binfmt_flat.c 27 KB

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  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/module.h>
  18. #include <linux/kernel.h>
  19. #include <linux/sched.h>
  20. #include <linux/mm.h>
  21. #include <linux/mman.h>
  22. #include <linux/a.out.h>
  23. #include <linux/errno.h>
  24. #include <linux/signal.h>
  25. #include <linux/string.h>
  26. #include <linux/fs.h>
  27. #include <linux/file.h>
  28. #include <linux/stat.h>
  29. #include <linux/fcntl.h>
  30. #include <linux/ptrace.h>
  31. #include <linux/user.h>
  32. #include <linux/slab.h>
  33. #include <linux/binfmts.h>
  34. #include <linux/personality.h>
  35. #include <linux/init.h>
  36. #include <linux/flat.h>
  37. #include <linux/syscalls.h>
  38. #include <asm/byteorder.h>
  39. #include <asm/system.h>
  40. #include <asm/uaccess.h>
  41. #include <asm/unaligned.h>
  42. #include <asm/cacheflush.h>
  43. /****************************************************************************/
  44. #if 0
  45. #define DEBUG 1
  46. #endif
  47. #ifdef DEBUG
  48. #define DBG_FLT(a...) printk(a)
  49. #else
  50. #define DBG_FLT(a...)
  51. #endif
  52. #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
  53. #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
  54. struct lib_info {
  55. struct {
  56. unsigned long start_code; /* Start of text segment */
  57. unsigned long start_data; /* Start of data segment */
  58. unsigned long start_brk; /* End of data segment */
  59. unsigned long text_len; /* Length of text segment */
  60. unsigned long entry; /* Start address for this module */
  61. unsigned long build_date; /* When this one was compiled */
  62. short loaded; /* Has this library been loaded? */
  63. } lib_list[MAX_SHARED_LIBS];
  64. };
  65. #ifdef CONFIG_BINFMT_SHARED_FLAT
  66. static int load_flat_shared_library(int id, struct lib_info *p);
  67. #endif
  68. static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  69. static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
  70. static struct linux_binfmt flat_format = {
  71. .module = THIS_MODULE,
  72. .load_binary = load_flat_binary,
  73. .core_dump = flat_core_dump,
  74. .min_coredump = PAGE_SIZE
  75. };
  76. /****************************************************************************/
  77. /*
  78. * Routine writes a core dump image in the current directory.
  79. * Currently only a stub-function.
  80. */
  81. static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
  82. {
  83. printk("Process %s:%d received signr %d and should have core dumped\n",
  84. current->comm, current->pid, (int) signr);
  85. return(1);
  86. }
  87. /****************************************************************************/
  88. /*
  89. * create_flat_tables() parses the env- and arg-strings in new user
  90. * memory and creates the pointer tables from them, and puts their
  91. * addresses on the "stack", returning the new stack pointer value.
