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-symbols.c"
  64. #include "dl-array.c"
  65. /* Forward function declarations */
  66. static int _dl_suid_ok(void);
  67. /*
  68. * This stub function is used by some debuggers. The idea is that they
  69. * can set an internal breakpoint on it, so that we are notified when the
  70. * address mapping is changed in some way.
  71. */
  72. void _dl_debug_state(void);
  73. rtld_hidden_proto(_dl_debug_state, noinline);
  74. void _dl_debug_state(void)
  75. {
  76. /* Make sure GCC doesn't recognize this function as pure, to avoid
  77. * having the calls optimized away.
  78. */
  79. __asm__("");
  80. }
  81. rtld_hidden_def(_dl_debug_state);
  82. static unsigned char *_dl_malloc_addr = 0; /* Lets _dl_malloc use the already allocated memory page */
  83. static unsigned char *_dl_mmap_zero = 0; /* Also used by _dl_malloc */
  84. static struct elf_resolve **init_fini_list;
  85. static unsigned int nlist; /* # items in init_fini_list */
  86. extern void _start(void);
  87. #ifdef __UCLIBC_HAS_SSP__
  88. # include <dl-osinfo.h>
  89. uintptr_t stack_chk_guard;
  90. # ifndef THREAD_SET_STACK_GUARD
  91. /* Only exported for architectures that don't store the stack guard canary
  92. * in local thread area. */
  93. uintptr_t __stack_chk_guard attribute_relro;
  94. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  95. strong_alias(__stack_chk_guard,__guard)
  96. # endif
  97. # elif defined __UCLIBC_HAS_SSP_COMPAT__
  98. uintptr_t __guard attribute_relro;
  99. # endif
  100. #endif
  101. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  102. {
  103. unsigned int i;
  104. struct elf_resolve * tpnt;
  105. for (i = 0; i < nlist; ++i) {
  106. tpnt = init_fini_list[i];
  107. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  108. continue;
  109. tpnt->init_flag |= FINI_FUNCS_CALLED;
  110. _dl_run_fini_array(tpnt);
  111. if (tpnt->dynamic_info[DT_FINI]) {
  112. void (*dl_elf_func) (void);
  113. dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
  114. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  115. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  116. }
  117. }
  118. }
  119. void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
  120. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  121. char **argv
  122. DL_GET_READY_TO_RUN_EXTRA_PARMS)
  123. {
  124. ElfW(Addr) app_mapaddr = 0;
  125. ElfW(Phdr) *ppnt;
  126. ElfW(Dyn) *dpnt;
  127. char *lpntstr;
  128. unsigned int i;
  129. int unlazy = 0, trace_loaded_objects = 0;
  130. struct dyn_elf *rpnt;
  131. struct elf_resolve *tcurr;
  132. struct elf_resolve *tpnt1;
  133. struct elf_resolve app_tpnt_tmp;
  134. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  135. struct r_debug *debug_addr;
  136. unsigned long *lpnt;
  137. unsigned long *_dl_envp; /* The environment address */
  138. ElfW(Addr) relro_addr = 0;
  139. size_t relro_size = 0;
  140. struct stat st;
  141. /* Wahoo!!! We managed to make a function call! Get malloc
  142. * setup so we can use _dl_dprintf() to print debug noise
  143. * instead of the SEND_STDERR macros used in dl-startup.c */
  144. _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
  145. /* Store the page size for later use */
  146. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  147. /* Make it so _dl_malloc can use the page of memory we have already
  148. * allocated. We shouldn't need to grab any more memory. This must
  149. * be first since things like _dl_dprintf() use _dl_malloc()...
  150. */
  151. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  152. _dl_mmap_zero = 0;
  153. /* Wahoo!!! */
  154. _dl_debug_early("Cool, ldso survived making function calls\n");
  155. /* Now we have done the mandatory linking of some things. We are now
  156. * free to start using global variables, since these things have all
  157. * been fixed up by now. Still no function calls outside of this
  158. * library, since the dynamic resolver is not yet ready.
  159. */
  160. if (argv[0]) {
  161. _dl_progname = argv[0];
  162. }
  163. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  164. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  165. _dl_exit(1);
  166. }
  167. /* Start to build the tables of the modules that are required for
  168. * this beast to run. We start with the basic executable, and then
  169. * go from there. Eventually we will run across ourself, and we
  170. * will need to properly deal with that as well.
