ldso.c 25 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 "dl-progname.h"
  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. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  78. {
  79. int i;
  80. struct elf_resolve * tpnt;
  81. for (i = 0; i < nlist; ++i) {
  82. tpnt = init_fini_list[i];
  83. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  84. continue;
  85. tpnt->init_flag |= FINI_FUNCS_CALLED;
  86. if (tpnt->dynamic_info[DT_FINI]) {
  87. void (*dl_elf_func) (void);
  88. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  89. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  90. (*dl_elf_func) ();
  91. }
  92. }
  93. }
  94. void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
  95. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  96. char **argv)
  97. {
  98. ElfW(Phdr) *ppnt;
  99. ElfW(Dyn) *dpnt;
  100. char *lpntstr;
  101. int i, goof = 0, unlazy = 0, trace_loaded_objects = 0;
  102. struct dyn_elf *rpnt;
  103. struct elf_resolve *tcurr;
  104. struct elf_resolve *tpnt1;
  105. struct elf_resolve app_tpnt_tmp;
  106. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  107. struct r_debug *debug_addr;
  108. unsigned long *lpnt;
  109. unsigned long *_dl_envp; /* The environment address */
  110. ElfW(Addr) relro_addr = 0;
  111. size_t relro_size = 0;
  112. /* Wahoo!!! We managed to make a function call! Get malloc
  113. * setup so we can use _dl_dprintf() to print debug noise
  114. * instead of the SEND_STDERR macros used in dl-startup.c */
  115. /* Store the page size for later use */
  116. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  117. /* Make it so _dl_malloc can use the page of memory we have already
  118. * allocated. We shouldn't need to grab any more memory. This must
  119. * be first since things like _dl_dprintf() use _dl_malloc()...
  120. */
  121. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  122. _dl_mmap_zero = 0;
  123. /* Wahoo!!! */
  124. _dl_debug_early("Cool, ldso survived making function calls\n");
  125. /* Now we have done the mandatory linking of some things. We are now
  126. * free to start using global variables, since these things have all
  127. * been fixed up by now. Still no function calls outside of this
  128. * library, since the dynamic resolver is not yet ready.
  129. */
  130. if (argv[0]) {
  131. _dl_progname = argv[0];
  132. }
  133. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  134. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  135. _dl_exit(1);
  136. }
  137. /* Start to build the tables of the modules that are required for
  138. * this beast to run. We start with the basic executable, and then
  139. * go from there. Eventually we will run across ourself, and we
  140. * will need to properly deal with that as well.
  141. */
  142. rpnt = NULL;
  143. if (_dl_getenv("LD_BIND_NOW", envp))
  144. unlazy = RTLD_NOW;
  145. /* Now we need to figure out what kind of options are selected.
  146. * Note that for SUID programs we ignore the settings in
  147. * LD_LIBRARY_PATH.
  148. */
  149. if ((auxvt[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) ||
  150. (auxvt[AT_UID].a_un.a_val != -1 &&
  151. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  152. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  153. _dl_secure = 0;
  154. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  155. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  156. } else {
  157. static const char unsecure_envvars[] =
  158. #ifdef EXTRA_UNSECURE_ENVVARS
  159. EXTRA_UNSECURE_ENVVARS
  160. #endif
  161. UNSECURE_ENVVARS;
  162. const char *nextp;
  163. _dl_secure = 1;
  164. nextp = unsecure_envvars;
  165. do {
  166. _dl_unsetenv (nextp, envp);
  167. /* We could use rawmemchr but this need not be fast. */
  168. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  169. } while (*nextp != '\0');
  170. _dl_preload = NULL;
  171. _dl_library_path = NULL;
  172. /* SUID binaries can be exploited if they do LAZY relocation. */
  173. unlazy = RTLD_NOW;
  174. }
  175. /* At this point we are now free to examine the user application,
  176. * and figure out which libraries are supposed to be called. Until
  177. * we have this list, we will not be completely ready for dynamic
  178. * linking.
  179. */
  180. /* Find the runtime load address of the main executable. This may be
  181. * different from what the ELF header says for ET_DYN/PIE executables.
  182. */
  183. {
  184. int i;
  185. ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  186. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
  187. if (ppnt->p_type == PT_PHDR) {
  188. app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
  189. break;
  190. }
  191. if (app_tpnt->loadaddr)
  192. _dl_debug_early("Position Independent Executable: "
  193. "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
  194. }
  195. /*
  196. * This is used by gdb to locate the chain of shared libraries that are
  197. * currently loaded.
