[PATCH] UCLINUX "flat" binary loader

This is much like the old m68k amiga/st loader world. Its a relocating
loader with optional compression. Shared libraries and A5 sharing stuff
is all handled by the userspace/libs

fs/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_BINFMT_MISC)	+= binfmt_misc.o
 obj-y				+= binfmt_script.o
 
 obj-$(CONFIG_BINFMT_ELF)	+= binfmt_elf.o
+obj-$(CONFIG_BINFMT_FLAT)	+= binfmt_flat.o
 
 obj-$(CONFIG_FS_MBCACHE)	+= mbcache.o
 obj-$(CONFIG_FS_POSIX_ACL)	+= posix_acl.o xattr_acl.o

fs/binfmt_flat.c

+/*
+ *  linux/fs/binfmt_flat.c
+ *
+ *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@uclinux.org>
+ *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.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/pgalloc.h>
+#include <asm/unaligned.h>
+#include <asm/cacheflush.h>
+
+#undef DEBUG
+#ifdef DEBUG
+#define	DBG_FLT(a...)	printk(##a)
+#else
+#define	DBG_FLT(a...)
+#endif
+
+static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
+static int load_flat_library(struct file*);
+extern void dump_thread(struct pt_regs *, struct user *);
+
+static struct linux_binfmt flat_format = {
+	NULL, THIS_MODULE, load_flat_binary, load_flat_library, NULL, PAGE_SIZE
+};
+
+
+/*
+ * 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;
+	put_user((unsigned long) envp, --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;
+
+	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");
+		return -ENOMEM;
+	}
+
+	/* 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;
+
+	/* Check minimum size -- gzip header */
+	if (ret < 10) {
+		DBG_FLT("binfmt_flat: file too small?\n");
+		return -ENOEXEC;
+	}
+
+	/* Check gzip magic number */
+	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
+		DBG_FLT("binfmt_flat: unknown compression magic?\n");
+		return -ENOEXEC;
+	}
+
+	/* Check gzip method */
+	if (buf[2] != 8) {
+		DBG_FLT("binfmt_flat: unknown compression method?\n");
+		return -ENOEXEC;
+	}
+	/* Check gzip flags */
+	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
+	    (buf[3] & RESERVED)) {
+		DBG_FLT("binfmt_flat: unknown flags?\n");
+		return -ENOEXEC;
+	}
+
+	ret = 10;
+	if (buf[3] & EXTRA_FIELD)
+		ret += 2 + buf[10] + (buf[11] << 8);
+	if (buf[3] & ORIG_NAME) {
+		for (; (buf[ret] != 0); ret++)
+			;
+	}
+	if (buf[3] & COMMENT) {
+		for (; (buf[ret] != 0); ret++)
+			;
+	}
+
+	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");
+		return -ENOEXEC;
+	}
+
+	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);
+		return -ENOEXEC;
+	}
+
+	zlib_inflateEnd(&strm);
+	kfree(buf);
+	kfree(strm.workspace);
+	return 0;
+}
+
+#endif /* CONFIG_BINFMT_ZFLAT */
+
+
+static unsigned long
+calc_reloc(unsigned long r, unsigned long text_len)
+{
+	unsigned long addr;
+
+	if (r > current->mm->start_brk - current->mm->start_data + text_len) {
+		printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x), killing!\n",
+				(int) r,(int)(current->mm->start_brk-current->mm->start_code));
+		send_sig(SIGSEGV, current, 0);
+		return(current->mm->start_brk); /* return something safe to write to */
+	}
+
+	if (r < text_len) {
+		/* In text segment */
+		return r + current->mm->start_code;
+	}
+
+	/*
+	 * we allow inclusive ranges here so that programs may do things
+	 * like reference the end of data (_end) without failing these tests
+	 */
+	addr =  r - text_len + current->mm->start_data;
+	if (addr >= current->mm->start_code &&
+			addr <= current->mm->start_code + text_len)
+		return(addr);
+
+	if (addr >= current->mm->start_data &&
+			addr <= current->mm->start_brk)
+		return(addr);
+
+	printk("BINFMT_FLAT: reloc addr outside text/data 0x%x "
+			"code(0x%x - 0x%x) data(0x%x - 0x%x) killing\n", (int) addr,
+			(int) current->mm->start_code,
+			(int) (current->mm->start_code + text_len),
+			(int) current->mm->start_data,
+			(int) current->mm->start_brk);
+	send_sig(SIGSEGV, current, 0);
+
+	return(current->mm->start_brk); /* return something safe to write to */
+}
+
+
+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
+}		
+
+
+/*
+ * 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 flat_hdr * hdr;
+	unsigned long textpos = 0, datapos = 0, result;
+	unsigned long text_len, data_len, bss_len, stack_len, flags;
+	unsigned long memp = 0, memkasked = 0; /* for finding the brk area */
+	unsigned long extra, rlim;
+	unsigned long p = bprm->p;
+	unsigned long *reloc = 0, *rp;
+	struct inode *inode;
+	int i, rev, relocs = 0;
+	loff_t fpos;
+
+	DBG_FLT("BINFMT_FLAT: Loading file: %x\n", bprm->file);
+
+	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);
+	relocs    = ntohl(hdr->reloc_count);
+	flags     = ntohl(hdr->flags);
+	rev       = ntohl(hdr->rev);
+
+	/*
+	 * 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 */
+
+	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;
+	}
+
+	/*
