ldso.c 27 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) 2000-2006 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. #include "dl-array.c"
  63. /* Forward function declarations */
  64. static int _dl_suid_ok(void);
  65. /*
  66. * This stub function is used by some debuggers. The idea is that they
  67. * can set an internal breakpoint on it, so that we are notified when the
  68. * address mapping is changed in some way.
  69. */
  70. void _dl_debug_state(void);
  71. rtld_hidden_proto(_dl_debug_state, noinline);
  72. void _dl_debug_state(void)
  73. {
  74. /* Make sure GCC doesn't recognize this function as pure, to avoid
  75. * having the calls optimized away.
  76. */
  77. __asm__("");
  78. }
  79. rtld_hidden_def(_dl_debug_state);
  80. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  81. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  82. static struct elf_resolve **init_fini_list;
  83. static unsigned int nlist; /* # items in init_fini_list */
  84. extern void _start(void);
  85. #ifdef __UCLIBC_HAS_SSP__
  86. # include <dl-osinfo.h>
  87. uintptr_t stack_chk_guard;
  88. # ifndef THREAD_SET_STACK_GUARD
  89. /* Only exported for architectures that don't store the stack guard canary
  90. * in local thread area. */
  91. uintptr_t __stack_chk_guard attribute_relro;
  92. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  93. strong_alias(__stack_chk_guard,__guard)
  94. # endif
  95. # elif __UCLIBC_HAS_SSP_COMPAT__
  96. uintptr_t __guard attribute_relro;
  97. # endif
  98. #endif
  99. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  100. {
  101. int i;
  102. struct elf_resolve * tpnt;
  103. for (i = 0; i < nlist; ++i) {
  104. tpnt = init_fini_list[i];
  105. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  106. continue;
  107. tpnt->init_flag |= FINI_FUNCS_CALLED;
  108. _dl_run_fini_array(tpnt);
  109. if (tpnt->dynamic_info[DT_FINI]) {
  110. void (*dl_elf_func) (void);
  111. dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
  112. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  113. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  114. }
  115. }
  116. }
  117. void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
  118. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  119. char **argv)
  120. {
  121. ElfW(Phdr) *ppnt;
  122. ElfW(Dyn) *dpnt;
  123. char *lpntstr;
  124. unsigned int i;
  125. int unlazy = 0, trace_loaded_objects = 0;
  126. struct dyn_elf *rpnt;
  127. struct elf_resolve *tcurr;
  128. struct elf_resolve *tpnt1;
  129. struct elf_resolve app_tpnt_tmp;
  130. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  131. struct r_debug *debug_addr;
  132. unsigned long *lpnt;
  133. unsigned long *_dl_envp; /* The environment address */
  134. ElfW(Addr) relro_addr = 0;
  135. size_t relro_size = 0;
  136. struct stat st;
  137. /* Wahoo!!! We managed to make a function call! Get malloc
  138. * setup so we can use _dl_dprintf() to print debug noise
  139. * instead of the SEND_STDERR macros used in dl-startup.c */
  140. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  141. /* Store the page size for later use */
  142. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  143. /* Make it so _dl_malloc can use the page of memory we have already
  144. * allocated. We shouldn't need to grab any more memory. This must
  145. * be first since things like _dl_dprintf() use _dl_malloc()...
  146. */
  147. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  148. _dl_mmap_zero = 0;
  149. /* Wahoo!!! */
  150. _dl_debug_early("Cool, ldso survived making function calls\n");
  151. /* Now we have done the mandatory linking of some things. We are now
  152. * free to start using global variables, since these things have all
  153. * been fixed up by now. Still no function calls outside of this
  154. * library, since the dynamic resolver is not yet ready.
  155. */
  156. if (argv[0]) {
  157. _dl_progname = argv[0];
  158. }
  159. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  160. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  161. _dl_exit(1);
  162. }
  163. /* Start to build the tables of the modules that are required for
  164. * this beast to run. We start with the basic executable, and then
  165. * go from there. Eventually we will run across ourself, and we
  166. * will need to properly deal with that as well.
