ldso.c 28 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949
  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 = NULL; /* Where we look for libraries */
  41. char *_dl_preload = NULL; /* Things to be loaded before the libs */
  42. char *_dl_ldsopath = NULL; /* Location of the shared lib loader */
  43. int _dl_errno = 0; /* We can't use the real errno in ldso */
  44. size_t _dl_pagesize = 0; /* Store the page size for use later */
  45. struct r_debug *_dl_debug_addr = NULL; /* Used to communicate with the gdb debugger */
  46. void *(*_dl_malloc_function) (size_t size) = NULL;
  47. void (*_dl_free_function) (void *p) = NULL;
  48. static int _dl_secure = 1; /* Are we dealing with setuid stuff? */
  49. #ifdef __SUPPORT_LD_DEBUG__
  50. char *_dl_debug = NULL;
  51. char *_dl_debug_symbols = NULL;
  52. char *_dl_debug_move = NULL;
  53. char *_dl_debug_reloc = NULL;
  54. char *_dl_debug_detail = NULL;
  55. char *_dl_debug_nofixups = NULL;
  56. char *_dl_debug_bindings = NULL;
  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. /*
  66. * This stub function is used by some debuggers. The idea is that they
  67. * can set an internal breakpoint on it, so that we are notified when the
  68. * address mapping is changed in some way.
  69. */
  70. void _dl_debug_state(void);
  71. rtld_hidden_proto(_dl_debug_state, noinline);
  72. void _dl_debug_state(void)
  73. {
  74. /* Make sure GCC doesn't recognize this function as pure, to avoid
  75. * having the calls optimized away.
  76. */
  77. __asm__("");
  78. }
  79. rtld_hidden_def(_dl_debug_state);
  80. static unsigned char *_dl_malloc_addr = NULL; /* Lets _dl_malloc use the already allocated memory page */
  81. static unsigned char *_dl_mmap_zero = NULL; /* Also used by _dl_malloc */
  82. static struct elf_resolve **init_fini_list;
  83. static unsigned int nlist; /* # items in init_fini_list */
  84. extern void _start(void);
  85. #ifdef __UCLIBC_HAS_SSP__
  86. # include <dl-osinfo.h>
  87. static uintptr_t stack_chk_guard;
  88. # ifndef THREAD_SET_STACK_GUARD
  89. /* Only exported for architectures that don't store the stack guard canary
  90. * in local thread area. */
  91. uintptr_t __stack_chk_guard attribute_relro;
  92. # endif
  93. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  94. uintptr_t __guard attribute_relro;
  95. # endif
  96. #endif
  97. char *_dl_getenv(const char *symbol, char **envp)
  98. {
  99. char *pnt;
  100. const char *pnt1;
  101. while ((pnt = *envp++)) {
  102. pnt1 = symbol;
  103. while (*pnt && *pnt == *pnt1)
  104. pnt1++, pnt++;
  105. if (!*pnt || *pnt != '=' || *pnt1)
  106. continue;
  107. return pnt + 1;
  108. }
  109. return 0;
  110. }
  111. void _dl_unsetenv(const char *symbol, char **envp)
  112. {
  113. char *pnt;
  114. const char *pnt1;
  115. char **newenvp = envp;
  116. for (pnt = *envp; pnt; pnt = *++envp) {
  117. pnt1 = symbol;
  118. while (*pnt && *pnt == *pnt1)
  119. pnt1++, pnt++;
  120. if (!*pnt || *pnt != '=' || *pnt1)
  121. *newenvp++ = *envp;
  122. }
  123. *newenvp++ = *envp;
  124. return;
  125. }
  126. static int _dl_suid_ok(void)
  127. {
  128. __kernel_uid_t uid, euid;
  129. __kernel_gid_t gid, egid;
  130. uid = _dl_getuid();
  131. euid = _dl_geteuid();
  132. gid = _dl_getgid();
  133. egid = _dl_getegid();
  134. if (uid == euid && gid == egid) {
  135. return 1;
  136. }
  137. return 0;
  138. }
  139. void *_dl_malloc(size_t size)
  140. {
  141. void *retval;
  142. #if 0
  143. _dl_debug_early("request for %d bytes\n", size);
  144. #endif
  145. if (_dl_malloc_function)
  146. return (*_dl_malloc_function) (size);
  147. if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
  148. size_t rounded_size;
  149. /* Since the above assumes we get a full page even if
  150. we request less than that, make sure we request a
  151. full page, since uClinux may give us less than than
  152. a full page. We might round even
  153. larger-than-a-page sizes, but we end up never
  154. reusing _dl_mmap_zero/_dl_malloc_addr in that case,
  155. so we don't do it.
