dl-elf.c 24 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837
  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * This file contains the helper routines to load an ELF shared
  4. * library into memory and add the symbol table info to the chain.
  5. *
  6. * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.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. #ifdef __LDSO_CACHE_SUPPORT__
  33. static caddr_t _dl_cache_addr = NULL;
  34. static size_t _dl_cache_size = 0;
  35. int _dl_map_cache(void)
  36. {
  37. int fd;
  38. struct stat st;
  39. header_t *header;
  40. libentry_t *libent;
  41. int i, strtabsize;
  42. if (_dl_cache_addr == (caddr_t) - 1)
  43. return -1;
  44. else if (_dl_cache_addr != NULL)
  45. return 0;
  46. if (_dl_stat(LDSO_CACHE, &st)
  47. || (fd = _dl_open(LDSO_CACHE, O_RDONLY, 0)) < 0) {
  48. _dl_cache_addr = (caddr_t) - 1; /* so we won't try again */
  49. return -1;
  50. }
  51. _dl_cache_size = st.st_size;
  52. _dl_cache_addr = (caddr_t) _dl_mmap(0, _dl_cache_size, PROT_READ, MAP_SHARED, fd, 0);
  53. _dl_close(fd);
  54. if (_dl_mmap_check_error(_dl_cache_addr)) {
  55. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  56. _dl_progname, __LINE__, LDSO_CACHE);
  57. return -1;
  58. }
  59. header = (header_t *) _dl_cache_addr;
  60. if (_dl_cache_size < sizeof(header_t) ||
  61. _dl_memcmp(header->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN)
  62. || _dl_memcmp(header->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN)
  63. || _dl_cache_size <
  64. (sizeof(header_t) + header->nlibs * sizeof(libentry_t))
  65. || _dl_cache_addr[_dl_cache_size - 1] != '\0')
  66. {
  67. _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname,
  68. LDSO_CACHE);
  69. goto fail;
  70. }
  71. strtabsize = _dl_cache_size - sizeof(header_t) -
  72. header->nlibs * sizeof(libentry_t);
  73. libent = (libentry_t *) & header[1];
  74. for (i = 0; i < header->nlibs; i++) {
  75. if (libent[i].sooffset >= strtabsize ||
  76. libent[i].liboffset >= strtabsize)
  77. {
  78. _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname, LDSO_CACHE);
  79. goto fail;
  80. }
  81. }
  82. return 0;
  83. fail:
  84. _dl_munmap(_dl_cache_addr, _dl_cache_size);
  85. _dl_cache_addr = (caddr_t) - 1;
  86. return -1;
  87. }
  88. int _dl_unmap_cache(void)
  89. {
  90. if (_dl_cache_addr == NULL || _dl_cache_addr == (caddr_t) - 1)
  91. return -1;
  92. #if 1
  93. _dl_munmap(_dl_cache_addr, _dl_cache_size);
  94. _dl_cache_addr = NULL;
  95. #endif
  96. return 0;
  97. }
  98. #endif
  99. void
  100. _dl_protect_relro (struct elf_resolve *l)
  101. {
  102. ElfW(Addr) start = (DL_RELOC_ADDR(l->loadaddr, l->relro_addr)
  103. & ~(_dl_pagesize - 1));
  104. ElfW(Addr) end = ((DL_RELOC_ADDR(l->loadaddr, l->relro_addr) + l->relro_size)
  105. & ~(_dl_pagesize - 1));
  106. _dl_if_debug_dprint("RELRO protecting %s: start:%x, end:%x\n", l->libname, start, end);
  107. if (start != end &&
  108. _dl_mprotect ((void *) start, end - start, PROT_READ) < 0) {
  109. _dl_dprintf(2, "%s: cannot apply additional memory protection after relocation", l->libname);
  110. _dl_exit(0);
  111. }
  112. }
  113. /* This function's behavior must exactly match that
  114. * in uClibc/ldso/util/ldd.c */
  115. static struct elf_resolve *
  116. search_for_named_library(const char *name, int secure, const char *path_list,
  117. struct dyn_elf **rpnt)
  118. {
  119. char *path, *path_n, *mylibname;
  120. struct elf_resolve *tpnt;
  121. int done;
  122. if (path_list==NULL)
  123. return NULL;
  124. /* We need a writable copy of this string, but we don't
  125. * need this allocated permanently since we don't want
