compat.c

/*
 *  linux/fs/compat.c
 *
 *  Kernel compatibililty routines for e.g. 32 bit syscall support
 *  on 64 bit kernels.
 *
 *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation
 *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
 *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be)
 *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 
 *  Copyright (C) 2003       Pavel Machek (pavel@suse.cz)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/vfs.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/smb.h>
#include <linux/smb_mount.h>
#include <linux/ncp_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/syscalls.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/dirent.h>
#include <linux/fsnotify.h>
#include <linux/highuid.h>
#include <linux/nfsd/syscall.h>
#include <linux/personality.h>
#include <linux/rwsem.h>
#include <linux/tsacct_kern.h>
#include <linux/security.h>
#include <linux/highmem.h>
#include <linux/signal.h>
#include <linux/poll.h>
#include <linux/mm.h>
#include <linux/eventpoll.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/ioctls.h>
#include "internal.h"

int compat_log = 1;

int compat_printk(const char *fmt, ...)
{
	va_list ap;
	int ret;
	if (!compat_log)
		return 0;
	va_start(ap, fmt);
	ret = vprintk(fmt, ap);
	va_end(ap);
	return ret;
}

#include "read_write.h"

/*
 * Not all architectures have sys_utime, so implement this in terms
 * of sys_utimes.
 */
asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __user *t)
{
	struct timespec tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t->actime) ||
		    get_user(tv[1].tv_sec, &t->modtime))
			return -EFAULT;
		tv[0].tv_nsec = 0;
		tv[1].tv_nsec = 0;
	}
	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
}

asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, struct compat_timespec __user *t, int flags)
{
	struct timespec tv[2];

	if  (t) {
		if (get_compat_timespec(&tv[0], &t[0]) ||
		    get_compat_timespec(&tv[1], &t[1]))
			return -EFAULT;

		if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
			return 0;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, flags);
}

asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, struct compat_timeval __user *t)
{
	struct timespec tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
		    get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
		    get_user(tv[1].tv_sec, &t[1].tv_sec) ||
		    get_user(tv[1].tv_nsec, &t[1].tv_usec))
			return -EFAULT;
		if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
		    tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
			return -EINVAL;
		tv[0].tv_nsec *= 1000;
		tv[1].tv_nsec *= 1000;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, 0);
}

asmlinkage long compat_sys_utimes(char __user *filename, struct compat_timeval __user *t)
{
	return compat_sys_futimesat(AT_FDCWD, filename, t);
}

static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
{
	compat_ino_t ino = stat->ino;
	typeof(ubuf->st_uid) uid = 0;
	typeof(ubuf->st_gid) gid = 0;
	int err;

	SET_UID(uid, stat->uid);
	SET_GID(gid, stat->gid);

	if ((u64) stat->size > MAX_NON_LFS ||
	    !old_valid_dev(stat->dev) ||
	    !old_valid_dev(stat->rdev))
		return -EOVERFLOW;
	if (sizeof(ino) < sizeof(stat->ino) && ino != stat->ino)
		return -EOVERFLOW;

	if (clear_user(ubuf, sizeof(*ubuf)))
		return -EFAULT;

	err  = __put_user(old_encode_dev(stat->dev), &ubuf->st_dev);
	err |= __put_user(ino, &ubuf->st_ino);
	err |= __put_user(stat->mode, &ubuf->st_mode);
	err |= __put_user(stat->nlink, &ubuf->st_nlink);
	err |= __put_user(uid, &ubuf->st_uid);
	err |= __put_user(gid, &ubuf->st_gid);
	err |= __put_user(old_encode_dev(stat->rdev), &ubuf->st_rdev);
	err |= __put_user(stat->size, &ubuf->st_size);
	err |= __put_user(stat->atime.tv_sec, &ubuf->st_atime);
	err |= __put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec);
	err |= __put_user(stat->mtime.tv_sec, &ubuf->st_mtime);
	err |= __put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec);
	err |= __put_user(stat->ctime.tv_sec, &ubuf->st_ctime);
	err |= __put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec);
	err |= __put_user(stat->blksize, &ubuf->st_blksize);
	err |= __put_user(stat->blocks, &ubuf->st_blocks);
	return err;
}

asmlinkage long compat_sys_newstat(char __user * filename,
		struct compat_stat __user *statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_stat(filename, &stat);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}

asmlinkage long compat_sys_newlstat(char __user * filename,
		struct compat_stat __user *statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_lstat(filename, &stat);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}

