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. void _dl_debug_state()
  71. {
  72. }
  73. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  74. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  75. static struct elf_resolve **init_fini_list;
  76. static unsigned int nlist; /* # items in init_fini_list */
  77. extern void _start(void);
  78. #ifdef __UCLIBC_HAS_SSP__
  79. #include <dl-osinfo.h>
  80. #ifndef THREAD_SET_STACK_GUARD
  81. /* Only exported for architectures that don't store the stack guard canary
  82. * in local thread area. */
  83. uintptr_t __stack_chk_guard attribute_relro;
  84. strong_alias(__stack_chk_guard,__guard)
  85. #endif
  86. #endif
  87. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  88. {
  89. int i;
  90. struct elf_resolve * tpnt;
  91. for (i = 0; i < nlist; ++i) {
  92. tpnt = init_fini_list[i];
  93. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  94. continue;
  95. tpnt->init_flag |= FINI_FUNCS_CALLED;
  96. if (tpnt->dynamic_info[DT_FINI]) {
  97. void (*dl_elf_func) (void);
  98. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  99. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  100. (*dl_elf_func) ();
  101. }
  102. }
  103. }
  104. void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
  105. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  106. char **argv)
  107. {
  108. ElfW(Phdr) *ppnt;
  109. ElfW(Dyn) *dpnt;
  110. char *lpntstr;
  111. unsigned int i;
  112. int unlazy = 0, trace_loaded_objects = 0;
  113. struct dyn_elf *rpnt;
  114. struct elf_resolve *tcurr;
  115. struct elf_resolve *tpnt1;
  116. struct elf_resolve app_tpnt_tmp;
  117. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  118. struct r_debug *debug_addr;
  119. unsigned long *lpnt;
  120. unsigned long *_dl_envp; /* The environment address */
  121. ElfW(Addr) relro_addr = 0;
  122. size_t relro_size = 0;
  123. /* Wahoo!!! We managed to make a function call! Get malloc
  124. * setup so we can use _dl_dprintf() to print debug noise
  125. * instead of the SEND_STDERR macros used in dl-startup.c */
  126. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  127. /* Store the page size for later use */
  128. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  129. /* Make it so _dl_malloc can use the page of memory we have already
  130. * allocated. We shouldn't need to grab any more memory. This must
  131. * be first since things like _dl_dprintf() use _dl_malloc()...
  132. */
  133. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  134. _dl_mmap_zero = 0;
  135. /* Wahoo!!! */
  136. _dl_debug_early("Cool, ldso survived making function calls\n");
  137. /* Now we have done the mandatory linking of some things. We are now
  138. * free to start using global variables, since these things have all
  139. * been fixed up by now. Still no function calls outside of this
  140. * library, since the dynamic resolver is not yet ready.
  141. */
  142. if (argv[0]) {
  143. _dl_progname = argv[0];
  144. }
  145. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  146. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  147. _dl_exit(1);
  148. }
  149. /* Start to build the tables of the modules that are required for
  150. * this beast to run. We start with the basic executable, and then
  151. * go from there. Eventually we will run across ourself, and we
  152. * will need to properly deal with that as well.
  153. */
  154. rpnt = NULL;
  155. if (_dl_getenv("LD_BIND_NOW", envp))
  156. unlazy = RTLD_NOW;
  157. /* Now we need to figure out what kind of options are selected.
  158. * Note that for SUID programs we ignore the settings in
  159. * LD_LIBRARY_PATH.
  160. */
  161. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  162. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  163. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  164. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  165. _dl_secure = 0;
  166. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  167. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  168. } else {
  169. static const char unsecure_envvars[] =
  170. #ifdef EXTRA_UNSECURE_ENVVARS
  171. EXTRA_UNSECURE_ENVVARS
  172. #endif
  173. UNSECURE_ENVVARS;
  174. const char *nextp;
  175. _dl_secure = 1;
  176. nextp = unsecure_envvars;
  177. do {
  178. _dl_unsetenv (nextp, envp);
  179. /* We could use rawmemchr but this need not be fast. */
  180. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  181. } while (*nextp != '\0');
  182. _dl_preload = NULL;
  183. _dl_library_path = NULL;
  184. /* SUID binaries can be exploited if they do LAZY relocation. */
  185. unlazy = RTLD_NOW;
  186. }
  187. /* sjhill: your TLS init should go before this */
  188. #ifdef __UCLIBC_HAS_SSP__
  189. /* Set up the stack checker's canary. */
  190. uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
  191. # ifdef THREAD_SET_STACK_GUARD
  192. THREAD_SET_STACK_GUARD (stack_chk_guard);
  193. # else
  194. __stack_chk_guard = stack_chk_guard;
  195. # endif
  196. #endif
  197. /* At this point we are now free to examine the user application,
  198. * and figure out which libraries are supposed to be called. Until
  199. * we have this list, we will not be completely ready for dynamic
  200. * linking.
