binfmt_flat.c 26 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953
  1. /****************************************************************************/
  2. /*
  3. * linux/fs/binfmt_flat.c
  4. *
  5. * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
  6. * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
  7. * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
  8. * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
  9. * based heavily on:
  10. *
  11. * linux/fs/binfmt_aout.c:
  12. * Copyright (C) 1991, 1992, 1996 Linus Torvalds
  13. * linux/fs/binfmt_flat.c for 2.0 kernel
  14. * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
  15. * JAN/99 -- coded full program relocation (gerg@snapgear.com)
  16. */
  17. #include <linux/export.h>
  18. #include <linux/kernel.h>
  19. #include <linux/sched.h>
  20. #include <linux/mm.h>
  21. #include <linux/mman.h>
  22. #include <linux/errno.h>
  23. #include <linux/signal.h>
  24. #include <linux/string.h>
  25. #include <linux/fs.h>
  26. #include <linux/file.h>
  27. #include <linux/stat.h>
  28. #include <linux/fcntl.h>
  29. #include <linux/ptrace.h>
  30. #include <linux/user.h>
  31. #include <linux/slab.h>
  32. #include <linux/binfmts.h>
  33. #include <linux/personality.h>
  34. #include <linux/init.h>
  35. #include <linux/flat.h>
  36. #include <linux/syscalls.h>
  37. #include <asm/byteorder.h>
  38. #include <asm/uaccess.h>
  39. #include <asm/unaligned.h>
  40. #include <asm/cacheflush.h>
  41. #include <asm/page.h>
  42. /****************************************************************************/
  43. #if 0
  44. #define DEBUG 1
  45. #endif
  46. #ifdef DEBUG
  47. #define DBG_FLT(a...) printk(a)
  48. #else
  49. #define DBG_FLT(a...)
  50. #endif
  51. /*
  52. * User data (data section and bss) needs to be aligned.
  53. * We pick 0x20 here because it is the max value elf2flt has always
  54. * used in producing FLAT files, and because it seems to be large
  55. * enough to make all the gcc alignment related tests happy.
  56. */
  57. #define FLAT_DATA_ALIGN (0x20)
  58. /*
  59. * User data (stack) also needs to be aligned.
  60. * Here we can be a bit looser than the data sections since this
  61. * needs to only meet arch ABI requirements.
  62. */
  63. #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
  64. #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
  65. #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
  66. struct lib_info {
  67. struct {
  68. unsigned long start_code; /* Start of text segment */
  69. unsigned long start_data; /* Start of data segment */
  70. unsigned long start_brk; /* End of data segment */
  71. unsigned long text_len; /* Length of text segment */
  72. unsigned long entry; /* Start address for this module */
  73. unsigned long build_date; /* When this one was compiled */
  74. short loaded; /* Has this library been loaded? */
  75. } lib_list[MAX_SHARED_LIBS];
  76. };
  77. #ifdef CONFIG_BINFMT_SHARED_FLAT
  78. static int load_flat_shared_library(int id, struct lib_info *p);
  79. #endif
  80. static int load_flat_binary(struct linux_binprm *);
  81. static int flat_core_dump(struct coredump_params *cprm);
  82. static struct linux_binfmt flat_format = {
  83. .module = THIS_MODULE,
  84. .load_binary = load_flat_binary,
  85. .core_dump = flat_core_dump,
  86. .min_coredump = PAGE_SIZE
  87. };
  88. /****************************************************************************/
  89. /*
  90. * Routine writes a core dump image in the current directory.
  91. * Currently only a stub-function.
  92. */
  93. static int flat_core_dump(struct coredump_params *cprm)
  94. {
  95. printk("Process %s:%d received signr %d and should have core dumped\n",
  96. current->comm, current->pid, (int) cprm->siginfo->si_signo);
  97. return(1);
  98. }
  99. /****************************************************************************/
  100. /*
  101. * create_flat_tables() parses the env- and arg-strings in new user
  102. * memory and creates the pointer tables from them, and puts their
  103. * addresses on the "stack", returning the new stack pointer value.