  171. */
  172. rpnt = NULL;
  173. if (_dl_getenv("LD_BIND_NOW", envp))
  174. unlazy = RTLD_NOW;
  175. /* Now we need to figure out what kind of options are selected.
  176. * Note that for SUID programs we ignore the settings in
  177. * LD_LIBRARY_PATH.
  178. */
  179. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  180. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  181. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  182. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  183. _dl_secure = 0;
  184. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  185. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  186. } else {
  187. static const char unsecure_envvars[] =
  188. #ifdef EXTRA_UNSECURE_ENVVARS
  189. EXTRA_UNSECURE_ENVVARS
  190. #endif
  191. UNSECURE_ENVVARS;
  192. const char *nextp;
  193. _dl_secure = 1;
  194. nextp = unsecure_envvars;
  195. do {
  196. _dl_unsetenv (nextp, envp);
  197. /* We could use rawmemchr but this need not be fast. */
  198. nextp = (char *) _dl_strchr(nextp, '\0') + 1;
  199. } while (*nextp != '\0');
  200. _dl_preload = NULL;
  201. _dl_library_path = NULL;
  202. /* SUID binaries can be exploited if they do LAZY relocation. */
  203. unlazy = RTLD_NOW;
  204. }
  205. /* sjhill: your TLS init should go before this */
  206. #ifdef __UCLIBC_HAS_SSP__
  207. /* Set up the stack checker's canary. */
  208. stack_chk_guard = _dl_setup_stack_chk_guard ();
  209. # ifdef THREAD_SET_STACK_GUARD
  210. THREAD_SET_STACK_GUARD (stack_chk_guard);
  211. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  212. __guard = stack_chk_guard;
  213. # endif
  214. # else
  215. __stack_chk_guard = stack_chk_guard;
  216. # endif
  217. #endif
  218. /* At this point we are now free to examine the user application,
  219. * and figure out which libraries are supposed to be called. Until
  220. * we have this list, we will not be completely ready for dynamic
  221. * linking.
  222. */
  223. /* Find the runtime load address of the main executable. This may be
  224. * different from what the ELF header says for ET_DYN/PIE executables.
  225. */
  226. {
  227. unsigned int idx;
  228. ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  229. for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
  230. if (phdr->p_type == PT_PHDR) {
  231. DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
  232. break;
  233. }
  234. if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
  235. _dl_debug_early("Position Independent Executable: "
  236. "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
  237. }
  238. /*
  239. * This is used by gdb to locate the chain of shared libraries that are
  240. * currently loaded.
  241. */
  242. debug_addr = _dl_malloc(sizeof(struct r_debug));
  243. _dl_memset(debug_addr, 0, sizeof(struct r_debug));
  244. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  245. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  246. if (ppnt->p_type == PT_GNU_RELRO) {
  247. relro_addr = ppnt->p_vaddr;
  248. relro_size = ppnt->p_memsz;
  249. }
  250. if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
  251. app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
  252. }
  253. if (ppnt->p_type == PT_DYNAMIC) {
  254. dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  255. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  256. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  257. /* Ugly, ugly. We need to call mprotect to change the
  258. * protection of the text pages so that we can do the
  259. * dynamic linking. We can set the protection back
  260. * again once we are done.