#ifndef __ARCH_WANT_STAT64
asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user *filename,
		struct compat_stat __user *statbuf, int flag)
{
	struct kstat stat;
	int error;

	error = vfs_fstatat(dfd, filename, &stat, flag);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}
#endif

asmlinkage long compat_sys_newfstat(unsigned int fd,
		struct compat_stat __user * statbuf)
{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
		error = cp_compat_stat(&stat, statbuf);
	return error;
}

static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf)
{
	
	if (sizeof ubuf->f_blocks == 4) {
		if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
		     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
			return -EOVERFLOW;
		/* f_files and f_ffree may be -1; it's okay
		 * to stuff that into 32 bits */
		if (kbuf->f_files != 0xffffffffffffffffULL
		 && (kbuf->f_files & 0xffffffff00000000ULL))
			return -EOVERFLOW;
		if (kbuf->f_ffree != 0xffffffffffffffffULL
		 && (kbuf->f_ffree & 0xffffffff00000000ULL))
			return -EOVERFLOW;
	}
	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
	    __put_user(kbuf->f_type, &ubuf->f_type) ||
	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
	    __put_user(kbuf->f_files, &ubuf->f_files) ||
	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
	    __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
	    __put_user(0, &ubuf->f_spare[0]) || 
	    __put_user(0, &ubuf->f_spare[1]) || 
	    __put_user(0, &ubuf->f_spare[2]) || 
	    __put_user(0, &ubuf->f_spare[3]) || 
	    __put_user(0, &ubuf->f_spare[4]))
		return -EFAULT;
	return 0;
}

/*
 * The following statfs calls are copies of code from fs/open.c and
 * should be checked against those from time to time
 */
asmlinkage long compat_sys_statfs(const char __user *pathname, struct compat_statfs __user *buf)
{
	struct path path;
	int error;

	error = user_path(pathname, &path);
	if (!error) {
		struct kstatfs tmp;
		error = vfs_statfs(path.dentry, &tmp);
		if (!error)
			error = put_compat_statfs(buf, &tmp);
		path_put(&path);
	}
	return error;
}

asmlinkage long compat_sys_fstatfs(unsigned int fd, struct compat_statfs __user *buf)
{
	struct file * file;
	struct kstatfs tmp;
	int error;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;
	error = vfs_statfs(file->f_path.dentry, &tmp);
	if (!error)
		error = put_compat_statfs(buf, &tmp);
	fput(file);
out:
	return error;
}

static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf)
{
	if (sizeof ubuf->f_blocks == 4) {
		if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
		     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
			return -EOVERFLOW;
		/* f_files and f_ffree may be -1; it's okay
		 * to stuff that into 32 bits */
		if (kbuf->f_files != 0xffffffffffffffffULL
		 && (kbuf->f_files & 0xffffffff00000000ULL))
			return -EOVERFLOW;
		if (kbuf->f_ffree != 0xffffffffffffffffULL
		 && (kbuf->f_ffree & 0xffffffff00000000ULL))
			return -EOVERFLOW;
	}
	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
	    __put_user(kbuf->f_type, &ubuf->f_type) ||
	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
	    __put_user(kbuf->f_files, &ubuf->f_files) ||
	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
	    __put_user(kbuf->f_frsize, &ubuf->f_frsize))
		return -EFAULT;
	return 0;
}

asmlinkage long compat_sys_statfs64(const char __user *pathname, compat_size_t sz, struct compat_statfs64 __user *buf)
{
	struct path path;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = user_path(pathname, &path);
	if (!error) {
		struct kstatfs tmp;
		error = vfs_statfs(path.dentry, &tmp);
		if (!error)
			error = put_compat_statfs64(buf, &tmp);
		path_put(&path);
	}
	return error;
}

asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user *buf)
{
	struct file * file;
	struct kstatfs tmp;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;
	error = vfs_statfs(file->f_path.dentry, &tmp);
	if (!error)
		error = put_compat_statfs64(buf, &tmp);
	fput(file);
out:
	return error;
}

