ldso.c 29 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(Addr) app_mapaddr = 0;
  124. ElfW(Phdr) *ppnt;
  125. ElfW(Dyn) *dpnt;
  126. char *lpntstr;
  127. unsigned int i;
  128. int unlazy = 0, trace_loaded_objects = 0;
  129. struct dyn_elf *rpnt;
  130. struct elf_resolve *tcurr;
  131. struct elf_resolve *tpnt1;
  132. struct elf_resolve app_tpnt_tmp;
  133. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  134. struct r_debug *debug_addr;
  135. unsigned long *lpnt;
  136. unsigned long *_dl_envp; /* The environment address */
  137. ElfW(Addr) relro_addr = 0;
  138. size_t relro_size = 0;
  139. struct stat st;
  140. /* Wahoo!!! We managed to make a function call! Get malloc
  141. * setup so we can use _dl_dprintf() to print debug noise
  142. * instead of the SEND_STDERR macros used in dl-startup.c */
  143. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  144. /* Store the page size for later use */
  145. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  146. /* Make it so _dl_malloc can use the page of memory we have already
  147. * allocated. We shouldn't need to grab any more memory. This must
  148. * be first since things like _dl_dprintf() use _dl_malloc()...
  149. */
  150. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  151. _dl_mmap_zero = 0;
  152. /* Wahoo!!! */
  153. _dl_debug_early("Cool, ldso survived making function calls\n");
  154. /* Now we have done the mandatory linking of some things. We are now
  155. * free to start using global variables, since these things have all
  156. * been fixed up by now. Still no function calls outside of this
  157. * library, since the dynamic resolver is not yet ready.
  158. */
  159. if (argv[0]) {
  160. _dl_progname = argv[0];
  161. }
  162. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  163. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  164. _dl_exit(1);
  165. }
  166. /* Start to build the tables of the modules that are required for
  167. * this beast to run. We start with the basic executable, and then
  168. * go from there. Eventually we will run across ourself, and we
  169. * will need to properly deal with that as well.
  170. */
  171. rpnt = NULL;
  172. if (_dl_getenv("LD_BIND_NOW", envp))
  173. unlazy = RTLD_NOW;
  174. /* Now we need to figure out what kind of options are selected.
  175. * Note that for SUID programs we ignore the settings in
  176. * LD_LIBRARY_PATH.
  177. */
  178. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  179. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  180. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  181. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  182. _dl_secure = 0;
  183. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  184. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  185. } else {
  186. static const char unsecure_envvars[] =
  187. #ifdef EXTRA_UNSECURE_ENVVARS
  188. EXTRA_UNSECURE_ENVVARS
  189. #endif
  190. UNSECURE_ENVVARS;
  191. const char *nextp;
  192. _dl_secure = 1;
  193. nextp = unsecure_envvars;
  194. do {
  195. _dl_unsetenv (nextp, envp);
  196. /* We could use rawmemchr but this need not be fast. */
  197. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  198. } while (*nextp != '\0');
  199. _dl_preload = NULL;
  200. _dl_library_path = NULL;
  201. /* SUID binaries can be exploited if they do LAZY relocation. */
  202. unlazy = RTLD_NOW;
  203. }
  204. /* sjhill: your TLS init should go before this */
  205. #ifdef __UCLIBC_HAS_SSP__
  206. /* Set up the stack checker's canary. */
  207. stack_chk_guard = _dl_setup_stack_chk_guard ();
  208. # ifdef THREAD_SET_STACK_GUARD
  209. THREAD_SET_STACK_GUARD (stack_chk_guard);
  210. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  211. __guard = stack_chk_guard;
  212. # endif
  213. # else
  214. __stack_chk_guard = stack_chk_guard;
  215. # endif
  216. #endif
  217. /* At this point we are now free to examine the user application,
  218. * and figure out which libraries are supposed to be called. Until
  219. * we have this list, we will not be completely ready for dynamic
  220. * linking.
