binfmt_flat.c

  1// SPDX-License-Identifier: GPL-2.0
  2/****************************************************************************/
  3/*
  4 *  linux/fs/binfmt_flat.c
  5 *
  6 *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
  7 *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
  8 *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
  9 *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
 10 *  based heavily on:
 11 *
 12 *  linux/fs/binfmt_aout.c:
 13 *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
 14 *  linux/fs/binfmt_flat.c for 2.0 kernel
 15 *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
 16 *	JAN/99 -- coded full program relocation (gerg@snapgear.com)
 17 */
 18
 19#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 20
 21#include <linux/kernel.h>
 22#include <linux/sched.h>
 23#include <linux/sched/task_stack.h>
 24#include <linux/mm.h>
 25#include <linux/mman.h>
 26#include <linux/errno.h>
 27#include <linux/signal.h>
 28#include <linux/string.h>
 29#include <linux/fs.h>
 30#include <linux/file.h>
 31#include <linux/ptrace.h>
 32#include <linux/user.h>
 33#include <linux/slab.h>
 34#include <linux/binfmts.h>
 35#include <linux/personality.h>
 36#include <linux/init.h>
 37#include <linux/flat.h>
 38#include <linux/uaccess.h>
 39#include <linux/vmalloc.h>
 40
 41#include <asm/byteorder.h>
 42#include <linux/unaligned.h>
 43#include <asm/cacheflush.h>
 44#include <asm/page.h>
 45#include <asm/flat.h>
 46
 47#ifndef flat_get_relocate_addr
 48#define flat_get_relocate_addr(rel)	(rel)
 49#endif
 50
 51/****************************************************************************/
 52
 53/*
 54 * User data (data section and bss) needs to be aligned.
 55 * We pick 0x20 here because it is the max value elf2flt has always
 56 * used in producing FLAT files, and because it seems to be large
 57 * enough to make all the gcc alignment related tests happy.
 58 */
 59#define FLAT_DATA_ALIGN	(0x20)
 60
 61/*
 62 * User data (stack) also needs to be aligned.
 63 * Here we can be a bit looser than the data sections since this
 64 * needs to only meet arch ABI requirements.
 65 */
 66#define FLAT_STACK_ALIGN	max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
 67
 68#define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
 69#define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */
 70
 71#define MAX_SHARED_LIBS			(1)
 72
 73#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET
 74#define DATA_START_OFFSET_WORDS		(0)
 75#define MAX_SHARED_LIBS_UPDATE		(0)
 76#else
 77#define DATA_START_OFFSET_WORDS		(MAX_SHARED_LIBS)
 78#define MAX_SHARED_LIBS_UPDATE		(MAX_SHARED_LIBS)
 79#endif
 80
 81struct lib_info {
 82	struct {
 83		unsigned long start_code;		/* Start of text segment */
 84		unsigned long start_data;		/* Start of data segment */
 85		unsigned long start_brk;		/* End of data segment */
 86		unsigned long text_len;			/* Length of text segment */
 87		unsigned long entry;			/* Start address for this module */
 88		unsigned long build_date;		/* When this one was compiled */
 89		bool loaded;				/* Has this library been loaded? */
 90	} lib_list[MAX_SHARED_LIBS];
 91};
 92
 93static int load_flat_binary(struct linux_binprm *);
 94
 95static struct linux_binfmt flat_format = {
 96	.module		= THIS_MODULE,
 97	.load_binary	= load_flat_binary,
 98};
 99
100
101/****************************************************************************/
102/*
103 * create_flat_tables() parses the env- and arg-strings in new user
104 * memory and creates the pointer tables from them, and puts their
105 * addresses on the "stack", recording the new stack pointer value.