  92. */
  93. static unsigned long create_flat_tables(
  94. unsigned long pp,
  95. struct linux_binprm * bprm)
  96. {
  97. unsigned long *argv,*envp;
  98. unsigned long * sp;
  99. char * p = (char*)pp;
  100. int argc = bprm->argc;
  101. int envc = bprm->envc;
  102. char dummy;
  103. sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
  104. sp -= envc+1;
  105. envp = sp;
  106. sp -= argc+1;
  107. argv = sp;
  108. flat_stack_align(sp);
  109. if (flat_argvp_envp_on_stack()) {
  110. --sp; put_user((unsigned long) envp, sp);
  111. --sp; put_user((unsigned long) argv, sp);
  112. }
  113. put_user(argc,--sp);
  114. current->mm->arg_start = (unsigned long) p;
  115. while (argc-->0) {
  116. put_user((unsigned long) p, argv++);
  117. do {
  118. get_user(dummy, p); p++;
  119. } while (dummy);
  120. }
  121. put_user((unsigned long) NULL, argv);
  122. current->mm->arg_end = current->mm->env_start = (unsigned long) p;
  123. while (envc-->0) {
  124. put_user((unsigned long)p, envp); envp++;
  125. do {
  126. get_user(dummy, p); p++;
  127. } while (dummy);
  128. }
  129. put_user((unsigned long) NULL, envp);
  130. current->mm->env_end = (unsigned long) p;
  131. return (unsigned long)sp;
  132. }
  133. /****************************************************************************/
  134. #ifdef CONFIG_BINFMT_ZFLAT
  135. #include <linux/zlib.h>
  136. #define LBUFSIZE 4000
  137. /* gzip flag byte */
  138. #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
  139. #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  140. #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
  141. #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
  142. #define COMMENT 0x10 /* bit 4 set: file comment present */
  143. #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
  144. #define RESERVED 0xC0 /* bit 6,7: reserved */
  145. static int decompress_exec(
  146. struct linux_binprm *bprm,
  147. unsigned long offset,
  148. char *dst,
  149. long len,
  150. int fd)
  151. {
  152. unsigned char *buf;
  153. z_stream strm;
  154. loff_t fpos;
  155. int ret, retval;
  156. DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
  157. memset(&strm, 0, sizeof(strm));
  158. strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
  159. if (strm.workspace == NULL) {
  160. DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
  161. return -ENOMEM;
  162. }
  163. buf = kmalloc(LBUFSIZE, GFP_KERNEL);
  164. if (buf == NULL) {
  165. DBG_FLT("binfmt_flat: no memory for read buffer\n");
  166. retval = -ENOMEM;
  167. goto out_free;
  168. }
  169. /* Read in first chunk of data and parse gzip header. */
  170. fpos = offset;
  171. ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
  172. strm.next_in = buf;
  173. strm.avail_in = ret;
  174. strm.total_in = 0;
  175. retval = -ENOEXEC;
  176. /* Check minimum size -- gzip header */
  177. if (ret < 10) {
  178. DBG_FLT("binfmt_flat: file too small?\n");
  179. goto out_free_buf;
  180. }
  181. /* Check gzip magic number */
  182. if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
  183. DBG_FLT("binfmt_flat: unknown compression magic?\n");
  184. goto out_free_buf;
  185. }
  186. /* Check gzip method */
  187. if (buf[2] != 8) {
  188. DBG_FLT("binfmt_flat: unknown compression method?\n");
  189. goto out_free_buf;
  190. }
  191. /* Check gzip flags */
  192. if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
  193. (buf[3] & RESERVED)) {
  194. DBG_FLT("binfmt_flat: unknown flags?\n");
  195. goto out_free_buf;
  196. }
  197. ret = 10;
  198. if (buf[3] & EXTRA_FIELD) {
  199. ret += 2 + buf[10] + (buf[11] << 8);
  200. if (unlikely(LBUFSIZE == ret)) {
  201. DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
  202. goto out_free_buf;
  203. }
  204. }
  205. if (buf[3] & ORIG_NAME) {
  206. for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
  207. ;
  208. if (unlikely(LBUFSIZE == ret)) {
  209. DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
  210. goto out_free_buf;
  211. }
  212. }
  213. if (buf[3] & COMMENT) {
  214. for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