  221. */
  222. /* Find the runtime load address of the main executable. This may be
  223. * different from what the ELF header says for ET_DYN/PIE executables.
  224. */
  225. {
  226. unsigned int idx;
  227. ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  228. for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
  229. if (phdr->p_type == PT_PHDR) {
  230. DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
  231. break;
  232. }
  233. if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
  234. _dl_debug_early("Position Independent Executable: "
  235. "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
  236. }
  237. /*
  238. * This is used by gdb to locate the chain of shared libraries that are
  239. * currently loaded.
  240. */
  241. debug_addr = _dl_malloc(sizeof(struct r_debug));
  242. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  243. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  244. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  245. if (ppnt->p_type == PT_GNU_RELRO) {
  246. relro_addr = ppnt->p_vaddr;
  247. relro_size = ppnt->p_memsz;
  248. }
  249. if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
  250. app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
  251. }
  252. if (ppnt->p_type == PT_DYNAMIC) {
  253. dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  254. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  255. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  256. /* Ugly, ugly. We need to call mprotect to change the
  257. * protection of the text pages so that we can do the
  258. * dynamic linking. We can set the protection back
  259. * again once we are done.
  260. */
  261. _dl_debug_early("calling mprotect on the application program\n");
  262. /* Now cover the application program. */
  263. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  264. ElfW(Phdr) *ppnt_outer = ppnt;
  265. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  266. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  267. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  268. _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
  269. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  270. (unsigned long) ppnt->p_filesz,
  271. PROT_READ | PROT_WRITE | PROT_EXEC);
  272. }
  273. ppnt = ppnt_outer;
  274. }
  275. #else
  276. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  277. _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
  278. _dl_exit(1);
  279. }
  280. #endif
  281. #ifndef ALLOW_ZERO_PLTGOT
  282. /* make sure it's really there. */
  283. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  284. continue;
  285. #endif
  286. /* OK, we have what we need - slip this one into the list. */
  287. app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
  288. app_tpnt->dynamic_info,
  289. (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
  290. ppnt->p_filesz);
  291. _dl_loaded_modules->libtype = elf_executable;
  292. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  293. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  294. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  295. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  296. rpnt->dyn = _dl_loaded_modules;
  297. app_tpnt->mapaddr = app_mapaddr;
  298. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  299. app_tpnt->usage_count++;
  300. app_tpnt->symbol_scope = _dl_symbol_tables;
  301. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  302. #ifdef ALLOW_ZERO_PLTGOT
  303. if (lpnt)
  304. #endif
  305. INIT_GOT(lpnt, _dl_loaded_modules);
  306. }
  307. /* OK, fill this in - we did not have this before */
  308. if (ppnt->p_type == PT_INTERP) {
  309. char *ptmp;
  310. tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  311. /* Store the path where the shared lib loader was found
  312. * for later use
  313. */
  314. _dl_ldsopath = _dl_strdup(tpnt->libname);
  315. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  316. if (ptmp != _dl_ldsopath)
  317. *ptmp = '\0';
  318. _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
  319. }
  320. }
  321. app_tpnt->relro_addr = relro_addr;
  322. app_tpnt->relro_size = relro_size;
  323. #ifdef __SUPPORT_LD_DEBUG__
  324. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  325. if (_dl_debug) {
  326. if (_dl_strstr(_dl_debug, "all")) {
  327. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  328. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  329. } else {
  330. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  331. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  332. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  333. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  334. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  335. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  336. }
  337. }
  338. {
  339. const char *dl_debug_output;
  340. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  341. if (dl_debug_output) {
  342. char tmp[22], *tmp1, *filename;
  343. int len1, len2;
  344. _dl_memset(tmp, 0, sizeof(tmp));
  345. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  346. len1 = _dl_strlen(dl_debug_output);
  347. len2 = _dl_strlen(tmp1);
  348. filename = _dl_malloc(len1+len2+2);
  349. if (filename) {
  350. _dl_strcpy (filename, dl_debug_output);
  351. filename[len1] = '.';
  352. _dl_strcpy (&filename[len1+1], tmp1);
  353. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  354. if (_dl_debug_file < 0) {
  355. _dl_debug_file = 2;
  356. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  357. }
  358. }
  359. }
  360. }
  361. #endif
  362. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  363. trace_loaded_objects++;
  364. }
  365. #ifndef __LDSO_LDD_SUPPORT__
  366. if (trace_loaded_objects) {
  367. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  368. _dl_exit(1);
  369. }
  370. #endif
  371. /*
  372. * OK, fix one more thing - set up debug_addr so it will point
  373. * to our chain. Later we may need to fill in more fields, but this
  374. * should be enough for now.