/*
 * This is a copy of sys_ustat, just dealing with a structure layout.
 * Given how simple this syscall is that apporach is more maintainable
 * than the various conversion hacks.
 */
asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u)
{
	struct super_block *sb;
	struct compat_ustat tmp;
	struct kstatfs sbuf;
	int err;

	sb = user_get_super(new_decode_dev(dev));
	if (!sb)
		return -EINVAL;
	err = vfs_statfs(sb->s_root, &sbuf);
	drop_super(sb);
	if (err)
		return err;

	memset(&tmp, 0, sizeof(struct compat_ustat));
	tmp.f_tfree = sbuf.f_bfree;
	tmp.f_tinode = sbuf.f_ffree;
	if (copy_to_user(u, &tmp, sizeof(struct compat_ustat)))
		return -EFAULT;
	return 0;
}

static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
	if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
	    __get_user(kfl->l_type, &ufl->l_type) ||
	    __get_user(kfl->l_whence, &ufl->l_whence) ||
	    __get_user(kfl->l_start, &ufl->l_start) ||
	    __get_user(kfl->l_len, &ufl->l_len) ||
	    __get_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}

static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
	if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
	    __put_user(kfl->l_type, &ufl->l_type) ||
	    __put_user(kfl->l_whence, &ufl->l_whence) ||
	    __put_user(kfl->l_start, &ufl->l_start) ||
	    __put_user(kfl->l_len, &ufl->l_len) ||
	    __put_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}

#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
	if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
	    __get_user(kfl->l_type, &ufl->l_type) ||
	    __get_user(kfl->l_whence, &ufl->l_whence) ||
	    __get_user(kfl->l_start, &ufl->l_start) ||
	    __get_user(kfl->l_len, &ufl->l_len) ||
	    __get_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}
#endif

#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
	if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
	    __put_user(kfl->l_type, &ufl->l_type) ||
	    __put_user(kfl->l_whence, &ufl->l_whence) ||
	    __put_user(kfl->l_start, &ufl->l_start) ||
	    __put_user(kfl->l_len, &ufl->l_len) ||
	    __put_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}
#endif

asmlinkage long compat_sys_fcntl64(unsigned int fd, unsigned int cmd,
		unsigned long arg)
{
	mm_segment_t old_fs;
	struct flock f;
	long ret;

	switch (cmd) {
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
		ret = get_compat_flock(&f, compat_ptr(arg));
		if (ret != 0)
			break;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		ret = sys_fcntl(fd, cmd, (unsigned long)&f);
		set_fs(old_fs);
		if (cmd == F_GETLK && ret == 0) {
			/* GETLK was successful and we need to return the data...
			 * but it needs to fit in the compat structure.
			 * l_start shouldn't be too big, unless the original
			 * start + end is greater than COMPAT_OFF_T_MAX, in which
			 * case the app was asking for trouble, so we return
			 * -EOVERFLOW in that case.
			 * l_len could be too big, in which case we just truncate it,
			 * and only allow the app to see that part of the conflicting
			 * lock that might make sense to it anyway
			 */

			if (f.l_start > COMPAT_OFF_T_MAX)
				ret = -EOVERFLOW;
			if (f.l_len > COMPAT_OFF_T_MAX)
				f.l_len = COMPAT_OFF_T_MAX;
			if (ret == 0)
				ret = put_compat_flock(&f, compat_ptr(arg));
		}
		break;

	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
		ret = get_compat_flock64(&f, compat_ptr(arg));
		if (ret != 0)
			break;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		ret = sys_fcntl(fd, (cmd == F_GETLK64) ? F_GETLK :
				((cmd == F_SETLK64) ? F_SETLK : F_SETLKW),
				(unsigned long)&f);
		set_fs(old_fs);
		if (cmd == F_GETLK64 && ret == 0) {
			/* need to return lock information - see above for commentary */
			if (f.l_start > COMPAT_LOFF_T_MAX)
				ret = -EOVERFLOW;
			if (f.l_len > COMPAT_LOFF_T_MAX)
				f.l_len = COMPAT_LOFF_T_MAX;
			if (ret == 0)
				ret = put_compat_flock64(&f, compat_ptr(arg));
		}
		break;