  156. The actual page size doesn't really matter; as long
  157. as we're self-consistent here, we're safe. */
  158. if (size < _dl_pagesize)
  159. rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
  160. else
  161. rounded_size = size;
  162. _dl_debug_early("mmapping more memory\n");
  163. _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
  164. PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  165. if (_dl_mmap_check_error(_dl_mmap_zero)) {
  166. _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
  167. _dl_exit(20);
  168. }
  169. }
  170. retval = _dl_malloc_addr;
  171. _dl_malloc_addr += size;
  172. /*
  173. * Align memory to DL_MALLOC_ALIGN byte boundary. Some
  174. * platforms require this, others simply get better
  175. * performance.
  176. */
  177. _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
  178. return retval;
  179. }
  180. static void *_dl_zalloc(size_t size)
  181. {
  182. void *p = _dl_malloc(size);
  183. if (p)
  184. _dl_memset(p, 0, size);
  185. return p;
  186. }
  187. void _dl_free (void *p)
  188. {
  189. if (_dl_free_function)
  190. (*_dl_free_function) (p);
  191. }
  192. static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  193. {
  194. unsigned int i;
  195. struct elf_resolve * tpnt;
  196. for (i = 0; i < nlist; ++i) {
  197. tpnt = init_fini_list[i];
  198. if (tpnt->init_flag & FINI_FUNCS_CALLED)
  199. continue;
  200. tpnt->init_flag |= FINI_FUNCS_CALLED;
  201. _dl_run_fini_array(tpnt);
  202. if (tpnt->dynamic_info[DT_FINI]) {
  203. void (*dl_elf_func) (void);
  204. dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
  205. _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
  206. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  207. }
  208. }
  209. }
  210. void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
  211. ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
  212. char **argv
  213. DL_GET_READY_TO_RUN_EXTRA_PARMS)
  214. {
  215. ElfW(Addr) app_mapaddr = 0;
  216. ElfW(Phdr) *ppnt;
  217. ElfW(Dyn) *dpnt;
  218. char *lpntstr;
  219. unsigned int i;
  220. int unlazy = 0, trace_loaded_objects = 0;
  221. struct dyn_elf *rpnt;
  222. struct elf_resolve *tcurr;
  223. struct elf_resolve *tpnt1;
  224. struct elf_resolve app_tpnt_tmp;
  225. struct elf_resolve *app_tpnt = &app_tpnt_tmp;
  226. struct r_debug *debug_addr;
  227. unsigned long *lpnt;
  228. unsigned long *_dl_envp; /* The environment address */
  229. ElfW(Addr) relro_addr = 0;
  230. size_t relro_size = 0;
  231. struct stat st;
  232. /* Wahoo!!! We managed to make a function call! Get malloc
  233. * setup so we can use _dl_dprintf() to print debug noise
  234. * instead of the SEND_STDERR macros used in dl-startup.c */
  235. _dl_memset(app_tpnt, 0, sizeof(*app_tpnt));
  236. /* Store the page size for later use */
  237. _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
  238. /* Make it so _dl_malloc can use the page of memory we have already
  239. * allocated. We shouldn't need to grab any more memory. This must
  240. * be first since things like _dl_dprintf() use _dl_malloc()...