  126. * to leak memory, so use alloca to put path on the stack */
  127. done = _dl_strlen(path_list);
  128. path = alloca(done + 1);
  129. /* another bit of local storage */
  130. mylibname = alloca(2050);
  131. /* gcc inlines alloca using a single instruction adjusting
  132. * the stack pointer and no stack overflow check and thus
  133. * no NULL error return. No point leaving in dead code... */
  134. #if 0
  135. if (!path || !mylibname) {
  136. _dl_dprintf(2, "Out of memory!\n");
  137. _dl_exit(0);
  138. }
  139. #endif
  140. _dl_memcpy(path, path_list, done+1);
  141. /* Unlike ldd.c, don't bother to eliminate double //s */
  142. /* Replace colons with zeros in path_list */
  143. /* : at the beginning or end of path maps to CWD */
  144. /* :: anywhere maps CWD */
  145. /* "" maps to CWD */
  146. done = 0;
  147. path_n = path;
  148. do {
  149. if (*path == 0) {
  150. *path = ':';
  151. done = 1;
  152. }
  153. if (*path == ':') {
  154. *path = 0;
  155. if (*path_n)
  156. _dl_strcpy(mylibname, path_n);
  157. else
  158. _dl_strcpy(mylibname, "."); /* Assume current dir if empty path */
  159. _dl_strcat(mylibname, "/");
  160. _dl_strcat(mylibname, name);
  161. if ((tpnt = _dl_load_elf_shared_library(secure, rpnt, mylibname)) != NULL)
  162. return tpnt;
  163. path_n = path+1;
  164. }
  165. path++;
  166. } while (!done);
  167. return NULL;
  168. }
  169. /* Used to return error codes back to dlopen et. al. */
  170. unsigned long _dl_error_number;
  171. unsigned long _dl_internal_error_number;
  172. struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
  173. struct elf_resolve *tpnt, char *full_libname, int __attribute__((unused)) trace_loaded_objects)
  174. {
  175. char *pnt;
  176. struct elf_resolve *tpnt1;
  177. char *libname;
  178. _dl_internal_error_number = 0;
  179. libname = full_libname;
  180. /* quick hack to ensure mylibname buffer doesn't overflow. don't
  181. allow full_libname or any directory to be longer than 1024. */
  182. if (_dl_strlen(full_libname) > 1024)
  183. goto goof;
  184. /* Skip over any initial initial './' and '/' stuff to
  185. * get the short form libname with no path garbage */
  186. pnt = _dl_strrchr(libname, '/');
  187. if (pnt) {
  188. libname = pnt + 1;
  189. }
  190. _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname);
  191. /* If the filename has any '/', try it straight and leave it at that.
  192. For IBCS2 compatibility under linux, we substitute the string
  193. /usr/i486-sysv4/lib for /usr/lib in library names. */
  194. if (libname != full_libname) {
  195. _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname);
  196. tpnt1 = _dl_load_elf_shared_library(secure, rpnt, full_libname);
  197. if (tpnt1) {
  198. return tpnt1;
  199. }
  200. }
  201. /*
  202. * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or
  203. * the default path of /usr/lib. Check in rpath directories.
  204. */
  205. #ifdef __LDSO_RUNPATH__
  206. pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL);
  207. if (pnt) {
  208. pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
  209. _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt);
  210. if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
  211. return tpnt1;
  212. }
  213. #endif
  214. /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */
  215. if (_dl_library_path) {
  216. _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path);
  217. if ((tpnt1 = search_for_named_library(libname, secure, _dl_library_path, rpnt)) != NULL)
  218. {
  219. return tpnt1;
  220. }
  221. }
  222. /*
  223. * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH.
