compat.c

out_putf:
	fput(file);
out:
	return error;
}

#ifndef __ARCH_OMIT_COMPAT_SYS_GETDENTS64
#define COMPAT_ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))

struct compat_getdents_callback64 {
	struct linux_dirent64 __user *current_dir;
	struct linux_dirent64 __user *previous;
	int count;
	int error;
};

static int compat_filldir64(void * __buf, const char * name, int namlen, loff_t offset,
		     ino_t ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct compat_getdents_callback64 *buf = __buf;
	int jj = NAME_OFFSET(dirent);
	int reclen = COMPAT_ROUND_UP64(jj + namlen + 1);
	u64 off;

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;

	if (dirent) {
		if (__put_user_unaligned(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user_unaligned(ino, &dirent->d_ino))
		goto efault;
	off = 0;
	if (__put_user_unaligned(off, &dirent->d_off))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (__put_user(d_type, &dirent->d_type))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

asmlinkage long compat_sys_getdents64(unsigned int fd,
		struct linux_dirent64 __user * dirent, unsigned int count)
{
	struct file * file;
	struct linux_dirent64 __user * lastdirent;
	struct compat_getdents_callback64 buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, compat_filldir64, &buf);
	if (error < 0)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = file->f_pos;
		__put_user_unaligned(d_off, &lastdirent->d_off);
		error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}
#endif /* ! __ARCH_OMIT_COMPAT_SYS_GETDENTS64 */

static ssize_t compat_do_readv_writev(int type, struct file *file,
			       const struct compat_iovec __user *uvector,
			       unsigned long nr_segs, loff_t *pos)
{
	typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
	typedef ssize_t (*iov_fn_t)(struct file *, const struct iovec *, unsigned long, loff_t *);

	compat_ssize_t tot_len;
	struct iovec iovstack[UIO_FASTIOV];
	struct iovec *iov=iovstack, *vector;
	ssize_t ret;
	int seg;
	io_fn_t fn;
	iov_fn_t fnv;

	/*
	 * SuS says "The readv() function *may* fail if the iovcnt argument
	 * was less than or equal to 0, or greater than {IOV_MAX}.  Linux has
	 * traditionally returned zero for zero segments, so...
	 */
	ret = 0;
	if (nr_segs == 0)
		goto out;

	/*
	 * First get the "struct iovec" from user memory and
	 * verify all the pointers
	 */
	ret = -EINVAL;
	if ((nr_segs > UIO_MAXIOV) || (nr_segs <= 0))
		goto out;
	if (!file->f_op)
		goto out;
	if (nr_segs > UIO_FASTIOV) {
		ret = -ENOMEM;
		iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
		if (!iov)
			goto out;
	}
	ret = -EFAULT;
	if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
		goto out;

	/*
	 * Single unix specification:
	 * We should -EINVAL if an element length is not >= 0 and fitting an
	 * ssize_t.  The total length is fitting an ssize_t
	 *
	 * Be careful here because iov_len is a size_t not an ssize_t
	 */
	tot_len = 0;
	vector = iov;
	ret = -EINVAL;
	for (seg = 0 ; seg < nr_segs; seg++) {
		compat_ssize_t tmp = tot_len;
		compat_ssize_t len;
		compat_uptr_t buf;

		if (__get_user(len, &uvector->iov_len) ||
		    __get_user(buf, &uvector->iov_base)) {
			ret = -EFAULT;
			goto out;
		}
		if (len < 0)	/* size_t not fitting an compat_ssize_t .. */
			goto out;
		tot_len += len;
		if (tot_len < tmp) /* maths overflow on the compat_ssize_t */
			goto out;
		vector->iov_base = compat_ptr(buf);
		vector->iov_len = (compat_size_t) len;
		uvector++;
		vector++;
	}
	if (tot_len == 0) {
		ret = 0;
		goto out;
	}

	ret = rw_verify_area(type, file, pos, tot_len);
	if (ret)
		goto out;

	fnv = NULL;
	if (type == READ) {
		fn = file->f_op->read;
		fnv = file->f_op->readv;
	} else {
		fn = (io_fn_t)file->f_op->write;
		fnv = file->f_op->writev;
	}
	if (fnv) {
		ret = fnv(file, iov, nr_segs, pos);
		goto out;
	}