	default:
		ret = sys_fcntl(fd, cmd, arg);
		break;
	}
	return ret;
}

asmlinkage long compat_sys_fcntl(unsigned int fd, unsigned int cmd,
		unsigned long arg)
{
	if ((cmd == F_GETLK64) || (cmd == F_SETLK64) || (cmd == F_SETLKW64))
		return -EINVAL;
	return compat_sys_fcntl64(fd, cmd, arg);
}

asmlinkage long
compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p)
{
	long ret;
	aio_context_t ctx64;

	mm_segment_t oldfs = get_fs();
	if (unlikely(get_user(ctx64, ctx32p)))
		return -EFAULT;

	set_fs(KERNEL_DS);
	/* The __user pointer cast is valid because of the set_fs() */
	ret = sys_io_setup(nr_reqs, (aio_context_t __user *) &ctx64);
	set_fs(oldfs);
	/* truncating is ok because it's a user address */
	if (!ret)
		ret = put_user((u32) ctx64, ctx32p);
	return ret;
}

asmlinkage long
compat_sys_io_getevents(aio_context_t ctx_id,
				 unsigned long min_nr,
				 unsigned long nr,
				 struct io_event __user *events,
				 struct compat_timespec __user *timeout)
{
	long ret;
	struct timespec t;
	struct timespec __user *ut = NULL;

	ret = -EFAULT;
	if (unlikely(!access_ok(VERIFY_WRITE, events, 
				nr * sizeof(struct io_event))))
		goto out;
	if (timeout) {
		if (get_compat_timespec(&t, timeout))
			goto out;

		ut = compat_alloc_user_space(sizeof(*ut));
		if (copy_to_user(ut, &t, sizeof(t)) )
			goto out;
	} 
	ret = sys_io_getevents(ctx_id, min_nr, nr, events, ut);
out:
	return ret;
}

static inline long
copy_iocb(long nr, u32 __user *ptr32, struct iocb __user * __user *ptr64)
{
	compat_uptr_t uptr;
	int i;

	for (i = 0; i < nr; ++i) {
		if (get_user(uptr, ptr32 + i))
			return -EFAULT;
		if (put_user(compat_ptr(uptr), ptr64 + i))
			return -EFAULT;
	}
	return 0;
}

#define MAX_AIO_SUBMITS 	(PAGE_SIZE/sizeof(struct iocb *))

asmlinkage long
compat_sys_io_submit(aio_context_t ctx_id, int nr, u32 __user *iocb)
{
	struct iocb __user * __user *iocb64; 
	long ret;

	if (unlikely(nr < 0))
		return -EINVAL;

	if (nr > MAX_AIO_SUBMITS)
		nr = MAX_AIO_SUBMITS;
	
	iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
	ret = copy_iocb(nr, iocb, iocb64);
	if (!ret)
		ret = sys_io_submit(ctx_id, nr, iocb64);
	return ret;
}

struct compat_ncp_mount_data {
	compat_int_t version;
	compat_uint_t ncp_fd;
	__compat_uid_t mounted_uid;
	compat_pid_t wdog_pid;
	unsigned char mounted_vol[NCP_VOLNAME_LEN + 1];
	compat_uint_t time_out;
	compat_uint_t retry_count;
	compat_uint_t flags;
	__compat_uid_t uid;
	__compat_gid_t gid;
	compat_mode_t file_mode;
	compat_mode_t dir_mode;
};

struct compat_ncp_mount_data_v4 {
	compat_int_t version;
	compat_ulong_t flags;
	compat_ulong_t mounted_uid;
	compat_long_t wdog_pid;
	compat_uint_t ncp_fd;
	compat_uint_t time_out;
	compat_uint_t retry_count;
	compat_ulong_t uid;
	compat_ulong_t gid;
	compat_ulong_t file_mode;
	compat_ulong_t dir_mode;
};

static void *do_ncp_super_data_conv(void *raw_data)
{
	int version = *(unsigned int *)raw_data;

	if (version == 3) {
		struct compat_ncp_mount_data *c_n = raw_data;
		struct ncp_mount_data *n = raw_data;