  201. */
  202. /* Find the runtime load address of the main executable. This may be
  203. * different from what the ELF header says for ET_DYN/PIE executables.
  204. */
  205. {
  206. unsigned int i;
  207. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  208. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  209. if (ppnt->p_type == PT_PHDR) {
  210. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  211. break;
  212. }
  213. if (app_tpnt->loadaddr)
  214. _dl_debug_early("Position Independent Executable: "
  215. "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
  216. }
  217. /*
  218. * This is used by gdb to locate the chain of shared libraries that are
  219. * currently loaded.
  220. */
  221. debug_addr = _dl_malloc(sizeof(struct r_debug));
  222. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  223. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  224. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  225. if (ppnt->p_type == PT_GNU_RELRO) {
  226. relro_addr = ppnt->p_vaddr;
  227. relro_size = ppnt->p_memsz;
  228. }
  229. if (ppnt->p_type == PT_DYNAMIC) {
  230. dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  231. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  232. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  233. /* Ugly, ugly. We need to call mprotect to change the
  234. * protection of the text pages so that we can do the
  235. * dynamic linking. We can set the protection back
  236. * again once we are done.
  237. */
  238. _dl_debug_early("calling mprotect on the application program\n");
  239. /* Now cover the application program. */
  240. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  241. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  242. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  243. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  244. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  245. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  246. (unsigned long) ppnt->p_filesz,
  247. PROT_READ | PROT_WRITE | PROT_EXEC);
  248. }
  249. }
  250. #endif
  251. #ifndef ALLOW_ZERO_PLTGOT
  252. /* make sure it's really there. */
  253. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  254. continue;
  255. #endif
  256. /* OK, we have what we need - slip this one into the list. */
  257. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  258. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  259. _dl_loaded_modules->libtype = elf_executable;
  260. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  261. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  262. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  263. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  264. rpnt->dyn = _dl_loaded_modules;
  265. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  266. app_tpnt->usage_count++;
  267. app_tpnt->symbol_scope = _dl_symbol_tables;
  268. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  269. #ifdef ALLOW_ZERO_PLTGOT
  270. if (lpnt)
  271. #endif
  272. INIT_GOT(lpnt, _dl_loaded_modules);
  273. }
  274. /* OK, fill this in - we did not have this before */
  275. if (ppnt->p_type == PT_INTERP) {
  276. char *ptmp;
  277. tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
  278. /* Store the path where the shared lib loader was found
  279. * for later use
  280. */
  281. _dl_ldsopath = _dl_strdup(tpnt->libname);
  282. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  283. if (ptmp != _dl_ldsopath)
  284. *ptmp = '\0';
  285. _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
  286. }
  287. }
  288. app_tpnt->relro_addr = relro_addr;
  289. app_tpnt->relro_size = relro_size;
  290. #ifdef __SUPPORT_LD_DEBUG__
  291. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  292. if (_dl_debug) {
  293. if (_dl_strstr(_dl_debug, "all")) {
  294. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  295. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  296. } else {
  297. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  298. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  299. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  300. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  301. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  302. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  303. }
  304. }
  305. {
  306. const char *dl_debug_output;
  307. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  308. if (dl_debug_output) {
  309. char tmp[22], *tmp1, *filename;
  310. int len1, len2;
  311. _dl_memset(tmp, 0, sizeof(tmp));
  312. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  313. len1 = _dl_strlen(dl_debug_output);
  314. len2 = _dl_strlen(tmp1);
  315. filename = _dl_malloc(len1+len2+2);
  316. if (filename) {
  317. _dl_strcpy (filename, dl_debug_output);
  318. filename[len1] = '.';
  319. _dl_strcpy (&filename[len1+1], tmp1);
  320. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  321. if (_dl_debug_file < 0) {
  322. _dl_debug_file = 2;
  323. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  324. }
  325. }
  326. }
  327. }
  328. #endif
  329. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  330. trace_loaded_objects++;
  331. }
  332. #ifndef __LDSO_LDD_SUPPORT__
  333. if (trace_loaded_objects) {
  334. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  335. _dl_exit(1);
  336. }
  337. #endif
  338. /*
  339. * OK, fix one more thing - set up debug_addr so it will point
  340. * to our chain. Later we may need to fill in more fields, but this
  341. * should be enough for now.