  224. */
  225. #ifdef __LDSO_RUNPATH__
  226. pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL);
  227. if (pnt) {
  228. pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
  229. _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt);
  230. if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
  231. return tpnt1;
  232. }
  233. #endif
  234. /*
  235. * Where should the cache be searched? There is no such concept in the
  236. * ABI, so we have some flexibility here. For now, search it before
  237. * the hard coded paths that follow (i.e before /lib and /usr/lib).
  238. */
  239. #ifdef __LDSO_CACHE_SUPPORT__
  240. if (_dl_cache_addr != NULL && _dl_cache_addr != (caddr_t) - 1) {
  241. int i;
  242. header_t *header = (header_t *) _dl_cache_addr;
  243. libentry_t *libent = (libentry_t *) & header[1];
  244. char *strs = (char *) &libent[header->nlibs];
  245. _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE);
  246. for (i = 0; i < header->nlibs; i++) {
  247. if ((libent[i].flags == LIB_ELF ||
  248. libent[i].flags == LIB_ELF_LIBC0 ||
  249. libent[i].flags == LIB_ELF_LIBC5) &&
  250. _dl_strcmp(libname, strs + libent[i].sooffset) == 0 &&
  251. (tpnt1 = _dl_load_elf_shared_library(secure,
  252. rpnt, strs + libent[i].liboffset)))
  253. return tpnt1;
  254. }
  255. }
  256. #endif
  257. /* Look for libraries wherever the shared library loader
  258. * was installed */
  259. _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath);
  260. if ((tpnt1 = search_for_named_library(libname, secure, _dl_ldsopath, rpnt)) != NULL)
  261. {
  262. return tpnt1;
  263. }
  264. /* Lastly, search the standard list of paths for the library.
  265. This list must exactly match the list in uClibc/ldso/util/ldd.c */
  266. _dl_if_debug_dprint("\tsearching full lib path list\n");
  267. if ((tpnt1 = search_for_named_library(libname, secure,
  268. UCLIBC_RUNTIME_PREFIX "lib:"
  269. UCLIBC_RUNTIME_PREFIX "usr/lib"
  270. #ifndef __LDSO_CACHE_SUPPORT__
  271. ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
  272. #endif
  273. , rpnt)
  274. ) != NULL)
  275. {
  276. return tpnt1;
  277. }
  278. goof:
  279. /* Well, we shot our wad on that one. All we can do now is punt */
  280. if (_dl_internal_error_number)
  281. _dl_error_number = _dl_internal_error_number;
  282. else
  283. _dl_error_number = LD_ERROR_NOFILE;
  284. _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname);
  285. return NULL;
  286. }
  287. /*
  288. * Read one ELF library into memory, mmap it into the correct locations and
  289. * add the symbol info to the symbol chain. Perform any relocations that
  290. * are required.
