libdl.c 18 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) 2000-2004 by Erik Andersen <andersen@codpoet.org>
  7. * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
  8. * David Engel, Hongjiu Lu and Mitch D'Souza
  9. *
  10. * Redistribution and use in source and binary forms, with or without
  11. * modification, are permitted provided that the following conditions
  12. * are met:
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. * 2. The name of the above contributors may not be
  16. * used to endorse or promote products derived from this software
  17. * without specific prior written permission.
  18. *
  19. * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  20. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22. * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  23. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29. * SUCH DAMAGE.
  30. */
  31. #include <ldso.h>
  32. #include <stdio.h>
  33. #if defined (__LIBDL_SHARED__)
  34. /* When libdl is loaded as a shared library, we need to load in
  35. * and use a pile of symbols from ldso... */
  36. extern char *_dl_find_hash(const char *, struct dyn_elf *, int)
  37. __attribute__ ((__weak__));
  38. extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  39. struct elf_resolve *, char *, int) __attribute__ ((__weak__));
  40. extern struct elf_resolve * _dl_check_if_named_library_is_loaded(const char *, int)
  41. __attribute__ ((__weak__));
  42. extern int _dl_fixup(struct dyn_elf *rpnt, int lazy)
  43. __attribute__ ((__weak__));
  44. extern int _dl_errno __attribute__ ((__weak__));
  45. extern struct dyn_elf *_dl_symbol_tables __attribute__ ((__weak__));
  46. extern struct dyn_elf *_dl_handles __attribute__ ((__weak__));
  47. extern struct elf_resolve *_dl_loaded_modules __attribute__ ((__weak__));
  48. extern struct r_debug *_dl_debug_addr __attribute__ ((__weak__));
  49. extern unsigned long _dl_error_number __attribute__ ((__weak__));
  50. extern void *(*_dl_malloc_function)(size_t) __attribute__ ((__weak__));
  51. #ifdef __LDSO_CACHE_SUPPORT__
  52. int _dl_map_cache(void) __attribute__ ((__weak__));
  53. int _dl_unmap_cache(void) __attribute__ ((__weak__));
  54. #endif
  55. #ifdef __mips__
  56. extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt)
  57. __attribute__ ((__weak__));
  58. #endif
  59. #ifdef __SUPPORT_LD_DEBUG__
  60. extern char *_dl_debug __attribute__ ((__weak__));
  61. #endif
  62. #else /* __LIBDL_SHARED__ */
  63. /* When libdl is linked as a static library, we need to replace all
  64. * the symbols that otherwise would have been loaded in from ldso... */
  65. #ifdef __SUPPORT_LD_DEBUG__
  66. char *_dl_debug = 0;
  67. #endif
  68. char *_dl_library_path = 0; /* Where we look for libraries */
  69. char *_dl_ldsopath = 0; /* Location of the shared lib loader */
  70. int _dl_errno = 0; /* We can't use the real errno in ldso */
  71. size_t _dl_pagesize = PAGE_SIZE; /* Store the page size for use later */
  72. /* This global variable is also to communicate with debuggers such as gdb. */
  73. struct r_debug *_dl_debug_addr = NULL;
  74. #define _dl_malloc malloc
  75. #include "dl-progname.h"
  76. #include "../ldso/dl-hash.c"
  77. #define _dl_trace_loaded_objects 0
  78. #include "../ldso/dl-elf.c"
  79. #endif
  80. static int do_dlclose(void *, int need_fini);
  81. static const char *dl_error_names[] = {
  82. "",
  83. "File not found",
  84. "Unable to open /dev/zero",
  85. "Not an ELF file",
  86. #if defined (__i386__)
  87. "Not i386 binary",
  88. #elif defined (__sparc__)
  89. "Not sparc binary",
  90. #elif defined (__mc68000__)
  91. "Not m68k binary",
  92. #else
  93. "Unrecognized binary type",
  94. #endif
  95. "Not an ELF shared library",
  96. "Unable to mmap file",
  97. "No dynamic section",
  98. #ifdef ELF_USES_RELOCA
  99. "Unable to process REL relocs",
  100. #else
  101. "Unable to process RELA relocs",
  102. #endif
  103. "Bad handle",
  104. "Unable to resolve symbol"
  105. };
  106. void __attribute__ ((destructor)) dl_cleanup(void)
  107. {
  108. struct dyn_elf *d;
  109. for (d = _dl_handles; d; d = d->next_handle) {
  110. do_dlclose(d, 1);
  111. }
  112. }
  113. void *dlopen(const char *libname, int flag)
  114. {
  115. struct elf_resolve *tpnt, *tfrom, *tcurr;
  116. struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr;
  117. struct dyn_elf *dpnt;
  118. ElfW(Addr) from;
  119. struct elf_resolve *tpnt1;
  120. void (*dl_brk) (void);
  121. int now_flag;
  122. struct init_fini_list *tmp;
  123. int nlist, i;
  124. struct elf_resolve **init_fini_list;
  125. /* A bit of sanity checking... */
  126. if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
  127. _dl_error_number = LD_BAD_HANDLE;
  128. return NULL;
  129. }
  130. from = (ElfW(Addr)) __builtin_return_address(0);
  131. /* Cover the trivial case first */
  132. if (!libname)
  133. return _dl_symbol_tables;
  134. _dl_map_cache();
  135. /*
  136. * Try and locate the module we were called from - we
  137. * need this so that we get the correct RPATH. Note that
  138. * this is the current behavior under Solaris, but the
  139. * ABI+ specifies that we should only use the RPATH from
  140. * the application. Thus this may go away at some time
  141. * in the future.