106 */
107
108static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
109{
110	char __user *p;
111	unsigned long __user *sp;
112	long i, len;
113
114	p = (char __user *)arg_start;
115	sp = (unsigned long __user *)current->mm->start_stack;
116
117	sp -= bprm->envc + 1;
118	sp -= bprm->argc + 1;
119	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
120		sp -= 2; /* argvp + envp */
121	sp -= 1;  /* &argc */
122
123	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
124	sp = (unsigned long __user *)current->mm->start_stack;
125
126	if (put_user(bprm->argc, sp++))
127		return -EFAULT;
128	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
129		unsigned long argv, envp;
130		argv = (unsigned long)(sp + 2);
131		envp = (unsigned long)(sp + 2 + bprm->argc + 1);
132		if (put_user(argv, sp++) || put_user(envp, sp++))
133			return -EFAULT;
134	}
135
136	current->mm->arg_start = (unsigned long)p;
137	for (i = bprm->argc; i > 0; i--) {
138		if (put_user((unsigned long)p, sp++))
139			return -EFAULT;
140		len = strnlen_user(p, MAX_ARG_STRLEN);
141		if (!len || len > MAX_ARG_STRLEN)
142			return -EINVAL;
143		p += len;
144	}
145	if (put_user(0, sp++))
146		return -EFAULT;
147	current->mm->arg_end = (unsigned long)p;
148
149	current->mm->env_start = (unsigned long) p;
150	for (i = bprm->envc; i > 0; i--) {
151		if (put_user((unsigned long)p, sp++))
152			return -EFAULT;
153		len = strnlen_user(p, MAX_ARG_STRLEN);
154		if (!len || len > MAX_ARG_STRLEN)
155			return -EINVAL;
156		p += len;
157	}
158	if (put_user(0, sp++))
159		return -EFAULT;
160	current->mm->env_end = (unsigned long)p;
161
162	return 0;
163}
164
165/****************************************************************************/
166
167#ifdef CONFIG_BINFMT_ZFLAT
168
169#include <linux/zlib.h>
170
171#define LBUFSIZE	4000
172
173/* gzip flag byte */
174#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
175#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
176#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
177#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
178#define COMMENT      0x10 /* bit 4 set: file comment present */
179#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
180#define RESERVED     0xC0 /* bit 6,7:   reserved */
181
182static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
183		long len, int fd)
184{
185	unsigned char *buf;
186	z_stream strm;
187	int ret, retval;
188
189	pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
190
191	memset(&strm, 0, sizeof(strm));
192	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
193	if (!strm.workspace)
194		return -ENOMEM;
195
196	buf = kmalloc(LBUFSIZE, GFP_KERNEL);
197	if (!buf) {
198		retval = -ENOMEM;
199		goto out_free;
200	}
201
202	/* Read in first chunk of data and parse gzip header. */
203	ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
204
205	strm.next_in = buf;
206	strm.avail_in = ret;
207	strm.total_in = 0;
208
209	retval = -ENOEXEC;
210
211	/* Check minimum size -- gzip header */
212	if (ret < 10) {
213		pr_debug("file too small?\n");
214		goto out_free_buf;
215	}
216
217	/* Check gzip magic number */
218	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
219		pr_debug("unknown compression magic?\n");
220		goto out_free_buf;
221	}
222
223	/* Check gzip method */
224	if (buf[2] != 8) {
225		pr_debug("unknown compression method?\n");
226		goto out_free_buf;
227	}
228	/* Check gzip flags */
229	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
230	    (buf[3] & RESERVED)) {
231		pr_debug("unknown flags?\n");
232		goto out_free_buf;
233	}
234
235	ret = 10;
236	if (buf[3] & EXTRA_FIELD) {
237		ret += 2 + buf[10] + (buf[11] << 8);
238		if (unlikely(ret >= LBUFSIZE)) {
239			pr_debug("buffer overflow (EXTRA)?\n");
240			goto out_free_buf;
241		}
242	}