  215. ;
  216. if (unlikely(LBUFSIZE == ret)) {
  217. DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
  218. goto out_free_buf;
  219. }
  220. }
  221. strm.next_in += ret;
  222. strm.avail_in -= ret;
  223. strm.next_out = dst;
  224. strm.avail_out = len;
  225. strm.total_out = 0;
  226. if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
  227. DBG_FLT("binfmt_flat: zlib init failed?\n");
  228. goto out_free_buf;
  229. }
  230. while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
  231. ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
  232. if (ret <= 0)
  233. break;
  234. if (ret >= (unsigned long) -4096)
  235. break;
  236. len -= ret;
  237. strm.next_in = buf;
  238. strm.avail_in = ret;
  239. strm.total_in = 0;
  240. }
  241. if (ret < 0) {
  242. DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
  243. ret, strm.msg);
  244. goto out_zlib;
  245. }
  246. retval = 0;
  247. out_zlib:
  248. zlib_inflateEnd(&strm);
  249. out_free_buf:
  250. kfree(buf);
  251. out_free:
  252. kfree(strm.workspace);
  253. out:
  254. return retval;
  255. }
  256. #endif /* CONFIG_BINFMT_ZFLAT */
  257. /****************************************************************************/
  258. static unsigned long
  259. calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
  260. {
  261. unsigned long addr;
  262. int id;
  263. unsigned long start_brk;
  264. unsigned long start_data;
  265. unsigned long text_len;
  266. unsigned long start_code;
  267. #ifdef CONFIG_BINFMT_SHARED_FLAT
  268. if (r == 0)
  269. id = curid; /* Relocs of 0 are always self referring */
  270. else {
  271. id = (r >> 24) & 0xff; /* Find ID for this reloc */
  272. r &= 0x00ffffff; /* Trim ID off here */
  273. }
  274. if (id >= MAX_SHARED_LIBS) {
  275. printk("BINFMT_FLAT: reference 0x%x to shared library %d",
  276. (unsigned) r, id);
  277. goto failed;
  278. }
  279. if (curid != id) {
  280. if (internalp) {
  281. printk("BINFMT_FLAT: reloc address 0x%x not in same module "
  282. "(%d != %d)", (unsigned) r, curid, id);
  283. goto failed;
  284. } else if ( ! p->lib_list[id].loaded &&
  285. load_flat_shared_library(id, p) > (unsigned long) -4096) {
  286. printk("BINFMT_FLAT: failed to load library %d", id);
  287. goto failed;
  288. }
  289. /* Check versioning information (i.e. time stamps) */
  290. if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
  291. p->lib_list[curid].build_date < p->lib_list[id].build_date) {
  292. printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
  293. goto failed;
  294. }
  295. }
  296. #else
  297. id = 0;
  298. #endif
  299. start_brk = p->lib_list[id].start_brk;
  300. start_data = p->lib_list[id].start_data;
  301. start_code = p->lib_list[id].start_code;
  302. text_len = p->lib_list[id].text_len;
  303. if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
  304. printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
  305. (int) r,(int)(start_brk-start_code),(int)text_len);
  306. goto failed;
  307. }
  308. if (r < text_len) /* In text segment */
  309. addr = r + start_code;
  310. else /* In data segment */
  311. addr = r - text_len + start_data;
  312. /* Range checked already above so doing the range tests is redundant...*/
  313. return(addr);
  314. failed:
  315. printk(", killing %s!\n", current->comm);
  316. send_sig(SIGSEGV, current, 0);
  317. return RELOC_FAILED;
  318. }
  319. /****************************************************************************/
  320. void old_reloc(unsigned long rl)
  321. {
  322. #ifdef DEBUG
  323. char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
  324. #endif
  325. flat_v2_reloc_t r;
  326. unsigned long *ptr;
  327. r.value = rl;
  328. #if defined(CONFIG_COLDFIRE)
  329. ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
  330. #else
  331. ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
  332. #endif
  333. #ifdef DEBUG
  334. printk("Relocation of variable at DATASEG+%x "
  335. "(address %p, currently %x) into segment %s\n",
  336. r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