  342. */
  343. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  344. debug_addr->r_version = 1;
  345. debug_addr->r_ldbase = load_addr;
  346. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  347. _dl_debug_addr = debug_addr;
  348. /* Notify the debugger we are in a consistant state */
  349. _dl_debug_addr->r_state = RT_CONSISTENT;
  350. _dl_debug_state();
  351. /* OK, we now have the application in the list, and we have some
  352. * basic stuff in place. Now search through the list for other shared
  353. * libraries that should be loaded, and insert them on the list in the
  354. * correct order.
  355. */
  356. _dl_map_cache();
  357. if (_dl_preload) {
  358. char c, *str, *str2;
  359. str = _dl_preload;
  360. while (*str == ':' || *str == ' ' || *str == '\t')
  361. str++;
  362. while (*str) {
  363. str2 = str;
  364. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  365. str2++;
  366. c = *str2;
  367. *str2 = '\0';
  368. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  369. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  370. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  371. if (!tpnt1) {
  372. #ifdef __LDSO_LDD_SUPPORT__
  373. if (trace_loaded_objects)
  374. _dl_dprintf(1, "\t%s => not found\n", str);
  375. else
  376. #endif
  377. {
  378. _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
  379. _dl_exit(15);
  380. }
  381. } else {
  382. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  383. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  384. #ifdef __LDSO_LDD_SUPPORT__
  385. if (trace_loaded_objects &&
  386. tpnt1->usage_count == 1) {
  387. /* This is a real hack to make
  388. * ldd not print the library
  389. * itself when run on a
  390. * library.
  391. */
  392. if (_dl_strcmp(_dl_progname, str) != 0)
  393. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  394. tpnt1->loadaddr);
  395. }
  396. #endif
  397. }
  398. }
  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(_dl_debug_file, "%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(_dl_debug_file, "%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. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  449. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  450. if (!tpnt1) {
  451. #ifdef __LDSO_LDD_SUPPORT__
  452. if (trace_loaded_objects)
  453. _dl_dprintf(1, "\t%s => not found\n", cp2);
  454. else
  455. #endif
  456. {
  457. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
  458. _dl_exit(15);
  459. }
  460. } else {
  461. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  462. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  463. #ifdef __LDSO_LDD_SUPPORT__
  464. if (trace_loaded_objects &&
  465. tpnt1->usage_count == 1) {
  466. _dl_dprintf(1, "\t%s => %s (%x)\n",
  467. cp2, tpnt1->libname,
  468. (unsigned)tpnt1->loadaddr);
  469. }
  470. #endif
  471. }
  472. /* find start of next library */
  473. *cp = c;
  474. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  475. /*nada */ ;
  476. }
  477. _dl_munmap(preload, st.st_size + 1);
  478. } while (0);
  479. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  480. nlist = 0;
  481. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  482. ElfW(Dyn) *dpnt;
  483. nlist++;
  484. for (dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  485. if (dpnt->d_tag == DT_NEEDED) {
  486. char *name;
  487. struct init_fini_list *tmp;
  488. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
  489. name = _dl_get_last_path_component(lpntstr);
  490. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  491. continue;
  492. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  493. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  494. #ifdef __LDSO_LDD_SUPPORT__
  495. if (trace_loaded_objects) {
  496. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  497. continue;
  498. } else
  499. #endif
  500. {
  501. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  502. _dl_exit(16);
  503. }
  504. }
  505. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  506. tmp->tpnt = tpnt1;
  507. tmp->next = tcurr->init_fini;
  508. tcurr->init_fini = tmp;
  509. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  510. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  511. #ifdef __LDSO_LDD_SUPPORT__