  241. */
  242. _dl_malloc_addr = (unsigned char *)_dl_pagesize;
  243. _dl_mmap_zero = 0;
  244. /* Wahoo!!! */
  245. _dl_debug_early("Cool, ldso survived making function calls\n");
  246. /* Now we have done the mandatory linking of some things. We are now
  247. * free to start using global variables, since these things have all
  248. * been fixed up by now. Still no function calls outside of this
  249. * library, since the dynamic resolver is not yet ready.
  250. */
  251. if (argv[0]) {
  252. _dl_progname = argv[0];
  253. }
  254. if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
  255. _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
  256. _dl_exit(1);
  257. }
  258. /* Start to build the tables of the modules that are required for
  259. * this beast to run. We start with the basic executable, and then
  260. * go from there. Eventually we will run across ourself, and we
  261. * will need to properly deal with that as well.
  262. */
  263. rpnt = NULL;
  264. if (_dl_getenv("LD_BIND_NOW", envp))
  265. unlazy = RTLD_NOW;
  266. /* Now we need to figure out what kind of options are selected.
  267. * Note that for SUID programs we ignore the settings in
  268. * LD_LIBRARY_PATH.
  269. */
  270. if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
  271. (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
  272. auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
  273. auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
  274. _dl_secure = 0;
  275. _dl_preload = _dl_getenv("LD_PRELOAD", envp);
  276. _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
  277. } else {
  278. static const char unsecure_envvars[] =
  279. #ifdef EXTRA_UNSECURE_ENVVARS
  280. EXTRA_UNSECURE_ENVVARS
  281. #endif
  282. UNSECURE_ENVVARS;
  283. const char *nextp;
  284. _dl_secure = 1;
  285. nextp = unsecure_envvars;
  286. do {
  287. _dl_unsetenv (nextp, envp);
  288. /* We could use rawmemchr but this need not be fast. */
  289. nextp = _dl_strchr(nextp, '\0') + 1;
  290. } while (*nextp != '\0');
  291. _dl_preload = NULL;
  292. _dl_library_path = NULL;
  293. /* SUID binaries can be exploited if they do LAZY relocation. */
  294. unlazy = RTLD_NOW;
  295. }
  296. /* sjhill: your TLS init should go before this */
  297. #ifdef __UCLIBC_HAS_SSP__
  298. /* Set up the stack checker's canary. */
  299. stack_chk_guard = _dl_setup_stack_chk_guard ();
  300. # ifdef THREAD_SET_STACK_GUARD
  301. THREAD_SET_STACK_GUARD (stack_chk_guard);
  302. # else
  303. __stack_chk_guard = stack_chk_guard;
  304. # endif
  305. # ifdef __UCLIBC_HAS_SSP_COMPAT__
  306. __guard = stack_chk_guard;
  307. # endif
  308. #endif
  309. /* At this point we are now free to examine the user application,
  310. * and figure out which libraries are supposed to be called. Until
  311. * we have this list, we will not be completely ready for dynamic
  312. * linking.
  313. */
  314. /* Find the runtime load address of the main executable. This may be
  315. * different from what the ELF header says for ET_DYN/PIE executables.
  316. */
  317. {
  318. unsigned int idx;
  319. ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  320. for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
  321. if (phdr->p_type == PT_PHDR) {
  322. DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
  323. break;
  324. }
  325. if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
  326. _dl_debug_early("Position Independent Executable: "
  327. "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
  328. }
  329. /*
  330. * This is used by gdb to locate the chain of shared libraries that are
  331. * currently loaded.
  332. */
  333. debug_addr = _dl_zalloc(sizeof(struct r_debug));
  334. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  335. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  336. if (ppnt->p_type == PT_GNU_RELRO) {
  337. relro_addr = ppnt->p_vaddr;
  338. relro_size = ppnt->p_memsz;
  339. }
  340. if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
  341. app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
  342. }
  343. if (ppnt->p_type == PT_DYNAMIC) {
  344. dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  345. _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
  346. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  347. /* Ugly, ugly. We need to call mprotect to change the
  348. * protection of the text pages so that we can do the
  349. * dynamic linking. We can set the protection back
  350. * again once we are done.
