ldso.c 28 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. void (*_dl_free_function) (void *p) = NULL;
  49. #ifdef __SUPPORT_LD_DEBUG__
  50. char *_dl_debug = 0;
  51. char *_dl_debug_symbols = 0;
  52. char *_dl_debug_move = 0;
  53. char *_dl_debug_reloc = 0;
  54. char *_dl_debug_detail = 0;
  55. char *_dl_debug_nofixups = 0;
  56. char *_dl_debug_bindings = 0;
  57. int _dl_debug_file = 2;
  58. #endif
  59. /* Needed for standalone execution. */
  60. unsigned long attribute_hidden _dl_skip_args = 0;
  61. const char *_dl_progname = UCLIBC_LDSO; /* The name of the executable being run */
  62. #include "dl-startup.c"
  63. #include "dl-array.c"
  64. /* Forward function declarations */
  65. static int _dl_suid_ok(void);
  66. /*
  67. * This stub function is used by some debuggers. The idea is that they
  68. * can set an internal breakpoint on it, so that we are notified when the
  69. * address mapping is changed in some way.
  70. */
  71. void _dl_debug_state(void);
  72. rtld_hidden_proto(_dl_debug_state, noinline);
  73. void _dl_debug_state(void)
  74. {
  75. /* Make sure GCC doesn't recognize this function as pure, to avoid
  76. * having the calls optimized away.
  77. */
  78. __asm__("");
  79. }
  80. rtld_hidden_def(_dl_debug_state);
  81. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  82. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  83. static struct elf_resolve **init_fini_list;
  84. static unsigned int nlist; /* # items in init_fini_list */
  85. extern void _start(void);
  86. #ifdef __UCLIBC_HAS_SSP__
  87. # include <dl-osinfo.h>
  88. uintptr_t stack_chk_guard;
  89. # ifndef THREAD_SET_STACK_GUARD
  90. /* Only exported for architectures that don't store the stack guard canary
  91. * in local thread area. */
  92. uintptr_t __stack_chk_guard attribute_relro;
  93. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  94. strong_alias(__stack_chk_guard,__guard)
  95. # endif
  96. # elif __UCLIBC_HAS_SSP_COMPAT__
  97. uintptr_t __guard attribute_relro;
  98. # endif
  99. #endif
  100. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  101. {
  102. int i;
  103. struct elf_resolve * tpnt;
  104. for (i = 0; i < nlist; ++i) {
  105. tpnt = init_fini_list[i];
  106. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  107. continue;
  108. tpnt->init_flag |= FINI_FUNCS_CALLED;
  109. _dl_run_fini_array(tpnt);
  110. if (tpnt->dynamic_info[DT_FINI]) {
  111. void (*dl_elf_func) (void);
  112. dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
  113. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  114. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  115. }
  116. }
  117. }
  118. void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
  119. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  120. char **argv
  121. DL_GET_READY_TO_RUN_EXTRA_PARMS)
  122. {
  123. ElfW(Phdr) *ppnt;
  124. ElfW(Dyn) *dpnt;
  125. char *lpntstr;
  126. unsigned int i;
  127. int unlazy = 0, trace_loaded_objects = 0;
  128. struct dyn_elf *rpnt;
  129. struct elf_resolve *tcurr;
  130. struct elf_resolve *tpnt1;
  131. struct elf_resolve app_tpnt_tmp;
  132. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  133. struct r_debug *debug_addr;
  134. unsigned long *lpnt;
  135. unsigned long *_dl_envp; /* The environment address */
  136. ElfW(Addr) relro_addr = 0;
  137. size_t relro_size = 0;
  138. struct stat st;
  139. /* Wahoo!!! We managed to make a function call! Get malloc
  140. * setup so we can use _dl_dprintf() to print debug noise
  141. * instead of the SEND_STDERR macros used in dl-startup.c */
  142. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  143. /* Store the page size for later use */
  144. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  145. /* Make it so _dl_malloc can use the page of memory we have already
  146. * allocated. We shouldn't need to grab any more memory. This must
  147. * be first since things like _dl_dprintf() use _dl_malloc()...
  148. */
  149. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  150. _dl_mmap_zero = 0;
  151. /* Wahoo!!! */
  152. _dl_debug_early("Cool, ldso survived making function calls\n");
  153. /* Now we have done the mandatory linking of some things. We are now
  154. * free to start using global variables, since these things have all
  155. * been fixed up by now. Still no function calls outside of this
  156. * library, since the dynamic resolver is not yet ready.