  291. */
  292. struct elf_resolve *_dl_load_elf_shared_library(int secure,
  293. struct dyn_elf **rpnt, char *libname)
  294. {
  295. ElfW(Ehdr) *epnt;
  296. unsigned long dynamic_addr = 0;
  297. ElfW(Dyn) *dpnt;
  298. struct elf_resolve *tpnt;
  299. ElfW(Phdr) *ppnt;
  300. char *status, *header;
  301. unsigned long dynamic_info[DYNAMIC_SIZE];
  302. unsigned long *lpnt;
  303. unsigned long libaddr;
  304. unsigned long minvma = 0xffffffff, maxvma = 0;
  305. int i, flags, piclib, infile;
  306. ElfW(Addr) relro_addr = 0;
  307. size_t relro_size = 0;
  308. struct stat st;
  309. DL_LOADADDR_TYPE lib_loadaddr;
  310. DL_INIT_LOADADDR_EXTRA_DECLS
  311. infile = _dl_open(libname, O_RDONLY, 0);
  312. if (infile < 0) {
  313. _dl_internal_error_number = LD_ERROR_NOFILE;
  314. return NULL;
  315. }
  316. if (_dl_fstat(infile, &st) < 0) {
  317. _dl_internal_error_number = LD_ERROR_NOFILE;
  318. _dl_close(infile);
  319. return NULL;
  320. }
  321. /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD),
  322. we don't load the library if it isn't setuid. */
  323. if (secure)
  324. if (!(st.st_mode & S_ISUID)) {
  325. _dl_close(infile);
  326. return NULL;
  327. }
  328. /* Check if file is already loaded */
  329. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  330. if (tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) {
  331. /* Already loaded */
  332. tpnt->usage_count++;
  333. _dl_close(infile);
  334. return tpnt;
  335. }
  336. }
  337. header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
  338. MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  339. if (_dl_mmap_check_error(header)) {
  340. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  341. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  342. _dl_close(infile);
  343. return NULL;
  344. }
  345. _dl_read(infile, header, _dl_pagesize);
  346. epnt = (ElfW(Ehdr) *) (intptr_t) header;
  347. if (epnt->e_ident[0] != 0x7f ||
  348. epnt->e_ident[1] != 'E' ||
  349. epnt->e_ident[2] != 'L' ||
  350. epnt->e_ident[3] != 'F')
  351. {
  352. _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
  353. libname);
  354. _dl_internal_error_number = LD_ERROR_NOTELF;
  355. _dl_close(infile);
  356. _dl_munmap(header, _dl_pagesize);
  357. return NULL;
  358. }
  359. if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
  360. #ifdef MAGIC2
  361. && epnt->e_machine != MAGIC2
  362. #endif
  363. ))
  364. {
  365. _dl_internal_error_number =
  366. (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
  367. _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
  368. "\n", _dl_progname, libname);
  369. _dl_close(infile);
  370. _dl_munmap(header, _dl_pagesize);
  371. return NULL;
  372. }
  373. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  374. piclib = 1;
  375. for (i = 0; i < epnt->e_phnum; i++) {
  376. if (ppnt->p_type == PT_DYNAMIC) {
  377. if (dynamic_addr)
  378. _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
  379. _dl_progname, libname);
  380. dynamic_addr = ppnt->p_vaddr;
  381. }
  382. if (ppnt->p_type == PT_LOAD) {
  383. /* See if this is a PIC library. */
  384. if (i == 0 && ppnt->p_vaddr > 0x1000000) {
  385. piclib = 0;
  386. minvma = ppnt->p_vaddr;
  387. }
  388. if (piclib && ppnt->p_vaddr < minvma) {
  389. minvma = ppnt->p_vaddr;
  390. }
  391. if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
  392. maxvma = ppnt->p_vaddr + ppnt->p_memsz;
  393. }
  394. }
  395. ppnt++;
  396. }
  397. maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
  398. minvma = minvma & ~0xffffU;
  399. flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
  400. if (!piclib)
  401. flags |= MAP_FIXED;
  402. status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
  403. maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
  404. if (_dl_mmap_check_error(status)) {
  405. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  406. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  407. _dl_close(infile);
  408. _dl_munmap(header, _dl_pagesize);
  409. return NULL;
  410. }
  411. libaddr = (unsigned long) status;
  412. flags |= MAP_FIXED;
  413. /* Get the memory to store the library */
  414. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  415. DL_INIT_LOADADDR(lib_loadaddr, libaddr, ppnt, epnt->e_phnum);
  416. for (i = 0; i < epnt->e_phnum; i++) {
  417. if (ppnt->p_type == PT_GNU_RELRO) {
  418. relro_addr = ppnt->p_vaddr;
  419. relro_size = ppnt->p_memsz;
  420. }
  421. if (ppnt->p_type == PT_LOAD) {
  422. /* See if this is a PIC library. */
  423. if (i == 0 && ppnt->p_vaddr > 0x1000000) {
  424. piclib = 0;
  425. /* flags |= MAP_FIXED; */
  426. }
  427. if (ppnt->p_flags & PF_W) {
  428. unsigned long map_size;