243	if (buf[3] & ORIG_NAME) {
244		while (ret < LBUFSIZE && buf[ret++] != 0)
245			;
246		if (unlikely(ret == LBUFSIZE)) {
247			pr_debug("buffer overflow (ORIG_NAME)?\n");
248			goto out_free_buf;
249		}
250	}
251	if (buf[3] & COMMENT) {
252		while (ret < LBUFSIZE && buf[ret++] != 0)
253			;
254		if (unlikely(ret == LBUFSIZE)) {
255			pr_debug("buffer overflow (COMMENT)?\n");
256			goto out_free_buf;
257		}
258	}
259
260	strm.next_in += ret;
261	strm.avail_in -= ret;
262
263	strm.next_out = dst;
264	strm.avail_out = len;
265	strm.total_out = 0;
266
267	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
268		pr_debug("zlib init failed?\n");
269		goto out_free_buf;
270	}
271
272	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
273		ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
274		if (ret <= 0)
275			break;
276		len -= ret;
277
278		strm.next_in = buf;
279		strm.avail_in = ret;
280		strm.total_in = 0;
281	}
282
283	if (ret < 0) {
284		pr_debug("decompression failed (%d), %s\n",
285			ret, strm.msg);
286		goto out_zlib;
287	}
288
289	retval = 0;
290out_zlib:
291	zlib_inflateEnd(&strm);
292out_free_buf:
293	kfree(buf);
294out_free:
295	kfree(strm.workspace);
296	return retval;
297}
298
299#endif /* CONFIG_BINFMT_ZFLAT */
300
301/****************************************************************************/
302
303static unsigned long
304calc_reloc(unsigned long r, struct lib_info *p)
305{
306	unsigned long addr;
307	unsigned long start_brk;
308	unsigned long start_data;
309	unsigned long text_len;
310	unsigned long start_code;
311
312	start_brk = p->lib_list[0].start_brk;
313	start_data = p->lib_list[0].start_data;
314	start_code = p->lib_list[0].start_code;
315	text_len = p->lib_list[0].text_len;
316
317	if (r > start_brk - start_data + text_len) {
318		pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
319		       r, start_brk-start_data+text_len, text_len);
320		goto failed;
321	}
322
323	if (r < text_len)			/* In text segment */
324		addr = r + start_code;
325	else					/* In data segment */
326		addr = r - text_len + start_data;
327
328	/* Range checked already above so doing the range tests is redundant...*/
329	return addr;
330
331failed:
332	pr_cont(", killing %s!\n", current->comm);
333	send_sig(SIGSEGV, current, 0);
334
335	return RELOC_FAILED;
336}
337
338/****************************************************************************/
339
340#ifdef CONFIG_BINFMT_FLAT_OLD
341static void old_reloc(unsigned long rl)
342{
343	static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
344	flat_v2_reloc_t	r;
345	unsigned long __user *ptr;
346	unsigned long val;
347
348	r.value = rl;
349#if defined(CONFIG_COLDFIRE)
350	ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
351#else
352	ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
353#endif
354	get_user(val, ptr);
355
356	pr_debug("Relocation of variable at DATASEG+%x "
357		 "(address %p, currently %lx) into segment %s\n",
358		 r.reloc.offset, ptr, val, segment[r.reloc.type]);
359
360	switch (r.reloc.type) {
361	case OLD_FLAT_RELOC_TYPE_TEXT:
362		val += current->mm->start_code;
363		break;
364	case OLD_FLAT_RELOC_TYPE_DATA:
365		val += current->mm->start_data;
366		break;
367	case OLD_FLAT_RELOC_TYPE_BSS:
368		val += current->mm->end_data;
369		break;
370	default:
371		pr_err("Unknown relocation type=%x\n", r.reloc.type);
372		break;
373	}
374	put_user(val, ptr);
375
376	pr_debug("Relocation became %lx\n", val);
377}
378#endif /* CONFIG_BINFMT_FLAT_OLD */
379
380/****************************************************************************/
381
382static inline u32 __user *skip_got_header(u32 __user *rp)
383{
384	if (IS_ENABLED(CONFIG_RISCV)) {
385		/*
386		 * RISC-V has a 16 byte GOT PLT header for elf64-riscv
387		 * and 8 byte GOT PLT header for elf32-riscv.
