dl-elf.c 23 KB

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  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 = ((l->loadaddr + l->relro_addr)
  103. & ~(_dl_pagesize - 1));
  104. ElfW(Addr) end = ((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. libaddr = 0;
  310. infile = _dl_open(libname, O_RDONLY, 0);
  311. if (infile < 0) {
  312. _dl_internal_error_number = LD_ERROR_NOFILE;
  313. return NULL;
  314. }
  315. if (_dl_fstat(infile, &st) < 0) {
  316. _dl_internal_error_number = LD_ERROR_NOFILE;
  317. _dl_close(infile);
  318. return NULL;
  319. }
  320. /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD),
  321. we don't load the library if it isn't setuid. */
  322. if (secure)
  323. if (!(st.st_mode & S_ISUID)) {
  324. _dl_close(infile);
  325. return NULL;
  326. }
  327. /* Check if file is already loaded */
  328. for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
  329. if (tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) {
  330. /* Already loaded */
  331. tpnt->usage_count++;
  332. _dl_close(infile);
  333. return tpnt;
  334. }
  335. }
  336. header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
  337. MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  338. if (_dl_mmap_check_error(header)) {
  339. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  340. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  341. _dl_close(infile);
  342. return NULL;
  343. }
  344. _dl_read(infile, header, _dl_pagesize);
  345. epnt = (ElfW(Ehdr) *) (intptr_t) header;
  346. if (epnt->e_ident[0] != 0x7f ||
  347. epnt->e_ident[1] != 'E' ||
  348. epnt->e_ident[2] != 'L' ||
  349. epnt->e_ident[3] != 'F')
  350. {
  351. _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
  352. libname);
  353. _dl_internal_error_number = LD_ERROR_NOTELF;
  354. _dl_close(infile);
  355. _dl_munmap(header, _dl_pagesize);
  356. return NULL;
  357. }
  358. if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
  359. #ifdef MAGIC2
  360. && epnt->e_machine != MAGIC2
  361. #endif
  362. ))
  363. {
  364. _dl_internal_error_number =
  365. (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
  366. _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
  367. "\n", _dl_progname, libname);
  368. _dl_close(infile);
  369. _dl_munmap(header, _dl_pagesize);
  370. return NULL;
  371. }
  372. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  373. piclib = 1;
  374. for (i = 0; i < epnt->e_phnum; i++) {
  375. if (ppnt->p_type == PT_DYNAMIC) {
  376. if (dynamic_addr)
  377. _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
  378. _dl_progname, libname);
  379. dynamic_addr = ppnt->p_vaddr;
  380. }
  381. if (ppnt->p_type == PT_LOAD) {
  382. /* See if this is a PIC library. */
  383. if (i == 0 && ppnt->p_vaddr > 0x1000000) {
  384. piclib = 0;
  385. minvma = ppnt->p_vaddr;
  386. }
  387. if (piclib && ppnt->p_vaddr < minvma) {
  388. minvma = ppnt->p_vaddr;
  389. }
  390. if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
  391. maxvma = ppnt->p_vaddr + ppnt->p_memsz;
  392. }
  393. }
  394. ppnt++;
  395. }
  396. maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
  397. minvma = minvma & ~0xffffU;
  398. flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
  399. if (!piclib)
  400. flags |= MAP_FIXED;
  401. status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
  402. maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
  403. if (_dl_mmap_check_error(status)) {
  404. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  405. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  406. _dl_close(infile);
  407. _dl_munmap(header, _dl_pagesize);
  408. return NULL;
  409. }
  410. libaddr = (unsigned long) status;
  411. flags |= MAP_FIXED;
  412. /* Get the memory to store the library */
  413. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  414. for (i = 0; i < epnt->e_phnum; i++) {
  415. if (ppnt->p_type == PT_GNU_RELRO) {
  416. relro_addr = ppnt->p_vaddr;
  417. relro_size = ppnt->p_memsz;
  418. }
  419. if (ppnt->p_type == PT_LOAD) {
  420. /* See if this is a PIC library. */
  421. if (i == 0 && ppnt->p_vaddr > 0x1000000) {
  422. piclib = 0;
  423. /* flags |= MAP_FIXED; */
  424. }
  425. if (ppnt->p_flags & PF_W) {
  426. unsigned long map_size;
  427. char *cpnt;
  428. status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
  429. (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
  430. + ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