  142. */
  143. tfrom = NULL;
  144. for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
  145. tpnt = dpnt->dyn;
  146. if (tpnt->loadaddr < from
  147. && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
  148. tfrom = tpnt;
  149. }
  150. for(rpnt = _dl_symbol_tables; rpnt->next; rpnt=rpnt->next);
  151. /* Try to load the specified library */
  152. #ifdef __SUPPORT_LD_DEBUG__
  153. if(_dl_debug)
  154. fprintf(stderr, "Trying to dlopen '%s'\n", (char*)libname);
  155. #endif
  156. tpnt = _dl_check_if_named_library_is_loaded((char *)libname, 0);
  157. if (!(tpnt))
  158. tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
  159. else
  160. tpnt->usage_count++;
  161. if (tpnt == NULL) {
  162. _dl_unmap_cache();
  163. return NULL;
  164. }
  165. dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
  166. _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
  167. dyn_chain->dyn = tpnt;
  168. tpnt->rtld_flags |= RTLD_GLOBAL;
  169. dyn_chain->next_handle = _dl_handles;
  170. _dl_handles = dyn_ptr = dyn_chain;
  171. #ifdef __SUPPORT_LD_DEBUG__
  172. if(_dl_debug)
  173. fprintf(stderr, "Looking for needed libraries\n");
  174. #endif
  175. nlist = 0;
  176. for (tcurr = tpnt; tcurr; tcurr = tcurr->next)
  177. {
  178. Elf32_Dyn *dpnt;
  179. char *lpntstr;
  180. nlist++;
  181. tcurr->init_fini = NULL; /* clear any previous dependcies */
  182. for (dpnt = (Elf32_Dyn *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
  183. if (dpnt->d_tag == DT_NEEDED) {
  184. char *name;
  185. lpntstr = (char*) (tcurr->loadaddr + tcurr->dynamic_info[DT_STRTAB] +
  186. dpnt->d_un.d_val);
  187. name = _dl_get_last_path_component(lpntstr);
  188. tpnt1 = _dl_check_if_named_library_is_loaded(name, 0);
  189. #ifdef __SUPPORT_LD_DEBUG__
  190. if(_dl_debug)
  191. fprintf(stderr, "Trying to load '%s', needed by '%s'\n",
  192. lpntstr, tcurr->libname);
  193. #endif
  194. if (tpnt1) {
  195. tpnt1->usage_count++;
  196. } else {
  197. tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, 0);
  198. if (!tpnt1)
  199. goto oops;
  200. }
  201. tpnt1->rtld_flags |= RTLD_GLOBAL;
  202. dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
  203. _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
  204. dyn_ptr = dyn_ptr->next;
  205. dyn_ptr->dyn = tpnt1;
  206. tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
  207. tmp->tpnt = tpnt1;
  208. tmp->next = tcurr->init_fini;
  209. tcurr->init_fini = tmp;
  210. }
  211. }
  212. }
  213. init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
  214. dyn_chain->init_fini.init_fini = init_fini_list;
  215. dyn_chain->init_fini.nlist = nlist;
  216. i = 0;
  217. for (tcurr = tpnt; tcurr; tcurr = tcurr->next) {
  218. init_fini_list[i++] = tcurr;
  219. }
  220. /* Sort the INIT/FINI list in dependency order. */
  221. for (tcurr = tpnt; tcurr; tcurr = tcurr->next) {
  222. int j, k;
  223. for (j = 0; init_fini_list[j] != tcurr; ++j)
  224. /* Empty */;
  225. for (k = j + 1; k < nlist; ++k) {
  226. struct init_fini_list *runp = init_fini_list[k]->init_fini;
  227. for (; runp; runp = runp->next) {
  228. if (runp->tpnt == tcurr) {
  229. struct elf_resolve *here = init_fini_list[k];
  230. #ifdef __SUPPORT_LD_DEBUG__
  231. if(_dl_debug)
  232. fprintf(stderr, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
  233. #endif
  234. for (i = (k - j); i; --i)
  235. init_fini_list[i+j] = init_fini_list[i+j-1];
  236. init_fini_list[j] = here;
  237. ++j;
  238. break;
  239. }
  240. }
  241. }
  242. }
  243. #ifdef __SUPPORT_LD_DEBUG__
  244. if(_dl_debug) {
  245. fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
  246. for (i=0;i < nlist;i++) {