  157. */
  158. if (argv[0]) {
  159. _dl_progname = argv[0];
  160. }
  161. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  162. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  163. _dl_exit(1);
  164. }
  165. /* Start to build the tables of the modules that are required for
  166. * this beast to run. We start with the basic executable, and then
  167. * go from there. Eventually we will run across ourself, and we
  168. * will need to properly deal with that as well.
  169. */
  170. rpnt = NULL;
  171. if (_dl_getenv("LD_BIND_NOW", envp))
  172. unlazy = RTLD_NOW;
  173. /* Now we need to figure out what kind of options are selected.
  174. * Note that for SUID programs we ignore the settings in
  175. * LD_LIBRARY_PATH.
  176. */
  177. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  178. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  179. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  180. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  181. _dl_secure = 0;
  182. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  183. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  184. } else {
  185. static const char unsecure_envvars[] =
  186. #ifdef EXTRA_UNSECURE_ENVVARS
  187. EXTRA_UNSECURE_ENVVARS
  188. #endif
  189. UNSECURE_ENVVARS;
  190. const char *nextp;
  191. _dl_secure = 1;
  192. nextp = unsecure_envvars;
  193. do {
  194. _dl_unsetenv (nextp, envp);
  195. /* We could use rawmemchr but this need not be fast. */
  196. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  197. } while (*nextp != '\0');
  198. _dl_preload = NULL;
  199. _dl_library_path = NULL;
  200. /* SUID binaries can be exploited if they do LAZY relocation. */
  201. unlazy = RTLD_NOW;
  202. }
  203. /* sjhill: your TLS init should go before this */
  204. #ifdef __UCLIBC_HAS_SSP__
  205. /* Set up the stack checker's canary. */
  206. stack_chk_guard = _dl_setup_stack_chk_guard ();
  207. # ifdef THREAD_SET_STACK_GUARD
  208. THREAD_SET_STACK_GUARD (stack_chk_guard);
  209. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  210. __guard = stack_chk_guard;
  211. # endif
  212. # else
  213. __stack_chk_guard = stack_chk_guard;
  214. # endif
  215. #endif
  216. /* At this point we are now free to examine the user application,
  217. * and figure out which libraries are supposed to be called. Until
  218. * we have this list, we will not be completely ready for dynamic
  219. * linking.
  220. */
  221. /* Find the runtime load address of the main executable. This may be
  222. * different from what the ELF header says for ET_DYN/PIE executables.
  223. */
  224. {
  225. unsigned int idx;
  226. ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  227. for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
  228. if (phdr->p_type == PT_PHDR) {
  229. DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
  230. break;
  231. }
  232. if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
  233. _dl_debug_early("Position Independent Executable: "
  234. "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
  235. }
  236. /*
  237. * This is used by gdb to locate the chain of shared libraries that are
  238. * currently loaded.
  239. */
  240. debug_addr = _dl_malloc(sizeof(struct r_debug));
  241. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  242. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  243. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  244. if (ppnt->p_type == PT_GNU_RELRO) {
  245. relro_addr = ppnt->p_vaddr;
  246. relro_size = ppnt->p_memsz;
  247. }
  248. if (ppnt->p_type == PT_DYNAMIC) {
  249. dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  250. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  251. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  252. /* Ugly, ugly. We need to call mprotect to change the
  253. * protection of the text pages so that we can do the
  254. * dynamic linking. We can set the protection back
  255. * again once we are done.