	/* Do it by hand, with file-ops */
	ret = 0;
	vector = iov;
	while (nr_segs > 0) {
		void __user * base;
		size_t len;
		ssize_t nr;

		base = vector->iov_base;
		len = vector->iov_len;
		vector++;
		nr_segs--;

		nr = fn(file, base, len, pos);

		if (nr < 0) {
			if (!ret) ret = nr;
			break;
		}
		ret += nr;
		if (nr != len)
			break;
	}
out:
	if (iov != iovstack)
		kfree(iov);
	if ((ret + (type == READ)) > 0) {
		struct dentry *dentry = file->f_dentry;
		if (type == READ)
			fsnotify_access(dentry);
		else
			fsnotify_modify(dentry);
	}
	return ret;
}

asmlinkage ssize_t
compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen)
{
	struct file *file;
	ssize_t ret = -EBADF;

	file = fget(fd);
	if (!file)
		return -EBADF;

	if (!(file->f_mode & FMODE_READ))
		goto out;

	ret = -EINVAL;
	if (!file->f_op || (!file->f_op->readv && !file->f_op->read))
		goto out;

	ret = compat_do_readv_writev(READ, file, vec, vlen, &file->f_pos);

out:
	fput(file);
	return ret;
}

asmlinkage ssize_t
compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen)
{
	struct file *file;
	ssize_t ret = -EBADF;

	file = fget(fd);
	if (!file)
		return -EBADF;
	if (!(file->f_mode & FMODE_WRITE))
		goto out;

	ret = -EINVAL;
	if (!file->f_op || (!file->f_op->writev && !file->f_op->write))
		goto out;

	ret = compat_do_readv_writev(WRITE, file, vec, vlen, &file->f_pos);

out:
	fput(file);
	return ret;
}

/*
 * compat_count() counts the number of arguments/envelopes. It is basically
 * a copy of count() from fs/exec.c, except that it works with 32 bit argv
 * and envp pointers.
 */
static int compat_count(compat_uptr_t __user *argv, int max)
{
	int i = 0;

	if (argv != NULL) {
		for (;;) {
			compat_uptr_t p;

			if (get_user(p, argv))
				return -EFAULT;
			if (!p)
				break;
			argv++;
			if(++i > max)
				return -E2BIG;
		}
	}
	return i;
}

/*
 * compat_copy_strings() is basically a copy of copy_strings() from fs/exec.c
 * except that it works with 32 bit argv and envp pointers.
 */
static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
				struct linux_binprm *bprm)
{
	struct page *kmapped_page = NULL;
	char *kaddr = NULL;
	int ret;

	while (argc-- > 0) {
		compat_uptr_t str;
		int len;
		unsigned long pos;

		if (get_user(str, argv+argc) ||
			!(len = strnlen_user(compat_ptr(str), bprm->p))) {
			ret = -EFAULT;
			goto out;
		}

		if (bprm->p < len)  {
			ret = -E2BIG;
			goto out;
		}

		bprm->p -= len;
		/* XXX: add architecture specific overflow check here. */
		pos = bprm->p;

		while (len > 0) {
			int i, new, err;
			int offset, bytes_to_copy;
			struct page *page;

			offset = pos % PAGE_SIZE;
			i = pos/PAGE_SIZE;
			page = bprm->page[i];
			new = 0;
			if (!page) {
				page = alloc_page(GFP_HIGHUSER);
				bprm->page[i] = page;
				if (!page) {
					ret = -ENOMEM;
					goto out;
				}
				new = 1;
			}

			if (page != kmapped_page) {
				if (kmapped_page)
					kunmap(kmapped_page);
				kmapped_page = page;
				kaddr = kmap(kmapped_page);
			}
			if (new && offset)
				memset(kaddr, 0, offset);
			bytes_to_copy = PAGE_SIZE - offset;
			if (bytes_to_copy > len) {
				bytes_to_copy = len;
				if (new)
					memset(kaddr+offset+len, 0,
						PAGE_SIZE-offset-len);
			}
			err = copy_from_user(kaddr+offset, compat_ptr(str),
						bytes_to_copy);
			if (err) {
				ret = -EFAULT;
				goto out;
			}

			pos += bytes_to_copy;
			str += bytes_to_copy;
			len -= bytes_to_copy;
		}
	}
	ret = 0;
out:
	if (kmapped_page)
		kunmap(kmapped_page);
	return ret;
}

#ifdef CONFIG_MMU

#define free_arg_pages(bprm) do { } while (0)