  512. if (trace_loaded_objects &&
  513. tpnt1->usage_count == 1) {
  514. _dl_dprintf(1, "\t%s => %s (%x)\n",
  515. lpntstr, tpnt1->libname,
  516. (unsigned)tpnt1->loadaddr);
  517. }
  518. #endif
  519. }
  520. }
  521. }
  522. _dl_unmap_cache();
  523. --nlist; /* Exclude the application. */
  524. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  525. i = 0;
  526. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  527. init_fini_list[i++] = tcurr;
  528. }
  529. /* Sort the INIT/FINI list in dependency order. */
  530. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  531. int j, k;
  532. for (j = 0; init_fini_list[j] != tcurr; ++j)
  533. /* Empty */;
  534. for (k = j + 1; k < nlist; ++k) {
  535. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  536. for (; runp; runp = runp->next) {
  537. if (runp->tpnt == tcurr) {
  538. struct elf_resolve *here = init_fini_list[k];
  539. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  540. for (i = (k - j); i; --i)
  541. init_fini_list[i+j] = init_fini_list[i+j-1];
  542. init_fini_list[j] = here;
  543. ++j;
  544. break;
  545. }
  546. }
  547. }
  548. }
  549. #ifdef __SUPPORT_LD_DEBUG__
  550. if(_dl_debug) {
  551. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  552. for (i = 0; i < nlist; i++) {
  553. struct init_fini_list *tmp;
  554. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  555. init_fini_list[i]->libname);
  556. tmp = init_fini_list[i]->init_fini;
  557. for (; tmp; tmp = tmp->next)
  558. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  559. _dl_dprintf(_dl_debug_file, "\n");
  560. }
  561. }
  562. #endif
  563. /*
  564. * If the program interpreter is not in the module chain, add it.
  565. * This will be required for dlopen to be able to access the internal
  566. * functions in the dynamic linker and to relocate the interpreter
  567. * again once all libs are loaded.
  568. */
  569. if (tpnt) {
  570. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  571. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  572. int j;
  573. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  574. tpnt->dynamic_info,
  575. (unsigned long)tpnt->dynamic_addr,
  576. 0);
  577. tpnt->n_phent = epnt->e_phnum;
  578. tpnt->ppnt = myppnt;
  579. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  580. if (myppnt->p_type == PT_GNU_RELRO) {
  581. tpnt->relro_addr = myppnt->p_vaddr;
  582. tpnt->relro_size = myppnt->p_memsz;
  583. break;
  584. }
  585. }
  586. tpnt->libtype = program_interpreter;
  587. tpnt->usage_count++;
  588. tpnt->symbol_scope = _dl_symbol_tables;
  589. if (rpnt) {
  590. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  591. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  592. rpnt->next->prev = rpnt;
  593. rpnt = rpnt->next;
  594. } else {
  595. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  596. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  597. }
  598. rpnt->dyn = tpnt;
  599. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  600. #ifdef RERELOCATE_LDSO
  601. /* Only rerelocate functions for now. */
  602. tpnt->init_flag = RELOCS_DONE;
  603. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  604. # ifdef ALLOW_ZERO_PLTGOT
  605. if (tpnt->dynamic_info[DT_PLTGOT])
  606. # endif
  607. INIT_GOT(lpnt, tpnt);
  608. #else
  609. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  610. #endif
  611. tpnt = NULL;
  612. }
  613. #ifdef __LDSO_LDD_SUPPORT__
  614. /* End of the line for ldd.... */
  615. if (trace_loaded_objects) {
  616. _dl_dprintf(1, "\t%s => %s (%x)\n",
  617. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  618. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  619. _dl_exit(0);
  620. }
  621. #endif
  622. _dl_debug_early("Beginning relocation fixups\n");
  623. #ifdef __mips__
  624. /*
  625. * Relocation of the GOT entries for MIPS have to be done
  626. * after all the libraries have been loaded.
  627. */
  628. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  629. #endif
  630. /*
  631. * OK, now all of the kids are tucked into bed in their proper
  632. * addresses. Now we go through and look for REL and RELA records that
  633. * indicate fixups to the GOT tables. We need to do this in reverse
  634. * order so that COPY directives work correctly.