  256. */
  257. _dl_debug_early("calling mprotect on the application program\n");
  258. /* Now cover the application program. */
  259. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  260. ElfW(Phdr) *ppnt_outer = ppnt;
  261. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  262. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  263. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  264. _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
  265. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  266. (unsigned long) ppnt->p_filesz,
  267. PROT_READ | PROT_WRITE | PROT_EXEC);
  268. }
  269. ppnt = ppnt_outer;
  270. }
  271. #else
  272. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  273. _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
  274. _dl_exit(1);
  275. }
  276. #endif
  277. #ifndef ALLOW_ZERO_PLTGOT
  278. /* make sure it's really there. */
  279. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  280. continue;
  281. #endif
  282. /* OK, we have what we need - slip this one into the list. */
  283. app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
  284. app_tpnt->dynamic_info,
  285. (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
  286. ppnt->p_filesz);
  287. _dl_loaded_modules->libtype = elf_executable;
  288. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  289. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  290. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  291. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  292. rpnt->dyn = _dl_loaded_modules;
  293. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  294. app_tpnt->usage_count++;
  295. app_tpnt->symbol_scope = _dl_symbol_tables;
  296. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  297. #ifdef ALLOW_ZERO_PLTGOT
  298. if (lpnt)
  299. #endif
  300. INIT_GOT(lpnt, _dl_loaded_modules);
  301. }
  302. /* OK, fill this in - we did not have this before */
  303. if (ppnt->p_type == PT_INTERP) {
  304. char *ptmp;
  305. tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  306. /* Store the path where the shared lib loader was found
  307. * for later use
  308. */
  309. _dl_ldsopath = _dl_strdup(tpnt->libname);
  310. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  311. if (ptmp != _dl_ldsopath)
  312. *ptmp = '\0';
  313. _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
  314. }
  315. }
  316. app_tpnt->relro_addr = relro_addr;
  317. app_tpnt->relro_size = relro_size;
  318. #ifdef __SUPPORT_LD_DEBUG__
  319. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  320. if (_dl_debug) {
  321. if (_dl_strstr(_dl_debug, "all")) {
  322. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  323. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  324. } else {
  325. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  326. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  327. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  328. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  329. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  330. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  331. }
  332. }
  333. {
  334. const char *dl_debug_output;
  335. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  336. if (dl_debug_output) {
  337. char tmp[22], *tmp1, *filename;
  338. int len1, len2;
  339. _dl_memset(tmp, 0, sizeof(tmp));
  340. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  341. len1 = _dl_strlen(dl_debug_output);
  342. len2 = _dl_strlen(tmp1);
  343. filename = _dl_malloc(len1+len2+2);
  344. if (filename) {
  345. _dl_strcpy (filename, dl_debug_output);
  346. filename[len1] = '.';
  347. _dl_strcpy (&filename[len1+1], tmp1);
  348. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  349. if (_dl_debug_file < 0) {
  350. _dl_debug_file = 2;
  351. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  352. }
  353. }
  354. }
  355. }
  356. #endif
  357. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  358. trace_loaded_objects++;
  359. }
  360. #ifndef __LDSO_LDD_SUPPORT__
  361. if (trace_loaded_objects) {
  362. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  363. _dl_exit(1);
  364. }
  365. #endif
  366. /*
  367. * OK, fix one more thing - set up debug_addr so it will point
  368. * to our chain. Later we may need to fill in more fields, but this
  369. * should be enough for now.
  370. */
  371. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  372. debug_addr->r_version = 1;
  373. debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
  374. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  375. _dl_debug_addr = debug_addr;
  376. /* Notify the debugger we are in a consistant state */
  377. _dl_debug_addr->r_state = RT_CONSISTENT;
  378. _dl_debug_state();
  379. /* OK, we now have the application in the list, and we have some
  380. * basic stuff in place. Now search through the list for other shared
  381. * libraries that should be loaded, and insert them on the list in the
  382. * correct order.
  383. */
  384. _dl_map_cache();
  385. if (_dl_preload) {
  386. char c, *str, *str2;
  387. str = _dl_preload;
  388. while (*str == ':' || *str == ' ' || *str == '\t')
  389. str++;
  390. while (*str) {
  391. str2 = str;
  392. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  393. str2++;
  394. c = *str2;
  395. *str2 = '\0';
  396. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  397. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  398. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  399. if (!tpnt1) {
  400. #ifdef __LDSO_LDD_SUPPORT__
  401. if (trace_loaded_objects)
  402. _dl_dprintf(1, "\t%s => not found\n", str);
  403. else
  404. #endif
  405. {
  406. _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
  407. _dl_exit(15);
  408. }
  409. } else {
  410. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  411. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  412. #ifdef __LDSO_LDD_SUPPORT__
  413. if (trace_loaded_objects &&
  414. tpnt1->usage_count == 1) {
  415. /* This is a real hack to make
  416. * ldd not print the library
  417. * itself when run on a
  418. * library.
