. /* Global variables used within the shared library loader */
  38. char *_dl_library_path = 0; /* Where we look for libraries */
  39. char *_dl_preload = 0; /* Things to be loaded before the libs */
  40. char *_dl_ldsopath = 0; /* Location of the shared lib loader */
  41. int _dl_secure = 1; /* Are we dealing with setuid stuff? */
  42. int _dl_errno = 0; /* We can't use the real errno in ldso */
  43. size_t _dl_pagesize = 0; /* Store the page size for use later */
  44. struct r_debug *_dl_debug_addr = NULL; /* Used to communicate with the gdb debugger */
  45. void *(*_dl_malloc_function) (size_t size) = NULL;
  46. #ifdef __SUPPORT_LD_DEBUG__
  47. char *_dl_debug = 0;
  48. char *_dl_debug_symbols = 0;
  49. char *_dl_debug_move = 0;
  50. char *_dl_debug_reloc = 0;
  51. char *_dl_debug_detail = 0;
  52. char *_dl_debug_nofixups = 0;
  53. char *_dl_debug_bindings = 0;
  54. int _dl_debug_file = 2;
  55. #endif
  56. /* Needed for standalone execution. */
  57. unsigned long attribute_hidden _dl_skip_args = 0;
  58. #include "dl-startup.c"
  59. /* Forward function declarations */
  60. static int _dl_suid_ok(void);
  61. /*
  62. * This stub function is used by some debuggers. The idea is that they
  63. * can set an internal breakpoint on it, so that we are notified when the
  64. * address mapping is changed in some way.
  65. */
  66. void _dl_debug_state(void)
  67. {
  68. }
  69. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  70. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  71. static struct elf_resolve **init_fini_list;
  72. static int nlist; /* # items in init_fini_list */
  73. extern void _start(void);
  74. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  75. {
  76. int i;
  77. struct elf_resolve * tpnt;
  78. for (i = 0; i < nlist; ++i) {
  79. tpnt = init_fini_list[i];
  80. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  81. continue;
  82. tpnt->init_flag |= FINI_FUNCS_CALLED;
  83. if (tpnt->dynamic_info[DT_FINI]) {
  84. void (*dl_elf_func) (void);
  85. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  86. #if defined (__SUPPORT_LD_DEBUG__)
  87. if(_dl_debug)
  88. _dl_dprintf(_dl_debug_file,
  89. "\ncalling FINI: %s\n\n",
  90. tpnt->libname);
  91. #endif
  92. (*dl_elf_func) ();
  93. }
  94. }
  95. }
  96. void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
  97. Elf32_auxv_t auxvt[AT_EGID + 1], char **envp,
  98. char **argv)
  99. {
  100. ElfW(Phdr) *ppnt;
  101. Elf32_Dyn *dpnt;
  102. char *lpntstr;
  103. int i, goof = 0, unlazy = 0, trace_loaded_objects = 0;
  104. struct dyn_elf *rpnt;
  105. struct elf_resolve *tcurr;
  106. struct elf_resolve *tpnt1;
  107. struct elf_resolve app_tpnt_tmp;
  108. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  109. struct r_debug *debug_addr;
  110. unsigned long *lpnt;
  111. unsigned long *_dl_envp; /* The environment address */
  112. ElfW(Addr) relro_addr = 0;
  113. size_t relro_size = 0;
  114. /* Wahoo!!! We managed to make a function call! Get malloc
  115. * setup so we can use _dl_dprintf() to print debug noise
  116. * instead of the SEND_STDERR macros used in dl-startup.c */
  117. /* Store the page size for later use */
  118. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  119. /* Make it so _dl_malloc can use the page of memory we have already
  120. * allocated. We shouldn't need to grab any more memory. This must
  121. * be first since things like _dl_dprintf() use _dl_malloc()...
  122. */
  123. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  124. _dl_mmap_zero = 0;
  125. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  126. /* Wahoo!!! */
  127. _dl_dprintf(2, "\nCool, ldso survived making function calls.\n");
  128. #endif
  129. /* Now we have done the mandatory linking of some things. We are now
  130. * free to start using global variables, since these things have all
  131. * been fixed up by now. Still no function calls outside of this
  132. * library, since the dynamic resolver is not yet ready.
