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) 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. #include "dl-startup.c"
  57. /* Forward function declarations */
  58. static int _dl_suid_ok(void);
  59. /*
  60. * This stub function is used by some debuggers. The idea is that they
  61. * can set an internal breakpoint on it, so that we are notified when the
  62. * address mapping is changed in some way.
  63. */
  64. void _dl_debug_state(void)
  65. {
  66. }
  67. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  68. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  69. static struct elf_resolve **init_fini_list;
  70. static int nlist; /* # items in init_fini_list */
  71. extern void _start(void);
  72. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  73. {
  74. int i;
  75. struct elf_resolve * tpnt;
  76. for (i = 0; i < nlist; ++i) {
  77. tpnt = init_fini_list[i];
  78. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  79. continue;
  80. tpnt->init_flag |= FINI_FUNCS_CALLED;
  81. if (tpnt->dynamic_info[DT_FINI]) {
  82. void (*dl_elf_func) (void);
  83. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  84. #if defined (__SUPPORT_LD_DEBUG__)
  85. if(_dl_debug)
  86. _dl_dprintf(_dl_debug_file,
  87. "\ncalling FINI: %s\n\n",
  88. tpnt->libname);
  89. #endif
  90. (*dl_elf_func) ();
  91. }
  92. }
  93. }
  94. void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
  95. Elf32_auxv_t auxvt[AT_EGID + 1], char **envp,
  96. char **argv)
  97. {
  98. ElfW(Phdr) *ppnt;
  99. Elf32_Dyn *dpnt;
  100. char *lpntstr;
  101. int i, goof = 0, unlazy = 0, trace_loaded_objects = 0;
  102. struct dyn_elf *rpnt;
  103. struct elf_resolve *tcurr;
  104. struct elf_resolve *tpnt1;
  105. struct elf_resolve app_tpnt_tmp;
  106. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  107. struct r_debug *debug_addr;
  108. unsigned long *lpnt;
  109. unsigned long *_dl_envp; /* The environment address */
  110. ElfW(Addr) relro_addr = 0;
  111. size_t relro_size = 0;
  112. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  113. /* Wahoo!!! */
  114. SEND_STDERR("Cool, we managed to make a function call.\n");
  115. #endif
  116. /* Store the page size for later use */
  117. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  118. /* Make it so _dl_malloc can use the page of memory we have already
  119. * allocated. We shouldn't need to grab any more memory. This must
  120. * be first since things like _dl_dprintf() use _dl_malloc()...
  121. */
  122. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  123. _dl_mmap_zero = 0;
  124. /* Now we have done the mandatory linking of some things. We are now
  125. * free to start using global variables, since these things have all
  126. * been fixed up by now. Still no function calls outside of this
  127. * library, since the dynamic resolver is not yet ready.
  128. */
  129. if (argv[0]) {
  130. _dl_progname = argv[0];
  131. }
  132. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_fcn) {
  133. _dl_dprintf(2, "Standalone execution is not supported yet\n");
  134. _dl_exit(1);
  135. }
  136. /* Start to build the tables of the modules that are required for
  137. * this beast to run. We start with the basic executable, and then
  138. * go from there. Eventually we will run across ourself, and we
  139. * will need to properly deal with that as well.
  140. */
  141. rpnt = NULL;
  142. if (_dl_getenv("LD_BIND_NOW", envp))
  143. unlazy = RTLD_NOW;
  144. /* Now we need to figure out what kind of options are selected.
  145. * Note that for SUID programs we ignore the settings in
  146. * LD_LIBRARY_PATH.
  147. */
  148. if ((auxvt[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) ||
  149. (auxvt[AT_UID].a_un.a_val != -1 &&
  150. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  151. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  152. _dl_secure = 0;
  153. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  154. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  155. } else {
  156. static const char unsecure_envvars[] =
  157. #ifdef EXTRA_UNSECURE_ENVVARS
  158. EXTRA_UNSECURE_ENVVARS
  159. #endif
  160. UNSECURE_ENVVARS;
  161. const char *nextp;
  162. _dl_secure = 1;
  163. nextp = unsecure_envvars;
  164. do {
  165. _dl_unsetenv (nextp, envp);
  166. /* We could use rawmemchr but this need not be fast. */
  167. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  168. } while (*nextp != '\0');
  169. _dl_preload = NULL;
  170. _dl_library_path = NULL;
  171. /* SUID binaries can be exploited if they do LAZY relocation. */
  172. unlazy = RTLD_NOW;
  173. }
  174. /* At this point we are now free to examine the user application,
  175. * and figure out which libraries are supposed to be called. Until
  176. * we have this list, we will not be completely ready for dynamic
  177. * linking.