  351. */
  352. _dl_debug_early("calling mprotect on the application program\n");
  353. /* Now cover the application program. */
  354. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  355. ElfW(Phdr) *ppnt_outer = ppnt;
  356. ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  357. for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
  358. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  359. _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
  360. (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & ADDR_ALIGN) +
  361. (unsigned long) ppnt->p_filesz,
  362. PROT_READ | PROT_WRITE | PROT_EXEC);
  363. }
  364. ppnt = ppnt_outer;
  365. }
  366. #else
  367. if (app_tpnt->dynamic_info[DT_TEXTREL]) {
  368. _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
  369. _dl_exit(1);
  370. }
  371. #endif
  372. #ifndef ALLOW_ZERO_PLTGOT
  373. /* make sure it's really there. */
  374. if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
  375. continue;
  376. #endif
  377. /* OK, we have what we need - slip this one into the list. */
  378. app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
  379. app_tpnt->dynamic_info,
  380. (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
  381. ppnt->p_filesz);
  382. _dl_loaded_modules->libtype = elf_executable;
  383. _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
  384. _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
  385. _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
  386. rpnt->dyn = _dl_loaded_modules;
  387. app_tpnt->mapaddr = app_mapaddr;
  388. app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
  389. app_tpnt->usage_count++;
  390. app_tpnt->symbol_scope = _dl_symbol_tables;
  391. lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
  392. #ifdef ALLOW_ZERO_PLTGOT
  393. if (lpnt)
  394. #endif
  395. INIT_GOT(lpnt, _dl_loaded_modules);
  396. }
  397. /* OK, fill this in - we did not have this before */
  398. if (ppnt->p_type == PT_INTERP) {
  399. char *ptmp;
  400. tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
  401. /* Store the path where the shared lib loader was found
  402. * for later use
  403. */
  404. _dl_ldsopath = _dl_strdup(tpnt->libname);
  405. ptmp = _dl_strrchr(_dl_ldsopath, '/');
  406. if (ptmp != _dl_ldsopath)
  407. *ptmp = '\0';
  408. _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
  409. }
  410. }
  411. app_tpnt->relro_addr = relro_addr;
  412. app_tpnt->relro_size = relro_size;
  413. #ifdef __SUPPORT_LD_DEBUG__
  414. _dl_debug = _dl_getenv("LD_DEBUG", envp);
  415. if (_dl_debug) {
  416. if (_dl_strstr(_dl_debug, "all")) {
  417. _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
  418. = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
  419. } else {
  420. _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
  421. _dl_debug_move = _dl_strstr(_dl_debug, "move");
  422. _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
  423. _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
  424. _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
  425. _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
  426. }
  427. }
  428. {
  429. const char *dl_debug_output;
  430. dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
  431. if (dl_debug_output) {
  432. char tmp[22], *tmp1, *filename;
  433. int len1, len2;
  434. _dl_memset(tmp, 0, sizeof(tmp));
  435. tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
  436. len1 = _dl_strlen(dl_debug_output);
  437. len2 = _dl_strlen(tmp1);
  438. filename = _dl_malloc(len1 + len2 + 2);
  439. if (filename) {
  440. _dl_strcpy (filename, dl_debug_output);
  441. filename[len1] = '.';
  442. _dl_strcpy (&filename[len1+1], tmp1);
  443. _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
  444. if (_dl_debug_file < 0) {
  445. _dl_debug_file = 2;
  446. _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
  447. }
  448. }
  449. }
  450. }
  451. #endif
  452. if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
  453. trace_loaded_objects++;
  454. }
  455. #ifndef __LDSO_LDD_SUPPORT__
  456. if (trace_loaded_objects) {
  457. _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
  458. _dl_exit(1);
  459. }
  460. #endif
  461. /*
  462. * OK, fix one more thing - set up debug_addr so it will point
  463. * to our chain. Later we may need to fill in more fields, but this
  464. * should be enough for now.