  133. */
  134. if (argv[0]) {
  135. _dl_progname = argv[0];
  136. }
  137. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_fcn) {
  138. _dl_dprintf(2, "Standalone execution is not supported yet\n");
  139. _dl_exit(1);
  140. }
  141. /* Start to build the tables of the modules that are required for
  142. * this beast to run. We start with the basic executable, and then
  143. * go from there. Eventually we will run across ourself, and we
  144. * will need to properly deal with that as well.
  145. */
  146. rpnt = NULL;
  147. if (_dl_getenv("LD_BIND_NOW", envp))
  148. unlazy = RTLD_NOW;
  149. /* Now we need to figure out what kind of options are selected.
  150. * Note that for SUID programs we ignore the settings in
  151. * LD_LIBRARY_PATH.
  152. */
  153. if ((auxvt[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) ||
  154. (auxvt[AT_UID].a_un.a_val != -1 &&
  155. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  156. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  157. _dl_secure = 0;
  158. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  159. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  160. } else {
  161. static const char unsecure_envvars[] =
  162. #ifdef EXTRA_UNSECURE_ENVVARS
  163. EXTRA_UNSECURE_ENVVARS
  164. #endif
  165. UNSECURE_ENVVARS;
  166. const char *nextp;
  167. _dl_secure = 1;
  168. nextp = unsecure_envvars;
  169. do {
  170. _dl_unsetenv (nextp, envp);
  171. /* We could use rawmemchr but this need not be fast. */
  172. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  173. } while (*nextp != '\0');
  174. _dl_preload = NULL;
  175. _dl_library_path = NULL;
  176. /* SUID binaries can be exploited if they do LAZY relocation. */
  177. unlazy = RTLD_NOW;
  178. }
  179. /* At this point we are now free to examine the user application,
  180. * and figure out which libraries are supposed to be called. Until
  181. * we have this list, we will not be completely ready for dynamic
  182. * linking.
  183. */
  184. /* Find the runtime load address of the main executable. This may be
  185. * different from what the ELF header says for ET_DYN/PIE executables.
  186. */
  187. {
  188. int i;
  189. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  190. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  191. if (ppnt->p_type == PT_PHDR) {
  192. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  193. break;
  194. }
  195. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  196. if (app_tpnt->loadaddr) {
  197. _dl_dprintf(2, "Position Independent Executable: "
  198. "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
  199. }
  200. #endif
  201. }
  202. /*
  203. * This is used by gdb to locate the chain of shared libraries that are
  204. * currently loaded.
  205. */
  206. debug_addr = _dl_malloc(sizeof(struct r_debug));
  207. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  208. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  209. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  210. if (ppnt->p_type == PT_GNU_RELRO) {
  211. relro_addr = ppnt->p_vaddr;
  212. relro_size = ppnt->p_memsz;
  213. }
  214. if (ppnt->p_type == PT_DYNAMIC) {
  215. dpnt = (Elf32_Dyn *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  216. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  217. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  218. /* Ugly, ugly. We need to call mprotect to change the
  219. * protection of the text pages so that we can do the
  220. * dynamic linking. We can set the protection back
  221. * again once we are done.
  222. */
  223. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  224. _dl_dprintf(2, "calling mprotect on the application program\n");
  225. #endif
  226. /* Now cover the application program. */
  227. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  228. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  229. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  230. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  231. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  232. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  233. (unsigned long) ppnt->p_filesz,
  234. PROT_READ | PROT_WRITE | PROT_EXEC);
  235. }
  236. }
  237. #endif
  238. #ifndef ALLOW_ZERO_PLTGOT
  239. /* make sure it's really there. */
  240. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  241. continue;
  242. #endif
  243. /* OK, we have what we need - slip this one into the list. */
  244. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  245. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  246. _dl_loaded_modules->libtype = elf_executable;
  247. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  248. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  249. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  250. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  251. rpnt->dyn = _dl_loaded_modules;