  104. */
  105. static unsigned long create_flat_tables(
  106. unsigned long pp,
  107. struct linux_binprm * bprm)
  108. {
  109. unsigned long *argv,*envp;
  110. unsigned long * sp;
  111. char * p = (char*)pp;
  112. int argc = bprm->argc;
  113. int envc = bprm->envc;
  114. char uninitialized_var(dummy);
  115. sp = (unsigned long *)p;
  116. sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
  117. sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN);
  118. argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
  119. envp = argv + (argc + 1);
  120. if (flat_argvp_envp_on_stack()) {
  121. put_user((unsigned long) envp, sp + 2);
  122. put_user((unsigned long) argv, sp + 1);
  123. }
  124. put_user(argc, sp);
  125. current->mm->arg_start = (unsigned long) p;
  126. while (argc-->0) {
  127. put_user((unsigned long) p, argv++);
  128. do {
  129. get_user(dummy, p); p++;
  130. } while (dummy);
  131. }
  132. put_user((unsigned long) NULL, argv);
  133. current->mm->arg_end = current->mm->env_start = (unsigned long) p;
  134. while (envc-->0) {
  135. put_user((unsigned long)p, envp); envp++;
  136. do {
  137. get_user(dummy, p); p++;
  138. } while (dummy);
  139. }
  140. put_user((unsigned long) NULL, envp);
  141. current->mm->env_end = (unsigned long) p;
  142. return (unsigned long)sp;
  143. }
  144. /****************************************************************************/
  145. #ifdef CONFIG_BINFMT_ZFLAT
  146. #include <linux/zlib.h>
  147. #define LBUFSIZE 4000
  148. /* gzip flag byte */
  149. #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
  150. #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  151. #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
  152. #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
  153. #define COMMENT 0x10 /* bit 4 set: file comment present */
  154. #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
  155. #define RESERVED 0xC0 /* bit 6,7: reserved */
  156. static int decompress_exec(
  157. struct linux_binprm *bprm,
  158. unsigned long offset,
  159. char *dst,
  160. long len,
  161. int fd)
  162. {
  163. unsigned char *buf;
  164. z_stream strm;
  165. loff_t fpos;
  166. int ret, retval;
  167. DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
  168. memset(&strm, 0, sizeof(strm));
  169. strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
  170. if (strm.workspace == NULL) {
  171. DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
  172. return -ENOMEM;
  173. }
  174. buf = kmalloc(LBUFSIZE, GFP_KERNEL);
  175. if (buf == NULL) {
  176. DBG_FLT("binfmt_flat: no memory for read buffer\n");
  177. retval = -ENOMEM;
  178. goto out_free;
  179. }
  180. /* Read in first chunk of data and parse gzip header. */
  181. fpos = offset;
  182. ret = kernel_read(bprm->file, offset, buf, LBUFSIZE);
  183. strm.next_in = buf;
  184. strm.avail_in = ret;
  185. strm.total_in = 0;
  186. fpos += ret;
  187. retval = -ENOEXEC;
  188. /* Check minimum size -- gzip header */
  189. if (ret < 10) {
  190. DBG_FLT("binfmt_flat: file too small?\n");
  191. goto out_free_buf;
  192. }
  193. /* Check gzip magic number */
  194. if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
  195. DBG_FLT("binfmt_flat: unknown compression magic?\n");
  196. goto out_free_buf;
  197. }
  198. /* Check gzip method */
  199. if (buf[2] != 8) {
  200. DBG_FLT("binfmt_flat: unknown compression method?\n");
  201. goto out_free_buf;
  202. }
  203. /* Check gzip flags */
  204. if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
  205. (buf[3] & RESERVED)) {
  206. DBG_FLT("binfmt_flat: unknown flags?\n");
  207. goto out_free_buf;
  208. }
  209. ret = 10;
  210. if (buf[3] & EXTRA_FIELD) {
  211. ret += 2 + buf[10] + (buf[11] << 8);
  212. if (unlikely(LBUFSIZE <= ret)) {
  213. DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
  214. goto out_free_buf;
  215. }