  429. char *cpnt;
  430. status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
  431. (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
  432. + ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
  433. ppnt->p_offset & OFFS_ALIGN);
  434. if (_dl_mmap_check_error(status)) {
  435. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  436. _dl_progname, __LINE__, libname);
  437. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  438. _dl_munmap((char *) libaddr, maxvma - minvma);
  439. _dl_close(infile);
  440. _dl_munmap(header, _dl_pagesize);
  441. return NULL;
  442. }
  443. /* Pad the last page with zeroes. */
  444. cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
  445. ppnt->p_filesz);
  446. while (((unsigned long) cpnt) & ADDR_ALIGN)
  447. *cpnt++ = 0;
  448. /* I am not quite sure if this is completely
  449. * correct to do or not, but the basic way that
  450. * we handle bss segments is that we mmap
  451. * /dev/zero if there are any pages left over
  452. * that are not mapped as part of the file */
  453. map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;
  454. if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
  455. status = (char *) _dl_mmap((char *) map_size +
  456. (piclib ? libaddr : 0),
  457. ppnt->p_vaddr + ppnt->p_memsz - map_size,
  458. LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
  459. } else
  460. status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
  461. + (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
  462. ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
  463. infile, ppnt->p_offset & OFFS_ALIGN);
  464. if (_dl_mmap_check_error(status)) {
  465. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  466. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  467. _dl_munmap((char *) libaddr, maxvma - minvma);
  468. _dl_close(infile);
  469. _dl_munmap(header, _dl_pagesize);
  470. return NULL;
  471. }
  472. /* if (libaddr == 0 && piclib) {
  473. libaddr = (unsigned long) status;
  474. flags |= MAP_FIXED;
  475. } */
  476. }
  477. ppnt++;
  478. }
  479. _dl_close(infile);
  480. /* For a non-PIC library, the addresses are all absolute */
  481. if (piclib) {
  482. dynamic_addr = (unsigned long) DL_RELOC_ADDR(lib_loadaddr, dynamic_addr);
  483. }
  484. /*
  485. * OK, the ELF library is now loaded into VM in the correct locations
  486. * The next step is to go through and do the dynamic linking (if needed).
  487. */
  488. /* Start by scanning the dynamic section to get all of the pointers */
  489. if (!dynamic_addr) {
  490. _dl_internal_error_number = LD_ERROR_NODYNAMIC;
  491. _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
  492. _dl_progname, libname);
  493. _dl_munmap(header, _dl_pagesize);
  494. return NULL;
  495. }
  496. dpnt = (ElfW(Dyn) *) dynamic_addr;
  497. _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
  498. _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, lib_loadaddr);
  499. /* If the TEXTREL is set, this means that we need to make the pages
  500. writable before we perform relocations. Do this now. They get set
  501. back again later. */
  502. if (dynamic_info[DT_TEXTREL]) {
  503. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  504. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  505. for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
  506. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  507. _dl_mprotect((void *) ((piclib ? libaddr : 0) +
  508. (ppnt->p_vaddr & PAGE_ALIGN)),
  509. (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
  510. PROT_READ | PROT_WRITE | PROT_EXEC);
  511. }
  512. #else
  513. _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
  514. _dl_exit(1);
  515. #endif
  516. }
  517. tpnt = _dl_add_elf_hash_table(libname, lib_loadaddr, dynamic_info,
  518. dynamic_addr, 0);
  519. tpnt->relro_addr = relro_addr;
  520. tpnt->relro_size = relro_size;
  521. tpnt->st_dev = st.st_dev;
  522. tpnt->st_ino = st.st_ino;
  523. tpnt->ppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(tpnt->loadaddr, epnt->e_phoff);
  524. tpnt->n_phent = epnt->e_phnum;
  525. /*
  526. * Add this object into the symbol chain
  527. */
  528. if (*rpnt) {
  529. (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  530. _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
  531. (*rpnt)->next->prev = (*rpnt);
  532. *rpnt = (*rpnt)->next;
  533. (*rpnt)->dyn = tpnt;
  534. tpnt->symbol_scope = _dl_symbol_tables;
  535. }
  536. tpnt->usage_count++;
  537. tpnt->libtype = elf_lib;
  538. /*
  539. * OK, the next thing we need to do is to insert the dynamic linker into
  540. * the proper entry in the GOT so that the PLT symbols can be properly
  541. * resolved.