  198. */
  199. debug_addr = _dl_malloc(sizeof(struct r_debug));
  200. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  201. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  202. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  203. if (ppnt->p_type == PT_GNU_RELRO) {
  204. relro_addr = ppnt->p_vaddr;
  205. relro_size = ppnt->p_memsz;
  206. }
  207. if (ppnt->p_type == PT_DYNAMIC) {
  208. dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
  209. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  210. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  211. /* Ugly, ugly. We need to call mprotect to change the
  212. * protection of the text pages so that we can do the
  213. * dynamic linking. We can set the protection back
  214. * again once we are done.
  215. */
  216. _dl_debug_early("calling mprotect on the application program\n");
  217. /* Now cover the application program. */
  218. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  219. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  220. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  221. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  222. _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
  223. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  224. (unsigned long) ppnt->p_filesz,
  225. PROT_READ | PROT_WRITE | PROT_EXEC);
  226. }
  227. }
  228. #endif
  229. #ifndef ALLOW_ZERO_PLTGOT
  230. /* make sure it's really there. */
  231. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  232. continue;
  233. #endif
  234. /* OK, we have what we need - slip this one into the list. */
  235. app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
  236. app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
  237. _dl_loaded_modules->libtype = elf_executable;
  238. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  239. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  240. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  241. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  242. rpnt->dyn = _dl_loaded_modules;
  243. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  244. app_tpnt->usage_count++;
  245. app_tpnt->symbol_scope = _dl_symbol_tables;
  246. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  247. #ifdef ALLOW_ZERO_PLTGOT
  248. if (lpnt)
  249. #endif
  250. INIT_GOT(lpnt, _dl_loaded_modules);
  251. }
  252. /* OK, fill this in - we did not have this before */
  253. if (ppnt->p_type == PT_INTERP) {
  254. char *ptmp;
  255. tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
  256. /* Store the path where the shared lib loader was found
  257. * for later use
  258. */
  259. _dl_ldsopath = _dl_strdup(tpnt->libname);
  260. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  261. if (ptmp != _dl_ldsopath)
  262. *ptmp = '\0';
  263. _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
  264. }
  265. }
  266. app_tpnt->relro_addr = relro_addr;
  267. app_tpnt->relro_size = relro_size;
  268. #ifdef __SUPPORT_LD_DEBUG__
  269. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  270. if (_dl_debug) {
  271. if (_dl_strstr(_dl_debug, "all")) {
  272. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  273. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  274. } else {
  275. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  276. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  277. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  278. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  279. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  280. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  281. }
  282. }
  283. {
  284. const char *dl_debug_output;
  285. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  286. if (dl_debug_output) {
  287. char tmp[22], *tmp1, *filename;
  288. int len1, len2;
  289. _dl_memset(tmp, 0, sizeof(tmp));
  290. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  291. len1 = _dl_strlen(dl_debug_output);
  292. len2 = _dl_strlen(tmp1);
  293. filename = _dl_malloc(len1+len2+2);
  294. if (filename) {
  295. _dl_strcpy (filename, dl_debug_output);
  296. filename[len1] = '.';
  297. _dl_strcpy (&filename[len1+1], tmp1);
  298. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  299. if (_dl_debug_file < 0) {
  300. _dl_debug_file = 2;
  301. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  302. }
  303. }
  304. }
  305. }
  306. #endif
  307. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  308. trace_loaded_objects++;
  309. }
  310. #ifndef __LDSO_LDD_SUPPORT__
  311. if (trace_loaded_objects) {
  312. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  313. _dl_exit(1);
  314. }
  315. #endif
  316. /*
  317. * OK, fix one more thing - set up debug_addr so it will point
  318. * to our chain. Later we may need to fill in more fields, but this
  319. * should be enough for now.
  320. */
  321. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  322. debug_addr->r_version = 1;
  323. debug_addr->r_ldbase = load_addr;
  324. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  325. _dl_debug_addr = debug_addr;
  326. /* Notify the debugger we are in a consistant state */
  327. _dl_debug_addr->r_state = RT_CONSISTENT;
  328. _dl_debug_state();
  329. /* OK, we now have the application in the list, and we have some
  330. * basic stuff in place. Now search through the list for other shared
  331. * libraries that should be loaded, and insert them on the list in the
  332. * correct order.