  375. */
  376. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  377. debug_addr->r_version = 1;
  378. debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
  379. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  380. _dl_debug_addr = debug_addr;
  381. /* Notify the debugger we are in a consistant state */
  382. _dl_debug_addr->r_state = RT_CONSISTENT;
  383. _dl_debug_state();
  384. /* OK, we now have the application in the list, and we have some
  385. * basic stuff in place. Now search through the list for other shared
  386. * libraries that should be loaded, and insert them on the list in the
  387. * correct order.
  388. */
  389. _dl_map_cache();
  390. if (_dl_preload) {
  391. char c, *str, *str2;
  392. str = _dl_preload;
  393. while (*str == ':' || *str == ' ' || *str == '\t')
  394. str++;
  395. while (*str) {
  396. str2 = str;
  397. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  398. str2++;
  399. c = *str2;
  400. *str2 = '\0';
  401. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  402. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  403. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  404. if (!tpnt1) {
  405. #ifdef __LDSO_LDD_SUPPORT__
  406. if (trace_loaded_objects)
  407. _dl_dprintf(1, "\t%s => not found\n", str);
  408. else
  409. #endif
  410. {
  411. _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
  412. _dl_exit(15);
  413. }
  414. } else {
  415. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  416. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  417. #ifdef __LDSO_LDD_SUPPORT__
  418. if (trace_loaded_objects &&
  419. tpnt1->usage_count == 1) {
  420. /* This is a real hack to make
  421. * ldd not print the library
  422. * itself when run on a
  423. * library.
  424. */
  425. if (_dl_strcmp(_dl_progname, str) != 0)
  426. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  427. DL_LOADADDR_BASE(tpnt1->loadaddr));
  428. }
  429. #endif
  430. }
  431. }
  432. *str2 = c;
  433. str = str2;
  434. while (*str == ':' || *str == ' ' || *str == '\t')
  435. str++;
  436. }
  437. }
  438. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  439. do {
  440. struct stat st;
  441. char *preload;
  442. int fd;
  443. char c, *cp, *cp2;
  444. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  445. break;
  446. }
  447. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  448. _dl_dprintf(2, "%s: can't open file '%s'\n",
  449. _dl_progname, LDSO_PRELOAD);
  450. break;
  451. }
  452. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  453. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  454. _dl_close(fd);
  455. if (preload == (caddr_t) -1) {
  456. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  457. _dl_progname, __LINE__, LDSO_PRELOAD);
  458. break;
  459. }
  460. /* convert all separators and comments to spaces */
  461. for (cp = preload; *cp; /*nada */ ) {
  462. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  463. *cp++ = ' ';
  464. } else if (*cp == '#') {
  465. do {
  466. *cp++ = ' ';
  467. } while (*cp != '\n' && *cp != '\0');
  468. } else {
  469. cp++;
  470. }
  471. }
  472. /* find start of first library */
  473. for (cp = preload; *cp && *cp == ' '; cp++)
  474. /*nada */ ;
  475. while (*cp) {
  476. /* find end of library */
  477. for (cp2 = cp; *cp && *cp != ' '; cp++)
  478. /*nada */ ;
  479. c = *cp;
  480. *cp = '\0';
  481. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  482. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  483. if (!tpnt1) {
  484. #ifdef __LDSO_LDD_SUPPORT__
  485. if (trace_loaded_objects)
  486. _dl_dprintf(1, "\t%s => not found\n", cp2);
  487. else
  488. #endif
  489. {
  490. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