388		 * Skip the whole GOT PLT header, since it is reserved
389		 * for the dynamic linker (ld.so).
390		 */
391		u32 rp_val0, rp_val1;
392
393		if (get_user(rp_val0, rp))
394			return rp;
395		if (get_user(rp_val1, rp + 1))
396			return rp;
397
398		if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff)
399			rp += 4;
400		else if (rp_val0 == 0xffffffff)
401			rp += 2;
402	}
403	return rp;
404}
405
406static int load_flat_file(struct linux_binprm *bprm,
407		struct lib_info *libinfo, unsigned long *extra_stack)
408{
409	struct flat_hdr *hdr;
410	unsigned long textpos, datapos, realdatastart;
411	u32 text_len, data_len, bss_len, stack_len, full_data, flags;
412	unsigned long len, memp, memp_size, extra, rlim;
413	__be32 __user *reloc;
414	u32 __user *rp;
415	int i, rev, relocs;
416	loff_t fpos;
417	unsigned long start_code, end_code;
418	ssize_t result;
419	int ret;
420
421	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */
422
423	text_len  = ntohl(hdr->data_start);
424	data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
425	bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
426	stack_len = ntohl(hdr->stack_size);
427	if (extra_stack) {
428		stack_len += *extra_stack;
429		*extra_stack = stack_len;
430	}
431	relocs    = ntohl(hdr->reloc_count);
432	flags     = ntohl(hdr->flags);
433	rev       = ntohl(hdr->rev);
434	full_data = data_len + relocs * sizeof(unsigned long);
435
436	if (strncmp(hdr->magic, "bFLT", 4)) {
437		/*
438		 * Previously, here was a printk to tell people
439		 *   "BINFMT_FLAT: bad header magic".
440		 * But for the kernel which also use ELF FD-PIC format, this
441		 * error message is confusing.
442		 * because a lot of people do not manage to produce good
443		 */
444		ret = -ENOEXEC;
445		goto err;
446	}
447
448	if (flags & FLAT_FLAG_KTRACE)
449		pr_info("Loading file: %s\n", bprm->filename);
450
451#ifdef CONFIG_BINFMT_FLAT_OLD
452	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
453		pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
454		       rev, FLAT_VERSION, OLD_FLAT_VERSION);
455		ret = -ENOEXEC;
456		goto err;
457	}
458
459	/*
460	 * fix up the flags for the older format,  there were all kinds
461	 * of endian hacks,  this only works for the simple cases
462	 */
463	if (rev == OLD_FLAT_VERSION &&
464	   (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
465		flags = FLAT_FLAG_RAM;
466
467#else /* CONFIG_BINFMT_FLAT_OLD */
468	if (rev != FLAT_VERSION) {
469		pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
470		       rev, FLAT_VERSION);
471		ret = -ENOEXEC;
472		goto err;
473	}
474#endif /* !CONFIG_BINFMT_FLAT_OLD */
475
476	/*
477	 * Make sure the header params are sane.
478	 * 28 bits (256 MB) is way more than reasonable in this case.
479	 * If some top bits are set we have probable binary corruption.
480	*/
481	if ((text_len | data_len | bss_len | stack_len | relocs | full_data) >> 28) {
482		pr_err("bad header\n");
483		ret = -ENOEXEC;
484		goto err;
485	}
486
487#ifndef CONFIG_BINFMT_ZFLAT
488	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
489		pr_err("Support for ZFLAT executables is not enabled.\n");
490		ret = -ENOEXEC;
491		goto err;
492	}
493#endif
494
495	/*
496	 * Check initial limits. This avoids letting people circumvent
497	 * size limits imposed on them by creating programs with large
498	 * arrays in the data or bss.