  337. #endif
  338. switch (r.reloc.type) {
  339. case OLD_FLAT_RELOC_TYPE_TEXT:
  340. *ptr += current->mm->start_code;
  341. break;
  342. case OLD_FLAT_RELOC_TYPE_DATA:
  343. *ptr += current->mm->start_data;
  344. break;
  345. case OLD_FLAT_RELOC_TYPE_BSS:
  346. *ptr += current->mm->end_data;
  347. break;
  348. default:
  349. printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
  350. break;
  351. }
  352. #ifdef DEBUG
  353. printk("Relocation became %x\n", (int)*ptr);
  354. #endif
  355. }
  356. /****************************************************************************/
  357. static int load_flat_file(struct linux_binprm * bprm,
  358. struct lib_info *libinfo, int id, unsigned long *extra_stack)
  359. {
  360. struct flat_hdr * hdr;
  361. unsigned long textpos = 0, datapos = 0, result;
  362. unsigned long realdatastart = 0;
  363. unsigned long text_len, data_len, bss_len, stack_len, flags;
  364. unsigned long len, reallen, memp = 0;
  365. unsigned long extra, rlim;
  366. unsigned long *reloc = 0, *rp;
  367. struct inode *inode;
  368. int i, rev, relocs = 0;
  369. loff_t fpos;
  370. unsigned long start_code, end_code;
  371. int ret;
  372. hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
  373. inode = bprm->file->f_path.dentry->d_inode;
  374. text_len = ntohl(hdr->data_start);
  375. data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
  376. bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
  377. stack_len = ntohl(hdr->stack_size);
  378. if (extra_stack) {
  379. stack_len += *extra_stack;
  380. *extra_stack = stack_len;
  381. }
  382. relocs = ntohl(hdr->reloc_count);
  383. flags = ntohl(hdr->flags);
  384. rev = ntohl(hdr->rev);
  385. if (strncmp(hdr->magic, "bFLT", 4)) {
  386. /*
  387. * because a lot of people do not manage to produce good
  388. * flat binaries, we leave this printk to help them realise
  389. * the problem. We only print the error if its not a script file
  390. */
  391. if (strncmp(hdr->magic, "#!", 2))
  392. printk("BINFMT_FLAT: bad header magic\n");
  393. ret = -ENOEXEC;
  394. goto err;
  395. }
  396. if (flags & FLAT_FLAG_KTRACE)
  397. printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
  398. if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
  399. printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
  400. ret = -ENOEXEC;
  401. goto err;
  402. }
  403. /* Don't allow old format executables to use shared libraries */
  404. if (rev == OLD_FLAT_VERSION && id != 0) {
  405. printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
  406. (int) FLAT_VERSION);
  407. ret = -ENOEXEC;
  408. goto err;
  409. }
  410. /*
  411. * fix up the flags for the older format, there were all kinds
  412. * of endian hacks, this only works for the simple cases
  413. */
  414. if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
  415. flags = FLAT_FLAG_RAM;
  416. #ifndef CONFIG_BINFMT_ZFLAT
  417. if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
  418. printk("Support for ZFLAT executables is not enabled.\n");
  419. ret = -ENOEXEC;
  420. goto err;
  421. }
  422. #endif
  423. /*
  424. * Check initial limits. This avoids letting people circumvent
  425. * size limits imposed on them by creating programs with large
  426. * arrays in the data or bss.
  427. */
  428. rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
  429. if (rlim >= RLIM_INFINITY)
  430. rlim = ~0;
  431. if (data_len + bss_len > rlim) {
  432. ret = -ENOMEM;
  433. goto err;
  434. }
  435. /* Flush all traces of the currently running executable */
  436. if (id == 0) {
  437. result = flush_old_exec(bprm);
  438. if (result) {
  439. ret = result;
  440. goto err;
  441. }
  442. /* OK, This is the point of no return */
  443. set_personality(PER_LINUX_32BIT);
  444. }
  445. /*
  446. * calculate the extra space we need to map in
  447. */
  448. extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
  449. /*
  450. * there are a couple of cases here, the separate code/data
  451. * case, and then the fully copied to RAM case which lumps
  452. * it all together.
