binfmt_flat.c 26.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937
/****************************************************************************/
/*
 *  linux/fs/binfmt_flat.c
 *
 *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
 *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
 *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
 *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
 *  based heavily on:
 *
 *  linux/fs/binfmt_aout.c:
 *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
 *  linux/fs/binfmt_flat.c for 2.0 kernel
 *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
 *	JAN/99 -- coded full program relocation (gerg@snapgear.com)
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/slab.h>
#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/init.h>
#include <linux/flat.h>
#include <linux/syscalls.h>

#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
#include <asm/cacheflush.h>

/****************************************************************************/

#if 0
#define DEBUG 1
#endif

#ifdef DEBUG
#define	DBG_FLT(a...)	printk(a)
#else
#define	DBG_FLT(a...)
#endif

#define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
#define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */

struct lib_info {
	struct {
		unsigned long start_code;		/* Start of text segment */
		unsigned long start_data;		/* Start of data segment */
		unsigned long start_brk;		/* End of data segment */
		unsigned long text_len;			/* Length of text segment */
		unsigned long entry;			/* Start address for this module */
		unsigned long build_date;		/* When this one was compiled */
		short loaded;				/* Has this library been loaded? */
	} lib_list[MAX_SHARED_LIBS];
};

#ifdef CONFIG_BINFMT_SHARED_FLAT
static int load_flat_shared_library(int id, struct lib_info *p);
#endif

static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);

static struct linux_binfmt flat_format = {
	.module		= THIS_MODULE,
	.load_binary	= load_flat_binary,
	.core_dump	= flat_core_dump,
	.min_coredump	= PAGE_SIZE
};

/****************************************************************************/
/*
 * Routine writes a core dump image in the current directory.
 * Currently only a stub-function.
 */

static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
{
	printk("Process %s:%d received signr %d and should have core dumped\n",
			current->comm, current->pid, (int) signr);
	return(1);
}

/****************************************************************************/
/*
 * create_flat_tables() parses the env- and arg-strings in new user
 * memory and creates the pointer tables from them, and puts their
 * addresses on the "stack", returning the new stack pointer value.
 */

static unsigned long create_flat_tables(
	unsigned long pp,
	struct linux_binprm * bprm)
{
	unsigned long *argv,*envp;
	unsigned long * sp;
	char * p = (char*)pp;
	int argc = bprm->argc;
	int envc = bprm->envc;
	char uninitialized_var(dummy);

	sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);

	sp -= envc+1;
	envp = sp;
	sp -= argc+1;
	argv = sp;

	flat_stack_align(sp);
	if (flat_argvp_envp_on_stack()) {
		--sp; put_user((unsigned long) envp, sp);
		--sp; put_user((unsigned long) argv, sp);
	}

	put_user(argc,--sp);
	current->mm->arg_start = (unsigned long) p;
	while (argc-->0) {
		put_user((unsigned long) p, argv++);
		do {
			get_user(dummy, p); p++;
		} while (dummy);
	}
	put_user((unsigned long) NULL, argv);
	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	while (envc-->0) {
		put_user((unsigned long)p, envp); envp++;
		do {
			get_user(dummy, p); p++;
		} while (dummy);
	}
	put_user((unsigned long) NULL, envp);
	current->mm->env_end = (unsigned long) p;
	return (unsigned long)sp;
}

/****************************************************************************/

#ifdef CONFIG_BINFMT_ZFLAT

#include <linux/zlib.h>

#define LBUFSIZE	4000

/* gzip flag byte */
#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
#define COMMENT      0x10 /* bit 4 set: file comment present */
#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
#define RESERVED     0xC0 /* bit 6,7:   reserved */

static int decompress_exec(
	struct linux_binprm *bprm,
	unsigned long offset,
	char *dst,
	long len,
	int fd)
{
	unsigned char *buf;
	z_stream strm;
	loff_t fpos;
	int ret, retval;

	DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);

	memset(&strm, 0, sizeof(strm));
	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
	if (strm.workspace == NULL) {
		DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
		return -ENOMEM;
	}
	buf = kmalloc(LBUFSIZE, GFP_KERNEL);
	if (buf == NULL) {
		DBG_FLT("binfmt_flat: no memory for read buffer\n");
		retval = -ENOMEM;
		goto out_free;
	}