  542. */
  543. lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
  544. if (lpnt) {
  545. lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
  546. INIT_GOT(lpnt, tpnt);
  547. }
  548. _dl_if_debug_dprint("\n\tfile='%s'; generating link map\n", libname);
  549. _dl_if_debug_dprint("\t\tdynamic: %x base: %x\n", dynamic_addr, DL_LOADADDR_BASE(libaddr));
  550. _dl_if_debug_dprint("\t\t entry: %x phdr: %x phnum: %x\n\n",
  551. DL_RELOC_ADDR(lib_loadaddr, epnt->e_entry), tpnt->ppnt, tpnt->n_phent);
  552. _dl_munmap(header, _dl_pagesize);
  553. return tpnt;
  554. }
  555. /* now_flag must be RTLD_NOW or zero */
  556. int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
  557. {
  558. int goof = 0;
  559. struct elf_resolve *tpnt;
  560. ElfW(Word) reloc_size, relative_count;
  561. ElfW(Addr) reloc_addr;
  562. if (rpnt->next)
  563. goof = _dl_fixup(rpnt->next, now_flag);
  564. if (goof)
  565. return goof;
  566. tpnt = rpnt->dyn;
  567. if (!(tpnt->init_flag & RELOCS_DONE))
  568. _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
  569. if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
  570. _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
  571. _dl_progname, UNSUPPORTED_RELOC_STR);
  572. goof++;
  573. return goof;
  574. }
  575. reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
  576. /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
  577. range. Note that according to the ELF spec, this is completely legal! */
  578. #ifdef ELF_MACHINE_PLTREL_OVERLAP
  579. reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
  580. #endif
  581. if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
  582. !(tpnt->init_flag & RELOCS_DONE)) {
  583. reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
  584. relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
  585. if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
  586. reloc_size -= relative_count * sizeof(ELF_RELOC);
  587. elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
  588. reloc_addr += relative_count * sizeof(ELF_RELOC);
  589. }
  590. goof += _dl_parse_relocation_information(rpnt,
  591. reloc_addr,
  592. reloc_size);
  593. tpnt->init_flag |= RELOCS_DONE;
  594. }
  595. if (tpnt->dynamic_info[DT_BIND_NOW])
  596. now_flag = RTLD_NOW;
  597. if (tpnt->dynamic_info[DT_JMPREL] &&
  598. (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
  599. (now_flag && !(tpnt->rtld_flags & now_flag)))) {
  600. tpnt->rtld_flags |= now_flag;
  601. if (!(tpnt->rtld_flags & RTLD_NOW)) {
  602. _dl_parse_lazy_relocation_information(rpnt,
  603. tpnt->dynamic_info[DT_JMPREL],
  604. tpnt->dynamic_info [DT_PLTRELSZ]);
  605. } else {
  606. goof += _dl_parse_relocation_information(rpnt,
  607. tpnt->dynamic_info[DT_JMPREL],
  608. tpnt->dynamic_info[DT_PLTRELSZ]);
  609. }
  610. tpnt->init_flag |= JMP_RELOCS_DONE;
  611. }
  612. return goof;
  613. }
  614. /* Minimal printf which handles only %s, %d, and %x */
  615. void _dl_dprintf(int fd, const char *fmt, ...)