  333. */
  334. _dl_map_cache();
  335. if (_dl_preload) {
  336. char c, *str, *str2;
  337. str = _dl_preload;
  338. while (*str == ':' || *str == ' ' || *str == '\t')
  339. str++;
  340. while (*str) {
  341. str2 = str;
  342. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  343. str2++;
  344. c = *str2;
  345. *str2 = '\0';
  346. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  347. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  348. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  349. if (!tpnt1) {
  350. #ifdef __LDSO_LDD_SUPPORT__
  351. if (trace_loaded_objects)
  352. _dl_dprintf(1, "\t%s => not found\n", str);
  353. else
  354. #endif
  355. {
  356. _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
  357. _dl_exit(15);
  358. }
  359. } else {
  360. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  361. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  362. #ifdef __LDSO_LDD_SUPPORT__
  363. if (trace_loaded_objects &&
  364. tpnt1->usage_count == 1) {
  365. /* This is a real hack to make
  366. * ldd not print the library
  367. * itself when run on a
  368. * library.
  369. */
  370. if (_dl_strcmp(_dl_progname, str) != 0)
  371. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  372. tpnt1->loadaddr);
  373. }
  374. #endif
  375. }
  376. }
  377. *str2 = c;
  378. str = str2;
  379. while (*str == ':' || *str == ' ' || *str == '\t')
  380. str++;
  381. }
  382. }
  383. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  384. do {
  385. struct stat st;
  386. char *preload;
  387. int fd;
  388. char c, *cp, *cp2;
  389. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  390. break;
  391. }
  392. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  393. _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
  394. _dl_progname, LDSO_PRELOAD);
  395. break;
  396. }
  397. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  398. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  399. _dl_close(fd);
  400. if (preload == (caddr_t) -1) {
  401. _dl_dprintf(_dl_debug_file, "%s: can't map file '%s'\n",
  402. _dl_progname, LDSO_PRELOAD);
  403. break;
  404. }
  405. /* convert all separators and comments to spaces */
  406. for (cp = preload; *cp; /*nada */ ) {
  407. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  408. *cp++ = ' ';
  409. } else if (*cp == '#') {
  410. do {
  411. *cp++ = ' ';
  412. } while (*cp != '\n' && *cp != '\0');
  413. } else {
  414. cp++;
  415. }
  416. }
  417. /* find start of first library */
  418. for (cp = preload; *cp && *cp == ' '; cp++)
  419. /*nada */ ;
  420. while (*cp) {
  421. /* find end of library */
  422. for (cp2 = cp; *cp && *cp != ' '; cp++)
  423. /*nada */ ;
  424. c = *cp;
  425. *cp = '\0';
  426. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  427. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  428. if (!tpnt1) {
  429. #ifdef __LDSO_LDD_SUPPORT__
  430. if (trace_loaded_objects)
  431. _dl_dprintf(1, "\t%s => not found\n", cp2);
  432. else
  433. #endif
  434. {
  435. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
  436. _dl_exit(15);
  437. }
  438. } else {
  439. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  440. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  441. #ifdef __LDSO_LDD_SUPPORT__
  442. if (trace_loaded_objects &&
  443. tpnt1->usage_count == 1) {
  444. _dl_dprintf(1, "\t%s => %s (%x)\n",
  445. cp2, tpnt1->libname,
  446. (unsigned)tpnt1->loadaddr);
  447. }
  448. #endif
  449. }
  450. /* find start of next library */
  451. *cp = c;
  452. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  453. /*nada */ ;
  454. }
  455. _dl_munmap(preload, st.st_size + 1);
  456. } while (0);
  457. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  458. nlist = 0;
  459. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  460. ElfW(Dyn) *dpnt;
  461. nlist++;
  462. for (dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  463. if (dpnt->d_tag == DT_NEEDED) {
  464. char *name;
  465. struct init_fini_list *tmp;
  466. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
  467. name = _dl_get_last_path_component(lpntstr);
  468. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  469. continue;
  470. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  471. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  472. #ifdef __LDSO_LDD_SUPPORT__
  473. if (trace_loaded_objects) {