499	 */
500	rlim = rlimit(RLIMIT_DATA);
501	if (rlim >= RLIM_INFINITY)
502		rlim = ~0;
503	if (data_len + bss_len > rlim) {
504		ret = -ENOMEM;
505		goto err;
506	}
507
508	/* Flush all traces of the currently running executable */
509	ret = begin_new_exec(bprm);
510	if (ret)
511		goto err;
512
513	/* OK, This is the point of no return */
514	set_personality(PER_LINUX_32BIT);
515	setup_new_exec(bprm);
516
517	/*
518	 * calculate the extra space we need to map in
519	 */
520	extra = max_t(unsigned long, bss_len + stack_len,
521			relocs * sizeof(unsigned long));
522
523	/*
524	 * there are a couple of cases here,  the separate code/data
525	 * case,  and then the fully copied to RAM case which lumps
526	 * it all together.
527	 */
528	if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
529		/*
530		 * this should give us a ROM ptr,  but if it doesn't we don't
531		 * really care
532		 */
533		pr_debug("ROM mapping of file (we hope)\n");
534
535		textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
536				  MAP_PRIVATE, 0);
537		if (!textpos || IS_ERR_VALUE(textpos)) {
538			ret = textpos;
539			if (!textpos)
540				ret = -ENOMEM;
541			pr_err("Unable to mmap process text, errno %d\n", ret);
542			goto err;
543		}
544
545		len = data_len + extra +
546			DATA_START_OFFSET_WORDS * sizeof(unsigned long);
547		len = PAGE_ALIGN(len);
548		realdatastart = vm_mmap(NULL, 0, len,
549			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
550
551		if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
552			ret = realdatastart;
553			if (!realdatastart)
554				ret = -ENOMEM;
555			pr_err("Unable to allocate RAM for process data, "
556			       "errno %d\n", ret);
557			vm_munmap(textpos, text_len);
558			goto err;
559		}
560		datapos = ALIGN(realdatastart +
561				DATA_START_OFFSET_WORDS * sizeof(unsigned long),
562				FLAT_DATA_ALIGN);
563
564		pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
565			 data_len + bss_len + stack_len, datapos);
566
567		fpos = ntohl(hdr->data_start);
568#ifdef CONFIG_BINFMT_ZFLAT
569		if (flags & FLAT_FLAG_GZDATA) {
570			result = decompress_exec(bprm, fpos, (char *)datapos,
571						 full_data, 0);
572		} else
573#endif
574		{
575			result = read_code(bprm->file, datapos, fpos,
576					full_data);
577		}
578		if (IS_ERR_VALUE(result)) {
579			ret = result;
580			pr_err("Unable to read data+bss, errno %d\n", ret);
581			vm_munmap(textpos, text_len);
582			vm_munmap(realdatastart, len);
583			goto err;
584		}
585
586		reloc = (__be32 __user *)
587			(datapos + (ntohl(hdr->reloc_start) - text_len));
588		memp = realdatastart;
589		memp_size = len;
590	} else {
591
592		len = text_len + data_len + extra +
593			DATA_START_OFFSET_WORDS * sizeof(u32);
594		len = PAGE_ALIGN(len);
595		textpos = vm_mmap(NULL, 0, len,
596			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
597
598		if (!textpos || IS_ERR_VALUE(textpos)) {
599			ret = textpos;
600			if (!textpos)
601				ret = -ENOMEM;
602			pr_err("Unable to allocate RAM for process text/data, "
603			       "errno %d\n", ret);
604			goto err;
605		}
606
607		realdatastart = textpos + ntohl(hdr->data_start);
608		datapos = ALIGN(realdatastart +
609				DATA_START_OFFSET_WORDS * sizeof(u32),
610				FLAT_DATA_ALIGN);
611
612		reloc = (__be32 __user *)
613			(datapos + (ntohl(hdr->reloc_start) - text_len));
614		memp = textpos;
615		memp_size = len;
616#ifdef CONFIG_BINFMT_ZFLAT
617		/*
618		 * load it all in and treat it like a RAM load from now on
619		 */
620		if (flags & FLAT_FLAG_GZIP) {
621#ifndef CONFIG_MMU
622			result = decompress_exec(bprm, sizeof(struct flat_hdr),
623					 (((char *)textpos) + sizeof(struct flat_hdr)),
624					 (text_len + full_data
625						  - sizeof(struct flat_hdr)),
626					 0);
627			memmove((void *) datapos, (void *) realdatastart,
628					full_data);
629#else
630			/*
631			 * This is used on MMU systems mainly for testing.