	/* Read in first chunk of data and parse gzip header. */
	fpos = offset;
	ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);

	strm.next_in = buf;
	strm.avail_in = ret;
	strm.total_in = 0;

	retval = -ENOEXEC;

	/* Check minimum size -- gzip header */
	if (ret < 10) {
		DBG_FLT("binfmt_flat: file too small?\n");
		goto out_free_buf;
	}

	/* Check gzip magic number */
	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
		DBG_FLT("binfmt_flat: unknown compression magic?\n");
		goto out_free_buf;
	}

	/* Check gzip method */
	if (buf[2] != 8) {
		DBG_FLT("binfmt_flat: unknown compression method?\n");
		goto out_free_buf;
	}
	/* Check gzip flags */
	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
	    (buf[3] & RESERVED)) {
		DBG_FLT("binfmt_flat: unknown flags?\n");
		goto out_free_buf;
	}

	ret = 10;
	if (buf[3] & EXTRA_FIELD) {
		ret += 2 + buf[10] + (buf[11] << 8);
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
			goto out_free_buf;
		}
	}
	if (buf[3] & ORIG_NAME) {
		for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
			;
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
			goto out_free_buf;
		}
	}
	if (buf[3] & COMMENT) {
		for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
			;
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
			goto out_free_buf;
		}
	}

	strm.next_in += ret;
	strm.avail_in -= ret;

	strm.next_out = dst;
	strm.avail_out = len;
	strm.total_out = 0;

	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
		DBG_FLT("binfmt_flat: zlib init failed?\n");
		goto out_free_buf;
	}

	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
		ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
		if (ret <= 0)
			break;
		if (ret >= (unsigned long) -4096)
			break;
		len -= ret;

		strm.next_in = buf;
		strm.avail_in = ret;
		strm.total_in = 0;
	}

	if (ret < 0) {
		DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
			ret, strm.msg);
		goto out_zlib;
	}

	retval = 0;
out_zlib:
	zlib_inflateEnd(&strm);
out_free_buf:
	kfree(buf);
out_free:
	kfree(strm.workspace);
	return retval;
}

#endif /* CONFIG_BINFMT_ZFLAT */

/****************************************************************************/

static unsigned long
calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
{
	unsigned long addr;
	int id;
	unsigned long start_brk;
	unsigned long start_data;
	unsigned long text_len;
	unsigned long start_code;

#ifdef CONFIG_BINFMT_SHARED_FLAT
	if (r == 0)
		id = curid;	/* Relocs of 0 are always self referring */
	else {
		id = (r >> 24) & 0xff;	/* Find ID for this reloc */
		r &= 0x00ffffff;	/* Trim ID off here */
	}
	if (id >= MAX_SHARED_LIBS) {
		printk("BINFMT_FLAT: reference 0x%x to shared library %d",
				(unsigned) r, id);
		goto failed;
	}
	if (curid != id) {
		if (internalp) {
			printk("BINFMT_FLAT: reloc address 0x%x not in same module "
					"(%d != %d)", (unsigned) r, curid, id);
			goto failed;
		} else if ( ! p->lib_list[id].loaded &&
				load_flat_shared_library(id, p) > (unsigned long) -4096) {
			printk("BINFMT_FLAT: failed to load library %d", id);
			goto failed;
		}
		/* Check versioning information (i.e. time stamps) */
		if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
				p->lib_list[curid].build_date < p->lib_list[id].build_date) {
			printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
			goto failed;
		}
	}
#else
	id = 0;
#endif

	start_brk = p->lib_list[id].start_brk;
	start_data = p->lib_list[id].start_data;
	start_code = p->lib_list[id].start_code;
	text_len = p->lib_list[id].text_len;

	if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
		printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
		       (int) r,(int)(start_brk-start_code),(int)text_len);
		goto failed;
	}

	if (r < text_len)			/* In text segment */
		addr = r + start_code;
	else					/* In data segment */
		addr = r - text_len + start_data;

	/* Range checked already above so doing the range tests is redundant...*/
	return(addr);

failed:
	printk(", killing %s!\n", current->comm);
	send_sig(SIGSEGV, current, 0);

	return RELOC_FAILED;
}

/****************************************************************************/

void old_reloc(unsigned long rl)
{
#ifdef DEBUG
	char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
#endif
	flat_v2_reloc_t	r;
	unsigned long *ptr;
	
	r.value = rl;
#if defined(CONFIG_COLDFIRE)
	ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
#else
	ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
#endif