  261. */
  262. _dl_debug_early("calling mprotect on the application program\n");
  263. /* Now cover the application program. */
  264. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  265. ElfW(Phdr) *ppnt_outer = ppnt;
  266. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  267. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  268. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  269. _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
  270. ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
  271. (unsigned long) ppnt->p_filesz,
  272. PROT_READ | PROT_WRITE | PROT_EXEC);
  273. }
  274. ppnt = ppnt_outer;
  275. }
  276. #else
  277. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  278. _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
  279. _dl_exit(1);
  280. }
  281. #endif
  282. #ifndef ALLOW_ZERO_PLTGOT
  283. /* make sure it's really there. */
  284. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  285. continue;
  286. #endif
  287. /* OK, we have what we need - slip this one into the list. */
  288. app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
  289. app_tpnt->dynamic_info,
  290. (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
  291. ppnt->p_filesz);
  292. _dl_loaded_modules->libtype = elf_executable;
  293. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  294. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  295. _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  296. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  297. rpnt->dyn = _dl_loaded_modules;
  298. app_tpnt->mapaddr = app_mapaddr;
  299. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  300. app_tpnt->usage_count++;
  301. app_tpnt->symbol_scope = _dl_symbol_tables;
  302. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  303. #ifdef ALLOW_ZERO_PLTGOT
  304. if (lpnt)
  305. #endif
  306. INIT_GOT(lpnt, _dl_loaded_modules);
  307. }
  308. /* OK, fill this in - we did not have this before */
  309. if (ppnt->p_type == PT_INTERP) {
  310. char *ptmp;
  311. tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  312. /* Store the path where the shared lib loader was found
  313. * for later use
  314. */
  315. _dl_ldsopath = _dl_strdup(tpnt->libname);
  316. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  317. if (ptmp != _dl_ldsopath)
  318. *ptmp = '\0';
  319. _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
  320. }
  321. }
  322. app_tpnt->relro_addr = relro_addr;
  323. app_tpnt->relro_size = relro_size;
  324. #ifdef __SUPPORT_LD_DEBUG__
  325. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  326. if (_dl_debug) {
  327. if (_dl_strstr(_dl_debug, "all")) {
  328. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  329. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  330. } else {
  331. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  332. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  333. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  334. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  335. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  336. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  337. }
  338. }
  339. {
  340. const char *dl_debug_output;
  341. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  342. if (dl_debug_output) {
  343. char tmp[22], *tmp1, *filename;
  344. int len1, len2;
  345. _dl_memset(tmp, 0, sizeof(tmp));
  346. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  347. len1 = _dl_strlen(dl_debug_output);
  348. len2 = _dl_strlen(tmp1);
  349. filename = _dl_malloc(len1+len2+2);
  350. if (filename) {
  351. _dl_strcpy (filename, dl_debug_output);
  352. filename[len1] = '.';
  353. _dl_strcpy (&filename[len1+1], tmp1);
  354. _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  355. if (_dl_debug_file < 0) {
  356. _dl_debug_file = 2;
  357. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  358. }
  359. }
  360. }
  361. }
  362. #endif
  363. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  364. trace_loaded_objects++;
  365. }
  366. #ifndef __LDSO_LDD_SUPPORT__
  367. if (trace_loaded_objects) {
  368. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  369. _dl_exit(1);
  370. }
  371. #endif
  372. /*
  373. * OK, fix one more thing - set up debug_addr so it will point
  374. * to our chain. Later we may need to fill in more fields, but this
  375. * should be enough for now.
  376. */
  377. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  378. debug_addr->r_version = 1;
  379. debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
  380. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  381. _dl_debug_addr = debug_addr;
  382. /* Do not notify the debugger until the interpreter is in the list */
  383. /* OK, we now have the application in the list, and we have some
  384. * basic stuff in place. Now search through the list for other shared
  385. * libraries that should be loaded, and insert them on the list in the
  386. * correct order.
  387. */
  388. _dl_map_cache();
  389. if (_dl_preload) {
  390. char c, *str, *str2;
  391. str = _dl_preload;
  392. while (*str == ':' || *str == ' ' || *str == '\t')
  393. str++;
  394. while (*str) {
  395. str2 = str;
  396. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  397. str2++;
  398. c = *str2;
  399. *str2 = '\0';
  400. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  401. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  402. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  403. if (!tpnt1) {
  404. #ifdef __LDSO_LDD_SUPPORT__
  405. if (trace_loaded_objects)
  406. _dl_dprintf(1, "\t%s => not found\n", str);
  407. else
  408. #endif
  409. {
  410. _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
  411. _dl_exit(15);
  412. }
  413. } else {
  414. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  415. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  416. #ifdef __LDSO_LDD_SUPPORT__
  417. if (trace_loaded_objects &&
  418. tpnt1->usage_count == 1) {
  419. /* This is a real hack to make
  420. * ldd not print the library
  421. * itself when run on a
  422. * library.