632			 * Let's use a kernel buffer to simplify things.
633			 */
634			long unz_text_len = text_len - sizeof(struct flat_hdr);
635			long unz_len = unz_text_len + full_data;
636			char *unz_data = vmalloc(unz_len);
637			if (!unz_data) {
638				result = -ENOMEM;
639			} else {
640				result = decompress_exec(bprm, sizeof(struct flat_hdr),
641							 unz_data, unz_len, 0);
642				if (result == 0 &&
643				    (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
644						  unz_data, unz_text_len) ||
645				     copy_to_user((void __user *)datapos,
646						  unz_data + unz_text_len, full_data)))
647					result = -EFAULT;
648				vfree(unz_data);
649			}
650#endif
651		} else if (flags & FLAT_FLAG_GZDATA) {
652			result = read_code(bprm->file, textpos, 0, text_len);
653			if (!IS_ERR_VALUE(result)) {
654#ifndef CONFIG_MMU
655				result = decompress_exec(bprm, text_len, (char *) datapos,
656						 full_data, 0);
657#else
658				char *unz_data = vmalloc(full_data);
659				if (!unz_data) {
660					result = -ENOMEM;
661				} else {
662					result = decompress_exec(bprm, text_len,
663						       unz_data, full_data, 0);
664					if (result == 0 &&
665					    copy_to_user((void __user *)datapos,
666							 unz_data, full_data))
667						result = -EFAULT;
668					vfree(unz_data);
669				}
670#endif
671			}
672		} else
673#endif /* CONFIG_BINFMT_ZFLAT */
674		{
675			result = read_code(bprm->file, textpos, 0, text_len);
676			if (!IS_ERR_VALUE(result))
677				result = read_code(bprm->file, datapos,
678						   ntohl(hdr->data_start),
679						   full_data);
680		}
681		if (IS_ERR_VALUE(result)) {
682			ret = result;
683			pr_err("Unable to read code+data+bss, errno %d\n", ret);
684			vm_munmap(textpos, text_len + data_len + extra +
685				  DATA_START_OFFSET_WORDS * sizeof(u32));
686			goto err;
687		}
688	}
689
690	start_code = textpos + sizeof(struct flat_hdr);
691	end_code = textpos + text_len;
692	text_len -= sizeof(struct flat_hdr); /* the real code len */
693
694	/* The main program needs a little extra setup in the task structure */
695	current->mm->start_code = start_code;
696	current->mm->end_code = end_code;
697	current->mm->start_data = datapos;
698	current->mm->end_data = datapos + data_len;
699	/*
700	 * set up the brk stuff, uses any slack left in data/bss/stack
701	 * allocation.  We put the brk after the bss (between the bss
702	 * and stack) like other platforms.
703	 * Userspace code relies on the stack pointer starting out at
704	 * an address right at the end of a page.