#else

static inline void free_arg_pages(struct linux_binprm *bprm)
{
	int i;

	for (i = 0; i < MAX_ARG_PAGES; i++) {
		if (bprm->page[i])
			__free_page(bprm->page[i]);
		bprm->page[i] = NULL;
	}
}

#endif /* CONFIG_MMU */

/*
 * compat_do_execve() is mostly a copy of do_execve(), with the exception
 * that it processes 32 bit argv and envp pointers.
 */
int compat_do_execve(char * filename,
	compat_uptr_t __user *argv,
	compat_uptr_t __user *envp,
	struct pt_regs * regs)
{
	struct linux_binprm *bprm;
	struct file *file;
	int retval;
	int i;

	retval = -ENOMEM;
	bprm = kmalloc(sizeof(*bprm), GFP_KERNEL);
	if (!bprm)
		goto out_ret;
	memset(bprm, 0, sizeof(*bprm));

	file = open_exec(filename);
	retval = PTR_ERR(file);
	if (IS_ERR(file))
		goto out_kfree;

	sched_exec();

	bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
	bprm->file = file;
	bprm->filename = filename;
	bprm->interp = filename;
	bprm->mm = mm_alloc();
	retval = -ENOMEM;
	if (!bprm->mm)
		goto out_file;

	retval = init_new_context(current, bprm->mm);
	if (retval < 0)
		goto out_mm;

	bprm->argc = compat_count(argv, bprm->p / sizeof(compat_uptr_t));
	if ((retval = bprm->argc) < 0)
		goto out_mm;

	bprm->envc = compat_count(envp, bprm->p / sizeof(compat_uptr_t));
	if ((retval = bprm->envc) < 0)
		goto out_mm;

	retval = security_bprm_alloc(bprm);
	if (retval)
		goto out;

	retval = prepare_binprm(bprm);
	if (retval < 0)
		goto out;

	retval = copy_strings_kernel(1, &bprm->filename, bprm);
	if (retval < 0)
		goto out;

	bprm->exec = bprm->p;
	retval = compat_copy_strings(bprm->envc, envp, bprm);
	if (retval < 0)
		goto out;

	retval = compat_copy_strings(bprm->argc, argv, bprm);
	if (retval < 0)
		goto out;

	retval = search_binary_handler(bprm, regs);
	if (retval >= 0) {
		free_arg_pages(bprm);

		/* execve success */
		security_bprm_free(bprm);
		kfree(bprm);
		return retval;
	}

out:
	/* Something went wrong, return the inode and free the argument pages*/
	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
		struct page * page = bprm->page[i];
		if (page)
			__free_page(page);
	}

	if (bprm->security)
		security_bprm_free(bprm);

out_mm:
	if (bprm->mm)
		mmdrop(bprm->mm);

out_file:
	if (bprm->file) {
		allow_write_access(bprm->file);
		fput(bprm->file);
	}

out_kfree:
	kfree(bprm);

out_ret:
	return retval;
}

#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))

#define ROUND_UP(x,y) (((x)+(y)-1)/(y))

/*
 * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
 * 64-bit unsigned longs.
 */
static inline
int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
			unsigned long *fdset)
{
	nr = ROUND_UP(nr, __COMPAT_NFDBITS);
	if (ufdset) {
		unsigned long odd;

		if (!access_ok(VERIFY_WRITE, ufdset, nr*sizeof(compat_ulong_t)))
			return -EFAULT;

		odd = nr & 1UL;
		nr &= ~1UL;
		while (nr) {
			unsigned long h, l;
			__get_user(l, ufdset);
			__get_user(h, ufdset+1);
			ufdset += 2;
			*fdset++ = h << 32 | l;
			nr -= 2;
		}
		if (odd)
			__get_user(*fdset, ufdset);
	} else {
		/* Tricky, must clear full unsigned long in the
		 * kernel fdset at the end, this makes sure that
		 * actually happens.
		 */
		memset(fdset, 0, ((nr + 1) & ~1)*sizeof(compat_ulong_t));
	}
	return 0;
}

static inline
void compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
			unsigned long *fdset)
{
	unsigned long odd;
	nr = ROUND_UP(nr, __COMPAT_NFDBITS);

	if (!ufdset)
		return;

	odd = nr & 1UL;
	nr &= ~1UL;
	while (nr) {
		unsigned long h, l;
		l = *fdset++;
		h = l >> 32;
		__put_user(l, ufdset);
		__put_user(h, ufdset+1);
		ufdset += 2;
		nr -= 2;
	}
	if (odd)
		__put_user(*fdset, ufdset);
}