  419. */
  420. if (_dl_strcmp(_dl_progname, str) != 0)
  421. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  422. DL_LOADADDR_BASE(tpnt1->loadaddr));
  423. }
  424. #endif
  425. }
  426. }
  427. *str2 = c;
  428. str = str2;
  429. while (*str == ':' || *str == ' ' || *str == '\t')
  430. str++;
  431. }
  432. }
  433. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  434. do {
  435. struct stat st;
  436. char *preload;
  437. int fd;
  438. char c, *cp, *cp2;
  439. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  440. break;
  441. }
  442. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  443. _dl_dprintf(2, "%s: can't open file '%s'\n",
  444. _dl_progname, LDSO_PRELOAD);
  445. break;
  446. }
  447. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  448. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  449. _dl_close(fd);
  450. if (preload == (caddr_t) -1) {
  451. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  452. _dl_progname, __LINE__, LDSO_PRELOAD);
  453. break;
  454. }
  455. /* convert all separators and comments to spaces */
  456. for (cp = preload; *cp; /*nada */ ) {
  457. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  458. *cp++ = ' ';
  459. } else if (*cp == '#') {
  460. do {
  461. *cp++ = ' ';
  462. } while (*cp != '\n' && *cp != '\0');
  463. } else {
  464. cp++;
  465. }
  466. }
  467. /* find start of first library */
  468. for (cp = preload; *cp && *cp == ' '; cp++)
  469. /*nada */ ;
  470. while (*cp) {
  471. /* find end of library */
  472. for (cp2 = cp; *cp && *cp != ' '; cp++)
  473. /*nada */ ;
  474. c = *cp;
  475. *cp = '\0';
  476. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  477. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  478. if (!tpnt1) {
  479. #ifdef __LDSO_LDD_SUPPORT__
  480. if (trace_loaded_objects)
  481. _dl_dprintf(1, "\t%s => not found\n", cp2);
  482. else
  483. #endif
  484. {
  485. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
  486. _dl_exit(15);
  487. }
  488. } else {
  489. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  490. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  491. #ifdef __LDSO_LDD_SUPPORT__
  492. if (trace_loaded_objects &&
  493. tpnt1->usage_count == 1) {
  494. _dl_dprintf(1, "\t%s => %s (%x)\n",
  495. cp2, tpnt1->libname,
  496. DL_LOADADDR_BASE(tpnt1->loadaddr));
  497. }
  498. #endif
  499. }
  500. /* find start of next library */
  501. *cp = c;
  502. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  503. /*nada */ ;
  504. }
  505. _dl_munmap(preload, st.st_size + 1);
  506. } while (0);
  507. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  508. nlist = 0;
  509. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  510. ElfW(Dyn) *this_dpnt;
  511. nlist++;
  512. for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
  513. if (this_dpnt->d_tag == DT_NEEDED) {
  514. char *name;
  515. struct init_fini_list *tmp;
  516. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
  517. name = _dl_get_last_path_component(lpntstr);
  518. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  519. continue;
  520. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  521. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  522. #ifdef __LDSO_LDD_SUPPORT__
  523. if (trace_loaded_objects) {
  524. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  525. continue;
  526. } else
  527. #endif
  528. {
  529. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  530. _dl_exit(16);
  531. }
  532. }
  533. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  534. tmp->tpnt = tpnt1;
  535. tmp->next = tcurr->init_fini;
  536. tcurr->init_fini = tmp;
  537. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  538. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  539. #ifdef __LDSO_LDD_SUPPORT__
  540. if (trace_loaded_objects &&
  541. tpnt1->usage_count == 1) {
  542. _dl_dprintf(1, "\t%s => %s (%x)\n",
  543. lpntstr, tpnt1->libname,
  544. DL_LOADADDR_BASE(tpnt1->loadaddr));
  545. }
  546. #endif
  547. }
  548. }
  549. }
  550. _dl_unmap_cache();
  551. --nlist; /* Exclude the application. */
  552. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  553. i = 0;
  554. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  555. init_fini_list[i++] = tcurr;
  556. }
  557. /* Sort the INIT/FINI list in dependency order. */
  558. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  559. int j, k;
  560. for (j = 0; init_fini_list[j] != tcurr; ++j)
  561. /* Empty */;
  562. for (k = j + 1; k < nlist; ++k) {
  563. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  564. for (; runp; runp = runp->next) {
  565. if (runp->tpnt == tcurr) {
  566. struct elf_resolve *here = init_fini_list[k];
  567. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  568. for (i = (k - j); i; --i)
  569. init_fini_list[i+j] = init_fini_list[i+j-1];
  570. init_fini_list[j] = here;
  571. ++j;
  572. break;
  573. }
  574. }
  575. }
  576. }
  577. #ifdef __SUPPORT_LD_DEBUG__
  578. if (_dl_debug) {
  579. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  580. for (i = 0; i < nlist; i++) {
  581. struct init_fini_list *tmp;
  582. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  583. init_fini_list[i]->libname);
  584. tmp = init_fini_list[i]->init_fini;
  585. for (; tmp; tmp = tmp->next)
  586. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  587. _dl_dprintf(_dl_debug_file, "\n");
  588. }
  589. }
  590. #endif
  591. /*
  592. * If the program interpreter is not in the module chain, add it.