  474. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  475. continue;
  476. } else
  477. #endif
  478. {
  479. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  480. _dl_exit(16);
  481. }
  482. }
  483. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  484. tmp->tpnt = tpnt1;
  485. tmp->next = tcurr->init_fini;
  486. tcurr->init_fini = tmp;
  487. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  488. _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
  489. #ifdef __LDSO_LDD_SUPPORT__
  490. if (trace_loaded_objects &&
  491. tpnt1->usage_count == 1) {
  492. _dl_dprintf(1, "\t%s => %s (%x)\n",
  493. lpntstr, tpnt1->libname,
  494. (unsigned)tpnt1->loadaddr);
  495. }
  496. #endif
  497. }
  498. }
  499. }
  500. _dl_unmap_cache();
  501. --nlist; /* Exclude the application. */
  502. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  503. i = 0;
  504. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  505. init_fini_list[i++] = tcurr;
  506. }
  507. /* Sort the INIT/FINI list in dependency order. */
  508. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  509. int j, k;
  510. for (j = 0; init_fini_list[j] != tcurr; ++j)
  511. /* Empty */;
  512. for (k = j + 1; k < nlist; ++k) {
  513. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  514. for (; runp; runp = runp->next) {
  515. if (runp->tpnt == tcurr) {
  516. struct elf_resolve *here = init_fini_list[k];
  517. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  518. for (i = (k - j); i; --i)
  519. init_fini_list[i+j] = init_fini_list[i+j-1];
  520. init_fini_list[j] = here;
  521. ++j;
  522. break;
  523. }
  524. }
  525. }
  526. }
  527. #ifdef __SUPPORT_LD_DEBUG__
  528. if(_dl_debug) {
  529. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  530. for (i = 0; i < nlist; i++) {
  531. struct init_fini_list *tmp;
  532. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  533. init_fini_list[i]->libname);
  534. tmp = init_fini_list[i]->init_fini;
  535. for (; tmp; tmp = tmp->next)
  536. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  537. _dl_dprintf(_dl_debug_file, "\n");
  538. }
  539. }
  540. #endif
  541. /*
  542. * If the program interpreter is not in the module chain, add it.
  543. * This will be required for dlopen to be able to access the internal
  544. * functions in the dynamic linker and to relocate the interpreter
  545. * again once all libs are loaded.
  546. */
  547. if (tpnt) {
  548. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  549. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
  550. int j;
  551. tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
  552. tpnt->dynamic_info,
  553. (unsigned long)tpnt->dynamic_addr,
  554. 0);
  555. tpnt->n_phent = epnt->e_phnum;
  556. tpnt->ppnt = myppnt;
  557. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  558. if (myppnt->p_type == PT_GNU_RELRO) {
  559. tpnt->relro_addr = myppnt->p_vaddr;
  560. tpnt->relro_size = myppnt->p_memsz;
  561. break;
  562. }
  563. }
  564. tpnt->libtype = program_interpreter;
  565. tpnt->usage_count++;
  566. tpnt->symbol_scope = _dl_symbol_tables;
  567. if (rpnt) {
  568. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  569. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  570. rpnt->next->prev = rpnt;
  571. rpnt = rpnt->next;
  572. } else {
  573. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  574. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  575. }
  576. rpnt->dyn = tpnt;
  577. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  578. #ifdef RERELOCATE_LDSO
  579. /* Only rerelocate functions for now. */
  580. tpnt->init_flag = RELOCS_DONE;
  581. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  582. # ifdef ALLOW_ZERO_PLTGOT
  583. if (tpnt->dynamic_info[DT_PLTGOT])
  584. # endif
  585. INIT_GOT(lpnt, tpnt);
  586. #else
  587. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  588. #endif
  589. tpnt = NULL;
  590. }
  591. #ifdef __LDSO_LDD_SUPPORT__
  592. /* End of the line for ldd.... */
  593. if (trace_loaded_objects) {
  594. _dl_dprintf(1, "\t%s => %s (%x)\n",
  595. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  596. rpnt->dyn->libname, rpnt->dyn->loadaddr);
  597. _dl_exit(0);
  598. }
  599. #endif
  600. _dl_debug_early("Beginning relocation fixups\n");
  601. #ifdef __mips__
  602. /*
  603. * Relocation of the GOT entries for MIPS have to be done
  604. * after all the libraries have been loaded.
