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. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  126. /* Store the page size for later use */
  127. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  128. /* Make it so _dl_malloc can use the page of memory we have already
  129. * allocated. We shouldn't need to grab any more memory. This must
  130. * be first since things like _dl_dprintf() use _dl_malloc()...
  131. */
  132. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  133. _dl_mmap_zero = 0;
  134. /* Wahoo!!! */
  135. _dl_debug_early("Cool, ldso survived making function calls\n");
  136. /* Now we have done the mandatory linking of some things. We are now
  137. * free to start using global variables, since these things have all
  138. * been fixed up by now. Still no function calls outside of this
  139. * library, since the dynamic resolver is not yet ready.
  140. */
  141. if (argv[0]) {
  142. _dl_progname = argv[0];
  143. }
  144. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  145. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  146. _dl_exit(1);
  147. }
  148. /* Start to build the tables of the modules that are required for
  149. * this beast to run. We start with the basic executable, and then
  150. * go from there. Eventually we will run across ourself, and we
  151. * will need to properly deal with that as well.
  152. */
  153. rpnt = NULL;
  154. if (_dl_getenv("LD_BIND_NOW", envp))
  155. unlazy = RTLD_NOW;
  156. /* Now we need to figure out what kind of options are selected.
  157. * Note that for SUID programs we ignore the settings in
  158. * LD_LIBRARY_PATH.
  159. */
  160. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  161. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  162. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  163. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  164. _dl_secure = 0;
  165. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  166. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  167. } else {
  168. static const char unsecure_envvars[] =
  169. #ifdef EXTRA_UNSECURE_ENVVARS
  170. EXTRA_UNSECURE_ENVVARS
  171. #endif
  172. UNSECURE_ENVVARS;
  173. const char *nextp;
  174. _dl_secure = 1;
  175. nextp = unsecure_envvars;
  176. do {
  177. _dl_unsetenv (nextp, envp);
  178. /* We could use rawmemchr but this need not be fast. */
  179. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  180. } while (*nextp != '\0');
  181. _dl_preload = NULL;
  182. _dl_library_path = NULL;
  183. /* SUID binaries can be exploited if they do LAZY relocation. */
  184. unlazy = RTLD_NOW;
  185. }
  186. /* sjhill: your TLS init should go before this */
  187. #ifdef __UCLIBC_HAS_SSP__
  188. /* Set up the stack checker's canary. */
  189. uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
  190. # ifdef THREAD_SET_STACK_GUARD
  191. THREAD_SET_STACK_GUARD (stack_chk_guard);
  192. # else
  193. __stack_chk_guard = stack_chk_guard;
  194. # endif
  195. #endif
  196. /* At this point we are now free to examine the user application,
  197. * and figure out which libraries are supposed to be called. Until
  198. * we have this list, we will not be completely ready for dynamic
  199. * linking.
  200. */
  201. /* Find the runtime load address of the main executable. This may be
  202. * different from what the ELF header says for ET_DYN/PIE executables.
  203. */
  204. {
  205. unsigned int i;
  206. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  207. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  208. if (ppnt->p_type == PT_PHDR) {
  209. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  210. break;
  211. }
  212. if (app_tpnt->loadaddr)
  213. _dl_debug_early("Position Independent Executable: "
  214. "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
  215. }
  216. /*
  217. * This is used by gdb to locate the chain of shared libraries that are
  218. * currently loaded.
  219. */
  220. debug_addr = _dl_malloc(sizeof(struct r_debug));
  221. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  222. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  223. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  224. if (ppnt->p_type == PT_GNU_RELRO) {
  225. relro_addr = ppnt->p_vaddr;
  226. relro_size = ppnt->p_memsz;
  227. }
  228. if (ppnt->p_type == PT_DYNAMIC) {
  229. dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  230. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  231. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  232. /* Ugly, ugly. We need to call mprotect to change the
  233. * protection of the text pages so that we can do the
  234. * dynamic linking. We can set the protection back
  235. * again once we are done.
