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