#ifdef DEBUG
	printk("Relocation of variable at DATASEG+%x "
		"(address %p, currently %x) into segment %s\n",
		r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
#endif
	
	switch (r.reloc.type) {
	case OLD_FLAT_RELOC_TYPE_TEXT:
		*ptr += current->mm->start_code;
		break;
	case OLD_FLAT_RELOC_TYPE_DATA:
		*ptr += current->mm->start_data;
		break;
	case OLD_FLAT_RELOC_TYPE_BSS:
		*ptr += current->mm->end_data;
		break;
	default:
		printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
		break;
	}

#ifdef DEBUG
	printk("Relocation became %x\n", (int)*ptr);
#endif
}		

/****************************************************************************/

static int load_flat_file(struct linux_binprm * bprm,
		struct lib_info *libinfo, int id, unsigned long *extra_stack)
{
	struct flat_hdr * hdr;
	unsigned long textpos = 0, datapos = 0, result;
	unsigned long realdatastart = 0;
	unsigned long text_len, data_len, bss_len, stack_len, flags;
	unsigned long len, reallen, memp = 0;
	unsigned long extra, rlim;
	unsigned long *reloc = 0, *rp;
	struct inode *inode;
	int i, rev, relocs = 0;
	loff_t fpos;
	unsigned long start_code, end_code;
	int ret;

	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */
	inode = bprm->file->f_path.dentry->d_inode;

	text_len  = ntohl(hdr->data_start);
	data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
	bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
	stack_len = ntohl(hdr->stack_size);
	if (extra_stack) {
		stack_len += *extra_stack;
		*extra_stack = stack_len;
	}
	relocs    = ntohl(hdr->reloc_count);
	flags     = ntohl(hdr->flags);
	rev       = ntohl(hdr->rev);

	if (strncmp(hdr->magic, "bFLT", 4)) {
		/*
		 * Previously, here was a printk to tell people
		 *   "BINFMT_FLAT: bad header magic".
		 * But for the kernel which also use ELF FD-PIC format, this
		 * error message is confusing.
		 * because a lot of people do not manage to produce good
		 */
		ret = -ENOEXEC;
		goto err;
	}

	if (flags & FLAT_FLAG_KTRACE)
		printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);

	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
		printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
			"0x%lx and 0x%lx)\n",
			rev, FLAT_VERSION, OLD_FLAT_VERSION);
		ret = -ENOEXEC;
		goto err;
	}
	
	/* Don't allow old format executables to use shared libraries */
	if (rev == OLD_FLAT_VERSION && id != 0) {
		printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
				(int) FLAT_VERSION);
		ret = -ENOEXEC;
		goto err;
	}

	/*
	 * fix up the flags for the older format,  there were all kinds
	 * of endian hacks,  this only works for the simple cases
	 */
	if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
		flags = FLAT_FLAG_RAM;

#ifndef CONFIG_BINFMT_ZFLAT
	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
		printk("Support for ZFLAT executables is not enabled.\n");
		ret = -ENOEXEC;
		goto err;
	}
#endif

	/*
	 * Check initial limits. This avoids letting people circumvent
	 * size limits imposed on them by creating programs with large
	 * arrays in the data or bss.
	 */
	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
	if (rlim >= RLIM_INFINITY)
		rlim = ~0;
	if (data_len + bss_len > rlim) {
		ret = -ENOMEM;
		goto err;
	}

	/* Flush all traces of the currently running executable */
	if (id == 0) {
		result = flush_old_exec(bprm);
		if (result) {
			ret = result;
			goto err;
		}

		/* OK, This is the point of no return */
		set_personality(PER_LINUX_32BIT);
	}

	/*
	 * calculate the extra space we need to map in
	 */
	extra = max_t(unsigned long, bss_len + stack_len,
			relocs * sizeof(unsigned long));