  453. */
  454. if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
  455. /*
  456. * this should give us a ROM ptr, but if it doesn't we don't
  457. * really care
  458. */
  459. DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
  460. down_write(&current->mm->mmap_sem);
  461. textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
  462. up_write(&current->mm->mmap_sem);
  463. if (!textpos || textpos >= (unsigned long) -4096) {
  464. if (!textpos)
  465. textpos = (unsigned long) -ENOMEM;
  466. printk("Unable to mmap process text, errno %d\n", (int)-textpos);
  467. ret = textpos;
  468. goto err;
  469. }
  470. len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
  471. down_write(&current->mm->mmap_sem);
  472. realdatastart = do_mmap(0, 0, len,
  473. PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
  474. /* Remap to use all availabe slack region space */
  475. if (realdatastart && (realdatastart < (unsigned long)-4096)) {
  476. reallen = ksize(realdatastart);
  477. if (reallen > len) {
  478. realdatastart = do_mremap(realdatastart, len,
  479. reallen, MREMAP_FIXED, realdatastart);
  480. }
  481. }
  482. up_write(&current->mm->mmap_sem);
  483. if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
  484. if (!realdatastart)
  485. realdatastart = (unsigned long) -ENOMEM;
  486. printk("Unable to allocate RAM for process data, errno %d\n",
  487. (int)-datapos);
  488. do_munmap(current->mm, textpos, text_len);
  489. ret = realdatastart;
  490. goto err;
  491. }
  492. datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
  493. DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
  494. (int)(data_len + bss_len + stack_len), (int)datapos);
  495. fpos = ntohl(hdr->data_start);
  496. #ifdef CONFIG_BINFMT_ZFLAT
  497. if (flags & FLAT_FLAG_GZDATA) {
  498. result = decompress_exec(bprm, fpos, (char *) datapos,
  499. data_len + (relocs * sizeof(unsigned long)), 0);
  500. } else
  501. #endif
  502. {
  503. result = bprm->file->f_op->read(bprm->file, (char *) datapos,
  504. data_len + (relocs * sizeof(unsigned long)), &fpos);
  505. }
  506. if (result >= (unsigned long)-4096) {
  507. printk("Unable to read data+bss, errno %d\n", (int)-result);
  508. do_munmap(current->mm, textpos, text_len);
  509. do_munmap(current->mm, realdatastart, data_len + extra);
  510. ret = result;
  511. goto err;
  512. }
  513. reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
  514. memp = realdatastart;
  515. } else {
  516. len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
  517. down_write(&current->mm->mmap_sem);
  518. textpos = do_mmap(0, 0, len,
  519. PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
  520. /* Remap to use all availabe slack region space */
  521. if (textpos && (textpos < (unsigned long) -4096)) {
  522. reallen = ksize(textpos);
  523. if (reallen > len) {
  524. textpos = do_mremap(textpos, len, reallen,
  525. MREMAP_FIXED, textpos);
  526. }
  527. }
  528. up_write(&current->mm->mmap_sem);
  529. if (!textpos || textpos >= (unsigned long) -4096) {
  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 = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
  539. reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
  540. MAX_SHARED_LIBS * sizeof(unsigned long));
  541. memp = textpos;
  542. #ifdef CONFIG_BINFMT_ZFLAT
  543. /*
  544. * load it all in and treat it like a RAM load from now on
  545. */
  546. if (flags & FLAT_FLAG_GZIP) {
  547. result = decompress_exec(bprm, sizeof (struct flat_hdr),
  548. (((char *) textpos) + sizeof (struct flat_hdr)),
  549. (text_len + data_len + (relocs * sizeof(unsigned long))
  550. - sizeof (struct flat_hdr)),
  551. 0);