  167. */
  168. rpnt = NULL;
  169. if (_dl_getenv("LD_BIND_NOW", envp))
  170. unlazy = RTLD_NOW;
  171. /* Now we need to figure out what kind of options are selected.
  172. * Note that for SUID programs we ignore the settings in
  173. * LD_LIBRARY_PATH.
  174. */
  175. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  176. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  177. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  178. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  179. _dl_secure = 0;
  180. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  181. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  182. } else {
  183. static const char unsecure_envvars[] =
  184. #ifdef EXTRA_UNSECURE_ENVVARS
  185. EXTRA_UNSECURE_ENVVARS
  186. #endif
  187. UNSECURE_ENVVARS;
  188. const char *nextp;
  189. _dl_secure = 1;
  190. nextp = unsecure_envvars;
  191. do {
  192. _dl_unsetenv (nextp, envp);
  193. /* We could use rawmemchr but this need not be fast. */
  194. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  195. } while (*nextp != '\0');
  196. _dl_preload = NULL;
  197. _dl_library_path = NULL;
  198. /* SUID binaries can be exploited if they do LAZY relocation. */
  199. unlazy = RTLD_NOW;
  200. }
  201. /* sjhill: your TLS init should go before this */
  202. #ifdef __UCLIBC_HAS_SSP__
  203. /* Set up the stack checker's canary. */
  204. stack_chk_guard = _dl_setup_stack_chk_guard ();
  205. # ifdef THREAD_SET_STACK_GUARD
  206. THREAD_SET_STACK_GUARD (stack_chk_guard);
  207. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  208. __guard = stack_chk_guard;
  209. # endif
  210. # else
  211. __stack_chk_guard = stack_chk_guard;
  212. # endif
  213. #endif
  214. /* At this point we are now free to examine the user application,
  215. * and figure out which libraries are supposed to be called. Until
  216. * we have this list, we will not be completely ready for dynamic
  217. * linking.
  218. */
  219. /* Find the runtime load address of the main executable. This may be
  220. * different from what the ELF header says for ET_DYN/PIE executables.
  221. */
  222. {
  223. unsigned int idx;
  224. ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  225. for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
  226. if (phdr->p_type == PT_PHDR) {
  227. DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
  228. break;
  229. }
  230. if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
  231. _dl_debug_early("Position Independent Executable: "
  232. "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
  233. }
  234. /*
  235. * This is used by gdb to locate the chain of shared libraries that are
  236. * currently loaded.
  237. */
  238. debug_addr = _dl_malloc(sizeof(struct r_debug));
  239. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  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_GNU_RELRO) {
  243. relro_addr = ppnt->p_vaddr;
  244. relro_size = ppnt->p_memsz;
  245. }
  246. if (ppnt->p_type == PT_DYNAMIC) {
  247. dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  248. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  249. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  250. /* Ugly, ugly. We need to call mprotect to change the
  251. * protection of the text pages so that we can do the
  252. * dynamic linking. We can set the protection back
  253. * again once we are done.