  431. ppnt->p_offset & OFFS_ALIGN);
  432. if (_dl_mmap_check_error(status)) {
  433. _dl_dprintf(2, "%s:%i: can't map '%s'\n",
  434. _dl_progname, __LINE__, libname);
  435. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  436. _dl_munmap((char *) libaddr, maxvma - minvma);
  437. _dl_close(infile);
  438. _dl_munmap(header, _dl_pagesize);
  439. return NULL;
  440. }
  441. /* Pad the last page with zeroes. */
  442. cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
  443. ppnt->p_filesz);
  444. while (((unsigned long) cpnt) & ADDR_ALIGN)
  445. *cpnt++ = 0;
  446. /* I am not quite sure if this is completely
  447. * correct to do or not, but the basic way that
  448. * we handle bss segments is that we mmap
  449. * /dev/zero if there are any pages left over
  450. * that are not mapped as part of the file */
  451. map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;
  452. if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
  453. status = (char *) _dl_mmap((char *) map_size +
  454. (piclib ? libaddr : 0),
  455. ppnt->p_vaddr + ppnt->p_memsz - map_size,
  456. LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
  457. } else
  458. status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
  459. + (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
  460. ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
  461. infile, ppnt->p_offset & OFFS_ALIGN);
  462. if (_dl_mmap_check_error(status)) {
  463. _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
  464. _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
  465. _dl_munmap((char *) libaddr, maxvma - minvma);
  466. _dl_close(infile);
  467. _dl_munmap(header, _dl_pagesize);
  468. return NULL;
  469. }
  470. /* if (libaddr == 0 && piclib) {
  471. libaddr = (unsigned long) status;
  472. flags |= MAP_FIXED;
  473. } */
  474. }
  475. ppnt++;
  476. }
  477. _dl_close(infile);
  478. /* For a non-PIC library, the addresses are all absolute */
  479. if (piclib) {
  480. dynamic_addr += (unsigned long) libaddr;
  481. }
  482. /*
  483. * OK, the ELF library is now loaded into VM in the correct locations
  484. * The next step is to go through and do the dynamic linking (if needed).
  485. */
  486. /* Start by scanning the dynamic section to get all of the pointers */
  487. if (!dynamic_addr) {
  488. _dl_internal_error_number = LD_ERROR_NODYNAMIC;
  489. _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
  490. _dl_progname, libname);
  491. _dl_munmap(header, _dl_pagesize);
  492. return NULL;
  493. }
  494. dpnt = (ElfW(Dyn) *) dynamic_addr;
  495. _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
  496. _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, libaddr);
  497. /* If the TEXTREL is set, this means that we need to make the pages
  498. writable before we perform relocations. Do this now. They get set
  499. back again later. */
  500. if (dynamic_info[DT_TEXTREL]) {
  501. #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
  502. ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
  503. for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
  504. if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
  505. _dl_mprotect((void *) ((piclib ? libaddr : 0) +
  506. (ppnt->p_vaddr & PAGE_ALIGN)),
  507. (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
  508. PROT_READ | PROT_WRITE | PROT_EXEC);
  509. }
  510. #else
  511. _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
  512. _dl_exit(1);
  513. #endif
  514. }
  515. tpnt = _dl_add_elf_hash_table(libname, (char *) libaddr, dynamic_info,
  516. dynamic_addr, 0);
  517. tpnt->relro_addr = relro_addr;
  518. tpnt->relro_size = relro_size;
  519. tpnt->st_dev = st.st_dev;
  520. tpnt->st_ino = st.st_ino;
  521. tpnt->ppnt = (ElfW(Phdr) *)(intptr_t) (tpnt->loadaddr + epnt->e_phoff);
  522. tpnt->n_phent = epnt->e_phnum;
  523. /*
  524. * Add this object into the symbol chain
  525. */
  526. if (*rpnt) {
  527. (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
  528. _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
  529. (*rpnt)->next->prev = (*rpnt);
  530. *rpnt = (*rpnt)->next;
  531. (*rpnt)->dyn = tpnt;
  532. tpnt->symbol_scope = _dl_symbol_tables;
  533. }
  534. tpnt->usage_count++;
  535. tpnt->libtype = elf_lib;
  536. /*
  537. * OK, the next thing we need to do is to insert the dynamic linker into
  538. * the proper entry in the GOT so that the PLT symbols can be properly
  539. * resolved.