  216. }
  217. if (buf[3] & ORIG_NAME) {
  218. while (ret < LBUFSIZE && buf[ret++] != 0)
  219. ;
  220. if (unlikely(LBUFSIZE == ret)) {
  221. DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
  222. goto out_free_buf;
  223. }
  224. }
  225. if (buf[3] & COMMENT) {
  226. while (ret < LBUFSIZE && buf[ret++] != 0)
  227. ;
  228. if (unlikely(LBUFSIZE == ret)) {
  229. DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
  230. goto out_free_buf;
  231. }
  232. }
  233. strm.next_in += ret;
  234. strm.avail_in -= ret;
  235. strm.next_out = dst;
  236. strm.avail_out = len;
  237. strm.total_out = 0;
  238. if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
  239. DBG_FLT("binfmt_flat: zlib init failed?\n");
  240. goto out_free_buf;
  241. }
  242. while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
  243. ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);
  244. if (ret <= 0)
  245. break;
  246. len -= ret;
  247. strm.next_in = buf;
  248. strm.avail_in = ret;
  249. strm.total_in = 0;
  250. fpos += ret;
  251. }
  252. if (ret < 0) {
  253. DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
  254. ret, strm.msg);
  255. goto out_zlib;
  256. }
  257. retval = 0;
  258. out_zlib:
  259. zlib_inflateEnd(&strm);
  260. out_free_buf:
  261. kfree(buf);
  262. out_free:
  263. kfree(strm.workspace);
  264. return retval;
  265. }
  266. #endif /* CONFIG_BINFMT_ZFLAT */
  267. /****************************************************************************/
  268. static unsigned long
  269. calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
  270. {
  271. unsigned long addr;
  272. int id;
  273. unsigned long start_brk;
  274. unsigned long start_data;
  275. unsigned long text_len;
  276. unsigned long start_code;
  277. #ifdef CONFIG_BINFMT_SHARED_FLAT
  278. if (r == 0)
  279. id = curid; /* Relocs of 0 are always self referring */
  280. else {
  281. id = (r >> 24) & 0xff; /* Find ID for this reloc */
  282. r &= 0x00ffffff; /* Trim ID off here */
  283. }
  284. if (id >= MAX_SHARED_LIBS) {
  285. printk("BINFMT_FLAT: reference 0x%x to shared library %d",
  286. (unsigned) r, id);
  287. goto failed;
  288. }
  289. if (curid != id) {
  290. if (internalp) {
  291. printk("BINFMT_FLAT: reloc address 0x%x not in same module "
  292. "(%d != %d)", (unsigned) r, curid, id);
  293. goto failed;
  294. } else if ( ! p->lib_list[id].loaded &&
  295. IS_ERR_VALUE(load_flat_shared_library(id, p))) {
  296. printk("BINFMT_FLAT: failed to load library %d", id);
  297. goto failed;
  298. }
  299. /* Check versioning information (i.e. time stamps) */
  300. if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
  301. p->lib_list[curid].build_date < p->lib_list[id].build_date) {
  302. printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
  303. goto failed;
  304. }
  305. }
  306. #else
  307. id = 0;
  308. #endif
  309. start_brk = p->lib_list[id].start_brk;
  310. start_data = p->lib_list[id].start_data;
  311. start_code = p->lib_list[id].start_code;
  312. text_len = p->lib_list[id].text_len;
  313. if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
  314. printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
  315. (int) r,(int)(start_brk-start_data+text_len),(int)text_len);
  316. goto failed;
  317. }
  318. if (r < text_len) /* In text segment */
  319. addr = r + start_code;
  320. else /* In data segment */
  321. addr = r - text_len + start_data;
  322. /* Range checked already above so doing the range tests is redundant...*/
  323. return(addr);
  324. failed:
  325. printk(", killing %s!\n", current->comm);
  326. send_sig(SIGSEGV, current, 0);
  327. return RELOC_FAILED;
  328. }
  329. /****************************************************************************/
  330. static void old_reloc(unsigned long rl)
  331. {
  332. #ifdef DEBUG
  333. char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