  247. struct init_fini_list *tmp;
  248. fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
  249. tmp = init_fini_list[i]->init_fini;
  250. for ( ;tmp; tmp = tmp->next)
  251. printf(" %s ", tmp->tpnt->libname);
  252. printf("\n");
  253. }
  254. }
  255. #endif
  256. if (dyn_chain->dyn->init_flag & INIT_FUNCS_CALLED) {
  257. /* If the init and fini stuff has already been run, that means
  258. * the dlopen'd library has already been loaded, and nothing
  259. * further needs to be done. */
  260. return (void *) dyn_chain;
  261. }
  262. #ifdef __mips__
  263. /*
  264. * Relocation of the GOT entries for MIPS have to be done
  265. * after all the libraries have been loaded.
  266. */
  267. _dl_perform_mips_global_got_relocations(tpnt);
  268. #endif
  269. #ifdef __SUPPORT_LD_DEBUG__
  270. if(_dl_debug)
  271. fprintf(stderr, "Beginning dlopen relocation fixups\n");
  272. #endif
  273. /*
  274. * OK, now all of the kids are tucked into bed in their proper addresses.
  275. * Now we go through and look for REL and RELA records that indicate fixups
  276. * to the GOT tables. We need to do this in reverse order so that COPY
  277. * directives work correctly */
  278. now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
  279. if (getenv("LD_BIND_NOW"))
  280. now_flag = RTLD_NOW;
  281. if (_dl_fixup(dyn_chain, now_flag))
  282. goto oops;
  283. /* TODO: Should we set the protections of all pages back to R/O now ? */
  284. /* Notify the debugger we have added some objects. */
  285. if (_dl_debug_addr) {
  286. dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
  287. if (dl_brk != NULL) {
  288. _dl_debug_addr->r_state = RT_ADD;
  289. (*dl_brk) ();
  290. _dl_debug_addr->r_state = RT_CONSISTENT;
  291. (*dl_brk) ();
  292. }
  293. }
  294. #if defined (__LIBDL_SHARED__)
  295. /* Run the ctors and setup the dtors */
  296. for (i = nlist; i; --i) {
  297. tpnt = init_fini_list[i-1];
  298. if (tpnt->init_flag & INIT_FUNCS_CALLED)
  299. continue;
  300. tpnt->init_flag |= INIT_FUNCS_CALLED;
  301. if (tpnt->dynamic_info[DT_INIT]) {
  302. void (*dl_elf_func) (void);
  303. dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
  304. if (dl_elf_func && *dl_elf_func != NULL) {
  305. #ifdef __SUPPORT_LD_DEBUG__
  306. if(_dl_debug)
  307. fprintf(stderr, "running ctors for library %s at '%x'\n", tpnt->libname, dl_elf_func);
  308. #endif
  309. (*dl_elf_func) ();
  310. }
  311. }
  312. }
  313. #endif
  314. _dl_unmap_cache();
  315. return (void *) dyn_chain;
  316. oops:
  317. /* Something went wrong. Clean up and return NULL. */
  318. _dl_unmap_cache();
  319. do_dlclose(dyn_chain, 0);
  320. return NULL;
  321. }
  322. void *dlsym(void *vhandle, const char *name)
  323. {
  324. struct elf_resolve *tpnt, *tfrom;
  325. struct dyn_elf *handle;
  326. ElfW(Addr) from;
  327. struct dyn_elf *rpnt;
  328. void *ret;
  329. handle = (struct dyn_elf *) vhandle;
  330. /* First of all verify that we have a real handle
  331. of some kind. Return NULL if not a valid handle. */
  332. if (handle == NULL)
  333. handle = _dl_symbol_tables;
  334. else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
  335. for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
  336. if (rpnt == handle)
  337. break;
  338. if (!rpnt) {
  339. _dl_error_number = LD_BAD_HANDLE;
  340. return NULL;
  341. }
  342. } else if (handle == RTLD_NEXT) {
  343. /*
  344. * Try and locate the module we were called from - we
  345. * need this so that we know where to start searching
  346. * from. We never pass RTLD_NEXT down into the actual
  347. * dynamic loader itself, as it doesn't know
  348. * how to properly treat it.