  236. */
  237. _dl_debug_early("calling mprotect on the application program\n");
  238. /* Now cover the application program. */
  239. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  240. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  241. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  242. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  243. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  244. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  245. (unsigned long) ppnt->p_filesz,
  246. PROT_READ | PROT_WRITE | PROT_EXEC);
  247. }
  248. }
  249. #endif
  250. #ifndef ALLOW_ZERO_PLTGOT
  251. /* make sure it's really there. */
  252. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  253. continue;
  254. #endif
  255. /* OK, we have what we need - slip this one into the list. */
  256. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  257. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  258. _dl_loaded_modules->libtype = elf_executable;
  259. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  260. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  261. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  262. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  263. rpnt->dyn = _dl_loaded_modules;
  264. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  265. app_tpnt->usage_count++;
  266. app_tpnt->symbol_scope = _dl_symbol_tables;
  267. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  268. #ifdef ALLOW_ZERO_PLTGOT
  269. if (lpnt)
  270. #endif
  271. INIT_GOT(lpnt, _dl_loaded_modules);
  272. }
  273. /* OK, fill this in - we did not have this before */
  274. if (ppnt->p_type == PT_INTERP) {
  275. char *ptmp;
  276. tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
  277. /* Store the path where the shared lib loader was found
  278. * for later use
  279. */
  280. _dl_ldsopath = _dl_strdup(tpnt->libname);
  281. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  282. if (ptmp != _dl_ldsopath)
  283. *ptmp = '\0';
  284. _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
  285. }
  286. }
  287. app_tpnt->relro_addr = relro_addr;
  288. app_tpnt->relro_size = relro_size;
  289. #ifdef __SUPPORT_LD_DEBUG__
  290. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  291. if (_dl_debug) {
  292. if (_dl_strstr(_dl_debug, "all")) {
  293. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  294. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  295. } else {
  296. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  297. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  298. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  299. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  300. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  301. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  302. }
  303. }
  304. {
  305. const char *dl_debug_output;
  306. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  307. if (dl_debug_output) {
  308. char tmp[22], *tmp1, *filename;
  309. int len1, len2;
  310. _dl_memset(tmp, 0, sizeof(tmp));
  311. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  312. len1 = _dl_strlen(dl_debug_output);
  313. len2 = _dl_strlen(tmp1);
  314. filename = _dl_malloc(len1+len2+2);
  315. if (filename) {
  316. _dl_strcpy (filename, dl_debug_output);
  317. filename[len1] = '.';
  318. _dl_strcpy (&filename[len1+1], tmp1);
  319. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  320. if (_dl_debug_file < 0) {
  321. _dl_debug_file = 2;
  322. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  323. }
  324. }
  325. }
  326. }
  327. #endif
  328. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  329. trace_loaded_objects++;
  330. }
  331. #ifndef __LDSO_LDD_SUPPORT__
  332. if (trace_loaded_objects) {
  333. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  334. _dl_exit(1);
  335. }
  336. #endif
  337. /*
  338. * OK, fix one more thing - set up debug_addr so it will point
  339. * to our chain. Later we may need to fill in more fields, but this
  340. * should be enough for now.
  341. */
  342. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  343. debug_addr->r_version = 1;
  344. debug_addr->r_ldbase = load_addr;
  345. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  346. _dl_debug_addr = debug_addr;
  347. /* Notify the debugger we are in a consistant state */
  348. _dl_debug_addr->r_state = RT_CONSISTENT;
  349. _dl_debug_state();
  350. /* OK, we now have the application in the list, and we have some
  351. * basic stuff in place. Now search through the list for other shared
  352. * libraries that should be loaded, and insert them on the list in the
  353. * correct order.