  491. _dl_exit(15);
  492. }
  493. } else {
  494. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  495. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  496. #ifdef __LDSO_LDD_SUPPORT__
  497. if (trace_loaded_objects &&
  498. tpnt1->usage_count == 1) {
  499. _dl_dprintf(1, "\t%s => %s (%x)\n",
  500. cp2, tpnt1->libname,
  501. DL_LOADADDR_BASE(tpnt1->loadaddr));
  502. }
  503. #endif
  504. }
  505. /* find start of next library */
  506. *cp = c;
  507. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  508. /*nada */ ;
  509. }
  510. _dl_munmap(preload, st.st_size + 1);
  511. } while (0);
  512. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  513. nlist = 0;
  514. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  515. ElfW(Dyn) *this_dpnt;
  516. nlist++;
  517. for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
  518. if (this_dpnt->d_tag == DT_NEEDED) {
  519. char *name;
  520. struct init_fini_list *tmp;
  521. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
  522. name = _dl_get_last_path_component(lpntstr);
  523. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  524. continue;
  525. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  526. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  527. #ifdef __LDSO_LDD_SUPPORT__
  528. if (trace_loaded_objects) {
  529. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  530. continue;
  531. } else
  532. #endif
  533. {
  534. _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  535. _dl_exit(16);
  536. }
  537. }
  538. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  539. tmp->tpnt = tpnt1;
  540. tmp->next = tcurr->init_fini;
  541. tcurr->init_fini = tmp;
  542. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  543. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  544. #ifdef __LDSO_LDD_SUPPORT__
  545. if (trace_loaded_objects &&
  546. tpnt1->usage_count == 1) {
  547. _dl_dprintf(1, "\t%s => %s (%x)\n",
  548. lpntstr, tpnt1->libname,
  549. DL_LOADADDR_BASE(tpnt1->loadaddr));
  550. }
  551. #endif
  552. }
  553. }
  554. }
  555. _dl_unmap_cache();
  556. --nlist; /* Exclude the application. */
  557. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  558. i = 0;
  559. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  560. init_fini_list[i++] = tcurr;
  561. }
  562. /* Sort the INIT/FINI list in dependency order. */
  563. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  564. int j, k;
  565. for (j = 0; init_fini_list[j] != tcurr; ++j)
  566. /* Empty */;
  567. for (k = j + 1; k < nlist; ++k) {
  568. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  569. for (; runp; runp = runp->next) {
  570. if (runp->tpnt == tcurr) {
  571. struct elf_resolve *here = init_fini_list[k];
  572. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  573. for (i = (k - j); i; --i)
  574. init_fini_list[i+j] = init_fini_list[i+j-1];
  575. init_fini_list[j] = here;
  576. ++j;
  577. break;
  578. }
  579. }
  580. }
  581. }
  582. #ifdef __SUPPORT_LD_DEBUG__
  583. if (_dl_debug) {
  584. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  585. for (i = 0; i < nlist; i++) {
  586. struct init_fini_list *tmp;
  587. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  588. init_fini_list[i]->libname);
  589. tmp = init_fini_list[i]->init_fini;
  590. for (; tmp; tmp = tmp->next)
  591. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  592. _dl_dprintf(_dl_debug_file, "\n");
  593. }
  594. }
  595. #endif
  596. /*
  597. * If the program interpreter is not in the module chain, add it.
  598. * This will be required for dlopen to be able to access the internal
  599. * functions in the dynamic linker and to relocate the interpreter
  600. * again once all libs are loaded.