  540. */
  541. lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
  542. if (lpnt) {
  543. lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
  544. INIT_GOT(lpnt, tpnt);
  545. }
  546. _dl_if_debug_dprint("\n\tfile='%s'; generating link map\n", libname);
  547. _dl_if_debug_dprint("\t\tdynamic: %x base: %x\n", dynamic_addr, libaddr);
  548. _dl_if_debug_dprint("\t\t entry: %x phdr: %x phnum: %x\n\n",
  549. epnt->e_entry + libaddr, tpnt->ppnt, tpnt->n_phent);
  550. _dl_munmap(header, _dl_pagesize);
  551. return tpnt;
  552. }
  553. /* now_flag must be RTLD_NOW or zero */
  554. int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
  555. {
  556. int goof = 0;
  557. struct elf_resolve *tpnt;
  558. ElfW(Word) reloc_size, relative_count;
  559. ElfW(Addr) reloc_addr;
  560. if (rpnt->next)
  561. goof = _dl_fixup(rpnt->next, now_flag);
  562. if (goof)
  563. return goof;
  564. tpnt = rpnt->dyn;
  565. if (!(tpnt->init_flag & RELOCS_DONE))
  566. _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
  567. if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
  568. _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
  569. _dl_progname, UNSUPPORTED_RELOC_STR);
  570. goof++;
  571. return goof;
  572. }
  573. reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
  574. /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
  575. range. Note that according to the ELF spec, this is completely legal! */
  576. #ifdef ELF_MACHINE_PLTREL_OVERLAP
  577. reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
  578. #endif
  579. if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
  580. !(tpnt->init_flag & RELOCS_DONE)) {
  581. reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
  582. relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
  583. if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
  584. reloc_size -= relative_count * sizeof(ELF_RELOC);
  585. elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
  586. reloc_addr += relative_count * sizeof(ELF_RELOC);
  587. }
  588. goof += _dl_parse_relocation_information(rpnt,
  589. reloc_addr,
  590. reloc_size);
  591. tpnt->init_flag |= RELOCS_DONE;
  592. }
  593. if (tpnt->dynamic_info[DT_BIND_NOW])
  594. now_flag = RTLD_NOW;
  595. if (tpnt->dynamic_info[DT_JMPREL] &&
  596. (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
  597. (now_flag && !(tpnt->rtld_flags & now_flag)))) {
  598. tpnt->rtld_flags |= now_flag;
  599. if (!(tpnt->rtld_flags & RTLD_NOW)) {
  600. _dl_parse_lazy_relocation_information(rpnt,
  601. tpnt->dynamic_info[DT_JMPREL],
  602. tpnt->dynamic_info [DT_PLTRELSZ]);
  603. } else {
  604. goof += _dl_parse_relocation_information(rpnt,
  605. tpnt->dynamic_info[DT_JMPREL],
  606. tpnt->dynamic_info[DT_PLTRELSZ]);
  607. }
  608. tpnt->init_flag |= JMP_RELOCS_DONE;
  609. }
  610. return goof;
  611. }
  612. /* Minimal printf which handles only %s, %d, and %x */
  613. void _dl_dprintf(int fd, const char *fmt, ...)