  354. */
  355. _dl_map_cache();
  356. if (_dl_preload) {
  357. char c, *str, *str2;
  358. str = _dl_preload;
  359. while (*str == ':' || *str == ' ' || *str == '\t')
  360. str++;
  361. while (*str) {
  362. str2 = str;
  363. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  364. str2++;
  365. c = *str2;
  366. *str2 = '\0';
  367. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  368. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  369. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  370. if (!tpnt1) {
  371. #ifdef __LDSO_LDD_SUPPORT__
  372. if (trace_loaded_objects)
  373. _dl_dprintf(1, "\t%s => not found\n", str);
  374. else
  375. #endif
  376. {
  377. _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
  378. _dl_exit(15);
  379. }
  380. } else {
  381. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  382. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  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. tpnt1->loadaddr);
  394. }
  395. #endif
  396. }
  397. }
  398. *str2 = c;
  399. str = str2;
  400. while (*str == ':' || *str == ' ' || *str == '\t')
  401. str++;
  402. }
  403. }
  404. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  405. do {
  406. struct stat st;
  407. char *preload;
  408. int fd;
  409. char c, *cp, *cp2;
  410. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  411. break;
  412. }
  413. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  414. _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
  415. _dl_progname, LDSO_PRELOAD);
  416. break;
  417. }
  418. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  419. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  420. _dl_close(fd);
  421. if (preload == (caddr_t) -1) {
  422. _dl_dprintf(_dl_debug_file, "%s: can't map file '%s'\n",
  423. _dl_progname, LDSO_PRELOAD);
  424. break;
  425. }
  426. /* convert all separators and comments to spaces */
  427. for (cp = preload; *cp; /*nada */ ) {
  428. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  429. *cp++ = ' ';
  430. } else if (*cp == '#') {
  431. do {
  432. *cp++ = ' ';
  433. } while (*cp != '\n' && *cp != '\0');
  434. } else {
  435. cp++;
  436. }
  437. }
  438. /* find start of first library */
  439. for (cp = preload; *cp && *cp == ' '; cp++)
  440. /*nada */ ;
  441. while (*cp) {
  442. /* find end of library */
  443. for (cp2 = cp; *cp && *cp != ' '; cp++)
  444. /*nada */ ;
  445. c = *cp;
  446. *cp = '\0';
  447. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  448. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  449. if (!tpnt1) {
  450. #ifdef __LDSO_LDD_SUPPORT__
  451. if (trace_loaded_objects)
  452. _dl_dprintf(1, "\t%s => not found\n", cp2);
  453. else
  454. #endif
  455. {
  456. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
  457. _dl_exit(15);
  458. }
  459. } else {
  460. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  461. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  462. #ifdef __LDSO_LDD_SUPPORT__
  463. if (trace_loaded_objects &&
  464. tpnt1->usage_count == 1) {
  465. _dl_dprintf(1, "\t%s => %s (%x)\n",
  466. cp2, tpnt1->libname,
  467. (unsigned)tpnt1->loadaddr);
  468. }
  469. #endif
  470. }
  471. /* find start of next library */
  472. *cp = c;
  473. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  474. /*nada */ ;
  475. }
  476. _dl_munmap(preload, st.st_size + 1);
  477. } while (0);
  478. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  479. nlist = 0;
  480. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  481. ElfW(Dyn) *dpnt;
  482. nlist++;
  483. for (dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  484. if (dpnt->d_tag == DT_NEEDED) {
  485. char *name;
  486. struct init_fini_list *tmp;
  487. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
  488. name = _dl_get_last_path_component(lpntstr);
  489. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  490. continue;
  491. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  492. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  493. #ifdef __LDSO_LDD_SUPPORT__
  494. if (trace_loaded_objects) {
  495. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  496. continue;
  497. } else
  498. #endif
  499. {
  500. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  501. _dl_exit(16);
  502. }
  503. }
  504. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  505. tmp->tpnt = tpnt1;
  506. tmp->next = tcurr->init_fini;
  507. tcurr->init_fini = tmp;