  254. */
  255. _dl_debug_early("calling mprotect on the application program\n");
  256. /* Now cover the application program. */
  257. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  258. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  259. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  260. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  261. _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
  262. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  263. (unsigned long) ppnt->p_filesz,
  264. PROT_READ | PROT_WRITE | PROT_EXEC);
  265. }
  266. }
  267. #endif
  268. #ifndef ALLOW_ZERO_PLTGOT
  269. /* make sure it's really there. */
  270. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  271. continue;
  272. #endif
  273. /* OK, we have what we need - slip this one into the list. */
  274. app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
  275. app_tpnt->dynamic_info,
  276. DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
  277. ppnt->p_filesz);
  278. _dl_loaded_modules->libtype = elf_executable;
  279. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  280. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  281. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  282. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  283. rpnt->dyn = _dl_loaded_modules;
  284. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  285. app_tpnt->usage_count++;
  286. app_tpnt->symbol_scope = _dl_symbol_tables;
  287. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  288. #ifdef ALLOW_ZERO_PLTGOT
  289. if (lpnt)
  290. #endif
  291. INIT_GOT(lpnt, _dl_loaded_modules);
  292. }
  293. /* OK, fill this in - we did not have this before */
  294. if (ppnt->p_type == PT_INTERP) {
  295. char *ptmp;
  296. tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  297. /* Store the path where the shared lib loader was found
  298. * for later use
  299. */
  300. _dl_ldsopath = _dl_strdup(tpnt->libname);
  301. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  302. if (ptmp != _dl_ldsopath)
  303. *ptmp = '\0';
  304. _dl_debug_early("Lib Loader: (%x) %s\n", DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
  305. }
  306. }
  307. app_tpnt->relro_addr = relro_addr;
  308. app_tpnt->relro_size = relro_size;
  309. #ifdef __SUPPORT_LD_DEBUG__
  310. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  311. if (_dl_debug) {
  312. if (_dl_strstr(_dl_debug, "all")) {
  313. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  314. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  315. } else {
  316. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  317. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  318. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  319. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  320. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  321. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  322. }
  323. }
  324. {
  325. const char *dl_debug_output;
  326. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  327. if (dl_debug_output) {
  328. char tmp[22], *tmp1, *filename;
  329. int len1, len2;
  330. _dl_memset(tmp, 0, sizeof(tmp));
  331. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  332. len1 = _dl_strlen(dl_debug_output);
  333. len2 = _dl_strlen(tmp1);
  334. filename = _dl_malloc(len1+len2+2);
  335. if (filename) {
  336. _dl_strcpy (filename, dl_debug_output);
  337. filename[len1] = '.';
  338. _dl_strcpy (&filename[len1+1], tmp1);
  339. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  340. if (_dl_debug_file < 0) {
  341. _dl_debug_file = 2;
  342. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  343. }
  344. }
  345. }
  346. }
  347. #endif
  348. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  349. trace_loaded_objects++;
  350. }
  351. #ifndef __LDSO_LDD_SUPPORT__
  352. if (trace_loaded_objects) {
  353. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  354. _dl_exit(1);
  355. }
  356. #endif
  357. /*
  358. * OK, fix one more thing - set up debug_addr so it will point
  359. * to our chain. Later we may need to fill in more fields, but this
  360. * should be enough for now.
  361. */
  362. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  363. debug_addr->r_version = 1;
  364. debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
  365. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  366. _dl_debug_addr = debug_addr;
  367. /* Notify the debugger we are in a consistant state */
  368. _dl_debug_addr->r_state = RT_CONSISTENT;
  369. _dl_debug_state();
  370. /* OK, we now have the application in the list, and we have some
  371. * basic stuff in place. Now search through the list for other shared
  372. * libraries that should be loaded, and insert them on the list in the
  373. * correct order.
  374. */
  375. _dl_map_cache();
  376. if (_dl_preload) {
  377. char c, *str, *str2;
  378. str = _dl_preload;
  379. while (*str == ':' || *str == ' ' || *str == '\t')
  380. str++;
  381. while (*str) {
  382. str2 = str;
  383. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  384. str2++;
  385. c = *str2;
  386. *str2 = '\0';
  387. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  388. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  389. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  390. if (!tpnt1) {
  391. #ifdef __LDSO_LDD_SUPPORT__
  392. if (trace_loaded_objects)
  393. _dl_dprintf(1, "\t%s => not found\n", str);
  394. else
  395. #endif
  396. {
  397. _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
  398. _dl_exit(15);
  399. }
  400. } else {
  401. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  402. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  403. #ifdef __LDSO_LDD_SUPPORT__
  404. if (trace_loaded_objects &&
  405. tpnt1->usage_count == 1) {
  406. /* This is a real hack to make
  407. * ldd not print the library
  408. * itself when run on a
  409. * library.