  334. #endif
  335. flat_v2_reloc_t r;
  336. unsigned long *ptr;
  337. r.value = rl;
  338. #if defined(CONFIG_COLDFIRE)
  339. ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
  340. #else
  341. ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
  342. #endif
  343. #ifdef DEBUG
  344. printk("Relocation of variable at DATASEG+%x "
  345. "(address %p, currently %x) into segment %s\n",
  346. r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
  347. #endif
  348. switch (r.reloc.type) {
  349. case OLD_FLAT_RELOC_TYPE_TEXT:
  350. *ptr += current->mm->start_code;
  351. break;
  352. case OLD_FLAT_RELOC_TYPE_DATA:
  353. *ptr += current->mm->start_data;
  354. break;
  355. case OLD_FLAT_RELOC_TYPE_BSS:
  356. *ptr += current->mm->end_data;
  357. break;
  358. default:
  359. printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
  360. break;
  361. }
  362. #ifdef DEBUG
  363. printk("Relocation became %x\n", (int)*ptr);
  364. #endif
  365. }
  366. /****************************************************************************/
  367. static int load_flat_file(struct linux_binprm * bprm,
  368. struct lib_info *libinfo, int id, unsigned long *extra_stack)
  369. {
  370. struct flat_hdr * hdr;
  371. unsigned long textpos = 0, datapos = 0, result;
  372. unsigned long realdatastart = 0;
  373. unsigned long text_len, data_len, bss_len, stack_len, flags;
  374. unsigned long full_data;
  375. unsigned long len, memp = 0;
  376. unsigned long memp_size, extra, rlim;
  377. unsigned long *reloc = 0, *rp;
  378. struct inode *inode;
  379. int i, rev, relocs = 0;
  380. loff_t fpos;
  381. unsigned long start_code, end_code;
  382. int ret;
  383. hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
  384. inode = file_inode(bprm->file);
  385. text_len = ntohl(hdr->data_start);
  386. data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
  387. bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
  388. stack_len = ntohl(hdr->stack_size);
  389. if (extra_stack) {
  390. stack_len += *extra_stack;
  391. *extra_stack = stack_len;
  392. }
  393. relocs = ntohl(hdr->reloc_count);
  394. flags = ntohl(hdr->flags);
  395. rev = ntohl(hdr->rev);
  396. full_data = data_len + relocs * sizeof(unsigned long);
  397. if (strncmp(hdr->magic, "bFLT", 4)) {
  398. /*
  399. * Previously, here was a printk to tell people
  400. * "BINFMT_FLAT: bad header magic".
  401. * But for the kernel which also use ELF FD-PIC format, this
  402. * error message is confusing.
  403. * because a lot of people do not manage to produce good
  404. */
  405. ret = -ENOEXEC;
  406. goto err;
  407. }
  408. if (flags & FLAT_FLAG_KTRACE)
  409. printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
  410. if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
  411. printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
  412. "0x%lx and 0x%lx)\n",
  413. rev, FLAT_VERSION, OLD_FLAT_VERSION);
  414. ret = -ENOEXEC;
  415. goto err;
  416. }
  417. /* Don't allow old format executables to use shared libraries */
  418. if (rev == OLD_FLAT_VERSION && id != 0) {
  419. printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
  420. (int) FLAT_VERSION);
  421. ret = -ENOEXEC;
  422. goto err;
  423. }
  424. /*
  425. * fix up the flags for the older format, there were all kinds
  426. * of endian hacks, this only works for the simple cases
  427. */
  428. if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
  429. flags = FLAT_FLAG_RAM;
  430. #ifndef CONFIG_BINFMT_ZFLAT
  431. if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
  432. printk("Support for ZFLAT executables is not enabled.\n");
  433. ret = -ENOEXEC;
  434. goto err;
  435. }
  436. #endif
  437. /*
  438. * Check initial limits. This avoids letting people circumvent
  439. * size limits imposed on them by creating programs with large
  440. * arrays in the data or bss.