  252. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  253. app_tpnt->usage_count++;
  254. app_tpnt->symbol_scope = _dl_symbol_tables;
  255. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  256. #ifdef ALLOW_ZERO_PLTGOT
  257. if (lpnt)
  258. #endif
  259. INIT_GOT(lpnt, _dl_loaded_modules);
  260. }
  261. /* OK, fill this in - we did not have this before */
  262. if (ppnt->p_type == PT_INTERP) {
  263. char *ptmp;
  264. tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
  265. /* Store the path where the shared lib loader was found
  266. * for later use
  267. */
  268. _dl_ldsopath = _dl_strdup(tpnt->libname);
  269. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  270. if (ptmp != _dl_ldsopath)
  271. *ptmp = '\0';
  272. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  273. _dl_dprintf(2, "Lib Loader:\t(%x) %s\n",
  274. tpnt->loadaddr, tpnt->libname);
  275. #endif
  276. }
  277. }
  278. app_tpnt->relro_addr = relro_addr;
  279. app_tpnt->relro_size = relro_size;
  280. #ifdef __SUPPORT_LD_DEBUG__
  281. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  282. if (_dl_debug) {
  283. if (_dl_strstr(_dl_debug, "all")) {
  284. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  285. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  286. } else {
  287. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  288. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  289. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  290. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  291. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  292. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  293. }
  294. }
  295. {
  296. const char *dl_debug_output;
  297. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  298. if (dl_debug_output) {
  299. char tmp[22], *tmp1, *filename;
  300. int len1, len2;
  301. _dl_memset(tmp, 0, sizeof(tmp));
  302. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  303. len1 = _dl_strlen(dl_debug_output);
  304. len2 = _dl_strlen(tmp1);
  305. filename = _dl_malloc(len1+len2+2);
  306. if (filename) {
  307. _dl_strcpy (filename, dl_debug_output);
  308. filename[len1] = '.';
  309. _dl_strcpy (&filename[len1+1], tmp1);
  310. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  311. if (_dl_debug_file < 0) {
  312. _dl_debug_file = 2;
  313. _dl_dprintf (2, "can't open file: '%s'\n",filename);
  314. }
  315. }
  316. }
  317. }
  318. #endif
  319. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  320. trace_loaded_objects++;
  321. }
  322. #ifndef __LDSO_LDD_SUPPORT__
  323. if (trace_loaded_objects) {
  324. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  325. _dl_exit(1);
  326. }
  327. #endif
  328. /*
  329. * OK, fix one more thing - set up debug_addr so it will point
  330. * to our chain. Later we may need to fill in more fields, but this
  331. * should be enough for now.
  332. */
  333. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  334. debug_addr->r_version = 1;
  335. debug_addr->r_ldbase = load_addr;
  336. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  337. _dl_debug_addr = debug_addr;
  338. /* Notify the debugger we are in a consistant state */
  339. _dl_debug_addr->r_state = RT_CONSISTENT;
  340. _dl_debug_state();
  341. /* OK, we now have the application in the list, and we have some
  342. * basic stuff in place. Now search through the list for other shared
  343. * libraries that should be loaded, and insert them on the list in the
  344. * correct order.
  345. */
  346. _dl_map_cache();
  347. if (_dl_preload) {
  348. char c, *str, *str2;
  349. str = _dl_preload;
  350. while (*str == ':' || *str == ' ' || *str == '\t')
  351. str++;
  352. while (*str) {
  353. str2 = str;
  354. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  355. str2++;
  356. c = *str2;
  357. *str2 = '\0';
  358. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  359. #if defined (__SUPPORT_LD_DEBUG__)
  360. if(_dl_debug)
  361. _dl_dprintf(_dl_debug_file,
  362. "\tfile='%s'; needed by '%s'\n",
  363. str, _dl_progname);
  364. #endif
  365. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  366. if (!tpnt1) {
  367. #ifdef __LDSO_LDD_SUPPORT__
  368. if (trace_loaded_objects)
  369. _dl_dprintf(1, "\t%s => not found\n", str);
  370. else
  371. #endif
  372. {
  373. _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
  374. _dl_exit(15);
  375. }
  376. } else {
  377. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  378. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  379. _dl_dprintf(2,
  380. "Loading:\t(%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  381. #endif
  382. #ifdef __LDSO_LDD_SUPPORT__
  383. if (trace_loaded_objects &&
  384. tpnt1->usage_count == 1) {
  385. /* This is a real hack to make
  386. * ldd not print the library
  387. * itself when run on a
  388. * library.