  465. */
  466. debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
  467. debug_addr->r_version = 1;
  468. debug_addr->r_ldbase = (ElfW(Addr)) DL_LOADADDR_BASE(load_addr);
  469. debug_addr->r_brk = (unsigned long) &_dl_debug_state;
  470. _dl_debug_addr = debug_addr;
  471. /* Do not notify the debugger until the interpreter is in the list */
  472. /* OK, we now have the application in the list, and we have some
  473. * basic stuff in place. Now search through the list for other shared
  474. * libraries that should be loaded, and insert them on the list in the
  475. * correct order.
  476. */
  477. _dl_map_cache();
  478. if (_dl_preload) {
  479. char c, *str, *str2;
  480. str = _dl_preload;
  481. while (*str == ':' || *str == ' ' || *str == '\t')
  482. str++;
  483. while (*str) {
  484. str2 = str;
  485. while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
  486. str2++;
  487. c = *str2;
  488. *str2 = '\0';
  489. if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
  490. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
  491. tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
  492. if (!tpnt1) {
  493. #ifdef __LDSO_LDD_SUPPORT__
  494. if (trace_loaded_objects)
  495. _dl_dprintf(1, "\t%s => not found\n", str);
  496. else
  497. #endif
  498. {
  499. _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
  500. _dl_exit(15);
  501. }
  502. } else {
  503. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  504. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  505. #ifdef __LDSO_LDD_SUPPORT__
  506. if (trace_loaded_objects &&
  507. tpnt1->usage_count == 1) {
  508. /* This is a real hack to make
  509. * ldd not print the library
  510. * itself when run on a
  511. * library.
  512. */
  513. if (_dl_strcmp(_dl_progname, str) != 0)
  514. _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
  515. DL_LOADADDR_BASE(tpnt1->loadaddr));
  516. }
  517. #endif
  518. }
  519. }
  520. *str2 = c;
  521. str = str2;
  522. while (*str == ':' || *str == ' ' || *str == '\t')
  523. str++;
  524. }
  525. }
  526. #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
  527. do {
  528. char *preload;
  529. int fd;
  530. char c, *cp, *cp2;
  531. if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
  532. break;
  533. }
  534. if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
  535. _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
  536. _dl_progname, LDSO_PRELOAD);
  537. break;
  538. }
  539. preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
  540. PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
  541. _dl_close(fd);
  542. if (preload == (caddr_t) -1) {
  543. _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
  544. _dl_progname, __LINE__, LDSO_PRELOAD);
  545. break;
  546. }
  547. /* convert all separators and comments to spaces */
  548. for (cp = preload; *cp; /*nada */ ) {
  549. if (*cp == ':' || *cp == '\t' || *cp == '\n') {
  550. *cp++ = ' ';
  551. } else if (*cp == '#') {
  552. do {
  553. *cp++ = ' ';
  554. } while (*cp != '\n' && *cp != '\0');
  555. } else {
  556. cp++;
  557. }
  558. }
  559. /* find start of first library */
  560. for (cp = preload; *cp && *cp == ' '; cp++)
  561. /*nada */ ;
  562. while (*cp) {
  563. /* find end of library */
  564. for (cp2 = cp; *cp && *cp != ' '; cp++)
  565. /*nada */ ;
  566. c = *cp;
  567. *cp = '\0';
  568. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
  569. tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
  570. if (!tpnt1) {
  571. #ifdef __LDSO_LDD_SUPPORT__
  572. if (trace_loaded_objects)
  573. _dl_dprintf(1, "\t%s => not found\n", cp2);
  574. else
  575. #endif
  576. {
  577. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
  578. _dl_exit(15);
  579. }