	/*
	 * there are a couple of cases here,  the separate code/data
	 * case,  and then the fully copied to RAM case which lumps
	 * it all together.
	 */
	if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
		/*
		 * this should give us a ROM ptr,  but if it doesn't we don't
		 * really care
		 */
		DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");

		down_write(&current->mm->mmap_sem);
		textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
				  MAP_PRIVATE|MAP_EXECUTABLE, 0);
		up_write(&current->mm->mmap_sem);
		if (!textpos  || textpos >= (unsigned long) -4096) {
			if (!textpos)
				textpos = (unsigned long) -ENOMEM;
			printk("Unable to mmap process text, errno %d\n", (int)-textpos);
			ret = textpos;
			goto err;
		}

		len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
		down_write(&current->mm->mmap_sem);
		realdatastart = do_mmap(0, 0, len,
			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
		/* Remap to use all availabe slack region space */
		if (realdatastart && (realdatastart < (unsigned long)-4096)) {
			reallen = kobjsize((void *)realdatastart);
			if (reallen > len) {
				realdatastart = do_mremap(realdatastart, len,
					reallen, MREMAP_FIXED, realdatastart);
			}
		}
		up_write(&current->mm->mmap_sem);

		if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
			if (!realdatastart)
				realdatastart = (unsigned long) -ENOMEM;
			printk("Unable to allocate RAM for process data, errno %d\n",
					(int)-realdatastart);
			do_munmap(current->mm, textpos, text_len);
			ret = realdatastart;
			goto err;
		}
		datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);

		DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
				(int)(data_len + bss_len + stack_len), (int)datapos);

		fpos = ntohl(hdr->data_start);
#ifdef CONFIG_BINFMT_ZFLAT
		if (flags & FLAT_FLAG_GZDATA) {
			result = decompress_exec(bprm, fpos, (char *) datapos, 
						 data_len + (relocs * sizeof(unsigned long)), 0);
		} else
#endif
		{
			result = bprm->file->f_op->read(bprm->file, (char *) datapos,
					data_len + (relocs * sizeof(unsigned long)), &fpos);
		}
		if (result >= (unsigned long)-4096) {
			printk("Unable to read data+bss, errno %d\n", (int)-result);
			do_munmap(current->mm, textpos, text_len);
			do_munmap(current->mm, realdatastart, data_len + extra);
			ret = result;
			goto err;
		}

		reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
		memp = realdatastart;

	} else {

		len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
		down_write(&current->mm->mmap_sem);
		textpos = do_mmap(0, 0, len,
			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
		/* Remap to use all availabe slack region space */
		if (textpos && (textpos < (unsigned long) -4096)) {
			reallen = kobjsize((void *)textpos);
			if (reallen > len) {
				textpos = do_mremap(textpos, len, reallen,
					MREMAP_FIXED, textpos);
			}
		}
		up_write(&current->mm->mmap_sem);

		if (!textpos  || textpos >= (unsigned long) -4096) {
			if (!textpos)
				textpos = (unsigned long) -ENOMEM;
			printk("Unable to allocate RAM for process text/data, errno %d\n",
					(int)-textpos);
			ret = textpos;
			goto err;
		}

		realdatastart = textpos + ntohl(hdr->data_start);
		datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
		reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
				MAX_SHARED_LIBS * sizeof(unsigned long));
		memp = textpos;

#ifdef CONFIG_BINFMT_ZFLAT
		/*
		 * load it all in and treat it like a RAM load from now on
		 */
		if (flags & FLAT_FLAG_GZIP) {
			result = decompress_exec(bprm, sizeof (struct flat_hdr),
					 (((char *) textpos) + sizeof (struct flat_hdr)),
					 (text_len + data_len + (relocs * sizeof(unsigned long))
						  - sizeof (struct flat_hdr)),
					 0);
			memmove((void *) datapos, (void *) realdatastart,
					data_len + (relocs * sizeof(unsigned long)));
		} else if (flags & FLAT_FLAG_GZDATA) {
			fpos = 0;
			result = bprm->file->f_op->read(bprm->file,
					(char *) textpos, text_len, &fpos);
			if (result < (unsigned long) -4096)
				result = decompress_exec(bprm, text_len, (char *) datapos,
						 data_len + (relocs * sizeof(unsigned long)), 0);
		}
		else
#endif
		{
			fpos = 0;
			result = bprm->file->f_op->read(bprm->file,
					(char *) textpos, text_len, &fpos);
			if (result < (unsigned long) -4096) {
				fpos = ntohl(hdr->data_start);
				result = bprm->file->f_op->read(bprm->file, (char *) datapos,
					data_len + (relocs * sizeof(unsigned long)), &fpos);
			}
		}
		if (result >= (unsigned long)-4096) {
			printk("Unable to read code+data+bss, errno %d\n",(int)-result);
			do_munmap(current->mm, textpos, text_len + data_len + extra +
				MAX_SHARED_LIBS * sizeof(unsigned long));
			ret = result;
			goto err;
		}
	}

	if (flags & FLAT_FLAG_KTRACE)
		printk("Mapping is %x, Entry point is %x, data_start is %x\n",
			(int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));