  423. */
  424. if (_dl_strcmp(_dl_progname, str) != 0)
  425. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  426. DL_LOADADDR_BASE(tpnt1->loadaddr));
  427. }
  428. #endif
  429. }
  430. }
  431. *str2 = c;
  432. str = str2;
  433. while (*str == ':' || *str == ' ' || *str == '\t')
  434. str++;
  435. }
  436. }
  437. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  438. do {
  439. char *preload;
  440. int fd;
  441. char c, *cp, *cp2;
  442. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  443. break;
  444. }
  445. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  446. _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
  447. _dl_progname, LDSO_PRELOAD);
  448. break;
  449. }
  450. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  451. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  452. _dl_close(fd);
  453. if (preload == (caddr_t) -1) {
  454. _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
  455. _dl_progname, __LINE__, LDSO_PRELOAD);
  456. break;
  457. }
  458. /* convert all separators and comments to spaces */
  459. for (cp = preload; *cp; /*nada */ ) {
  460. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  461. *cp++ = ' ';
  462. } else if (*cp == '#') {
  463. do {
  464. *cp++ = ' ';
  465. } while (*cp != '\n' && *cp != '\0');
  466. } else {
  467. cp++;
  468. }
  469. }
  470. /* find start of first library */
  471. for (cp = preload; *cp && *cp == ' '; cp++)
  472. /*nada */ ;
  473. while (*cp) {
  474. /* find end of library */
  475. for (cp2 = cp; *cp && *cp != ' '; cp++)
  476. /*nada */ ;
  477. c = *cp;
  478. *cp = '\0';
  479. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  480. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  481. if (!tpnt1) {
  482. #ifdef __LDSO_LDD_SUPPORT__
  483. if (trace_loaded_objects)
  484. _dl_dprintf(1, "\t%s => not found\n", cp2);
  485. else
  486. #endif
  487. {
  488. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
  489. _dl_exit(15);
  490. }
  491. } else {
  492. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  493. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  494. #ifdef __LDSO_LDD_SUPPORT__
  495. if (trace_loaded_objects &&
  496. tpnt1->usage_count == 1) {
  497. _dl_dprintf(1, "\t%s => %s (%x)\n",
  498. cp2, tpnt1->libname,
  499. DL_LOADADDR_BASE(tpnt1->loadaddr));
  500. }
  501. #endif
  502. }
  503. /* find start of next library */
  504. *cp = c;
  505. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  506. /*nada */ ;
  507. }
  508. _dl_munmap(preload, st.st_size + 1);
  509. } while (0);
  510. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  511. nlist = 0;
  512. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  513. ElfW(Dyn) *this_dpnt;
  514. nlist++;
  515. for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
  516. if (this_dpnt->d_tag == DT_NEEDED) {
  517. char *name;
  518. struct init_fini_list *tmp;
  519. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
  520. name = _dl_get_last_path_component(lpntstr);
  521. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  522. continue;
  523. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  524. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  525. #ifdef __LDSO_LDD_SUPPORT__
  526. if (trace_loaded_objects) {
  527. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  528. continue;
  529. } else
  530. #endif
  531. {
  532. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  533. _dl_exit(16);
  534. }
  535. }
  536. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  537. tmp->tpnt = tpnt1;
  538. tmp->next = tcurr->init_fini;
  539. tcurr->init_fini = tmp;
  540. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  541. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  542. #ifdef __LDSO_LDD_SUPPORT__
  543. if (trace_loaded_objects &&
  544. tpnt1->usage_count == 1) {
  545. _dl_dprintf(1, "\t%s => %s (%x)\n",
  546. lpntstr, tpnt1->libname,
  547. DL_LOADADDR_BASE(tpnt1->loadaddr));
  548. }
  549. #endif
  550. }
  551. }
  552. }
  553. _dl_unmap_cache();
  554. --nlist; /* Exclude the application. */
  555. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  556. i = 0;
  557. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  558. init_fini_list[i++] = tcurr;
  559. }
  560. /* Sort the INIT/FINI list in dependency order. */
  561. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  562. unsigned int j, k;
  563. for (j = 0; init_fini_list[j] != tcurr; ++j)
  564. /* Empty */;
  565. for (k = j + 1; k < nlist; ++k) {
  566. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  567. for (; runp; runp = runp->next) {
  568. if (runp->tpnt == tcurr) {
  569. struct elf_resolve *here = init_fini_list[k];
  570. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  571. for (i = (k - j); i; --i)
  572. init_fini_list[i+j] = init_fini_list[i+j-1];
  573. init_fini_list[j] = here;
  574. ++j;
  575. break;
  576. }
  577. }
  578. }
  579. }
  580. #ifdef __SUPPORT_LD_DEBUG__
  581. if (_dl_debug) {
  582. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  583. for (i = 0; i < nlist; i++) {
  584. struct init_fini_list *tmp;
  585. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  586. init_fini_list[i]->libname);
  587. tmp = init_fini_list[i]->init_fini;
  588. for (; tmp; tmp = tmp->next)
  589. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  590. _dl_dprintf(_dl_debug_file, "\n");
  591. }
  592. }
  593. #endif
  594. /*
  595. * If the program interpreter is not in the module chain, add it.