  580. } else {
  581. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  582. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  583. #ifdef __LDSO_LDD_SUPPORT__
  584. if (trace_loaded_objects &&
  585. tpnt1->usage_count == 1) {
  586. _dl_dprintf(1, "\t%s => %s (%x)\n",
  587. cp2, tpnt1->libname,
  588. DL_LOADADDR_BASE(tpnt1->loadaddr));
  589. }
  590. #endif
  591. }
  592. /* find start of next library */
  593. *cp = c;
  594. for ( /*nada */ ; *cp && *cp == ' '; cp++)
  595. /*nada */ ;
  596. }
  597. _dl_munmap(preload, st.st_size + 1);
  598. } while (0);
  599. #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
  600. nlist = 0;
  601. for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
  602. ElfW(Dyn) *this_dpnt;
  603. nlist++;
  604. for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
  605. if (this_dpnt->d_tag == DT_NEEDED) {
  606. char *name;
  607. struct init_fini_list *tmp;
  608. lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
  609. name = _dl_get_last_path_component(lpntstr);
  610. if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
  611. continue;
  612. _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
  613. if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
  614. #ifdef __LDSO_LDD_SUPPORT__
  615. if (trace_loaded_objects) {
  616. _dl_dprintf(1, "\t%s => not found\n", lpntstr);
  617. continue;
  618. } else
  619. #endif
  620. {
  621. _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
  622. _dl_exit(16);
  623. }
  624. }
  625. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  626. tmp->tpnt = tpnt1;
  627. tmp->next = tcurr->init_fini;
  628. tcurr->init_fini = tmp;
  629. tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
  630. _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
  631. #ifdef __LDSO_LDD_SUPPORT__
  632. if (trace_loaded_objects &&
  633. tpnt1->usage_count == 1) {
  634. _dl_dprintf(1, "\t%s => %s (%x)\n",
  635. lpntstr, tpnt1->libname,
  636. DL_LOADADDR_BASE(tpnt1->loadaddr));
  637. }
  638. #endif
  639. }
  640. }
  641. }
  642. _dl_unmap_cache();
  643. --nlist; /* Exclude the application. */
  644. init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
  645. i = 0;
  646. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  647. init_fini_list[i++] = tcurr;
  648. }
  649. /* Sort the INIT/FINI list in dependency order. */
  650. for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
  651. unsigned int j, k;
  652. for (j = 0; init_fini_list[j] != tcurr; ++j)
  653. /* Empty */;
  654. for (k = j + 1; k < nlist; ++k) {
  655. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  656. for (; runp; runp = runp->next) {
  657. if (runp->tpnt == tcurr) {
  658. struct elf_resolve *here = init_fini_list[k];
  659. _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
  660. for (i = (k - j); i; --i)
  661. init_fini_list[i+j] = init_fini_list[i+j-1];
  662. init_fini_list[j] = here;
  663. ++j;
  664. break;
  665. }
  666. }
  667. }
  668. }
  669. #ifdef __SUPPORT_LD_DEBUG__
  670. if (_dl_debug) {
  671. _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
  672. for (i = 0; i < nlist; i++) {
  673. struct init_fini_list *tmp;
  674. _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
  675. init_fini_list[i]->libname);
  676. tmp = init_fini_list[i]->init_fini;
  677. for (; tmp; tmp = tmp->next)
  678. _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
  679. _dl_dprintf(_dl_debug_file, "\n");
  680. }
  681. }
  682. #endif
  683. /*
  684. * If the program interpreter is not in the module chain, add it.
  685. * This will be required for dlopen to be able to access the internal
  686. * functions in the dynamic linker and to relocate the interpreter
  687. * again once all libs are loaded.