		n->dir_mode = c_n->dir_mode;
		n->file_mode = c_n->file_mode;
		n->gid = c_n->gid;
		n->uid = c_n->uid;
		memmove (n->mounted_vol, c_n->mounted_vol, (sizeof (c_n->mounted_vol) + 3 * sizeof (unsigned int)));
		n->wdog_pid = c_n->wdog_pid;
		n->mounted_uid = c_n->mounted_uid;
	} else if (version == 4) {
		struct compat_ncp_mount_data_v4 *c_n = raw_data;
		struct ncp_mount_data_v4 *n = raw_data;

		n->dir_mode = c_n->dir_mode;
		n->file_mode = c_n->file_mode;
		n->gid = c_n->gid;
		n->uid = c_n->uid;
		n->retry_count = c_n->retry_count;
		n->time_out = c_n->time_out;
		n->ncp_fd = c_n->ncp_fd;
		n->wdog_pid = c_n->wdog_pid;
		n->mounted_uid = c_n->mounted_uid;
		n->flags = c_n->flags;
	} else if (version != 5) {
		return NULL;
	}

	return raw_data;
}

struct compat_smb_mount_data {
	compat_int_t version;
	__compat_uid_t mounted_uid;
	__compat_uid_t uid;
	__compat_gid_t gid;
	compat_mode_t file_mode;
	compat_mode_t dir_mode;
};

static void *do_smb_super_data_conv(void *raw_data)
{
	struct smb_mount_data *s = raw_data;
	struct compat_smb_mount_data *c_s = raw_data;

	if (c_s->version != SMB_MOUNT_OLDVERSION)
		goto out;
	s->dir_mode = c_s->dir_mode;
	s->file_mode = c_s->file_mode;
	s->gid = c_s->gid;
	s->uid = c_s->uid;
	s->mounted_uid = c_s->mounted_uid;
 out:
	return raw_data;
}

struct compat_nfs_string {
	compat_uint_t len;
	compat_uptr_t data;
};

static inline void compat_nfs_string(struct nfs_string *dst,
				     struct compat_nfs_string *src)
{
	dst->data = compat_ptr(src->data);
	dst->len = src->len;
}

struct compat_nfs4_mount_data_v1 {
	compat_int_t version;
	compat_int_t flags;
	compat_int_t rsize;
	compat_int_t wsize;
	compat_int_t timeo;
	compat_int_t retrans;
	compat_int_t acregmin;
	compat_int_t acregmax;
	compat_int_t acdirmin;
	compat_int_t acdirmax;
	struct compat_nfs_string client_addr;
	struct compat_nfs_string mnt_path;
	struct compat_nfs_string hostname;
	compat_uint_t host_addrlen;
	compat_uptr_t host_addr;
	compat_int_t proto;
	compat_int_t auth_flavourlen;
	compat_uptr_t auth_flavours;
};

static int do_nfs4_super_data_conv(void *raw_data)
{
	int version = *(compat_uint_t *) raw_data;

	if (version == 1) {
		struct compat_nfs4_mount_data_v1 *raw = raw_data;
		struct nfs4_mount_data *real = raw_data;

		/* copy the fields backwards */
		real->auth_flavours = compat_ptr(raw->auth_flavours);
		real->auth_flavourlen = raw->auth_flavourlen;
		real->proto = raw->proto;
		real->host_addr = compat_ptr(raw->host_addr);
		real->host_addrlen = raw->host_addrlen;
		compat_nfs_string(&real->hostname, &raw->hostname);
		compat_nfs_string(&real->mnt_path, &raw->mnt_path);
		compat_nfs_string(&real->client_addr, &raw->client_addr);
		real->acdirmax = raw->acdirmax;
		real->acdirmin = raw->acdirmin;
		real->acregmax = raw->acregmax;
		real->acregmin = raw->acregmin;
		real->retrans = raw->retrans;
		real->timeo = raw->timeo;
		real->wsize = raw->wsize;
		real->rsize = raw->rsize;
		real->flags = raw->flags;
		real->version = raw->version;
	}

	return 0;
}

#define SMBFS_NAME      "smbfs"
#define NCPFS_NAME      "ncpfs"
#define NFS4_NAME	"nfs4"

asmlinkage long compat_sys_mount(char __user * dev_name, char __user * dir_name,
				 char __user * type, unsigned long flags,
				 void __user * data)
{
	char *kernel_type;
	unsigned long data_page;
	char *kernel_dev;
	char *dir_page;
	int retval;