  601. */
  602. if (tpnt) {
  603. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  604. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
  605. int j;
  606. tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
  607. tpnt->dynamic_info,
  608. (unsigned long)tpnt->dynamic_addr,
  609. 0);
  610. if (_dl_stat(tpnt->libname, &st) >= 0) {
  611. tpnt->st_dev = st.st_dev;
  612. tpnt->st_ino = st.st_ino;
  613. }
  614. tpnt->n_phent = epnt->e_phnum;
  615. tpnt->ppnt = myppnt;
  616. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  617. if (myppnt->p_type == PT_GNU_RELRO) {
  618. tpnt->relro_addr = myppnt->p_vaddr;
  619. tpnt->relro_size = myppnt->p_memsz;
  620. break;
  621. }
  622. }
  623. tpnt->libtype = program_interpreter;
  624. tpnt->usage_count++;
  625. tpnt->symbol_scope = _dl_symbol_tables;
  626. if (rpnt) {
  627. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  628. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  629. rpnt->next->prev = rpnt;
  630. rpnt = rpnt->next;
  631. } else {
  632. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  633. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  634. }
  635. rpnt->dyn = tpnt;
  636. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  637. #ifdef RERELOCATE_LDSO
  638. /* Only rerelocate functions for now. */
  639. tpnt->init_flag = RELOCS_DONE;
  640. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  641. # ifdef ALLOW_ZERO_PLTGOT
  642. if (tpnt->dynamic_info[DT_PLTGOT])
  643. # endif
  644. INIT_GOT(lpnt, tpnt);
  645. #else
  646. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  647. #endif
  648. tpnt = NULL;
  649. }
  650. #ifdef __LDSO_LDD_SUPPORT__
  651. /* End of the line for ldd.... */
  652. if (trace_loaded_objects) {
  653. _dl_dprintf(1, "\t%s => %s (%x)\n",
  654. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  655. rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
  656. _dl_exit(0);
  657. }
  658. #endif
  659. _dl_debug_early("Beginning relocation fixups\n");
  660. #ifdef __mips__
  661. /*
  662. * Relocation of the GOT entries for MIPS have to be done
  663. * after all the libraries have been loaded.
  664. */
  665. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  666. #endif
  667. /*
  668. * OK, now all of the kids are tucked into bed in their proper
  669. * addresses. Now we go through and look for REL and RELA records that
  670. * indicate fixups to the GOT tables. We need to do this in reverse
  671. * order so that COPY directives work correctly.
  672. */
  673. if (_dl_symbol_tables)
  674. if (_dl_fixup(_dl_symbol_tables, unlazy))
  675. _dl_exit(-1);
  676. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  677. if (tpnt->relro_size)
  678. _dl_protect_relro (tpnt);
  679. }
  680. /* OK, at this point things are pretty much ready to run. Now we need
  681. * to touch up a few items that are required, and then we can let the
  682. * user application have at it. Note that the dynamic linker itself
  683. * is not guaranteed to be fully dynamicly linked if we are using
  684. * ld.so.1, so we have to look up each symbol individually.
  685. */
  686. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0);
  687. if (_dl_envp)
  688. *_dl_envp = (unsigned long) envp;
  689. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  690. {
  691. unsigned int j;
  692. ElfW(Phdr) *myppnt;
  693. /* We had to set the protections of all pages to R/W for
  694. * dynamic linking. Set text pages back to R/O.