  441. */
  442. rlim = rlimit(RLIMIT_DATA);
  443. if (rlim >= RLIM_INFINITY)
  444. rlim = ~0;
  445. if (data_len + bss_len > rlim) {
  446. ret = -ENOMEM;
  447. goto err;
  448. }
  449. /* Flush all traces of the currently running executable */
  450. if (id == 0) {
  451. result = flush_old_exec(bprm);
  452. if (result) {
  453. ret = result;
  454. goto err;
  455. }
  456. /* OK, This is the point of no return */
  457. set_personality(PER_LINUX_32BIT);
  458. setup_new_exec(bprm);
  459. }
  460. /*
  461. * calculate the extra space we need to map in
  462. */
  463. extra = max_t(unsigned long, bss_len + stack_len,
  464. relocs * sizeof(unsigned long));
  465. /*
  466. * there are a couple of cases here, the separate code/data
  467. * case, and then the fully copied to RAM case which lumps
  468. * it all together.
  469. */
  470. if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
  471. /*
  472. * this should give us a ROM ptr, but if it doesn't we don't
  473. * really care
  474. */
  475. DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
  476. textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
  477. MAP_PRIVATE|MAP_EXECUTABLE, 0);
  478. if (!textpos || IS_ERR_VALUE(textpos)) {
  479. if (!textpos)
  480. textpos = (unsigned long) -ENOMEM;
  481. printk("Unable to mmap process text, errno %d\n", (int)-textpos);
  482. ret = textpos;
  483. goto err;
  484. }
  485. len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
  486. len = PAGE_ALIGN(len);
  487. realdatastart = vm_mmap(0, 0, len,
  488. PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
  489. if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
  490. if (!realdatastart)
  491. realdatastart = (unsigned long) -ENOMEM;
  492. printk("Unable to allocate RAM for process data, errno %d\n",
  493. (int)-realdatastart);
  494. vm_munmap(textpos, text_len);
  495. ret = realdatastart;
  496. goto err;
  497. }
  498. datapos = ALIGN(realdatastart +
  499. MAX_SHARED_LIBS * sizeof(unsigned long),
  500. FLAT_DATA_ALIGN);
  501. DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
  502. (int)(data_len + bss_len + stack_len), (int)datapos);
  503. fpos = ntohl(hdr->data_start);
  504. #ifdef CONFIG_BINFMT_ZFLAT
  505. if (flags & FLAT_FLAG_GZDATA) {
  506. result = decompress_exec(bprm, fpos, (char *) datapos,
  507. full_data, 0);
  508. } else
  509. #endif
  510. {
  511. result = read_code(bprm->file, datapos, fpos,
  512. full_data);
  513. }
  514. if (IS_ERR_VALUE(result)) {
  515. printk("Unable to read data+bss, errno %d\n", (int)-result);
  516. vm_munmap(textpos, text_len);
  517. vm_munmap(realdatastart, len);
  518. ret = result;
  519. goto err;
  520. }
  521. reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
  522. memp = realdatastart;
  523. memp_size = len;
  524. } else {
  525. len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
  526. len = PAGE_ALIGN(len);
  527. textpos = vm_mmap(0, 0, len,
  528. PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
  529. if (!textpos || IS_ERR_VALUE(textpos)) {
  530. if (!textpos)
  531. textpos = (unsigned long) -ENOMEM;
  532. printk("Unable to allocate RAM for process text/data, errno %d\n",
  533. (int)-textpos);
  534. ret = textpos;
  535. goto err;
  536. }
  537. realdatastart = textpos + ntohl(hdr->data_start);
  538. datapos = ALIGN(realdatastart +
  539. MAX_SHARED_LIBS * sizeof(unsigned long),
  540. FLAT_DATA_ALIGN);
  541. reloc = (unsigned long *)