	retval = copy_mount_string(type, &kernel_type);
	if (retval < 0)
		goto out;

	dir_page = getname(dir_name);
	retval = PTR_ERR(dir_page);
	if (IS_ERR(dir_page))
		goto out1;

	retval = copy_mount_string(dev_name, &kernel_dev);
	if (retval < 0)
		goto out2;

	retval = copy_mount_options(data, &data_page);
	if (retval < 0)
		goto out3;

	retval = -EINVAL;

	if (kernel_type && data_page) {
		if (!strcmp(kernel_type, SMBFS_NAME)) {
			do_smb_super_data_conv((void *)data_page);
		} else if (!strcmp(kernel_type, NCPFS_NAME)) {
			do_ncp_super_data_conv((void *)data_page);
		} else if (!strcmp(kernel_type, NFS4_NAME)) {
			if (do_nfs4_super_data_conv((void *) data_page))
				goto out4;
		}
	}

	retval = do_mount(kernel_dev, dir_page, kernel_type,
			flags, (void*)data_page);

 out4:
	free_page(data_page);
 out3:
	kfree(kernel_dev);
 out2:
	putname(dir_page);
 out1:
	kfree(kernel_type);
 out:
	return retval;
}

#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))

struct compat_old_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_offset;
	unsigned short	d_namlen;
	char		d_name[1];
};

struct compat_readdir_callback {
	struct compat_old_linux_dirent __user *dirent;
	int result;
};

static int compat_fillonedir(void *__buf, const char *name, int namlen,
			loff_t offset, u64 ino, unsigned int d_type)
{
	struct compat_readdir_callback *buf = __buf;
	struct compat_old_linux_dirent __user *dirent;
	compat_ulong_t d_ino;

	if (buf->result)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->result = -EOVERFLOW;
		return -EOVERFLOW;
	}
	buf->result++;
	dirent = buf->dirent;
	if (!access_ok(VERIFY_WRITE, dirent,
			(unsigned long)(dirent->d_name + namlen + 1) -
				(unsigned long)dirent))
		goto efault;
	if (	__put_user(d_ino, &dirent->d_ino) ||
		__put_user(offset, &dirent->d_offset) ||
		__put_user(namlen, &dirent->d_namlen) ||
		__copy_to_user(dirent->d_name, name, namlen) ||
		__put_user(0, dirent->d_name + namlen))
		goto efault;
	return 0;
efault:
	buf->result = -EFAULT;
	return -EFAULT;
}

asmlinkage long compat_sys_old_readdir(unsigned int fd,
	struct compat_old_linux_dirent __user *dirent, unsigned int count)
{
	int error;
	struct file *file;
	struct compat_readdir_callback buf;

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

	buf.result = 0;
	buf.dirent = dirent;

	error = vfs_readdir(file, compat_fillonedir, &buf);
	if (buf.result)
		error = buf.result;

	fput(file);
out:
	return error;
}

struct compat_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_off;
	unsigned short	d_reclen;
	char		d_name[1];
};

struct compat_getdents_callback {
	struct compat_linux_dirent __user *current_dir;
	struct compat_linux_dirent __user *previous;
	int count;
	int error;
};

static int compat_filldir(void *__buf, const char *name, int namlen,
		loff_t offset, u64 ino, unsigned int d_type)
{
	struct compat_linux_dirent __user * dirent;
	struct compat_getdents_callback *buf = __buf;
	compat_ulong_t d_ino;
	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(compat_long_t));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
	}
	dirent = buf->previous;
	if (dirent) {
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(d_ino, &dirent->d_ino))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	if (__put_user(d_type, (char  __user *) dirent + reclen - 1))
		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_getdents(unsigned int fd,
		struct compat_linux_dirent __user *dirent, unsigned int count)
{
	struct file * file;
	struct compat_linux_dirent __user * lastdirent;
	struct compat_getdents_callback 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_filldir, &buf);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fput(file);
out:
	return error;
}

#ifndef __ARCH_OMIT_COMPAT_SYS_GETDENTS64

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,
		     u64 ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct compat_getdents_callback64 *buf = __buf;
	int jj = NAME_OFFSET(dirent);
	int reclen = ALIGN(jj + namlen + 1, sizeof(u64));
	u64 off;