  688. */
  689. if (tpnt) {
  690. ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
  691. ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
  692. int j;
  693. tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
  694. tpnt->dynamic_info,
  695. (unsigned long)tpnt->dynamic_addr,
  696. 0);
  697. if (_dl_stat(tpnt->libname, &st) >= 0) {
  698. tpnt->st_dev = st.st_dev;
  699. tpnt->st_ino = st.st_ino;
  700. }
  701. tpnt->n_phent = epnt->e_phnum;
  702. tpnt->ppnt = myppnt;
  703. for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
  704. if (myppnt->p_type == PT_GNU_RELRO) {
  705. tpnt->relro_addr = myppnt->p_vaddr;
  706. tpnt->relro_size = myppnt->p_memsz;
  707. break;
  708. }
  709. }
  710. tpnt->libtype = program_interpreter;
  711. tpnt->usage_count++;
  712. tpnt->symbol_scope = _dl_symbol_tables;
  713. if (rpnt) {
  714. rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
  715. rpnt->next->prev = rpnt;
  716. rpnt = rpnt->next;
  717. } else {
  718. rpnt = _dl_zalloc(sizeof(struct dyn_elf));
  719. }
  720. rpnt->dyn = tpnt;
  721. tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
  722. #ifdef RERELOCATE_LDSO
  723. /* Only rerelocate functions for now. */
  724. tpnt->init_flag = RELOCS_DONE;
  725. lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
  726. # ifdef ALLOW_ZERO_PLTGOT
  727. if (tpnt->dynamic_info[DT_PLTGOT])
  728. # endif
  729. INIT_GOT(lpnt, tpnt);
  730. #else
  731. tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
  732. #endif
  733. tpnt = NULL;
  734. }
  735. #ifdef __LDSO_LDD_SUPPORT__
  736. /* End of the line for ldd.... */
  737. if (trace_loaded_objects) {
  738. _dl_dprintf(1, "\t%s => %s (%x)\n",
  739. rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
  740. rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
  741. _dl_exit(0);
  742. }
  743. #endif
  744. _dl_debug_early("Beginning relocation fixups\n");
  745. #ifdef __mips__
  746. /*
  747. * Relocation of the GOT entries for MIPS have to be done
  748. * after all the libraries have been loaded.
  749. */
  750. _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
  751. #endif
  752. /*
  753. * OK, now all of the kids are tucked into bed in their proper
  754. * addresses. Now we go through and look for REL and RELA records that
  755. * indicate fixups to the GOT tables. We need to do this in reverse
  756. * order so that COPY directives work correctly.
  757. */
  758. if (_dl_symbol_tables)
  759. if (_dl_fixup(_dl_symbol_tables, unlazy))
  760. _dl_exit(-1);
  761. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  762. if (tpnt->relro_size)
  763. _dl_protect_relro (tpnt);
  764. }
  765. /* OK, at this point things are pretty much ready to run. Now we need
  766. * to touch up a few items that are required, and then we can let the
  767. * user application have at it. Note that the dynamic linker itself
  768. * is not guaranteed to be fully dynamicly linked if we are using
  769. * ld.so.1, so we have to look up each symbol individually.
  770. */
  771. _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0);
  772. if (_dl_envp)
  773. *_dl_envp = (unsigned long) envp;
  774. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  775. {
  776. unsigned int j;
  777. ElfW(Phdr) *myppnt;
  778. /* We had to set the protections of all pages to R/W for
  779. * dynamic linking. Set text pages back to R/O.
  780. */
  781. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  782. for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
  783. if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
  784. _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
  785. (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
  786. }
  787. }
  788. }
  789. }
  790. #endif
  791. /* Notify the debugger we have added some objects. */
  792. _dl_debug_addr->r_state = RT_ADD;
  793. _dl_debug_state();
  794. /* Run pre-initialization functions for the executable. */
  795. _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
  796. _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
  797. _dl_loaded_modules->loadaddr);
  798. /* Run initialization functions for loaded objects. For the
  799. main executable, they will be run from __uClibc_main. */
  800. for (i = nlist; i; --i) {
  801. tpnt = init_fini_list[i-1];
  802. tpnt->init_fini = NULL; /* Clear, since alloca was used */
  803. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  804. continue;
  805. tpnt->init_flag |= INIT_FUNCS_CALLED;
  806. if (tpnt->dynamic_info[DT_INIT]) {
  807. void (*dl_elf_func) (void);
  808. dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
  809. _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
  810. DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
  811. }
  812. _dl_run_init_array(tpnt);
  813. }
  814. /* Find the real malloc function and make ldso functions use that from now on */
  815. _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
  816. _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
  817. /* Notify the debugger that all objects are now mapped in. */
  818. _dl_debug_addr->r_state = RT_CONSISTENT;
  819. _dl_debug_state();
  820. }
  821. #include "dl-hash.c"
  822. #include "dl-elf.c"