  616. {
  617. #if __WORDSIZE > 32
  618. long int num;
  619. #else
  620. int num;
  621. #endif
  622. va_list args;
  623. char *start, *ptr, *string;
  624. static char *buf;
  625. if (!fmt)
  626. return;
  627. buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
  628. MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  629. if (_dl_mmap_check_error(buf)) {
  630. _dl_write(fd, "mmap of a spare page failed!\n", 29);
  631. _dl_exit(20);
  632. }
  633. start = ptr = buf;
  634. if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
  635. _dl_write(fd, "overflow\n", 11);
  636. _dl_exit(20);
  637. }
  638. _dl_strcpy(buf, fmt);
  639. va_start(args, fmt);
  640. while (start) {
  641. while (*ptr != '%' && *ptr) {
  642. ptr++;
  643. }
  644. if (*ptr == '%') {
  645. *ptr++ = '\0';
  646. _dl_write(fd, start, _dl_strlen(start));
  647. switch (*ptr++) {
  648. case 's':
  649. string = va_arg(args, char *);
  650. if (!string)
  651. _dl_write(fd, "(null)", 6);
  652. else
  653. _dl_write(fd, string, _dl_strlen(string));
  654. break;
  655. case 'i':
  656. case 'd':
  657. {
  658. char tmp[22];
  659. #if __WORDSIZE > 32
  660. num = va_arg(args, long int);
  661. #else
  662. num = va_arg(args, int);
  663. #endif
  664. string = _dl_simple_ltoa(tmp, num);
  665. _dl_write(fd, string, _dl_strlen(string));
  666. break;
  667. }
  668. case 'x':
  669. case 'X':
  670. {
  671. char tmp[22];
  672. #if __WORDSIZE > 32
  673. num = va_arg(args, long int);
  674. #else
  675. num = va_arg(args, int);
  676. #endif
  677. string = _dl_simple_ltoahex(tmp, num);
  678. _dl_write(fd, string, _dl_strlen(string));
  679. break;
  680. }
  681. default:
  682. _dl_write(fd, "(null)", 6);
  683. break;
  684. }
  685. start = ptr;
  686. } else {
  687. _dl_write(fd, start, _dl_strlen(start));
  688. start = NULL;
  689. }
  690. }
  691. _dl_munmap(buf, _dl_pagesize);
  692. return;
  693. }
  694. char *_dl_strdup(const char *string)
  695. {
  696. char *retval;
  697. int len;
  698. len = _dl_strlen(string);
  699. retval = _dl_malloc(len + 1);
  700. _dl_strcpy(retval, string);
  701. return retval;
  702. }
  703. void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[],
  704. void *debug_addr, DL_LOADADDR_TYPE load_off)
  705. {
  706. __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);
  707. }
  708. /* we want this in ldso.so and libdl.a but nowhere else */
  709. #ifdef __USE_GNU
  710. #if defined IS_IN_rtld || (defined IS_IN_libdl && ! defined SHARED)
  711. extern __typeof(dl_iterate_phdr) __dl_iterate_phdr;
  712. int
  713. __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
  714. {
  715. struct elf_resolve *l;
  716. struct dl_phdr_info info;
  717. int ret = 0;
  718. for (l = _dl_loaded_modules; l != NULL; l = l->next) {
  719. info.dlpi_addr = DL_LOADADDR_BASE(l->loadaddr);
  720. info.dlpi_name = l->libname;
  721. info.dlpi_phdr = l->ppnt;
  722. info.dlpi_phnum = l->n_phent;
  723. ret = callback (&info, sizeof (struct dl_phdr_info), data);
  724. if (ret)
  725. break;
  726. }
  727. return ret;
  728. }
  729. strong_alias(__dl_iterate_phdr, dl_iterate_phdr)
  730. #endif
  731. #endif