  410. */
  411. if (_dl_strcmp(_dl_progname, str) != 0)
  412. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  413. DL_LOADADDR_BASE(tpnt1->loadaddr));
  414. }
  415. #endif
  416. }
  417. }
  418. *str2 = c;
  419. str = str2;
  420. while (*str == ':' || *str == ' ' || *str == '\t')
  421. str++;
  422. }
  423. }
  424. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  425. do {
  426. struct stat st;
  427. char *preload;
  428. int fd;
  429. char c, *cp, *cp2;
  430. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  431. break;
  432. }
  433. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  434. _dl_dprintf(2, "%s: can't open file '%s'\n",
  435. _dl_progname, LDSO_PRELOAD);
  436. break;
  437. }
  438. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  439. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  440. _dl_close(fd);
  441. if (preload == (caddr_t) -1) {
  442. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  443. _dl_progname, __LINE__, LDSO_PRELOAD);
  444. break;
  445. }
  446. /* convert all separators and comments to spaces */
  447. for (cp = preload; *cp; /*nada */ ) {
  448. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  449. *cp++ = ' ';
  450. } else if (*cp == '#') {
  451. do {
  452. *cp++ = ' ';
  453. } while (*cp != '\n' && *cp != '\0');
  454. } else {
  455. cp++;
  456. }
  457. }
  458. /* find start of first library */
  459. for (cp = preload; *cp && *cp == ' '; cp++)
  460. /*nada */ ;
  461. while (*cp) {
  462. /* find end of library */
  463. for (cp2 = cp; *cp && *cp != ' '; cp++)
  464. /*nada */ ;
  465. c = *cp;
  466. *cp = '\0';
  467. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  468. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  469. if (!tpnt1) {
  470. #ifdef __LDSO_LDD_SUPPORT__
  471. if (trace_loaded_objects)
  472. _dl_dprintf(1, "\t%s => not found\n", cp2);
  473. else
  474. #endif
  475. {
  476. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
  477. _dl_exit(15);
  478. }
  479. } else {
  480. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  481. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  482. #ifdef __LDSO_LDD_SUPPORT__
  483. if (trace_loaded_objects &&
  484. tpnt1->usage_count == 1) {
  485. _dl_dprintf(1, "\t%s => %s (%x)\n",
  486. cp2, tpnt1->libname,
  487. DL_LOADADDR_BASE(tpnt1->loadaddr));
  488. }
  489. #endif
  490. }
  491. /* find start of next library */
  492. *cp = c;
  493. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  494. /*nada */ ;
  495. }
  496. _dl_munmap(preload, st.st_size + 1);
  497. } while (0);
  498. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  499. nlist = 0;
  500. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  501. ElfW(Dyn) *this_dpnt;
  502. nlist++;
  503. for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
  504. if (this_dpnt->d_tag == DT_NEEDED) {
  505. char *name;
  506. struct init_fini_list *tmp;
  507. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
  508. name = _dl_get_last_path_component(lpntstr);
  509. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  510. continue;
  511. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  512. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  513. #ifdef __LDSO_LDD_SUPPORT__
  514. if (trace_loaded_objects) {
  515. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  516. continue;
  517. } else
  518. #endif
  519. {
  520. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  521. _dl_exit(16);
  522. }
  523. }
  524. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  525. tmp->tpnt = tpnt1;
  526. tmp->next = tcurr->init_fini;
  527. tcurr->init_fini = tmp;
  528. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  529. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  530. #ifdef __LDSO_LDD_SUPPORT__
  531. if (trace_loaded_objects &&
  532. tpnt1->usage_count == 1) {
  533. _dl_dprintf(1, "\t%s => %s (%x)\n",
  534. lpntstr, tpnt1->libname,
  535. DL_LOADADDR_BASE(tpnt1->loadaddr));
  536. }
  537. #endif
  538. }
  539. }
  540. }
  541. _dl_unmap_cache();
  542. --nlist; /* Exclude the application. */
  543. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  544. i = 0;
  545. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  546. init_fini_list[i++] = tcurr;
  547. }
  548. /* Sort the INIT/FINI list in dependency order. */
  549. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  550. int j, k;
  551. for (j = 0; init_fini_list[j] != tcurr; ++j)
  552. /* Empty */;
  553. for (k = j + 1; k < nlist; ++k) {
  554. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  555. for (; runp; runp = runp->next) {
  556. if (runp->tpnt == tcurr) {
  557. struct elf_resolve *here = init_fini_list[k];
  558. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  559. for (i = (k - j); i; --i)
  560. init_fini_list[i+j] = init_fini_list[i+j-1];
  561. init_fini_list[j] = here;
  562. ++j;
  563. break;
  564. }
  565. }
  566. }
  567. }
  568. #ifdef __SUPPORT_LD_DEBUG__
  569. if (_dl_debug) {
  570. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  571. for (i = 0; i < nlist; i++) {
  572. struct init_fini_list *tmp;
  573. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  574. init_fini_list[i]->libname);
  575. tmp = init_fini_list[i]->init_fini;
  576. for (; tmp; tmp = tmp->next)
  577. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  578. _dl_dprintf(_dl_debug_file, "\n");
  579. }
  580. }
  581. #endif
  582. /*
  583. * If the program interpreter is not in the module chain, add it.