  596. * This will be required for dlopen to be able to access the internal
  597. * functions in the dynamic linker and to relocate the interpreter
  598. * again once all libs are loaded.
  599. */
  600. if (tpnt) {
  601. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  602. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
  603. int j;
  604. tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
  605. tpnt->dynamic_info,
  606. (unsigned long)tpnt->dynamic_addr,
  607. 0);
  608. if (_dl_stat(tpnt->libname, &st) >= 0) {
  609. tpnt->st_dev = st.st_dev;
  610. tpnt->st_ino = st.st_ino;
  611. }
  612. tpnt->n_phent = epnt->e_phnum;
  613. tpnt->ppnt = myppnt;
  614. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  615. if (myppnt->p_type == PT_GNU_RELRO) {
  616. tpnt->relro_addr = myppnt->p_vaddr;
  617. tpnt->relro_size = myppnt->p_memsz;
  618. break;
  619. }
  620. }
  621. tpnt->libtype = program_interpreter;
  622. tpnt->usage_count++;
  623. tpnt->symbol_scope = _dl_symbol_tables;
  624. if (rpnt) {
  625. rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  626. _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
  627. rpnt->next->prev = rpnt;
  628. rpnt = rpnt->next;
  629. } else {
  630. rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  631. _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
  632. }
  633. rpnt->dyn = tpnt;
  634. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  635. #ifdef RERELOCATE_LDSO
  636. /* Only rerelocate functions for now. */
  637. tpnt->init_flag = RELOCS_DONE;
  638. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  639. # ifdef ALLOW_ZERO_PLTGOT
  640. if (tpnt->dynamic_info[DT_PLTGOT])
  641. # endif
  642. INIT_GOT(lpnt, tpnt);
  643. #else
  644. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  645. #endif
  646. tpnt = NULL;
  647. }
  648. #ifdef __LDSO_LDD_SUPPORT__
  649. /* End of the line for ldd.... */
  650. if (trace_loaded_objects) {
  651. _dl_dprintf(1, "\t%s => %s (%x)\n",
  652. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  653. rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
  654. _dl_exit(0);
  655. }
  656. #endif
  657. _dl_debug_early("Beginning relocation fixups\n");
  658. #ifdef __mips__
  659. /*
  660. * Relocation of the GOT entries for MIPS have to be done
  661. * after all the libraries have been loaded.
  662. */
  663. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  664. #endif
  665. /*
  666. * OK, now all of the kids are tucked into bed in their proper
  667. * addresses. Now we go through and look for REL and RELA records that
  668. * indicate fixups to the GOT tables. We need to do this in reverse
  669. * order so that COPY directives work correctly.
  670. */
  671. if (_dl_symbol_tables)
  672. if (_dl_fixup(_dl_symbol_tables, unlazy))
  673. _dl_exit(-1);
  674. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  675. if (tpnt->relro_size)
  676. _dl_protect_relro (tpnt);
  677. }
  678. /* OK, at this point things are pretty much ready to run. Now we need
  679. * to touch up a few items that are required, and then we can let the
  680. * user application have at it. Note that the dynamic linker itself
  681. * is not guaranteed to be fully dynamicly linked if we are using
  682. * ld.so.1, so we have to look up each symbol individually.
  683. */
  684. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0);
  685. if (_dl_envp)
  686. *_dl_envp = (unsigned long) envp;
  687. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  688. {
  689. unsigned int j;
  690. ElfW(Phdr) *myppnt;
  691. /* We had to set the protections of all pages to R/W for
  692. * dynamic linking. Set text pages back to R/O.