  605. */
  606. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  607. #endif
  608. /*
  609. * OK, now all of the kids are tucked into bed in their proper
  610. * addresses. Now we go through and look for REL and RELA records that
  611. * indicate fixups to the GOT tables. We need to do this in reverse
  612. * order so that COPY directives work correctly.
  613. */
  614. if (_dl_symbol_tables)
  615. goof += _dl_fixup(_dl_symbol_tables, unlazy);
  616. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  617. if (tpnt->relro_size)
  618. _dl_protect_relro (tpnt);
  619. }
  620. /* OK, at this point things are pretty much ready to run. Now we need
  621. * to touch up a few items that are required, and then we can let the
  622. * user application have at it. Note that the dynamic linker itself
  623. * is not guaranteed to be fully dynamicly linked if we are using
  624. * ld.so.1, so we have to look up each symbol individually.
  625. */
  626. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  627. if (_dl_envp)
  628. *_dl_envp = (unsigned long) envp;
  629. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  630. {
  631. unsigned int j;
  632. ElfW(Phdr) *myppnt;
  633. /* We had to set the protections of all pages to R/W for
  634. * dynamic linking. Set text pages back to R/O.
  635. */
  636. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  637. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  638. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  639. _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
  640. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  641. }
  642. }
  643. }
  644. }
  645. #endif
  646. /* Notify the debugger we have added some objects. */
  647. _dl_debug_addr->r_state = RT_ADD;
  648. _dl_debug_state();
  649. for (i = nlist; i; --i) {
  650. tpnt = init_fini_list[i-1];
  651. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  652. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  653. continue;
  654. tpnt->init_flag |= INIT_FUNCS_CALLED;
  655. if (tpnt->dynamic_info[DT_INIT]) {
  656. void (*dl_elf_func) (void);
  657. dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  658. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  659. (*dl_elf_func) ();
  660. }
  661. }
  662. /* Find the real malloc function and make ldso functions use that from now on */
  663. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  664. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  665. /* Notify the debugger that all objects are now mapped in. */
  666. _dl_debug_addr->r_state = RT_CONSISTENT;
  667. _dl_debug_state();
  668. }
  669. char *_dl_getenv(const char *symbol, char **envp)
  670. {
  671. char *pnt;
  672. const char *pnt1;
  673. while ((pnt = *envp++)) {
  674. pnt1 = symbol;
  675. while (*pnt && *pnt == *pnt1)
  676. pnt1++, pnt++;
  677. if (!*pnt || *pnt != '=' || *pnt1)
  678. continue;
  679. return pnt + 1;
  680. }
  681. return 0;
  682. }
  683. void _dl_unsetenv(const char *symbol, char **envp)
  684. {
  685. char *pnt;
  686. const char *pnt1;
  687. char **newenvp = envp;
  688. for (pnt = *envp; pnt; pnt = *++envp) {
  689. pnt1 = symbol;
  690. while (*pnt && *pnt == *pnt1)
  691. pnt1++, pnt++;
  692. if (!*pnt || *pnt != '=' || *pnt1)
  693. *newenvp++ = *envp;
  694. }
  695. *newenvp++ = *envp;
  696. return;
  697. }
  698. static int _dl_suid_ok(void)
  699. {
  700. __kernel_uid_t uid, euid;
  701. __kernel_gid_t gid, egid;
  702. uid = _dl_getuid();
  703. euid = _dl_geteuid();
  704. gid = _dl_getgid();
  705. egid = _dl_getegid();
  706. if(uid == euid && gid == egid) {
  707. return 1;
  708. }
  709. return 0;
  710. }
  711. void *_dl_malloc(int size)
  712. {
  713. void *retval;
  714. #if 0
  715. _dl_debug_early("request for %d bytes\n", size);
  716. #endif
  717. if (_dl_malloc_function)
  718. return (*_dl_malloc_function) (size);
  719. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  720. _dl_debug_early("mmapping more memory\n");
  721. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  722. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  723. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  724. _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
  725. _dl_exit(20);
  726. }
  727. }
  728. retval = _dl_malloc_addr;
  729. _dl_malloc_addr += size;
  730. /*
  731. * Align memory to 4 byte boundary. Some platforms require this,
  732. * others simply get better performance.
  733. */
  734. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
  735. return retval;
  736. }
  737. #include "dl-hash.c"
  738. #include "dl-elf.c"