  178. */
  179. /* Find the runtime load address of the main executable. This may be
  180. * different from what the ELF header says for ET_DYN/PIE executables.
  181. */
  182. {
  183. int i;
  184. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  185. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  186. if (ppnt->p_type == PT_PHDR) {
  187. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  188. break;
  189. }
  190. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  191. if (app_tpnt->loadaddr) {
  192. SEND_STDERR("Position Independent Executable: app_tpnt->loadaddr=");
  193. SEND_ADDRESS_STDERR(app_tpnt->loadaddr, 1);
  194. }
  195. #endif
  196. }
  197. /*
  198. * This is used by gdb to locate the chain of shared libraries that are
  199. * currently loaded.
  200. */
  201. debug_addr = _dl_malloc(sizeof(struct r_debug));
  202. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  203. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  204. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  205. if (ppnt->p_type == PT_GNU_RELRO) {
  206. relro_addr = ppnt->p_vaddr;
  207. relro_size = ppnt->p_memsz;
  208. }
  209. if (ppnt->p_type == PT_DYNAMIC) {
  210. dpnt = (Elf32_Dyn *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  211. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  212. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  213. /* Ugly, ugly. We need to call mprotect to change the
  214. * protection of the text pages so that we can do the
  215. * dynamic linking. We can set the protection back
  216. * again once we are done.
  217. */
  218. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  219. SEND_STDERR("calling mprotect on the application program\n");
  220. #endif
  221. /* Now cover the application program. */
  222. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  223. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  224. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  225. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  226. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  227. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  228. (unsigned long) ppnt->p_filesz,
  229. PROT_READ | PROT_WRITE | PROT_EXEC);
  230. }
  231. }
  232. #endif
  233. #ifndef ALLOW_ZERO_PLTGOT
  234. /* make sure it's really there. */
  235. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  236. continue;
  237. #endif
  238. /* OK, we have what we need - slip this one into the list. */
  239. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  240. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  241. _dl_loaded_modules->libtype = elf_executable;
  242. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
  243. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  244. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  245. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  246. rpnt->dyn = _dl_loaded_modules;
  247. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  248. app_tpnt->usage_count++;
  249. app_tpnt->symbol_scope = _dl_symbol_tables;
  250. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  251. #ifdef ALLOW_ZERO_PLTGOT
  252. if (lpnt)
  253. #endif
  254. INIT_GOT(lpnt, _dl_loaded_modules);
  255. }
  256. /* OK, fill this in - we did not have this before */
  257. if (ppnt->p_type == PT_INTERP) {
  258. char *ptmp;
  259. tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
  260. /* Store the path where the shared lib loader was found
  261. * for later use
  262. */
  263. _dl_ldsopath = _dl_strdup(tpnt->libname);
  264. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  265. if (ptmp != _dl_ldsopath)
  266. *ptmp = '\0';
  267. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  268. _dl_dprintf(_dl_debug_file, "Lib Loader:\t(%x) %s\n",
  269. tpnt->loadaddr, tpnt->libname);
  270. #endif
  271. }
  272. }
  273. app_tpnt->relro_addr = relro_addr;
  274. app_tpnt->relro_size = relro_size;
  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->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. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  551. i = 0;
  552. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  553. init_fini_list[i++] = tcurr;
  554. }
  555. /* Sort the INIT/FINI list in dependency order. */
  556. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  557. int j, k;
  558. for (j = 0; init_fini_list[j] != tcurr; ++j)
  559. /* Empty */;
  560. for (k = j + 1; k < nlist; ++k) {
  561. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  562. for (; runp; runp = runp->next) {
  563. if (runp->tpnt == tcurr) {
  564. struct elf_resolve *here = init_fini_list[k];
  565. #ifdef __SUPPORT_LD_DEBUG__
  566. if(_dl_debug)
  567. _dl_dprintf(2, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
  568. #endif
  569. for (i = (k - j); i; --i)
  570. init_fini_list[i+j] = init_fini_list[i+j-1];
  571. init_fini_list[j] = here;
  572. ++j;
  573. break;
  574. }
  575. }
  576. }
  577. }
  578. #ifdef __SUPPORT_LD_DEBUG__
  579. if(_dl_debug) {
  580. _dl_dprintf(2, "\nINIT/FINI order and dependencies:\n");
  581. for (i = 0; i < nlist; i++) {
  582. struct init_fini_list *tmp;
  583. _dl_dprintf(2, "lib: %s has deps:\n",
  584. init_fini_list[i]->libname);
  585. tmp = init_fini_list[i]->init_fini;
  586. for (; tmp; tmp = tmp->next)
  587. _dl_dprintf(2, " %s ", tmp->tpnt->libname);
  588. _dl_dprintf(2, "\n");
  589. }
  590. }
  591. #endif
  592. /*
  593. * If the program interpreter is not in the module chain, add it.