  542. (datapos + (ntohl(hdr->reloc_start) - text_len));
  543. memp = textpos;
  544. memp_size = len;
  545. #ifdef CONFIG_BINFMT_ZFLAT
  546. /*
  547. * load it all in and treat it like a RAM load from now on
  548. */
  549. if (flags & FLAT_FLAG_GZIP) {
  550. result = decompress_exec(bprm, sizeof (struct flat_hdr),
  551. (((char *) textpos) + sizeof (struct flat_hdr)),
  552. (text_len + full_data
  553. - sizeof (struct flat_hdr)),
  554. 0);
  555. memmove((void *) datapos, (void *) realdatastart,
  556. full_data);
  557. } else if (flags & FLAT_FLAG_GZDATA) {
  558. result = read_code(bprm->file, textpos, 0, text_len);
  559. if (!IS_ERR_VALUE(result))
  560. result = decompress_exec(bprm, text_len, (char *) datapos,
  561. full_data, 0);
  562. }
  563. else
  564. #endif
  565. {
  566. result = read_code(bprm->file, textpos, 0, text_len);
  567. if (!IS_ERR_VALUE(result))
  568. result = read_code(bprm->file, datapos,
  569. ntohl(hdr->data_start),
  570. full_data);
  571. }
  572. if (IS_ERR_VALUE(result)) {
  573. printk("Unable to read code+data+bss, errno %d\n",(int)-result);
  574. vm_munmap(textpos, text_len + data_len + extra +
  575. MAX_SHARED_LIBS * sizeof(unsigned long));
  576. ret = result;
  577. goto err;
  578. }
  579. }
  580. if (flags & FLAT_FLAG_KTRACE)
  581. printk("Mapping is %x, Entry point is %x, data_start is %x\n",
  582. (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
  583. /* The main program needs a little extra setup in the task structure */
  584. start_code = textpos + sizeof (struct flat_hdr);
  585. end_code = textpos + text_len;
  586. if (id == 0) {
  587. current->mm->start_code = start_code;
  588. current->mm->end_code = end_code;
  589. current->mm->start_data = datapos;
  590. current->mm->end_data = datapos + data_len;
  591. /*
  592. * set up the brk stuff, uses any slack left in data/bss/stack
  593. * allocation. We put the brk after the bss (between the bss
  594. * and stack) like other platforms.
  595. * Userspace code relies on the stack pointer starting out at
  596. * an address right at the end of a page.
  597. */
  598. current->mm->start_brk = datapos + data_len + bss_len;
  599. current->mm->brk = (current->mm->start_brk + 3) & ~3;
  600. current->mm->context.end_brk = memp + memp_size - stack_len;
  601. }
  602. if (flags & FLAT_FLAG_KTRACE)
  603. printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
  604. id ? "Lib" : "Load", bprm->filename,
  605. (int) start_code, (int) end_code,
  606. (int) datapos,
  607. (int) (datapos + data_len),
  608. (int) (datapos + data_len),
  609. (int) (((datapos + data_len + bss_len) + 3) & ~3));
  610. text_len -= sizeof(struct flat_hdr); /* the real code len */
  611. /* Store the current module values into the global library structure */
  612. libinfo->lib_list[id].start_code = start_code;
  613. libinfo->lib_list[id].start_data = datapos;
  614. libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
  615. libinfo->lib_list[id].text_len = text_len;
  616. libinfo->lib_list[id].loaded = 1;
  617. libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
  618. libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
  619. /*
  620. * We just load the allocations into some temporary memory to
  621. * help simplify all this mumbo jumbo
  622. *
  623. * We've got two different sections of relocation entries.
  624. * The first is the GOT which resides at the beginning of the data segment
  625. * and is terminated with a -1. This one can be relocated in place.