  508. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  509. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  510. #ifdef __LDSO_LDD_SUPPORT__
  511. if (trace_loaded_objects &&
  512. tpnt1->usage_count == 1) {
  513. _dl_dprintf(1, "\t%s => %s (%x)\n",
  514. lpntstr, tpnt1->libname,
  515. (unsigned)tpnt1->loadaddr);
  516. }
  517. #endif
  518. }
  519. }
  520. }
  521. _dl_unmap_cache();
  522. --nlist; /* Exclude the application. */
  523. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  524. i = 0;
  525. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  526. init_fini_list[i++] = tcurr;
  527. }
  528. /* Sort the INIT/FINI list in dependency order. */
  529. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  530. int j, k;
  531. for (j = 0; init_fini_list[j] != tcurr; ++j)
  532. /* Empty */;
  533. for (k = j + 1; k < nlist; ++k) {
  534. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  535. for (; runp; runp = runp->next) {
  536. if (runp->tpnt == tcurr) {
  537. struct elf_resolve *here = init_fini_list[k];
  538. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  539. for (i = (k - j); i; --i)
  540. init_fini_list[i+j] = init_fini_list[i+j-1];
  541. init_fini_list[j] = here;
  542. ++j;
  543. break;
  544. }
  545. }
  546. }
  547. }
  548. #ifdef __SUPPORT_LD_DEBUG__
  549. if(_dl_debug) {
  550. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  551. for (i = 0; i < nlist; i++) {
  552. struct init_fini_list *tmp;
  553. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  554. init_fini_list[i]->libname);
  555. tmp = init_fini_list[i]->init_fini;
  556. for (; tmp; tmp = tmp->next)
  557. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  558. _dl_dprintf(_dl_debug_file, "\n");
  559. }
  560. }
  561. #endif
  562. /*
  563. * If the program interpreter is not in the module chain, add it.
  564. * This will be required for dlopen to be able to access the internal
  565. * functions in the dynamic linker and to relocate the interpreter
  566. * again once all libs are loaded.
  567. */
  568. if (tpnt) {
  569. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  570. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  571. int j;
  572. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  573. tpnt->dynamic_info,
  574. (unsigned long)tpnt->dynamic_addr,
  575. 0);
  576. tpnt->n_phent = epnt->e_phnum;
  577. tpnt->ppnt = myppnt;
  578. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  579. if (myppnt->p_type == PT_GNU_RELRO) {
  580. tpnt->relro_addr = myppnt->p_vaddr;
  581. tpnt->relro_size = myppnt->p_memsz;
  582. break;
  583. }
  584. }
  585. tpnt->libtype = program_interpreter;
  586. tpnt->usage_count++;
  587. tpnt->symbol_scope = _dl_symbol_tables;
  588. if (rpnt) {
  589. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  590. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  591. rpnt->next->prev = rpnt;
  592. rpnt = rpnt->next;
  593. } else {
  594. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  595. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  596. }
  597. rpnt->dyn = tpnt;
  598. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  599. #ifdef RERELOCATE_LDSO
  600. /* Only rerelocate functions for now. */
  601. tpnt->init_flag = RELOCS_DONE;
  602. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  603. # ifdef ALLOW_ZERO_PLTGOT
  604. if (tpnt->dynamic_info[DT_PLTGOT])
  605. # endif
  606. INIT_GOT(lpnt, tpnt);
  607. #else
  608. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  609. #endif
  610. tpnt = NULL;
  611. }
  612. #ifdef __LDSO_LDD_SUPPORT__
  613. /* End of the line for ldd.... */
  614. if (trace_loaded_objects) {
  615. _dl_dprintf(1, "\t%s => %s (%x)\n",
  616. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  617. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  618. _dl_exit(0);
  619. }
  620. #endif
  621. _dl_debug_early("Beginning relocation fixups\n");
  622. #ifdef __mips__
  623. /*
  624. * Relocation of the GOT entries for MIPS have to be done
  625. * after all the libraries have been loaded.
  626. */
  627. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  628. #endif
  629. /*
  630. * OK, now all of the kids are tucked into bed in their proper
  631. * addresses. Now we go through and look for REL and RELA records that
  632. * indicate fixups to the GOT tables. We need to do this in reverse
  633. * order so that COPY directives work correctly.