  594. * This will be required for dlopen to be able to access the internal
  595. * functions in the dynamic linker and to relocate the interpreter
  596. * again once all libs are loaded.
  597. */
  598. if (tpnt) {
  599. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_ptr;
  600. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  601. int j;
  602. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  603. tpnt->dynamic_info,
  604. (unsigned long)tpnt->dynamic_addr,
  605. 0);
  606. tpnt->n_phent = epnt->e_phnum;
  607. tpnt->ppnt = myppnt;
  608. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  609. if (myppnt->p_type == PT_GNU_RELRO) {
  610. tpnt->relro_addr = myppnt->p_vaddr;
  611. tpnt->relro_size = myppnt->p_memsz;
  612. break;
  613. }
  614. }
  615. tpnt->libtype = program_interpreter;
  616. tpnt->usage_count++;
  617. tpnt->symbol_scope = _dl_symbol_tables;
  618. if (rpnt) {
  619. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  620. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  621. rpnt->next->prev = rpnt;
  622. rpnt = rpnt->next;
  623. } else {
  624. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  625. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  626. }
  627. rpnt->dyn = tpnt;
  628. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  629. #ifdef RERELOCATE_LDSO
  630. /* Only rerelocate functions for now. */
  631. tpnt->init_flag = RELOCS_DONE;
  632. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  633. # ifdef ALLOW_ZERO_PLTGOT
  634. if (tpnt->dynamic_info[DT_PLTGOT])
  635. # endif
  636. INIT_GOT(lpnt, tpnt);
  637. #else
  638. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  639. #endif
  640. tpnt = NULL;
  641. }
  642. #ifdef __LDSO_LDD_SUPPORT__
  643. /* End of the line for ldd.... */
  644. if (trace_loaded_objects) {
  645. _dl_dprintf(1, "\t%s => %s (%x)\n",
  646. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  647. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  648. _dl_exit(0);
  649. }
  650. #endif
  651. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  652. _dl_dprintf(_dl_debug_file, "Beginning relocation fixups\n");
  653. #endif
  654. #ifdef __mips__
  655. /*
  656. * Relocation of the GOT entries for MIPS have to be done
  657. * after all the libraries have been loaded.
  658. */
  659. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  660. #endif
  661. /*
  662. * OK, now all of the kids are tucked into bed in their proper
  663. * addresses. Now we go through and look for REL and RELA records that
  664. * indicate fixups to the GOT tables. We need to do this in reverse
  665. * order so that COPY directives work correctly.
  666. */
  667. if (_dl_symbol_tables)
  668. goof += _dl_fixup(_dl_symbol_tables, unlazy);
  669. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  670. if (tpnt->relro_size)
  671. _dl_protect_relro (tpnt);
  672. }
  673. /* OK, at this point things are pretty much ready to run. Now we need
  674. * to touch up a few items that are required, and then we can let the
  675. * user application have at it. Note that the dynamic linker itself
  676. * is not guaranteed to be fully dynamicly linked if we are using
  677. * ld.so.1, so we have to look up each symbol individually.