+	 * 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 && 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->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 */
+	result = flush_old_exec(bprm);
+	if (result)
+		return result;
+
+	/* OK, This is the point of no return */
+	set_personality(PER_LINUX);
+
+	/*
+	 * there are a couple of cases here,  the seperate 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, 0, 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);
+		}
+
+		extra = max(bss_len + stack_len, relocs * sizeof(unsigned long)),
+
+		down_write(&current->mm->mmap_sem);
+		datapos = do_mmap(0, 0, data_len + extra,
+				PROT_READ|PROT_WRITE|PROT_EXEC, 0, 0);
+		up_write(&current->mm->mmap_sem);
+
+		if (datapos == 0 || datapos >= (unsigned long)-4096) {
+			if (!datapos)
+				datapos = (unsigned long) -ENOMEM;
+			printk("Unable to allocate RAM for process data, errno %d\n",
+					(int)-datapos);
+			do_munmap(current->mm, textpos, text_len);
+			return datapos;
+		}
+
+		DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
+				data_len + bss_len + stack_len, 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 + extra, &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, datapos, data_len + extra);
+			return result;
+		}
+
+		reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
+		memp = datapos;
+		memkasked = data_len + extra;
+
+	} else {
+
+		/*
+		 * calculate the extra space we need to map in
+		 */
+
+		extra = max(bss_len + stack_len, relocs * sizeof(unsigned long)),
+
+		down_write(&current->mm->mmap_sem);
+		textpos = do_mmap(0, 0, text_len + data_len + extra,
+				PROT_READ | PROT_EXEC | PROT_WRITE, 0, 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);
+		}
+
+		datapos = textpos + ntohl (hdr->data_start);
+		reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start));
+		memp = textpos;
+		memkasked = text_len + data_len + extra;
+
+#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);
+		} 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 + data_len + extra, &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);
+			return result;
+		}
+	}
+
+	DBG_FLT("Mapping is %x, Entry point is %x, data_start is %x\n",
+			textpos, ntohl(hdr->entry), ntohl(hdr->data_start));
+
+	current->mm->start_code = textpos + sizeof (struct flat_hdr);
+	current->mm->end_code = textpos + text_len;
+	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;
+	current->mm->rss = 0;
+
+	DBG_FLT("Load %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
+		bprm->filename,
+		(int) current->mm->start_code, (int) current->mm->end_code,
+		(int) current->mm->start_data, (int) current->mm->end_data,
+		(int) current->mm->end_data, (int) current->mm->brk);
+
+	text_len -= sizeof(struct flat_hdr); /* the real code len */
+
+	/*
+	 * 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++)
+			*rp = calc_reloc(*rp, text_len);
+	}
+
+	/*
+	 * 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;
+
+			/* Get the address of the pointer to be
+			   relocated (of course, the address has to be
+			   relocated first).  */
+			rp = (unsigned long *) calc_reloc(ntohl(reloc[i]), text_len);
+
+			/* Get the pointer's value.  */
+			addr = get_unaligned (rp);
+
+			if (addr != 0) {
+				/*
+				 * Do the relocation.  PIC relocs in the data section are
+				 * already in target order
+				 */
+				addr = calc_reloc(
+						(flags & FLAT_FLAG_GOTPIC) ? addr : ntohl(addr),
+						text_len);
+				/* Write back the relocated pointer.  */
+				put_unaligned (addr, rp);
+			}
+		}
+	} else {
+		for (i=0; i < relocs; i++)
+			old_reloc(ntohl(reloc[i]));
+	}
+
+	/* zero the BSS,  BRK and stack areas */
+	memset((void*)(datapos + data_len), 0, bss_len + 
+			(current->mm->context.end_brk - current->mm->start_brk) +
+			stack_len);
+
+	compute_creds(bprm);
+ 	current->flags &= ~PF_FORKNOEXEC;
+
+	flush_icache_range(current->mm->start_code, current->mm->end_code);
+
+	set_binfmt(&flat_format);
+
+	p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
+	DBG_FLT("p=%x\n", 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];
+
+	current->mm->start_stack = (unsigned long) create_flat_tables(p, bprm);
+
+	DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
+		regs, textpos + ntohl(hdr->entry), current->mm->start_stack);
+	start_thread(regs,
+		     textpos + ntohl(hdr->entry),
+		     current->mm->start_stack);
+
+	if (current->ptrace & PT_PTRACED)
+		send_sig(SIGTRAP, current, 0);
+
+	return 0;
+}
+
+static int load_flat_library(struct file *file)
+{
+	return(-ENOEXEC);
+}
+
+static int __init init_flat_binfmt(void)
+{
+	return register_binfmt(&flat_format);
+}
+
+static void __exit exit_flat_binfmt(void)
+{
+	unregister_binfmt(&flat_format);
+}
+
+EXPORT_NO_SYMBOLS;
+
+module_init(init_flat_binfmt);
+module_exit(exit_flat_binfmt);