705	 */
706	current->mm->start_brk = datapos + data_len + bss_len;
707	current->mm->brk = (current->mm->start_brk + 3) & ~3;
708#ifndef CONFIG_MMU
709	current->mm->context.end_brk = memp + memp_size - stack_len;
710#endif
711
712	if (flags & FLAT_FLAG_KTRACE) {
713		pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
714			textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
715		pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
716			"Load", bprm->filename,
717			start_code, end_code, datapos, datapos + data_len,
718			datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
719	}
720
721	/* Store the current module values into the global library structure */
722	libinfo->lib_list[0].start_code = start_code;
723	libinfo->lib_list[0].start_data = datapos;
724	libinfo->lib_list[0].start_brk = datapos + data_len + bss_len;
725	libinfo->lib_list[0].text_len = text_len;
726	libinfo->lib_list[0].loaded = 1;
727	libinfo->lib_list[0].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
728	libinfo->lib_list[0].build_date = ntohl(hdr->build_date);
729
730	/*
731	 * We just load the allocations into some temporary memory to
732	 * help simplify all this mumbo jumbo
733	 *
734	 * We've got two different sections of relocation entries.
735	 * The first is the GOT which resides at the beginning of the data segment
736	 * and is terminated with a -1.  This one can be relocated in place.
737	 * The second is the extra relocation entries tacked after the image's
738	 * data segment. These require a little more processing as the entry is
739	 * really an offset into the image which contains an offset into the
740	 * image.
741	 */
742	if (flags & FLAT_FLAG_GOTPIC) {
743		rp = skip_got_header((u32 __user *) datapos);
744		for (; ; rp++) {
745			u32 addr, rp_val;
746			if (get_user(rp_val, rp))
747				return -EFAULT;
748			if (rp_val == 0xffffffff)
749				break;
750			if (rp_val) {
751				addr = calc_reloc(rp_val, libinfo);
752				if (addr == RELOC_FAILED) {
753					ret = -ENOEXEC;
754					goto err;
755				}
756				if (put_user(addr, rp))
757					return -EFAULT;
758			}
759		}
760	}
761
762	/*
763	 * Now run through the relocation entries.
764	 * We've got to be careful here as C++ produces relocatable zero
765	 * entries in the constructor and destructor tables which are then
766	 * tested for being not zero (which will always occur unless we're
767	 * based from address zero).  This causes an endless loop as __start
768	 * is at zero.  The solution used is to not relocate zero addresses.
769	 * This has the negative side effect of not allowing a global data
770	 * reference to be statically initialised to _stext (I've moved
771	 * __start to address 4 so that is okay).
772	 */
773	if (rev > OLD_FLAT_VERSION) {
774		for (i = 0; i < relocs; i++) {
775			u32 addr, relval;
776			__be32 tmp;
777
778			/*
779			 * Get the address of the pointer to be
780			 * relocated (of course, the address has to be
781			 * relocated first).
782			 */
783			if (get_user(tmp, reloc + i))
784				return -EFAULT;
785			relval = ntohl(tmp);
786			addr = flat_get_relocate_addr(relval);
787			rp = (u32 __user *)calc_reloc(addr, libinfo);
788			if (rp == (u32 __user *)RELOC_FAILED) {
789				ret = -ENOEXEC;
790				goto err;
791			}
792
793			/* Get the pointer's value.  */
794			ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
795			if (unlikely(ret))
796				goto err;
797
798			if (addr != 0) {
799				/*
800				 * Do the relocation.  PIC relocs in the data section are
801				 * already in target order
802				 */
803				if ((flags & FLAT_FLAG_GOTPIC) == 0) {
804					/*
805					 * Meh, the same value can have a different
806					 * byte order based on a flag..