  349. */
  350. from = (ElfW(Addr)) __builtin_return_address(0);
  351. tfrom = NULL;
  352. for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
  353. tpnt = rpnt->dyn;
  354. if (tpnt->loadaddr < from
  355. && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
  356. tfrom = tpnt;
  357. handle = rpnt->next;
  358. }
  359. }
  360. }
  361. ret = _dl_find_hash((char*)name, handle, 0);
  362. /*
  363. * Nothing found.
  364. */
  365. if (!ret)
  366. _dl_error_number = LD_NO_SYMBOL;
  367. return ret;
  368. }
  369. static int do_dlclose(void *vhandle, int need_fini)
  370. {
  371. struct dyn_elf *rpnt, *rpnt1;
  372. ElfW(Phdr) *ppnt;
  373. struct elf_resolve *tpnt;
  374. int (*dl_elf_fini) (void);
  375. void (*dl_brk) (void);
  376. struct dyn_elf *handle;
  377. unsigned int end;
  378. int i = 0;
  379. handle = (struct dyn_elf *) vhandle;
  380. rpnt1 = NULL;
  381. for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
  382. if (rpnt == handle)
  383. break;
  384. rpnt1 = rpnt;
  385. }
  386. if (!rpnt) {
  387. _dl_error_number = LD_BAD_HANDLE;
  388. return 1;
  389. }
  390. if (rpnt1)
  391. rpnt1->next_handle = rpnt->next_handle;
  392. else
  393. _dl_handles = rpnt->next_handle;
  394. if (need_fini) {
  395. for (i = 0; i < handle->init_fini.nlist; ++i) {
  396. tpnt = handle->init_fini.init_fini[i];
  397. if (tpnt->dynamic_info[DT_FINI] && tpnt->usage_count == 1 &&
  398. !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
  399. tpnt->init_flag |= FINI_FUNCS_CALLED;
  400. dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
  401. #ifdef __SUPPORT_LD_DEBUG__
  402. if(_dl_debug)
  403. fprintf(stderr, "running dtors for library %s at '%x'\n", tpnt->libname, dl_elf_fini);
  404. #endif
  405. (*dl_elf_fini) ();
  406. }
  407. }
  408. }
  409. free(handle->init_fini.init_fini);
  410. /* OK, this is a valid handle - now close out the file */
  411. for (rpnt = handle; rpnt; rpnt = rpnt->next) {
  412. tpnt = rpnt->dyn;
  413. if (--tpnt->usage_count == 0) {
  414. end = 0;
  415. for (i = 0, ppnt = tpnt->ppnt;
  416. i < tpnt->n_phent; ppnt++, i++) {
  417. if (ppnt->p_type != PT_LOAD)
  418. continue;
  419. if (end < ppnt->p_vaddr + ppnt->p_memsz)
  420. end = ppnt->p_vaddr + ppnt->p_memsz;
  421. }
  422. _dl_munmap((void*)tpnt->loadaddr, end);
  423. /* Next, remove tpnt from the loaded_module list */
  424. if (_dl_loaded_modules == tpnt) {
  425. _dl_loaded_modules = tpnt->next;
  426. if (_dl_loaded_modules)
  427. _dl_loaded_modules->prev = 0;
  428. } else
  429. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next)
  430. if (tpnt->next == rpnt->dyn) {
  431. tpnt->next = tpnt->next->next;
  432. if (tpnt->next)
  433. tpnt->next->prev = tpnt;
  434. break;
  435. }
  436. /* Next, remove tpnt from the global symbol table list */
  437. if (_dl_symbol_tables->dyn == rpnt->dyn) {
  438. _dl_symbol_tables = rpnt->next;
  439. if (_dl_symbol_tables)
  440. _dl_symbol_tables->prev = 0;
  441. } else
  442. for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
  443. if (rpnt1->next->dyn == rpnt->dyn) {
  444. free(rpnt1->next);
  445. rpnt1->next = rpnt1->next->next;
  446. if (rpnt1->next)
  447. rpnt1->next->prev = rpnt1;
  448. break;
  449. }
  450. }
  451. free(rpnt->dyn->libname);
  452. free(rpnt->dyn);
  453. }
  454. free(rpnt);
  455. }
  456. if (_dl_debug_addr) {
  457. dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
  458. if (dl_brk != NULL) {
  459. _dl_debug_addr->r_state = RT_DELETE;
  460. (*dl_brk) ();