  695. */
  696. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  697. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  698. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  699. _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
  700. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  701. }
  702. }
  703. }
  704. }
  705. #endif
  706. /* Notify the debugger we have added some objects. */
  707. _dl_debug_addr->r_state = RT_ADD;
  708. _dl_debug_state();
  709. /* Run pre-initialization functions for the executable. */
  710. _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
  711. _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
  712. _dl_loaded_modules->loadaddr);
  713. /* Run initialization functions for loaded objects. For the
  714. main executable, they will be run from __uClibc_main. */
  715. for (i = nlist; i; --i) {
  716. tpnt = init_fini_list[i-1];
  717. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  718. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  719. continue;
  720. tpnt->init_flag |= INIT_FUNCS_CALLED;
  721. if (tpnt->dynamic_info[DT_INIT]) {
  722. void (*dl_elf_func) (void);
  723. dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
  724. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  725. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  726. }
  727. _dl_run_init_array(tpnt);
  728. }
  729. /* Find the real malloc function and make ldso functions use that from now on */
  730. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
  731. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  732. /* Notify the debugger that all objects are now mapped in. */
  733. _dl_debug_addr->r_state = RT_CONSISTENT;
  734. _dl_debug_state();
  735. }
  736. char *_dl_getenv(const char *symbol, char **envp)
  737. {
  738. char *pnt;
  739. const char *pnt1;
  740. while ((pnt = *envp++)) {
  741. pnt1 = symbol;
  742. while (*pnt && *pnt == *pnt1)
  743. pnt1++, pnt++;
  744. if (!*pnt || *pnt != '=' || *pnt1)
  745. continue;
  746. return pnt + 1;
  747. }
  748. return 0;
  749. }
  750. void _dl_unsetenv(const char *symbol, char **envp)
  751. {
  752. char *pnt;
  753. const char *pnt1;
  754. char **newenvp = envp;
  755. for (pnt = *envp; pnt; pnt = *++envp) {
  756. pnt1 = symbol;
  757. while (*pnt && *pnt == *pnt1)
  758. pnt1++, pnt++;
  759. if (!*pnt || *pnt != '=' || *pnt1)
  760. *newenvp++ = *envp;
  761. }
  762. *newenvp++ = *envp;
  763. return;
  764. }
  765. static int _dl_suid_ok(void)
  766. {
  767. __kernel_uid_t uid, euid;
  768. __kernel_gid_t gid, egid;
  769. uid = _dl_getuid();
  770. euid = _dl_geteuid();
  771. gid = _dl_getgid();
  772. egid = _dl_getegid();
  773. if (uid == euid && gid == egid) {
  774. return 1;
  775. }
  776. return 0;
  777. }
  778. void *_dl_malloc(size_t size)
  779. {
  780. void *retval;
  781. #if 0
  782. _dl_debug_early("request for %d bytes\n", size);
  783. #endif
  784. if (_dl_malloc_function)
  785. return (*_dl_malloc_function) (size);
  786. if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
  787. size_t rounded_size;
  788. /* Since the above assumes we get a full page even if
  789. we request less than that, make sure we request a
  790. full page, since uClinux may give us less than than
  791. a full page. We might round even
  792. larger-than-a-page sizes, but we end up never
  793. reusing _dl_mmap_zero/_dl_malloc_addr in that case,
  794. so we don't do it.
  795. The actual page size doesn't really matter; as long
  796. as we're self-consistent here, we're safe. */
  797. if (size < _dl_pagesize)
  798. rounded_size = (size + _dl_pagesize - 1) & _dl_pagesize;
  799. else
  800. rounded_size = size;
  801. _dl_debug_early("mmapping more memory\n");
  802. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
  803. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  804. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  805. _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
  806. _dl_exit(20);
  807. }
  808. }
  809. retval = _dl_malloc_addr;
  810. _dl_malloc_addr += size;
  811. /*
  812. * Align memory to DL_MALLOC_ALIGN byte boundary. Some
  813. * platforms require this, others simply get better
  814. * performance.
  815. */
  816. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
  817. return retval;
  818. }
  819. void _dl_free (void *p)
  820. {
  821. if (_dl_free_function)
  822. (*_dl_free_function) (p);
  823. }
  824. #include "dl-hash.c"
  825. #include "dl-elf.c"