  552. memmove((void *) datapos, (void *) realdatastart,
  553. data_len + (relocs * sizeof(unsigned long)));
  554. } else if (flags & FLAT_FLAG_GZDATA) {
  555. fpos = 0;
  556. result = bprm->file->f_op->read(bprm->file,
  557. (char *) textpos, text_len, &fpos);
  558. if (result < (unsigned long) -4096)
  559. result = decompress_exec(bprm, text_len, (char *) datapos,
  560. data_len + (relocs * sizeof(unsigned long)), 0);
  561. }
  562. else
  563. #endif
  564. {
  565. fpos = 0;
  566. result = bprm->file->f_op->read(bprm->file,
  567. (char *) textpos, text_len, &fpos);
  568. if (result < (unsigned long) -4096) {
  569. fpos = ntohl(hdr->data_start);
  570. result = bprm->file->f_op->read(bprm->file, (char *) datapos,
  571. data_len + (relocs * sizeof(unsigned long)), &fpos);
  572. }
  573. }
  574. if (result >= (unsigned long)-4096) {
  575. printk("Unable to read code+data+bss, errno %d\n",(int)-result);
  576. do_munmap(current->mm, textpos, text_len + data_len + extra +
  577. MAX_SHARED_LIBS * sizeof(unsigned long));
  578. ret = result;
  579. goto err;
  580. }
  581. }
  582. if (flags & FLAT_FLAG_KTRACE)
  583. printk("Mapping is %x, Entry point is %x, data_start is %x\n",
  584. (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
  585. /* The main program needs a little extra setup in the task structure */
  586. start_code = textpos + sizeof (struct flat_hdr);
  587. end_code = textpos + text_len;
  588. if (id == 0) {
  589. current->mm->start_code = start_code;
  590. current->mm->end_code = end_code;
  591. current->mm->start_data = datapos;
  592. current->mm->end_data = datapos + data_len;
  593. /*
  594. * set up the brk stuff, uses any slack left in data/bss/stack
  595. * allocation. We put the brk after the bss (between the bss
  596. * and stack) like other platforms.
  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 + ksize((void *) memp) - 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 begining 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. for (i=0; i < relocs; i++) {
  657. unsigned long addr, relval;
  658. /* Get the address of the pointer to be
  659. relocated (of course, the address has to be
  660. relocated first). */
  661. relval = ntohl(reloc[i]);
  662. addr = flat_get_relocate_addr(relval);
  663. rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
  664. if (rp == (unsigned long *)RELOC_FAILED) {
  665. ret = -ENOEXEC;
  666. goto err;
  667. }
  668. /* Get the pointer's value. */
  669. addr = flat_get_addr_from_rp(rp, relval, flags);
  670. if (addr != 0) {
  671. /*
  672. * Do the relocation. PIC relocs in the data section are
  673. * already in target order
  674. */
  675. if ((flags & FLAT_FLAG_GOTPIC) == 0)
  676. addr = ntohl(addr);
  677. addr = calc_reloc(addr, libinfo, id, 0);
  678. if (addr == RELOC_FAILED) {
  679. ret = -ENOEXEC;
  680. goto err;
  681. }
  682. /* Write back the relocated pointer. */
  683. flat_put_addr_at_rp(rp, addr, relval);
  684. }
  685. }
  686. } else {
  687. for (i=0; i < relocs; i++)
  688. old_reloc(ntohl(reloc[i]));
  689. }
  690. flush_icache_range(start_code, end_code);
  691. /* zero the BSS, BRK and stack areas */
  692. memset((void*)(datapos + data_len), 0, bss_len +
  693. (memp + ksize((void *) memp) - stack_len - /* end brk */
  694. libinfo->lib_list[id].start_brk) + /* start brk */
  695. stack_len);
  696. return 0;
  697. err:
  698. return ret;
  699. }
  700. /****************************************************************************/
  701. #ifdef CONFIG_BINFMT_SHARED_FLAT
  702. /*
  703. * Load a shared library into memory. The library gets its own data
  704. * segment (including bss) but not argv/argc/environ.