  635. */
  636. if (_dl_symbol_tables)
  637. if (_dl_fixup(_dl_symbol_tables, unlazy))
  638. _dl_exit(-1);
  639. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  640. if (tpnt->relro_size)
  641. _dl_protect_relro (tpnt);
  642. }
  643. /* OK, at this point things are pretty much ready to run. Now we need
  644. * to touch up a few items that are required, and then we can let the
  645. * user application have at it. Note that the dynamic linker itself
  646. * is not guaranteed to be fully dynamicly linked if we are using
  647. * ld.so.1, so we have to look up each symbol individually.
  648. */
  649. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  650. if (_dl_envp)
  651. *_dl_envp = (unsigned long) envp;
  652. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  653. {
  654. unsigned int j;
  655. ElfW(Phdr) *myppnt;
  656. /* We had to set the protections of all pages to R/W for
  657. * dynamic linking. Set text pages back to R/O.
  658. */
  659. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  660. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  661. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  662. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  663. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  664. }
  665. }
  666. }
  667. }
  668. #endif
  669. /* Notify the debugger we have added some objects. */
  670. _dl_debug_addr->r_state = RT_ADD;
  671. _dl_debug_state();
  672. for (i = nlist; i; --i) {
  673. tpnt = init_fini_list[i-1];
  674. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  675. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  676. continue;
  677. tpnt->init_flag |= INIT_FUNCS_CALLED;
  678. if (tpnt->dynamic_info[DT_INIT]) {
  679. void (*dl_elf_func) (void);
  680. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  681. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  682. (*dl_elf_func) ();
  683. }
  684. }
  685. /* Find the real malloc function and make ldso functions use that from now on */
  686. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  687. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  688. /* Notify the debugger that all objects are now mapped in. */
  689. _dl_debug_addr->r_state = RT_CONSISTENT;
  690. _dl_debug_state();
  691. }
  692. char *_dl_getenv(const char *symbol, char **envp)
  693. {
  694. char *pnt;
  695. const char *pnt1;
  696. while ((pnt = *envp++)) {
  697. pnt1 = symbol;
  698. while (*pnt && *pnt == *pnt1)
  699. pnt1++, pnt++;
  700. if (!*pnt || *pnt != '=' || *pnt1)
  701. continue;
  702. return pnt + 1;
  703. }
  704. return 0;
  705. }
  706. void _dl_unsetenv(const char *symbol, char **envp)
  707. {
  708. char *pnt;
  709. const char *pnt1;
  710. char **newenvp = envp;
  711. for (pnt = *envp; pnt; pnt = *++envp) {
  712. pnt1 = symbol;
  713. while (*pnt && *pnt == *pnt1)
  714. pnt1++, pnt++;
  715. if (!*pnt || *pnt != '=' || *pnt1)
  716. *newenvp++ = *envp;
  717. }
  718. *newenvp++ = *envp;
  719. return;
  720. }
  721. static int _dl_suid_ok(void)
  722. {
  723. __kernel_uid_t uid, euid;
  724. __kernel_gid_t gid, egid;
  725. uid = _dl_getuid();
  726. euid = _dl_geteuid();
  727. gid = _dl_getgid();
  728. egid = _dl_getegid();
  729. if(uid == euid && gid == egid) {
  730. return 1;
  731. }
  732. return 0;
  733. }
  734. void *_dl_malloc(int size)
  735. {
  736. void *retval;
  737. #if 0
  738. _dl_debug_early("request for %d bytes\n", size);
  739. #endif
  740. if (_dl_malloc_function)
  741. return (*_dl_malloc_function) (size);
  742. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  743. _dl_debug_early("mmapping more memory\n");
  744. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  745. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  746. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  747. _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
  748. _dl_exit(20);
  749. }
  750. }
  751. retval = _dl_malloc_addr;
  752. _dl_malloc_addr += size;
  753. /*
  754. * Align memory to 4 byte boundary. Some platforms require this,
  755. * others simply get better performance.
  756. */
  757. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  758. return retval;
  759. }
  760. #include "dl-hash.c"
  761. #include "dl-elf.c"