  584. * This will be required for dlopen to be able to access the internal
  585. * functions in the dynamic linker and to relocate the interpreter
  586. * again once all libs are loaded.
  587. */
  588. if (tpnt) {
  589. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  590. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
  591. int j;
  592. tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
  593. tpnt->dynamic_info,
  594. (unsigned long)tpnt->dynamic_addr,
  595. 0);
  596. if (_dl_stat(tpnt->libname, &st) >= 0) {
  597. tpnt->st_dev = st.st_dev;
  598. tpnt->st_ino = st.st_ino;
  599. }
  600. tpnt->n_phent = epnt->e_phnum;
  601. tpnt->ppnt = myppnt;
  602. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  603. if (myppnt->p_type == PT_GNU_RELRO) {
  604. tpnt->relro_addr = myppnt->p_vaddr;
  605. tpnt->relro_size = myppnt->p_memsz;
  606. break;
  607. }
  608. }
  609. tpnt->libtype = program_interpreter;
  610. tpnt->usage_count++;
  611. tpnt->symbol_scope = _dl_symbol_tables;
  612. if (rpnt) {
  613. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  614. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  615. rpnt->next->prev = rpnt;
  616. rpnt = rpnt->next;
  617. } else {
  618. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  619. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  620. }
  621. rpnt->dyn = tpnt;
  622. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  623. #ifdef RERELOCATE_LDSO
  624. /* Only rerelocate functions for now. */
  625. tpnt->init_flag = RELOCS_DONE;
  626. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  627. # ifdef ALLOW_ZERO_PLTGOT
  628. if (tpnt->dynamic_info[DT_PLTGOT])
  629. # endif
  630. INIT_GOT(lpnt, tpnt);
  631. #else
  632. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  633. #endif
  634. tpnt = NULL;
  635. }
  636. #ifdef __LDSO_LDD_SUPPORT__
  637. /* End of the line for ldd.... */
  638. if (trace_loaded_objects) {
  639. _dl_dprintf(1, "\t%s => %s (%x)\n",
  640. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  641. rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
  642. _dl_exit(0);
  643. }
  644. #endif
  645. _dl_debug_early("Beginning relocation fixups\n");
  646. #ifdef __mips__
  647. /*
  648. * Relocation of the GOT entries for MIPS have to be done
  649. * after all the libraries have been loaded.
  650. */
  651. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  652. #endif
  653. /*
  654. * OK, now all of the kids are tucked into bed in their proper
  655. * addresses. Now we go through and look for REL and RELA records that
  656. * indicate fixups to the GOT tables. We need to do this in reverse
  657. * order so that COPY directives work correctly.
  658. */
  659. if (_dl_symbol_tables)
  660. if (_dl_fixup(_dl_symbol_tables, unlazy))
  661. _dl_exit(-1);
  662. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  663. if (tpnt->relro_size)
  664. _dl_protect_relro (tpnt);
  665. }
  666. /* OK, at this point things are pretty much ready to run. Now we need
  667. * to touch up a few items that are required, and then we can let the
  668. * user application have at it. Note that the dynamic linker itself
  669. * is not guaranteed to be fully dynamicly linked if we are using
  670. * ld.so.1, so we have to look up each symbol individually.
