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