  678. */
  679. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  680. if (_dl_envp)
  681. *_dl_envp = (unsigned long) envp;
  682. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  683. {
  684. unsigned int j;
  685. ElfW(Phdr) *myppnt;
  686. /* We had to set the protections of all pages to R/W for
  687. * dynamic linking. Set text pages back to R/O.
  688. */
  689. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  690. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  691. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  692. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  693. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  694. }
  695. }
  696. }
  697. }
  698. #endif
  699. /* Notify the debugger we have added some objects. */
  700. _dl_debug_addr->r_state = RT_ADD;
  701. _dl_debug_state();
  702. for (i = nlist; i; --i) {
  703. tpnt = init_fini_list[i-1];
  704. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  705. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  706. continue;
  707. tpnt->init_flag |= INIT_FUNCS_CALLED;
  708. if (tpnt->dynamic_info[DT_INIT]) {
  709. void (*dl_elf_func) (void);
  710. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  711. #if defined (__SUPPORT_LD_DEBUG__)
  712. if(_dl_debug)
  713. _dl_dprintf(_dl_debug_file,
  714. "\ncalling INIT: %s\n\n",
  715. tpnt->libname);
  716. #endif
  717. (*dl_elf_func) ();
  718. }
  719. }
  720. #ifndef _DL_DO_FINI_IN_LIBC
  721. /* arches that have moved their ldso FINI handling should skip this part */
  722. {
  723. int (*_dl_atexit) (void *) = (int (*)(void *)) (intptr_t) _dl_find_hash("atexit",
  724. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  725. if (_dl_atexit)
  726. (*_dl_atexit) (_dl_fini);
  727. }
  728. #endif
  729. /* Find the real malloc function and make ldso functions use that from now on */
  730. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  731. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  732. /* Notify the debugger that all objects are now mapped in. */
  733. _dl_debug_addr->r_state = RT_CONSISTENT;
  734. _dl_debug_state();
  735. }
  736. char *_dl_getenv(const char *symbol, char **envp)
  737. {
  738. char *pnt;
  739. const char *pnt1;
  740. while ((pnt = *envp++)) {
  741. pnt1 = symbol;
  742. while (*pnt && *pnt == *pnt1)
  743. pnt1++, pnt++;
  744. if (!*pnt || *pnt != '=' || *pnt1)
  745. continue;
  746. return pnt + 1;
  747. }
  748. return 0;
  749. }
  750. void _dl_unsetenv(const char *symbol, char **envp)
  751. {
  752. char *pnt;
  753. const char *pnt1;
  754. char **newenvp = envp;
  755. for (pnt = *envp; pnt; pnt = *++envp) {
  756. pnt1 = symbol;
  757. while (*pnt && *pnt == *pnt1)
  758. pnt1++, pnt++;
  759. if (!*pnt || *pnt != '=' || *pnt1)
  760. *newenvp++ = *envp;
  761. }
  762. *newenvp++ = *envp;
  763. return;
  764. }
  765. static int _dl_suid_ok(void)
  766. {
  767. __kernel_uid_t uid, euid;
  768. __kernel_gid_t gid, egid;
  769. uid = _dl_getuid();
  770. euid = _dl_geteuid();
  771. gid = _dl_getgid();
  772. egid = _dl_getegid();
  773. if(uid == euid && gid == egid) {
  774. return 1;
  775. }
  776. return 0;
  777. }
  778. void *_dl_malloc(int size)
  779. {
  780. void *retval;
  781. #if 0
  782. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  783. _dl_dprintf(2, "malloc: request for %d bytes\n", size);
  784. #endif
  785. #endif
  786. if (_dl_malloc_function)
  787. return (*_dl_malloc_function) (size);
  788. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  789. #ifdef __SUPPORT_LD_DEBUG_EARLY__
  790. _dl_dprintf(2, "malloc: mmapping more memory\n");
  791. #endif
  792. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  793. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  794. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  795. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  796. _dl_exit(20);
  797. }
  798. }
  799. retval = _dl_malloc_addr;
  800. _dl_malloc_addr += size;
  801. /*
  802. * Align memory to 4 byte boundary. Some platforms require this,
  803. * others simply get better performance.
  804. */
  805. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  806. return retval;
  807. }
  808. #include "dl-hash.c"
  809. #include "dl-elf.c"