aboutsummaryrefslogblamecommitdiffstats
path: root/fs/binfmt_flat.c
blob: 7974efa107bce19795f0889da79955416db41adb (plain) (tree)
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








































































































































































































































































































































































































































































































































                                                                                              
                                                                                                









                                                                                         
                                                                                







































                                                                                                 
                                                                                    


































































































































































































































































































































                                                                                                 
/****************************************************************************/
/*
 *  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/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/a.out.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 <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);

extern void dump_thread(struct pt_regs *, struct user *);

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)
{
	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 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);
out:
	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 memp = 0; /* for finding the brk area */
	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;

	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */
	inode = bprm->file->f_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 (flags & FLAT_FLAG_KTRACE)
		printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);

	if (strncmp(hdr->magic, "bFLT", 4) ||
			(rev != FLAT_VERSION && rev != OLD_FLAT_VERSION)) {
		/*
		 * because a lot of people do not manage to produce good
		 * flat binaries,  we leave this printk to help them realise
		 * the problem.  We only print the error if its not a script file
		 */
		if (strncmp(hdr->magic, "#!", 2))
			printk("BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
					rev, (int) FLAT_VERSION);
		return -ENOEXEC;
	}
	
	/* 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);
		return -ENOEXEC;
	}

	/*
	 * 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");
		return -ENOEXEC;
	}
#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)
		return -ENOMEM;

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

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

	/*
	 * calculate the extra space we need to map in
	 */
	extra = max(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, 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);
			return(textpos);
		}

		down_write(&current->mm->mmap_sem);
		realdatastart = do_mmap(0, 0, data_len + extra +
				MAX_SHARED_LIBS * sizeof(unsigned long),
				PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
		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)-datapos);
			do_munmap(current->mm, textpos, text_len);
			return realdatastart;
		}
		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);
			return result;
		}

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

	} else {

		down_write(&current->mm->mmap_sem);
		textpos = do_mmap(0, 0, text_len + data_len + extra +
					MAX_SHARED_LIBS * sizeof(unsigned long),
				PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
		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);
			return(textpos);
		}

		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));
			return result;
		}
	}

	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 + ksize((void *) memp) - stack_len;
		set_mm_counter(current->mm, rss, 0);
	}

	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)
					return -ENOEXEC;
				*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) {
		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]);
			addr = flat_get_relocate_addr(relval);
			rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
			if (rp == (unsigned long *)RELOC_FAILED)
				return -ENOEXEC;

			/* Get the pointer's value.  */
			addr = flat_get_addr_from_rp(rp, relval, flags);
			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)
					return -ENOEXEC;

				/* 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 + ksize((void *) memp) - stack_len -	/* end brk */
			libinfo->lib_list[id].start_brk) +		/* start brk */
			stack_len);

	return 0;
}


/****************************************************************************/
#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);

	if (current->ptrace & PT_PTRACED)
		send_sig(SIGTRAP, current, 0);

	return 0;
}

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

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

static void __exit exit_flat_binfmt(void)
{
	unregister_binfmt(&flat_format);
}

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

core_initcall(init_flat_binfmt);
module_exit(exit_flat_binfmt);

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