  389. */
  390. if (_dl_strcmp(_dl_progname, str) != 0)
  391. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  392. (unsigned)tpnt1->loadaddr);
  393. }
  394. #endif
  395. }
  396. }
  397. *str2 = c;
  398. str = str2;
  399. while (*str == ':' || *str == ' ' || *str == '\t')
  400. str++;
  401. }
  402. }
  403. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  404. do {
  405. struct stat st;
  406. char *preload;
  407. int fd;
  408. char c, *cp, *cp2;
  409. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  410. break;
  411. }
  412. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  413. _dl_dprintf(2, "%s: can't open file '%s'\n",
  414. _dl_progname, LDSO_PRELOAD);
  415. break;
  416. }
  417. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  418. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  419. _dl_close(fd);
  420. if (preload == (caddr_t) -1) {
  421. _dl_dprintf(2, "%s: can't map file '%s'\n",
  422. _dl_progname, LDSO_PRELOAD);
  423. break;
  424. }
  425. /* convert all separators and comments to spaces */
  426. for (cp = preload; *cp; /*nada */ ) {
  427. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  428. *cp++ = ' ';
  429. } else if (*cp == '#') {
  430. do {
  431. *cp++ = ' ';
  432. } while (*cp != '\n' && *cp != '\0');
  433. } else {
  434. cp++;
  435. }
  436. }
  437. /* find start of first library */
  438. for (cp = preload; *cp && *cp == ' '; cp++)
  439. /*nada */ ;
  440. while (*cp) {
  441. /* find end of library */
  442. for (cp2 = cp; *cp && *cp != ' '; cp++)
  443. /*nada */ ;
  444. c = *cp;
  445. *cp = '\0';
  446. #if defined (__SUPPORT_LD_DEBUG__)
  447. if(_dl_debug)
  448. _dl_dprintf(_dl_debug_file,
  449. "\tfile='%s'; needed by '%s'\n",
  450. cp2, _dl_progname);
  451. #endif
  452. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  453. if (!tpnt1) {
  454. #ifdef __LDSO_LDD_SUPPORT__
  455. if (trace_loaded_objects)
  456. _dl_dprintf(1, "\t%s => not found\n", cp2);
  457. else
  458. #endif
  459. {
  460. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
  461. _dl_exit(15);
  462. }
  463. } else {
  464. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  465. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  466. _dl_dprintf(2, "Loading:\t(%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  467. #endif
  468. #ifdef __LDSO_LDD_SUPPORT__
  469. if (trace_loaded_objects &&
  470. tpnt1->usage_count == 1) {
  471. _dl_dprintf(1, "\t%s => %s (%x)\n",
  472. cp2, tpnt1->libname,
  473. (unsigned)tpnt1->loadaddr);
  474. }
  475. #endif
  476. }
  477. /* find start of next library */
  478. *cp = c;
  479. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  480. /*nada */ ;
  481. }
  482. _dl_munmap(preload, st.st_size + 1);
  483. } while (0);
  484. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  485. nlist = 0;
  486. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  487. Elf32_Dyn *dpnt;
  488. nlist++;
  489. for (dpnt = (Elf32_Dyn *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  490. if (dpnt->d_tag == DT_NEEDED) {
  491. char *name;
  492. struct init_fini_list *tmp;
  493. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
  494. name = _dl_get_last_path_component(lpntstr);
  495. #if defined (__SUPPORT_LD_DEBUG__)
  496. if(_dl_debug)
  497. _dl_dprintf(_dl_debug_file,
  498. "\tfile='%s'; needed by '%s'\n",
  499. lpntstr, _dl_progname);
  500. #endif
  501. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  502. #ifdef __LDSO_LDD_SUPPORT__
  503. if (trace_loaded_objects) {
  504. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  505. continue;
  506. } else
  507. #endif
  508. {
  509. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  510. _dl_exit(16);
  511. }
  512. }
  513. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  514. tmp->tpnt = tpnt1;
  515. tmp->next = tcurr->init_fini;
  516. tcurr->init_fini = tmp;
  517. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  518. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  519. _dl_dprintf(2, "Loading:\t(%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  520. #endif
  521. #ifdef __LDSO_LDD_SUPPORT__
  522. if (trace_loaded_objects &&
  523. tpnt1->usage_count == 1) {
  524. _dl_dprintf(1, "\t%s => %s (%x)\n",
  525. lpntstr, tpnt1->libname,
  526. (unsigned)tpnt1->loadaddr);
  527. }
  528. #endif
  529. }
  530. }
  531. }
  532. _dl_unmap_cache();
  533. --nlist; /* Exclude the application. */
  534. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  535. i = 0;
  536. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  537. init_fini_list[i++] = tcurr;