/*
 * This is a virtual copy of sys_select from fs/select.c and probably
 * should be compared to it from time to time
 */
static void *select_bits_alloc(int size)
{
	return kmalloc(6 * size, GFP_KERNEL);
}

static void select_bits_free(void *bits, int size)
{
	kfree(bits);
}

/*
 * We can actually return ERESTARTSYS instead of EINTR, but I'd
 * like to be certain this leads to no problems. So I return
 * EINTR just for safety.
 *
 * Update: ERESTARTSYS breaks at least the xview clock binary, so
 * I'm trying ERESTARTNOHAND which restart only when you want to.
 */
#define MAX_SELECT_SECONDS \
	((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)

asmlinkage long
compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp,
		compat_ulong_t __user *exp, struct compat_timeval __user *tvp)
{
	fd_set_bits fds;
	char *bits;
	long timeout;
	int size, max_fdset, ret = -EINVAL;

	timeout = MAX_SCHEDULE_TIMEOUT;
	if (tvp) {
		time_t sec, usec;

		if (!access_ok(VERIFY_READ, tvp, sizeof(*tvp))
		    || __get_user(sec, &tvp->tv_sec)
		    || __get_user(usec, &tvp->tv_usec)) {
			ret = -EFAULT;
			goto out_nofds;
		}

		if (sec < 0 || usec < 0)
			goto out_nofds;

		if ((unsigned long) sec < MAX_SELECT_SECONDS) {
			timeout = ROUND_UP(usec, 1000000/HZ);
			timeout += sec * (unsigned long) HZ;
		}
	}

	if (n < 0)
		goto out_nofds;

	/* max_fdset can increase, so grab it once to avoid race */
	max_fdset = current->files->max_fdset;
	if (n > max_fdset)
		n = max_fdset;

	/*
	 * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
	 * since we used fdset we need to allocate memory in units of
	 * long-words.
	 */
	ret = -ENOMEM;
	size = FDS_BYTES(n);
	bits = select_bits_alloc(size);
	if (!bits)
		goto out_nofds;
	fds.in      = (unsigned long *)  bits;
	fds.out     = (unsigned long *) (bits +   size);
	fds.ex      = (unsigned long *) (bits + 2*size);
	fds.res_in  = (unsigned long *) (bits + 3*size);
	fds.res_out = (unsigned long *) (bits + 4*size);
	fds.res_ex  = (unsigned long *) (bits + 5*size);

	if ((ret = compat_get_fd_set(n, inp, fds.in)) ||
	    (ret = compat_get_fd_set(n, outp, fds.out)) ||
	    (ret = compat_get_fd_set(n, exp, fds.ex)))
		goto out;
	zero_fd_set(n, fds.res_in);
	zero_fd_set(n, fds.res_out);
	zero_fd_set(n, fds.res_ex);

	ret = do_select(n, &fds, &timeout);

	if (tvp && !(current->personality & STICKY_TIMEOUTS)) {
		time_t sec = 0, usec = 0;
		if (timeout) {
			sec = timeout / HZ;
			usec = timeout % HZ;
			usec *= (1000000/HZ);
		}
		if (put_user(sec, &tvp->tv_sec) ||
		    put_user(usec, &tvp->tv_usec))
			ret = -EFAULT;
	}

	if (ret < 0)
		goto out;
	if (!ret) {
		ret = -ERESTARTNOHAND;
		if (signal_pending(current))
			goto out;
		ret = 0;
	}

	compat_set_fd_set(n, inp, fds.res_in);
	compat_set_fd_set(n, outp, fds.res_out);
	compat_set_fd_set(n, exp, fds.res_ex);

out:
	select_bits_free(bits, size);
out_nofds:
	return ret;
}

#if defined(CONFIG_NFSD) || defined(CONFIG_NFSD_MODULE)
/* Stuff for NFS server syscalls... */
struct compat_nfsctl_svc {
	u16			svc32_port;
	s32			svc32_nthreads;
};