  593. * This will be required for dlopen to be able to access the internal
  594. * functions in the dynamic linker and to relocate the interpreter
  595. * again once all libs are loaded.
  596. */
  597. if (tpnt) {
  598. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  599. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
  600. int j;
  601. tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
  602. tpnt->dynamic_info,
  603. (unsigned long)tpnt->dynamic_addr,
  604. 0);
  605. if (_dl_stat(tpnt->libname, &st) >= 0) {
  606. tpnt->st_dev = st.st_dev;
  607. tpnt->st_ino = st.st_ino;
  608. }
  609. tpnt->n_phent = epnt->e_phnum;
  610. tpnt->ppnt = myppnt;
  611. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  612. if (myppnt->p_type == PT_GNU_RELRO) {
  613. tpnt->relro_addr = myppnt->p_vaddr;
  614. tpnt->relro_size = myppnt->p_memsz;
  615. break;
  616. }
  617. }
  618. tpnt->libtype = program_interpreter;
  619. tpnt->usage_count++;
  620. tpnt->symbol_scope = _dl_symbol_tables;
  621. if (rpnt) {
  622. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  623. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  624. rpnt->next->prev = rpnt;
  625. rpnt = rpnt->next;
  626. } else {
  627. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  628. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  629. }
  630. rpnt->dyn = tpnt;
  631. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  632. #ifdef RERELOCATE_LDSO
  633. /* Only rerelocate functions for now. */
  634. tpnt->init_flag = RELOCS_DONE;
  635. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  636. # ifdef ALLOW_ZERO_PLTGOT
  637. if (tpnt->dynamic_info[DT_PLTGOT])
  638. # endif
  639. INIT_GOT(lpnt, tpnt);
  640. #else
  641. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  642. #endif
  643. tpnt = NULL;
  644. }
  645. #ifdef __LDSO_LDD_SUPPORT__
  646. /* End of the line for ldd.... */
  647. if (trace_loaded_objects) {
  648. _dl_dprintf(1, "\t%s => %s (%x)\n",
  649. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  650. rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
  651. _dl_exit(0);
  652. }
  653. #endif
  654. _dl_debug_early("Beginning relocation fixups\n");
  655. #ifdef __mips__
  656. /*
  657. * Relocation of the GOT entries for MIPS have to be done
  658. * after all the libraries have been loaded.
  659. */
  660. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  661. #endif
  662. /*
  663. * OK, now all of the kids are tucked into bed in their proper
  664. * addresses. Now we go through and look for REL and RELA records that
  665. * indicate fixups to the GOT tables. We need to do this in reverse
  666. * order so that COPY directives work correctly.
  667. */
  668. if (_dl_symbol_tables)
  669. if (_dl_fixup(_dl_symbol_tables, unlazy))
  670. _dl_exit(-1);
  671. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  672. if (tpnt->relro_size)
  673. _dl_protect_relro (tpnt);
  674. }
  675. /* OK, at this point things are pretty much ready to run. Now we need
  676. * to touch up a few items that are required, and then we can let the
  677. * user application have at it. Note that the dynamic linker itself
  678. * is not guaranteed to be fully dynamicly linked if we are using
  679. * ld.so.1, so we have to look up each symbol individually.
  680. */
  681. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0);
  682. if (_dl_envp)
  683. *_dl_envp = (unsigned long) envp;
  684. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  685. {
  686. unsigned int j;
  687. ElfW(Phdr) *myppnt;
  688. /* We had to set the protections of all pages to R/W for
  689. * dynamic linking. Set text pages back to R/O.