  538. }
  539. /* Sort the INIT/FINI list in dependency order. */
  540. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  541. int j, k;
  542. for (j = 0; init_fini_list[j] != tcurr; ++j)
  543. /* Empty */;
  544. for (k = j + 1; k < nlist; ++k) {
  545. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  546. for (; runp; runp = runp->next) {
  547. if (runp->tpnt == tcurr) {
  548. struct elf_resolve *here = init_fini_list[k];
  549. #ifdef __SUPPORT_LD_DEBUG__
  550. if(_dl_debug)
  551. _dl_dprintf(2, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
  552. #endif
  553. for (i = (k - j); i; --i)
  554. init_fini_list[i+j] = init_fini_list[i+j-1];
  555. init_fini_list[j] = here;
  556. ++j;
  557. break;
  558. }
  559. }
  560. }
  561. }
  562. #ifdef __SUPPORT_LD_DEBUG__
  563. if(_dl_debug) {
  564. _dl_dprintf(2, "\nINIT/FINI order and dependencies:\n");
  565. for (i = 0; i < nlist; i++) {
  566. struct init_fini_list *tmp;
  567. _dl_dprintf(2, "lib: %s has deps:\n",
  568. init_fini_list[i]->libname);
  569. tmp = init_fini_list[i]->init_fini;
  570. for (; tmp; tmp = tmp->next)
  571. _dl_dprintf(2, " %s ", tmp->tpnt->libname);
  572. _dl_dprintf(2, "\n");
  573. }
  574. }
  575. #endif
  576. /*
  577. * If the program interpreter is not in the module chain, add it.
  578. * This will be required for dlopen to be able to access the internal
  579. * functions in the dynamic linker and to relocate the interpreter
  580. * again once all libs are loaded.
  581. */
  582. if (tpnt) {
  583. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_ptr;
  584. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  585. int j;
  586. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  587. tpnt->dynamic_info,
  588. (unsigned long)tpnt->dynamic_addr,
  589. 0);
  590. tpnt->n_phent = epnt->e_phnum;
  591. tpnt->ppnt = myppnt;
  592. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  593. if (myppnt->p_type == PT_GNU_RELRO) {
  594. tpnt->relro_addr = myppnt->p_vaddr;
  595. tpnt->relro_size = myppnt->p_memsz;
  596. break;
  597. }
  598. }
  599. tpnt->libtype = program_interpreter;
  600. tpnt->usage_count++;
  601. tpnt->symbol_scope = _dl_symbol_tables;
  602. if (rpnt) {
  603. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  604. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  605. rpnt->next->prev = rpnt;
  606. rpnt = rpnt->next;
  607. } else {
  608. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  609. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  610. }
  611. rpnt->dyn = tpnt;
  612. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  613. #ifdef RERELOCATE_LDSO
  614. /* Only rerelocate functions for now. */
  615. tpnt->init_flag = RELOCS_DONE;
  616. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  617. # ifdef ALLOW_ZERO_PLTGOT
  618. if (tpnt->dynamic_info[DT_PLTGOT])
  619. # endif
  620. INIT_GOT(lpnt, tpnt);
  621. #else
  622. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  623. #endif
  624. tpnt = NULL;
  625. }
  626. #ifdef __LDSO_LDD_SUPPORT__
  627. /* End of the line for ldd.... */
  628. if (trace_loaded_objects) {
  629. _dl_dprintf(1, "\t%s => %s (%x)\n",
  630. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  631. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  632. _dl_exit(0);
  633. }
  634. #endif
  635. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  636. _dl_dprintf(2, "Beginning relocation fixups\n");
  637. #endif
  638. #ifdef __mips__
  639. /*
  640. * Relocation of the GOT entries for MIPS have to be done
  641. * after all the libraries have been loaded.
  642. */
  643. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  644. #endif
  645. /*
  646. * OK, now all of the kids are tucked into bed in their proper
  647. * addresses. Now we go through and look for REL and RELA records that
  648. * indicate fixups to the GOT tables. We need to do this in reverse
  649. * order so that COPY directives work correctly.
  650. */
  651. if (_dl_symbol_tables)
  652. goof += _dl_fixup(_dl_symbol_tables, unlazy);
  653. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  654. if (tpnt->relro_size)
  655. _dl_protect_relro (tpnt);
  656. }
  657. /* OK, at this point things are pretty much ready to run. Now we need
  658. * to touch up a few items that are required, and then we can let the
  659. * user application have at it. Note that the dynamic linker itself
  660. * is not guaranteed to be fully dynamicly linked if we are using
  661. * ld.so.1, so we have to look up each symbol individually.