	/* The main program needs a little extra setup in the task structure */
	start_code = textpos + sizeof (struct flat_hdr);
	end_code = textpos + text_len;
	if (id == 0) {
		current->mm->start_code = start_code;
		current->mm->end_code = end_code;
		current->mm->start_data = datapos;
		current->mm->end_data = datapos + data_len;
		/*
		 * set up the brk stuff, uses any slack left in data/bss/stack
		 * allocation.  We put the brk after the bss (between the bss
		 * and stack) like other platforms.
		 */
		current->mm->start_brk = datapos + data_len + bss_len;
		current->mm->brk = (current->mm->start_brk + 3) & ~3;
		current->mm->context.end_brk = memp + kobjsize((void *) memp) - stack_len;
	}

	if (flags & FLAT_FLAG_KTRACE)
		printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
			id ? "Lib" : "Load", bprm->filename,
			(int) start_code, (int) end_code,
			(int) datapos,
			(int) (datapos + data_len),
			(int) (datapos + data_len),
			(int) (((datapos + data_len + bss_len) + 3) & ~3));

	text_len -= sizeof(struct flat_hdr); /* the real code len */

	/* Store the current module values into the global library structure */
	libinfo->lib_list[id].start_code = start_code;
	libinfo->lib_list[id].start_data = datapos;
	libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
	libinfo->lib_list[id].text_len = text_len;
	libinfo->lib_list[id].loaded = 1;
	libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
	libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
	
	/*
	 * We just load the allocations into some temporary memory to
	 * help simplify all this mumbo jumbo
	 *
	 * We've got two different sections of relocation entries.
	 * The first is the GOT which resides at the begining of the data segment
	 * and is terminated with a -1.  This one can be relocated in place.
	 * The second is the extra relocation entries tacked after the image's
	 * data segment. These require a little more processing as the entry is
	 * really an offset into the image which contains an offset into the
	 * image.
	 */
	if (flags & FLAT_FLAG_GOTPIC) {
		for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
			unsigned long addr;
			if (*rp) {
				addr = calc_reloc(*rp, libinfo, id, 0);
				if (addr == RELOC_FAILED) {
					ret = -ENOEXEC;
					goto err;
				}
				*rp = addr;
			}
		}
	}

	/*
	 * Now run through the relocation entries.
	 * We've got to be careful here as C++ produces relocatable zero
	 * entries in the constructor and destructor tables which are then
	 * tested for being not zero (which will always occur unless we're
	 * based from address zero).  This causes an endless loop as __start
	 * is at zero.  The solution used is to not relocate zero addresses.
	 * This has the negative side effect of not allowing a global data
	 * reference to be statically initialised to _stext (I've moved
	 * __start to address 4 so that is okay).
	 */
	if (rev > OLD_FLAT_VERSION) {
		unsigned long persistent = 0;
		for (i=0; i < relocs; i++) {
			unsigned long addr, relval;

			/* Get the address of the pointer to be
			   relocated (of course, the address has to be
			   relocated first).  */
			relval = ntohl(reloc[i]);
			if (flat_set_persistent (relval, &persistent))
				continue;
			addr = flat_get_relocate_addr(relval);
			rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
			if (rp == (unsigned long *)RELOC_FAILED) {
				ret = -ENOEXEC;
				goto err;
			}

			/* Get the pointer's value.  */
			addr = flat_get_addr_from_rp(rp, relval, flags,
							&persistent);
			if (addr != 0) {
				/*
				 * Do the relocation.  PIC relocs in the data section are
				 * already in target order
				 */
				if ((flags & FLAT_FLAG_GOTPIC) == 0)
					addr = ntohl(addr);
				addr = calc_reloc(addr, libinfo, id, 0);
				if (addr == RELOC_FAILED) {
					ret = -ENOEXEC;
					goto err;
				}