  614. {
  615. #if __WORDSIZE > 32
  616. long int num;
  617. #else
  618. int num;
  619. #endif
  620. va_list args;
  621. char *start, *ptr, *string;
  622. static char *buf;
  623. if (!fmt)
  624. return;
  625. buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
  626. MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  627. if (_dl_mmap_check_error(buf)) {
  628. _dl_write(fd, "mmap of a spare page failed!\n", 29);
  629. _dl_exit(20);
  630. }
  631. start = ptr = buf;
  632. if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
  633. _dl_write(fd, "overflow\n", 11);
  634. _dl_exit(20);
  635. }
  636. _dl_strcpy(buf, fmt);
  637. va_start(args, fmt);
  638. while (start) {
  639. while (*ptr != '%' && *ptr) {
  640. ptr++;
  641. }
  642. if (*ptr == '%') {
  643. *ptr++ = '\0';
  644. _dl_write(fd, start, _dl_strlen(start));
  645. switch (*ptr++) {
  646. case 's':
  647. string = va_arg(args, char *);
  648. if (!string)
  649. _dl_write(fd, "(null)", 6);
  650. else
  651. _dl_write(fd, string, _dl_strlen(string));
  652. break;
  653. case 'i':
  654. case 'd':
  655. {
  656. char tmp[22];
  657. #if __WORDSIZE > 32
  658. num = va_arg(args, long int);
  659. #else
  660. num = va_arg(args, int);
  661. #endif
  662. string = _dl_simple_ltoa(tmp, num);
  663. _dl_write(fd, string, _dl_strlen(string));
  664. break;
  665. }
  666. case 'x':
  667. case 'X':
  668. {
  669. char tmp[22];
  670. #if __WORDSIZE > 32
  671. num = va_arg(args, long int);
  672. #else
  673. num = va_arg(args, int);
  674. #endif
  675. string = _dl_simple_ltoahex(tmp, num);
  676. _dl_write(fd, string, _dl_strlen(string));
  677. break;
  678. }
  679. default:
  680. _dl_write(fd, "(null)", 6);
  681. break;
  682. }
  683. start = ptr;
  684. } else {
  685. _dl_write(fd, start, _dl_strlen(start));
  686. start = NULL;
  687. }
  688. }
  689. _dl_munmap(buf, _dl_pagesize);
  690. return;
  691. }
  692. char *_dl_strdup(const char *string)
  693. {
  694. char *retval;
  695. int len;
  696. len = _dl_strlen(string);
  697. retval = _dl_malloc(len + 1);
  698. _dl_strcpy(retval, string);
  699. return retval;
  700. }
  701. void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], void *debug_addr, ElfW(Addr) load_off)
  702. {
  703. __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);
  704. }
  705. /* we want this in ldso.so and libdl.a but nowhere else */
  706. #ifdef __USE_GNU
  707. #if defined IS_IN_rtld || (defined IS_IN_libdl && ! defined SHARED)
  708. extern __typeof(dl_iterate_phdr) __dl_iterate_phdr;
  709. int
  710. __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
  711. {
  712. struct elf_resolve *l;
  713. struct dl_phdr_info info;
  714. int ret = 0;
  715. for (l = _dl_loaded_modules; l != NULL; l = l->next) {
  716. info.dlpi_addr = l->loadaddr;
  717. info.dlpi_name = l->libname;
  718. info.dlpi_phdr = l->ppnt;
  719. info.dlpi_phnum = l->n_phent;
  720. ret = callback (&info, sizeof (struct dl_phdr_info), data);
  721. if (ret)
  722. break;
  723. }
  724. return ret;
  725. }
  726. strong_alias(__dl_iterate_phdr, dl_iterate_phdr)
  727. #endif
  728. #endif