struct compat_nfsctl_client {
	s8			cl32_ident[NFSCLNT_IDMAX+1];
	s32			cl32_naddr;
	struct in_addr		cl32_addrlist[NFSCLNT_ADDRMAX];
	s32			cl32_fhkeytype;
	s32			cl32_fhkeylen;
	u8			cl32_fhkey[NFSCLNT_KEYMAX];
};

struct compat_nfsctl_export {
	char		ex32_client[NFSCLNT_IDMAX+1];
	char		ex32_path[NFS_MAXPATHLEN+1];
	compat_dev_t	ex32_dev;
	compat_ino_t	ex32_ino;
	compat_int_t	ex32_flags;
	__compat_uid_t	ex32_anon_uid;
	__compat_gid_t	ex32_anon_gid;
};

struct compat_nfsctl_fdparm {
	struct sockaddr		gd32_addr;
	s8			gd32_path[NFS_MAXPATHLEN+1];
	compat_int_t		gd32_version;
};

struct compat_nfsctl_fsparm {
	struct sockaddr		gd32_addr;
	s8			gd32_path[NFS_MAXPATHLEN+1];
	compat_int_t		gd32_maxlen;
};

struct compat_nfsctl_arg {
	compat_int_t		ca32_version;	/* safeguard */
	union {
		struct compat_nfsctl_svc	u32_svc;
		struct compat_nfsctl_client	u32_client;
		struct compat_nfsctl_export	u32_export;
		struct compat_nfsctl_fdparm	u32_getfd;
		struct compat_nfsctl_fsparm	u32_getfs;
	} u;
#define ca32_svc	u.u32_svc
#define ca32_client	u.u32_client
#define ca32_export	u.u32_export
#define ca32_getfd	u.u32_getfd
#define ca32_getfs	u.u32_getfs
};

union compat_nfsctl_res {
	__u8			cr32_getfh[NFS_FHSIZE];
	struct knfsd_fh		cr32_getfs;
};

static int compat_nfs_svc_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg)
{
	int err;

	err = access_ok(VERIFY_READ, &arg->ca32_svc, sizeof(arg->ca32_svc));
	err |= get_user(karg->ca_version, &arg->ca32_version);
	err |= __get_user(karg->ca_svc.svc_port, &arg->ca32_svc.svc32_port);
	err |= __get_user(karg->ca_svc.svc_nthreads, &arg->ca32_svc.svc32_nthreads);
	return (err) ? -EFAULT : 0;
}

static int compat_nfs_clnt_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg)
{
	int err;

	err = access_ok(VERIFY_READ, &arg->ca32_client, sizeof(arg->ca32_client));
	err |= get_user(karg->ca_version, &arg->ca32_version);
	err |= __copy_from_user(&karg->ca_client.cl_ident[0],
			  &arg->ca32_client.cl32_ident[0],
			  NFSCLNT_IDMAX);
	err |= __get_user(karg->ca_client.cl_naddr, &arg->ca32_client.cl32_naddr);
	err |= __copy_from_user(&karg->ca_client.cl_addrlist[0],
			  &arg->ca32_client.cl32_addrlist[0],
			  (sizeof(struct in_addr) * NFSCLNT_ADDRMAX));
	err |= __get_user(karg->ca_client.cl_fhkeytype,
		      &arg->ca32_client.cl32_fhkeytype);
	err |= __get_user(karg->ca_client.cl_fhkeylen,
		      &arg->ca32_client.cl32_fhkeylen);
	err |= __copy_from_user(&karg->ca_client.cl_fhkey[0],
			  &arg->ca32_client.cl32_fhkey[0],
			  NFSCLNT_KEYMAX);

	return (err) ? -EFAULT : 0;
}

static int compat_nfs_exp_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg)
{
	int err;

	err = access_ok(VERIFY_READ, &arg->ca32_export, sizeof(arg->ca32_export));
	err |= get_user(karg->ca_version, &arg->ca32_version);
	err |= __copy_from_user(&karg->ca_export.ex_client[0],
			  &arg->ca32_export.ex32_client[0],
			  NFSCLNT_IDMAX);
	err |= __copy_from_user(&karg->ca_export.ex_path[0],
			  &arg->ca32_export.ex32_path[0],
			  NFS_MAXPATHLEN);
	err |= __get_user(karg->ca_export.ex_dev,
		      &arg->ca32_export.ex32_dev);
	err |= __get_user(karg->ca_export.ex_ino,
		      &arg->ca32_export.ex32_ino);
	err |= __get_user(karg->ca_export.ex_flags,
		      &arg->ca32_export.ex32_flags);
	err |= __get_user(karg->ca_export.ex_anon_uid,
		      &arg->ca32_export.ex32_anon_uid);
	err |= __get_user(karg->ca_export.ex_anon_gid,
		      &arg->ca32_export.ex32_anon_gid);
	SET_UID(karg->ca_export.ex_anon_uid, karg->ca_export.ex_anon_uid);
	SET_GID(karg->ca_export.ex_anon_gid, karg->ca_export.ex_anon_gid);