  690. */
  691. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  692. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  693. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  694. _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
  695. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  696. }
  697. }
  698. }
  699. }
  700. #endif
  701. /* Notify the debugger we have added some objects. */
  702. _dl_debug_addr->r_state = RT_ADD;
  703. _dl_debug_state();
  704. /* Run pre-initialization functions for the executable. */
  705. _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
  706. _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
  707. _dl_loaded_modules->loadaddr);
  708. /* Run initialization functions for loaded objects. For the
  709. main executable, they will be run from __uClibc_main. */
  710. for (i = nlist; i; --i) {
  711. tpnt = init_fini_list[i-1];
  712. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  713. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  714. continue;
  715. tpnt->init_flag |= INIT_FUNCS_CALLED;
  716. if (tpnt->dynamic_info[DT_INIT]) {
  717. void (*dl_elf_func) (void);
  718. dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
  719. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  720. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  721. }
  722. _dl_run_init_array(tpnt);
  723. }
  724. /* Find the real malloc function and make ldso functions use that from now on */
  725. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
  726. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  727. /* Notify the debugger that all objects are now mapped in. */
  728. _dl_debug_addr->r_state = RT_CONSISTENT;
  729. _dl_debug_state();
  730. }
  731. char *_dl_getenv(const char *symbol, char **envp)
  732. {
  733. char *pnt;
  734. const char *pnt1;
  735. while ((pnt = *envp++)) {
  736. pnt1 = symbol;
  737. while (*pnt && *pnt == *pnt1)
  738. pnt1++, pnt++;
  739. if (!*pnt || *pnt != '=' || *pnt1)
  740. continue;
  741. return pnt + 1;
  742. }
  743. return 0;
  744. }
  745. void _dl_unsetenv(const char *symbol, char **envp)
  746. {
  747. char *pnt;
  748. const char *pnt1;
  749. char **newenvp = envp;
  750. for (pnt = *envp; pnt; pnt = *++envp) {
  751. pnt1 = symbol;
  752. while (*pnt && *pnt == *pnt1)
  753. pnt1++, pnt++;
  754. if (!*pnt || *pnt != '=' || *pnt1)
  755. *newenvp++ = *envp;
  756. }
  757. *newenvp++ = *envp;
  758. return;
  759. }
  760. static int _dl_suid_ok(void)
  761. {
  762. __kernel_uid_t uid, euid;
  763. __kernel_gid_t gid, egid;
  764. uid = _dl_getuid();
  765. euid = _dl_geteuid();
  766. gid = _dl_getgid();
  767. egid = _dl_getegid();
  768. if (uid == euid && gid == egid) {
  769. return 1;
  770. }
  771. return 0;
  772. }
  773. void *_dl_malloc(size_t size)
  774. {
  775. void *retval;
  776. #if 0
  777. _dl_debug_early("request for %d bytes\n", size);
  778. #endif
  779. if (_dl_malloc_function)
  780. return (*_dl_malloc_function) (size);
  781. if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
  782. size_t rounded_size;
  783. /* Since the above assumes we get a full page even if
  784. we request less than that, make sure we request a
  785. full page, since uClinux may give us less than than
  786. a full page. We might round even
  787. larger-than-a-page sizes, but we end up never
  788. reusing _dl_mmap_zero/_dl_malloc_addr in that case,
  789. so we don't do it.
  790. The actual page size doesn't really matter; as long
  791. as we're self-consistent here, we're safe. */
  792. if (size < _dl_pagesize)
  793. rounded_size = (size + _dl_pagesize - 1) & _dl_pagesize;
  794. else
  795. rounded_size = size;
  796. _dl_debug_early("mmapping more memory\n");
  797. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
  798. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  799. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  800. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  801. _dl_exit(20);
  802. }
  803. }
  804. retval = _dl_malloc_addr;
  805. _dl_malloc_addr += size;
  806. /*
  807. * Align memory to DL_MALLOC_ALIGN byte boundary. Some
  808. * platforms require this, others simply get better
  809. * performance.
  810. */
  811. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
  812. return retval;
  813. }
  814. void _dl_free (void *p)
  815. {
  816. if (_dl_free_function)
  817. (*_dl_free_function) (p);
  818. }
  819. #include "dl-hash.c"
  820. #include "dl-elf.c"