  705. */
  706. static int load_flat_shared_library(int id, struct lib_info *libs)
  707. {
  708. struct linux_binprm bprm;
  709. int res;
  710. char buf[16];
  711. /* Create the file name */
  712. sprintf(buf, "/lib/lib%d.so", id);
  713. /* Open the file up */
  714. bprm.filename = buf;
  715. bprm.file = open_exec(bprm.filename);
  716. res = PTR_ERR(bprm.file);
  717. if (IS_ERR(bprm.file))
  718. return res;
  719. res = prepare_binprm(&bprm);
  720. if (res <= (unsigned long)-4096)
  721. res = load_flat_file(&bprm, libs, id, NULL);
  722. if (bprm.file) {
  723. allow_write_access(bprm.file);
  724. fput(bprm.file);
  725. bprm.file = NULL;
  726. }
  727. return(res);
  728. }
  729. #endif /* CONFIG_BINFMT_SHARED_FLAT */
  730. /****************************************************************************/
  731. /*
  732. * These are the functions used to load flat style executables and shared
  733. * libraries. There is no binary dependent code anywhere else.
  734. */
  735. static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
  736. {
  737. struct lib_info libinfo;
  738. unsigned long p = bprm->p;
  739. unsigned long stack_len;
  740. unsigned long start_addr;
  741. unsigned long *sp;
  742. int res;
  743. int i, j;
  744. memset(&libinfo, 0, sizeof(libinfo));
  745. /*
  746. * We have to add the size of our arguments to our stack size
  747. * otherwise it's too easy for users to create stack overflows
  748. * by passing in a huge argument list. And yes, we have to be
  749. * pedantic and include space for the argv/envp array as it may have
  750. * a lot of entries.
  751. */
  752. #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
  753. stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
  754. stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
  755. stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
  756. res = load_flat_file(bprm, &libinfo, 0, &stack_len);
  757. if (res > (unsigned long)-4096)
  758. return res;
  759. /* Update data segment pointers for all libraries */
  760. for (i=0; i<MAX_SHARED_LIBS; i++)
  761. if (libinfo.lib_list[i].loaded)
  762. for (j=0; j<MAX_SHARED_LIBS; j++)
  763. (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
  764. (libinfo.lib_list[j].loaded)?
  765. libinfo.lib_list[j].start_data:UNLOADED_LIB;
  766. compute_creds(bprm);
  767. current->flags &= ~PF_FORKNOEXEC;
  768. set_binfmt(&flat_format);
  769. p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
  770. DBG_FLT("p=%x\n", (int)p);
  771. /* copy the arg pages onto the stack, this could be more efficient :-) */
  772. for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
  773. * (char *) --p =
  774. ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
  775. sp = (unsigned long *) create_flat_tables(p, bprm);
  776. /* Fake some return addresses to ensure the call chain will
  777. * initialise library in order for us. We are required to call
  778. * lib 1 first, then 2, ... and finally the main program (id 0).
  779. */
  780. start_addr = libinfo.lib_list[0].entry;
  781. #ifdef CONFIG_BINFMT_SHARED_FLAT
  782. for (i = MAX_SHARED_LIBS-1; i>0; i--) {
  783. if (libinfo.lib_list[i].loaded) {
  784. /* Push previos first to call address */
  785. --sp; put_user(start_addr, sp);
  786. start_addr = libinfo.lib_list[i].entry;
  787. }
  788. }
  789. #endif
  790. /* Stash our initial stack pointer into the mm structure */
  791. current->mm->start_stack = (unsigned long )sp;
  792. DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
  793. (int)regs, (int)start_addr, (int)current->mm->start_stack);
  794. start_thread(regs, start_addr, current->mm->start_stack);
  795. if (current->ptrace & PT_PTRACED)
  796. send_sig(SIGTRAP, current, 0);
  797. return 0;
  798. }
  799. /****************************************************************************/
  800. static int __init init_flat_binfmt(void)
  801. {
  802. return register_binfmt(&flat_format);
  803. }
  804. static void __exit exit_flat_binfmt(void)
  805. {
  806. unregister_binfmt(&flat_format);
  807. }
  808. /****************************************************************************/
  809. core_initcall(init_flat_binfmt);
  810. module_exit(exit_flat_binfmt);
  811. /****************************************************************************/