  671. */
  672. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
  673. if (_dl_envp)
  674. *_dl_envp = (unsigned long) envp;
  675. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  676. {
  677. unsigned int j;
  678. ElfW(Phdr) *myppnt;
  679. /* We had to set the protections of all pages to R/W for
  680. * dynamic linking. Set text pages back to R/O.
  681. */
  682. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  683. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  684. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  685. _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
  686. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  687. }
  688. }
  689. }
  690. }
  691. #endif
  692. /* Notify the debugger we have added some objects. */
  693. _dl_debug_addr->r_state = RT_ADD;
  694. _dl_debug_state();
  695. /* Run pre-initialization functions for the executable. */
  696. _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
  697. _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
  698. _dl_loaded_modules->loadaddr);
  699. /* Run initialization functions for loaded objects. For the
  700. main executable, they will be run from __uClibc_main. */
  701. for (i = nlist; i; --i) {
  702. tpnt = init_fini_list[i-1];
  703. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  704. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  705. continue;
  706. tpnt->init_flag |= INIT_FUNCS_CALLED;
  707. if (tpnt->dynamic_info[DT_INIT]) {
  708. void (*dl_elf_func) (void);
  709. dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
  710. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  711. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  712. }
  713. _dl_run_init_array(tpnt);
  714. }
  715. /* Find the real malloc function and make ldso functions use that from now on */
  716. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
  717. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  718. /* Notify the debugger that all objects are now mapped in. */
  719. _dl_debug_addr->r_state = RT_CONSISTENT;
  720. _dl_debug_state();
  721. }
  722. char *_dl_getenv(const char *symbol, char **envp)
  723. {
  724. char *pnt;
  725. const char *pnt1;
  726. while ((pnt = *envp++)) {
  727. pnt1 = symbol;
  728. while (*pnt && *pnt == *pnt1)
  729. pnt1++, pnt++;
  730. if (!*pnt || *pnt != '=' || *pnt1)
  731. continue;
  732. return pnt + 1;
  733. }
  734. return 0;
  735. }
  736. void _dl_unsetenv(const char *symbol, char **envp)
  737. {
  738. char *pnt;
  739. const char *pnt1;
  740. char **newenvp = envp;
  741. for (pnt = *envp; pnt; pnt = *++envp) {
  742. pnt1 = symbol;
  743. while (*pnt && *pnt == *pnt1)
  744. pnt1++, pnt++;
  745. if (!*pnt || *pnt != '=' || *pnt1)
  746. *newenvp++ = *envp;
  747. }
  748. *newenvp++ = *envp;
  749. return;
  750. }
  751. static int _dl_suid_ok(void)
  752. {
  753. __kernel_uid_t uid, euid;
  754. __kernel_gid_t gid, egid;
  755. uid = _dl_getuid();
  756. euid = _dl_geteuid();
  757. gid = _dl_getgid();
  758. egid = _dl_getegid();
  759. if (uid == euid && gid == egid) {
  760. return 1;
  761. }
  762. return 0;
  763. }
  764. void *_dl_malloc(int size)
  765. {
  766. void *retval;
  767. #if 0
  768. _dl_debug_early("request for %d bytes\n", size);
  769. #endif
  770. if (_dl_malloc_function)
  771. return (*_dl_malloc_function) (size);
  772. if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
  773. _dl_debug_early("mmapping more memory\n");
  774. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
  775. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  776. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  777. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  778. _dl_exit(20);
  779. }
  780. }
  781. retval = _dl_malloc_addr;
  782. _dl_malloc_addr += size;
  783. /*
  784. * Align memory to DL_MALLOC_ALIGN byte boundary. Some
  785. * platforms require this, others simply get better
  786. * performance.
  787. */
  788. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
  789. return retval;
  790. }
  791. #include "dl-hash.c"
  792. #include "dl-elf.c"