  626. * The second is the extra relocation entries tacked after the image's
  627. * data segment. These require a little more processing as the entry is
  628. * really an offset into the image which contains an offset into the
  629. * image.
  630. */
  631. if (flags & FLAT_FLAG_GOTPIC) {
  632. for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
  633. unsigned long addr;
  634. if (*rp) {
  635. addr = calc_reloc(*rp, libinfo, id, 0);
  636. if (addr == RELOC_FAILED) {
  637. ret = -ENOEXEC;
  638. goto err;
  639. }
  640. *rp = addr;
  641. }
  642. }
  643. }
  644. /*
  645. * Now run through the relocation entries.
  646. * We've got to be careful here as C++ produces relocatable zero
  647. * entries in the constructor and destructor tables which are then
  648. * tested for being not zero (which will always occur unless we're
  649. * based from address zero). This causes an endless loop as __start
  650. * is at zero. The solution used is to not relocate zero addresses.
  651. * This has the negative side effect of not allowing a global data
  652. * reference to be statically initialised to _stext (I've moved
  653. * __start to address 4 so that is okay).
  654. */
  655. if (rev > OLD_FLAT_VERSION) {
  656. unsigned long persistent = 0;
  657. for (i=0; i < relocs; i++) {
  658. unsigned long addr, relval;
  659. /* Get the address of the pointer to be
  660. relocated (of course, the address has to be
  661. relocated first). */
  662. relval = ntohl(reloc[i]);
  663. if (flat_set_persistent (relval, &persistent))
  664. continue;
  665. addr = flat_get_relocate_addr(relval);
  666. rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
  667. if (rp == (unsigned long *)RELOC_FAILED) {
  668. ret = -ENOEXEC;
  669. goto err;
  670. }
  671. /* Get the pointer's value. */
  672. addr = flat_get_addr_from_rp(rp, relval, flags,
  673. &persistent);
  674. if (addr != 0) {
  675. /*
  676. * Do the relocation. PIC relocs in the data section are
  677. * already in target order
  678. */
  679. if ((flags & FLAT_FLAG_GOTPIC) == 0)
  680. addr = ntohl(addr);
  681. addr = calc_reloc(addr, libinfo, id, 0);
  682. if (addr == RELOC_FAILED) {
  683. ret = -ENOEXEC;
  684. goto err;
  685. }
  686. /* Write back the relocated pointer. */
  687. flat_put_addr_at_rp(rp, addr, relval);
  688. }
  689. }
  690. } else {
  691. for (i=0; i < relocs; i++)
  692. old_reloc(ntohl(reloc[i]));
  693. }
  694. flush_icache_range(start_code, end_code);
  695. /* zero the BSS, BRK and stack areas */
  696. memset((void*)(datapos + data_len), 0, bss_len +
  697. (memp + memp_size - stack_len - /* end brk */
  698. libinfo->lib_list[id].start_brk) + /* start brk */
  699. stack_len);
  700. return 0;
  701. err:
  702. return ret;
  703. }
  704. /****************************************************************************/
  705. #ifdef CONFIG_BINFMT_SHARED_FLAT
  706. /*
  707. * Load a shared library into memory. The library gets its own data
  708. * segment (including bss) but not argv/argc/environ.
  709. */
  710. static int load_flat_shared_library(int id, struct lib_info *libs)
  711. {
  712. struct linux_binprm bprm;
  713. int res;
  714. char buf[16];
  715. memset(&bprm, 0, sizeof(bprm));
  716. /* Create the file name */
  717. sprintf(buf, "/lib/lib%d.so", id);
  718. /* Open the file up */
  719. bprm.filename = buf;
  720. bprm.file = open_exec(bprm.filename);
  721. res = PTR_ERR(bprm.file);
  722. if (IS_ERR(bprm.file))
  723. return res;
  724. bprm.cred = prepare_exec_creds();
  725. res = -ENOMEM;
  726. if (!bprm.cred)
  727. goto out;
  728. /* We don't really care about recalculating credentials at this point
  729. * as we're past the point of no return and are dealing with shared
  730. * libraries.