  662. */
  663. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  664. if (_dl_envp)
  665. *_dl_envp = (unsigned long) envp;
  666. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  667. {
  668. unsigned int j;
  669. ElfW(Phdr) *myppnt;
  670. /* We had to set the protections of all pages to R/W for
  671. * dynamic linking. Set text pages back to R/O.
  672. */
  673. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  674. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  675. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  676. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  677. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  678. }
  679. }
  680. }
  681. }
  682. #endif
  683. /* Notify the debugger we have added some objects. */
  684. _dl_debug_addr->r_state = RT_ADD;
  685. _dl_debug_state();
  686. for (i = nlist; i; --i) {
  687. tpnt = init_fini_list[i-1];
  688. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  689. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  690. continue;
  691. tpnt->init_flag |= INIT_FUNCS_CALLED;
  692. if (tpnt->dynamic_info[DT_INIT]) {
  693. void (*dl_elf_func) (void);
  694. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  695. #if defined (__SUPPORT_LD_DEBUG__)
  696. if(_dl_debug)
  697. _dl_dprintf(_dl_debug_file,
  698. "\ncalling INIT: %s\n\n",
  699. tpnt->libname);
  700. #endif
  701. (*dl_elf_func) ();
  702. }
  703. }
  704. #ifdef _DL_FINI_CRT_COMPAT
  705. /* arches that have moved their ldso FINI handling should skip this part */
  706. {
  707. int (*_dl_atexit) (void *) = (int (*)(void *)) (intptr_t) _dl_find_hash("atexit",
  708. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  709. if (_dl_atexit)
  710. (*_dl_atexit) (_dl_fini);
  711. }
  712. #endif
  713. /* Find the real malloc function and make ldso functions use that from now on */
  714. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  715. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  716. /* Notify the debugger that all objects are now mapped in. */
  717. _dl_debug_addr->r_state = RT_CONSISTENT;
  718. _dl_debug_state();
  719. }
  720. char *_dl_getenv(const char *symbol, char **envp)
  721. {
  722. char *pnt;
  723. const char *pnt1;
  724. while ((pnt = *envp++)) {
  725. pnt1 = symbol;
  726. while (*pnt && *pnt == *pnt1)
  727. pnt1++, pnt++;
  728. if (!*pnt || *pnt != '=' || *pnt1)
  729. continue;
  730. return pnt + 1;
  731. }
  732. return 0;
  733. }
  734. void _dl_unsetenv(const char *symbol, char **envp)
  735. {
  736. char *pnt;
  737. const char *pnt1;
  738. char **newenvp = envp;
  739. for (pnt = *envp; pnt; pnt = *++envp) {
  740. pnt1 = symbol;
  741. while (*pnt && *pnt == *pnt1)
  742. pnt1++, pnt++;
  743. if (!*pnt || *pnt != '=' || *pnt1)
  744. *newenvp++ = *envp;
  745. }
  746. *newenvp++ = *envp;
  747. return;
  748. }
  749. static int _dl_suid_ok(void)
  750. {
  751. __kernel_uid_t uid, euid;
  752. __kernel_gid_t gid, egid;
  753. uid = _dl_getuid();
  754. euid = _dl_geteuid();
  755. gid = _dl_getgid();
  756. egid = _dl_getegid();
  757. if(uid == euid && gid == egid) {
  758. return 1;
  759. }
  760. return 0;
  761. }
  762. void *_dl_malloc(int size)
  763. {
  764. void *retval;
  765. #if 0
  766. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  767. _dl_dprintf(2, "malloc: request for %d bytes\n", size);
  768. #endif
  769. #endif
  770. if (_dl_malloc_function)
  771. return (*_dl_malloc_function) (size);
  772. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  773. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  774. _dl_dprintf(2, "malloc: mmapping more memory\n");
  775. #endif
  776. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  777. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  778. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  779. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  780. _dl_exit(20);
  781. }
  782. }
  783. retval = _dl_malloc_addr;
  784. _dl_malloc_addr += size;
  785. /*
  786. * Align memory to 4 byte boundary. Some platforms require this,
  787. * others simply get better performance.
  788. */
  789. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  790. return retval;
  791. }
  792. #include "dl-hash.c"
  793. #include "dl-elf.c"