  634. */
  635. if (_dl_symbol_tables)
  636. if (_dl_fixup(_dl_symbol_tables, unlazy))
  637. _dl_exit(-1);
  638. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  639. if (tpnt->relro_size)
  640. _dl_protect_relro (tpnt);
  641. }
  642. /* OK, at this point things are pretty much ready to run. Now we need
  643. * to touch up a few items that are required, and then we can let the
  644. * user application have at it. Note that the dynamic linker itself
  645. * is not guaranteed to be fully dynamicly linked if we are using
  646. * ld.so.1, so we have to look up each symbol individually.
  647. */
  648. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  649. if (_dl_envp)
  650. *_dl_envp = (unsigned long) envp;
  651. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  652. {
  653. unsigned int j;
  654. ElfW(Phdr) *myppnt;
  655. /* We had to set the protections of all pages to R/W for
  656. * dynamic linking. Set text pages back to R/O.
  657. */
  658. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  659. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  660. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  661. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  662. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  663. }
  664. }
  665. }
  666. }
  667. #endif
  668. /* Notify the debugger we have added some objects. */
  669. _dl_debug_addr->r_state = RT_ADD;
  670. _dl_debug_state();
  671. for (i = nlist; i; --i) {
  672. tpnt = init_fini_list[i-1];
  673. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  674. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  675. continue;
  676. tpnt->init_flag |= INIT_FUNCS_CALLED;
  677. if (tpnt->dynamic_info[DT_INIT]) {
  678. void (*dl_elf_func) (void);
  679. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  680. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  681. (*dl_elf_func) ();
  682. }
  683. }
  684. /* Find the real malloc function and make ldso functions use that from now on */
  685. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  686. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  687. /* Notify the debugger that all objects are now mapped in. */
  688. _dl_debug_addr->r_state = RT_CONSISTENT;
  689. _dl_debug_state();
  690. }
  691. char *_dl_getenv(const char *symbol, char **envp)
  692. {
  693. char *pnt;
  694. const char *pnt1;
  695. while ((pnt = *envp++)) {
  696. pnt1 = symbol;
  697. while (*pnt && *pnt == *pnt1)
  698. pnt1++, pnt++;
  699. if (!*pnt || *pnt != '=' || *pnt1)
  700. continue;
  701. return pnt + 1;
  702. }
  703. return 0;
  704. }
  705. void _dl_unsetenv(const char *symbol, char **envp)
  706. {
  707. char *pnt;
  708. const char *pnt1;
  709. char **newenvp = envp;
  710. for (pnt = *envp; pnt; pnt = *++envp) {
  711. pnt1 = symbol;
  712. while (*pnt && *pnt == *pnt1)
  713. pnt1++, pnt++;
  714. if (!*pnt || *pnt != '=' || *pnt1)
  715. *newenvp++ = *envp;
  716. }
  717. *newenvp++ = *envp;
  718. return;
  719. }
  720. static int _dl_suid_ok(void)
  721. {
  722. __kernel_uid_t uid, euid;
  723. __kernel_gid_t gid, egid;
  724. uid = _dl_getuid();
  725. euid = _dl_geteuid();
  726. gid = _dl_getgid();
  727. egid = _dl_getegid();
  728. if(uid == euid && gid == egid) {
  729. return 1;
  730. }
  731. return 0;
  732. }
  733. void *_dl_malloc(int size)
  734. {
  735. void *retval;
  736. #if 0
  737. _dl_debug_early("request for %d bytes\n", size);
  738. #endif
  739. if (_dl_malloc_function)
  740. return (*_dl_malloc_function) (size);
  741. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  742. _dl_debug_early("mmapping more memory\n");
  743. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  744. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  745. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  746. _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
  747. _dl_exit(20);
  748. }
  749. }
  750. retval = _dl_malloc_addr;
  751. _dl_malloc_addr += size;
  752. /*
  753. * Align memory to 4 byte boundary. Some platforms require this,
  754. * others simply get better performance.
  755. */
  756. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  757. return retval;
  758. }
  759. #include "dl-hash.c"
  760. #include "dl-elf.c"