				/* Write back the relocated pointer.  */
				flat_put_addr_at_rp(rp, addr, relval);
			}
		}
	} else {
		for (i=0; i < relocs; i++)
			old_reloc(ntohl(reloc[i]));
	}
	
	flush_icache_range(start_code, end_code);

	/* zero the BSS,  BRK and stack areas */
	memset((void*)(datapos + data_len), 0, bss_len + 
			(memp + kobjsize((void *) memp) - stack_len -	/* end brk */
			libinfo->lib_list[id].start_brk) +		/* start brk */
			stack_len);

	return 0;
err:
	return ret;
}


/****************************************************************************/
#ifdef CONFIG_BINFMT_SHARED_FLAT

/*
 * Load a shared library into memory.  The library gets its own data
 * segment (including bss) but not argv/argc/environ.
 */

static int load_flat_shared_library(int id, struct lib_info *libs)
{
	struct linux_binprm bprm;
	int res;
	char buf[16];

	/* Create the file name */
	sprintf(buf, "/lib/lib%d.so", id);

	/* Open the file up */
	bprm.filename = buf;
	bprm.file = open_exec(bprm.filename);
	res = PTR_ERR(bprm.file);
	if (IS_ERR(bprm.file))
		return res;

	res = prepare_binprm(&bprm);

	if (res <= (unsigned long)-4096)
		res = load_flat_file(&bprm, libs, id, NULL);
	if (bprm.file) {
		allow_write_access(bprm.file);
		fput(bprm.file);
		bprm.file = NULL;
	}
	return(res);
}

#endif /* CONFIG_BINFMT_SHARED_FLAT */
/****************************************************************************/

/*
 * These are the functions used to load flat style executables and shared
 * libraries.  There is no binary dependent code anywhere else.
 */

static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
	struct lib_info libinfo;
	unsigned long p = bprm->p;
	unsigned long stack_len;
	unsigned long start_addr;
	unsigned long *sp;
	int res;
	int i, j;

	memset(&libinfo, 0, sizeof(libinfo));
	/*
	 * We have to add the size of our arguments to our stack size
	 * otherwise it's too easy for users to create stack overflows
	 * by passing in a huge argument list.  And yes,  we have to be
	 * pedantic and include space for the argv/envp array as it may have
	 * a lot of entries.
	 */
#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
	stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
	stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
	stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */

	
	res = load_flat_file(bprm, &libinfo, 0, &stack_len);
	if (res > (unsigned long)-4096)
		return res;
	
	/* Update data segment pointers for all libraries */
	for (i=0; i<MAX_SHARED_LIBS; i++)
		if (libinfo.lib_list[i].loaded)
			for (j=0; j<MAX_SHARED_LIBS; j++)
				(-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
					(libinfo.lib_list[j].loaded)?
						libinfo.lib_list[j].start_data:UNLOADED_LIB;

	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;

	set_binfmt(&flat_format);

	p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
	DBG_FLT("p=%x\n", (int)p);

	/* copy the arg pages onto the stack, this could be more efficient :-) */
	for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
		* (char *) --p =
			((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];

	sp = (unsigned long *) create_flat_tables(p, bprm);
	
	/* Fake some return addresses to ensure the call chain will
	 * initialise library in order for us.  We are required to call
	 * lib 1 first, then 2, ... and finally the main program (id 0).
	 */
	start_addr = libinfo.lib_list[0].entry;

#ifdef CONFIG_BINFMT_SHARED_FLAT
	for (i = MAX_SHARED_LIBS-1; i>0; i--) {
		if (libinfo.lib_list[i].loaded) {
			/* Push previos first to call address */
			--sp;	put_user(start_addr, sp);
			start_addr = libinfo.lib_list[i].entry;
		}
	}
#endif
	
	/* Stash our initial stack pointer into the mm structure */
	current->mm->start_stack = (unsigned long )sp;

	
	DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
		(int)regs, (int)start_addr, (int)current->mm->start_stack);
	
	start_thread(regs, start_addr, current->mm->start_stack);

	return 0;
}

/****************************************************************************/

static int __init init_flat_binfmt(void)
{
	return register_binfmt(&flat_format);
}

/****************************************************************************/

core_initcall(init_flat_binfmt);

/****************************************************************************/