807					 */
808					addr = ntohl((__force __be32)addr);
809				}
810				addr = calc_reloc(addr, libinfo);
811				if (addr == RELOC_FAILED) {
812					ret = -ENOEXEC;
813					goto err;
814				}
815
816				/* Write back the relocated pointer.  */
817				ret = flat_put_addr_at_rp(rp, addr, relval);
818				if (unlikely(ret))
819					goto err;
820			}
821		}
822#ifdef CONFIG_BINFMT_FLAT_OLD
823	} else {
824		for (i = 0; i < relocs; i++) {
825			__be32 relval;
826			if (get_user(relval, reloc + i))
827				return -EFAULT;
828			old_reloc(ntohl(relval));
829		}
830#endif /* CONFIG_BINFMT_FLAT_OLD */
831	}
832
833	flush_icache_user_range(start_code, end_code);
834
835	/* zero the BSS,  BRK and stack areas */
836	if (clear_user((void __user *)(datapos + data_len), bss_len +
837		       (memp + memp_size - stack_len -		/* end brk */
838		       libinfo->lib_list[0].start_brk) +	/* start brk */
839		       stack_len))
840		return -EFAULT;
841
842	return 0;
843err:
844	return ret;
845}
846
847
848/****************************************************************************/
849
850/*
851 * These are the functions used to load flat style executables and shared
852 * libraries.  There is no binary dependent code anywhere else.
853 */
854
855static int load_flat_binary(struct linux_binprm *bprm)
856{
857	struct lib_info libinfo;
858	struct pt_regs *regs = current_pt_regs();
859	unsigned long stack_len = 0;
860	unsigned long start_addr;
861	int res;
862	int i, j;
863
864	memset(&libinfo, 0, sizeof(libinfo));
865
866	/*
867	 * We have to add the size of our arguments to our stack size
868	 * otherwise it's too easy for users to create stack overflows
869	 * by passing in a huge argument list.  And yes,  we have to be
870	 * pedantic and include space for the argv/envp array as it may have
871	 * a lot of entries.
872	 */
873#ifndef CONFIG_MMU
874	stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
875#endif
876	stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
877	stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
878	stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
879
880	res = load_flat_file(bprm, &libinfo, &stack_len);
881	if (res < 0)
882		return res;
883
884	/* Update data segment pointers for all libraries */
885	for (i = 0; i < MAX_SHARED_LIBS_UPDATE; i++) {
886		if (!libinfo.lib_list[i].loaded)
887			continue;
888		for (j = 0; j < MAX_SHARED_LIBS; j++) {
889			unsigned long val = libinfo.lib_list[j].loaded ?
890				libinfo.lib_list[j].start_data : UNLOADED_LIB;
891			unsigned long __user *p = (unsigned long __user *)
892				libinfo.lib_list[i].start_data;
893			p -= j + 1;
894			if (put_user(val, p))
895				return -EFAULT;
896		}
897	}
898
899	set_binfmt(&flat_format);
900
901#ifdef CONFIG_MMU
902	res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
903	if (!res)
904		res = create_flat_tables(bprm, bprm->p);
905#else
906	/* Stash our initial stack pointer into the mm structure */
907	current->mm->start_stack =
908		((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
909	pr_debug("sp=%lx\n", current->mm->start_stack);
910
911	/* copy the arg pages onto the stack */
912	res = transfer_args_to_stack(bprm, &current->mm->start_stack);
913	if (!res)
914		res = create_flat_tables(bprm, current->mm->start_stack);
915#endif
916	if (res)
917		return res;
918
919	/* Fake some return addresses to ensure the call chain will
920	 * initialise library in order for us.  We are required to call
921	 * lib 1 first, then 2, ... and finally the main program (id 0).
922	 */
923	start_addr = libinfo.lib_list[0].entry;
924
925#ifdef FLAT_PLAT_INIT
926	FLAT_PLAT_INIT(regs);
927#endif
928
929	finalize_exec(bprm);
930	pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
931		 regs, start_addr, current->mm->start_stack);
932	start_thread(regs, start_addr, current->mm->start_stack);
933
934	return 0;
935}
936
937/****************************************************************************/
938
939static int __init init_flat_binfmt(void)
940{
941	register_binfmt(&flat_format);
942	return 0;
943}
944core_initcall(init_flat_binfmt);
945
946/****************************************************************************/