  731. */
  732. bprm.cred_prepared = 1;
  733. res = prepare_binprm(&bprm);
  734. if (!IS_ERR_VALUE(res))
  735. res = load_flat_file(&bprm, libs, id, NULL);
  736. abort_creds(bprm.cred);
  737. out:
  738. allow_write_access(bprm.file);
  739. fput(bprm.file);
  740. return(res);
  741. }
  742. #endif /* CONFIG_BINFMT_SHARED_FLAT */
  743. /****************************************************************************/
  744. /*
  745. * These are the functions used to load flat style executables and shared
  746. * libraries. There is no binary dependent code anywhere else.
  747. */
  748. static int load_flat_binary(struct linux_binprm * bprm)
  749. {
  750. struct lib_info libinfo;
  751. struct pt_regs *regs = current_pt_regs();
  752. unsigned long p = bprm->p;
  753. unsigned long stack_len;
  754. unsigned long start_addr;
  755. unsigned long *sp;
  756. int res;
  757. int i, j;
  758. memset(&libinfo, 0, sizeof(libinfo));
  759. /*
  760. * We have to add the size of our arguments to our stack size
  761. * otherwise it's too easy for users to create stack overflows
  762. * by passing in a huge argument list. And yes, we have to be
  763. * pedantic and include space for the argv/envp array as it may have
  764. * a lot of entries.
  765. */
  766. #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
  767. stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
  768. stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
  769. stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
  770. stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */
  771. res = load_flat_file(bprm, &libinfo, 0, &stack_len);
  772. if (IS_ERR_VALUE(res))
  773. return res;
  774. /* Update data segment pointers for all libraries */
  775. for (i=0; i<MAX_SHARED_LIBS; i++)
  776. if (libinfo.lib_list[i].loaded)
  777. for (j=0; j<MAX_SHARED_LIBS; j++)
  778. (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
  779. (libinfo.lib_list[j].loaded)?
  780. libinfo.lib_list[j].start_data:UNLOADED_LIB;
  781. install_exec_creds(bprm);
  782. set_binfmt(&flat_format);
  783. p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
  784. DBG_FLT("p=%x\n", (int)p);
  785. /* copy the arg pages onto the stack, this could be more efficient :-) */
  786. for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
  787. * (char *) --p =
  788. ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
  789. sp = (unsigned long *) create_flat_tables(p, bprm);
  790. /* Fake some return addresses to ensure the call chain will
  791. * initialise library in order for us. We are required to call
  792. * lib 1 first, then 2, ... and finally the main program (id 0).
  793. */
  794. start_addr = libinfo.lib_list[0].entry;
  795. #ifdef CONFIG_BINFMT_SHARED_FLAT
  796. for (i = MAX_SHARED_LIBS-1; i>0; i--) {
  797. if (libinfo.lib_list[i].loaded) {
  798. /* Push previos first to call address */
  799. --sp; put_user(start_addr, sp);
  800. start_addr = libinfo.lib_list[i].entry;
  801. }
  802. }
  803. #endif
  804. /* Stash our initial stack pointer into the mm structure */
  805. current->mm->start_stack = (unsigned long )sp;
  806. #ifdef FLAT_PLAT_INIT
  807. FLAT_PLAT_INIT(regs);
  808. #endif
  809. DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
  810. (int)regs, (int)start_addr, (int)current->mm->start_stack);
  811. start_thread(regs, start_addr, current->mm->start_stack);
  812. return 0;
  813. }
  814. /****************************************************************************/
  815. static int __init init_flat_binfmt(void)
  816. {
  817. register_binfmt(&flat_format);
  818. return 0;
  819. }
  820. /****************************************************************************/
  821. core_initcall(init_flat_binfmt);
  822. /****************************************************************************/