  461. _dl_debug_addr->r_state = RT_CONSISTENT;
  462. (*dl_brk) ();
  463. }
  464. }
  465. return 0;
  466. }
  467. int dlclose(void *vhandle)
  468. {
  469. return do_dlclose(vhandle, 1);
  470. }
  471. const char *dlerror(void)
  472. {
  473. const char *retval;
  474. if (!_dl_error_number)
  475. return NULL;
  476. retval = dl_error_names[_dl_error_number];
  477. _dl_error_number = 0;
  478. return retval;
  479. }
  480. /*
  481. * Dump information to stderrr about the current loaded modules
  482. */
  483. static char *type[] = { "Lib", "Exe", "Int", "Mod" };
  484. void dlinfo(void)
  485. {
  486. struct elf_resolve *tpnt;
  487. struct dyn_elf *rpnt, *hpnt;
  488. fprintf(stderr, "List of loaded modules\n");
  489. /* First start with a complete list of all of the loaded files. */
  490. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  491. fprintf(stderr, "\t%x %x %x %s %d %s\n",
  492. (unsigned) tpnt->loadaddr, (unsigned) tpnt,
  493. (unsigned) tpnt->symbol_scope,
  494. type[tpnt->libtype],
  495. tpnt->usage_count, tpnt->libname);
  496. }
  497. /* Next dump the module list for the application itself */
  498. fprintf(stderr, "\nModules for application (%x):\n",
  499. (unsigned) _dl_symbol_tables);
  500. for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
  501. fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn, rpnt->dyn->libname);
  502. for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
  503. fprintf(stderr, "Modules for handle %x\n", (unsigned) hpnt);
  504. for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
  505. fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn,
  506. rpnt->dyn->libname);
  507. }
  508. }
  509. int dladdr(const void *__address, Dl_info * __info)
  510. {
  511. struct elf_resolve *pelf;
  512. struct elf_resolve *rpnt;
  513. _dl_map_cache();
  514. /*
  515. * Try and locate the module address is in
  516. */
  517. pelf = NULL;
  518. #if 0
  519. fprintf(stderr, "dladdr( %x, %x )\n", __address, __info);
  520. #endif
  521. for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
  522. struct elf_resolve *tpnt;
  523. tpnt = rpnt;
  524. #if 0
  525. fprintf(stderr, "Module \"%s\" at %x\n",
  526. tpnt->libname, tpnt->loadaddr);
  527. #endif
  528. if (tpnt->loadaddr < (ElfW(Addr)) __address
  529. && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
  530. pelf = tpnt;
  531. }
  532. }
  533. if (!pelf) {
  534. return 0;
  535. }
  536. /*
  537. * Try and locate the symbol of address
  538. */
  539. {
  540. char *strtab;
  541. Elf32_Sym *symtab;
  542. int hn, si;
  543. int sf;
  544. int sn = 0;
  545. ElfW(Addr) sa;
  546. sa = 0;
  547. symtab = (Elf32_Sym *) (pelf->dynamic_info[DT_SYMTAB] + pelf->loadaddr);
  548. strtab = (char *) (pelf->dynamic_info[DT_STRTAB] + pelf->loadaddr);
  549. sf = 0;
  550. for (hn = 0; hn < pelf->nbucket; hn++) {
  551. for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
  552. ElfW(Addr) symbol_addr;
  553. symbol_addr = pelf->loadaddr + symtab[si].st_value;
  554. if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
  555. sa = symbol_addr;
  556. sn = si;
  557. sf = 1;
  558. }
  559. #if 0
  560. fprintf(stderr, "Symbol \"%s\" at %x\n",
  561. strtab + symtab[si].st_name, symbol_addr);
  562. #endif
  563. }
  564. }
  565. if (sf) {
  566. __info->dli_fname = pelf->libname;
  567. __info->dli_fbase = (void *)pelf->loadaddr;
  568. __info->dli_sname = strtab + symtab[sn].st_name;
  569. __info->dli_saddr = (void *)sa;
  570. }
  571. return 1;
  572. }
  573. }