  693. */
  694. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  695. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  696. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  697. _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
  698. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  699. }
  700. }
  701. }
  702. }
  703. #endif
  704. /* Notify the debugger we have added some objects. */
  705. _dl_debug_addr->r_state = RT_ADD;
  706. _dl_debug_state();
  707. /* Run pre-initialization functions for the executable. */
  708. _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
  709. _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
  710. _dl_loaded_modules->loadaddr);
  711. /* Run initialization functions for loaded objects. For the
  712. main executable, they will be run from __uClibc_main. */
  713. for (i = nlist; i; --i) {
  714. tpnt = init_fini_list[i-1];
  715. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  716. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  717. continue;
  718. tpnt->init_flag |= INIT_FUNCS_CALLED;
  719. if (tpnt->dynamic_info[DT_INIT]) {
  720. void (*dl_elf_func) (void);
  721. dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
  722. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  723. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  724. }
  725. _dl_run_init_array(tpnt);
  726. }
  727. /* Find the real malloc function and make ldso functions use that from now on */
  728. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
  729. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  730. /* Notify the debugger that all objects are now mapped in. */
  731. _dl_debug_addr->r_state = RT_CONSISTENT;
  732. _dl_debug_state();
  733. }
  734. char *_dl_getenv(const char *symbol, char **envp)
  735. {
  736. char *pnt;
  737. const char *pnt1;
  738. while ((pnt = *envp++)) {
  739. pnt1 = symbol;
  740. while (*pnt && *pnt == *pnt1)
  741. pnt1++, pnt++;
  742. if (!*pnt || *pnt != '=' || *pnt1)
  743. continue;
  744. return pnt + 1;
  745. }
  746. return 0;
  747. }
  748. void _dl_unsetenv(const char *symbol, char **envp)
  749. {
  750. char *pnt;
  751. const char *pnt1;
  752. char **newenvp = envp;
  753. for (pnt = *envp; pnt; pnt = *++envp) {
  754. pnt1 = symbol;
  755. while (*pnt && *pnt == *pnt1)
  756. pnt1++, pnt++;
  757. if (!*pnt || *pnt != '=' || *pnt1)
  758. *newenvp++ = *envp;
  759. }
  760. *newenvp++ = *envp;
  761. return;
  762. }
  763. static int _dl_suid_ok(void)
  764. {
  765. __kernel_uid_t uid, euid;
  766. __kernel_gid_t gid, egid;
  767. uid = _dl_getuid();
  768. euid = _dl_geteuid();
  769. gid = _dl_getgid();
  770. egid = _dl_getegid();
  771. if (uid == euid && gid == egid) {
  772. return 1;
  773. }
  774. return 0;
  775. }
  776. void *_dl_malloc(size_t size)
  777. {
  778. void *retval;
  779. #if 0
  780. _dl_debug_early("request for %d bytes\n", size);
  781. #endif
  782. if (_dl_malloc_function)
  783. return (*_dl_malloc_function) (size);
  784. if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
  785. size_t rounded_size;
  786. /* Since the above assumes we get a full page even if
  787. we request less than that, make sure we request a
  788. full page, since uClinux may give us less than than
  789. a full page. We might round even
  790. larger-than-a-page sizes, but we end up never
  791. reusing _dl_mmap_zero/_dl_malloc_addr in that case,
  792. so we don't do it.
  793. The actual page size doesn't really matter; as long
  794. as we're self-consistent here, we're safe. */
  795. if (size < _dl_pagesize)
  796. rounded_size = (size + _dl_pagesize - 1) & _dl_pagesize;
  797. else
  798. rounded_size = size;
  799. _dl_debug_early("mmapping more memory\n");
  800. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
  801. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  802. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  803. _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
  804. _dl_exit(20);
  805. }
  806. }
  807. retval = _dl_malloc_addr;
  808. _dl_malloc_addr += size;
  809. /*
  810. * Align memory to DL_MALLOC_ALIGN byte boundary. Some
  811. * platforms require this, others simply get better
  812. * performance.
  813. */
  814. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
  815. return retval;
  816. }
  817. void _dl_free (void *p)
  818. {
  819. if (_dl_free_function)
  820. (*_dl_free_function) (p);
  821. }
  822. #include "dl-hash.c"
  823. #include "dl-elf.c"