	return (err) ? -EFAULT : 0;
}

static int compat_nfs_getfd_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg)
{
	int err;

	err = access_ok(VERIFY_READ, &arg->ca32_getfd, sizeof(arg->ca32_getfd));
	err |= get_user(karg->ca_version, &arg->ca32_version);
	err |= __copy_from_user(&karg->ca_getfd.gd_addr,
			  &arg->ca32_getfd.gd32_addr,
			  (sizeof(struct sockaddr)));
	err |= __copy_from_user(&karg->ca_getfd.gd_path,
			  &arg->ca32_getfd.gd32_path,
			  (NFS_MAXPATHLEN+1));
	err |= __get_user(karg->ca_getfd.gd_version,
		      &arg->ca32_getfd.gd32_version);

	return (err) ? -EFAULT : 0;
}

static int compat_nfs_getfs_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg)
{
	int err;

	err = access_ok(VERIFY_READ, &arg->ca32_getfs, sizeof(arg->ca32_getfs));
	err |= get_user(karg->ca_version, &arg->ca32_version);
	err |= __copy_from_user(&karg->ca_getfs.gd_addr,
			  &arg->ca32_getfs.gd32_addr,
			  (sizeof(struct sockaddr)));
	err |= __copy_from_user(&karg->ca_getfs.gd_path,
			  &arg->ca32_getfs.gd32_path,
			  (NFS_MAXPATHLEN+1));
	err |= __get_user(karg->ca_getfs.gd_maxlen,
		      &arg->ca32_getfs.gd32_maxlen);

	return (err) ? -EFAULT : 0;
}

/* This really doesn't need translations, we are only passing
 * back a union which contains opaque nfs file handle data.
 */
static int compat_nfs_getfh_res_trans(union nfsctl_res *kres, union compat_nfsctl_res __user *res)
{
	int err;

	err = copy_to_user(res, kres, sizeof(*res));

	return (err) ? -EFAULT : 0;
}

asmlinkage long compat_sys_nfsservctl(int cmd, struct compat_nfsctl_arg __user *arg,
					union compat_nfsctl_res __user *res)
{
	struct nfsctl_arg *karg;
	union nfsctl_res *kres;
	mm_segment_t oldfs;
	int err;

	karg = kmalloc(sizeof(*karg), GFP_USER);
	kres = kmalloc(sizeof(*kres), GFP_USER);
	if(!karg || !kres) {
		err = -ENOMEM;
		goto done;
	}

	switch(cmd) {
	case NFSCTL_SVC:
		err = compat_nfs_svc_trans(karg, arg);
		break;

	case NFSCTL_ADDCLIENT:
		err = compat_nfs_clnt_trans(karg, arg);
		break;

	case NFSCTL_DELCLIENT:
		err = compat_nfs_clnt_trans(karg, arg);
		break;

	case NFSCTL_EXPORT:
	case NFSCTL_UNEXPORT:
		err = compat_nfs_exp_trans(karg, arg);
		break;

	case NFSCTL_GETFD:
		err = compat_nfs_getfd_trans(karg, arg);
		break;

	case NFSCTL_GETFS:
		err = compat_nfs_getfs_trans(karg, arg);
		break;

	default:
		err = -EINVAL;
		goto done;
	}

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	/* The __user pointer casts are valid because of the set_fs() */
	err = sys_nfsservctl(cmd, (void __user *) karg, (void __user *) kres);
	set_fs(oldfs);

	if (err)
		goto done;

	if((cmd == NFSCTL_GETFD) ||
	   (cmd == NFSCTL_GETFS))
		err = compat_nfs_getfh_res_trans(kres, res);

done:
	kfree(karg);
	kfree(kres);
	return err;
}
#else /* !NFSD */
long asmlinkage compat_sys_nfsservctl(int cmd, void *notused, void *notused2)
{
	return sys_ni_syscall();
}
#endif