sh: export sh_bios_get_node_addr() symbol for stnic module.

[linux-2.6] / fs / 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/smp_lock.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/sunrpc/svc.h>
#include <linux/nfsd/nfsd.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 <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[0].tv_nsec == UTIME_NOW)
                    && tv[0].tv_sec != 0)
                        return -EINVAL;
                if ((tv[1].tv_nsec == UTIME_OMIT || tv[1].tv_nsec == UTIME_NOW)
                    && tv[1].tv_sec != 0)
                        return -EINVAL;

                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 = vfs_stat_fd(AT_FDCWD, filename, &stat);

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

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

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

#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 = -EINVAL;

        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
                goto out;

        if (flag & AT_SYMLINK_NOFOLLOW)
                error = vfs_lstat_fd(dfd, filename, &stat);
        else
                error = vfs_stat_fd(dfd, filename, &stat);

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

out:
        return error;
}
#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;
}

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 successfule 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)
{
        unsigned long type_page;
        unsigned long data_page;
        unsigned long dev_page;
        char *dir_page;
        int retval;

        retval = copy_mount_options (type, &type_page);
        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_options (dev_name, &dev_page);
        if (retval < 0)
                goto out2;

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

        retval = -EINVAL;

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

        lock_kernel();
        retval = do_mount((char*)dev_page, dir_page, (char*)type_page,
                        flags, (void*)data_page);
        unlock_kernel();

 out4:
        free_page(data_page);
 out3:
        free_page(dev_page);
 out2:
        putname(dir_page);
 out1:
        free_page(type_page);
 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;

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

        fnv = NULL;
        if (type == READ) {
                fn = file->f_op->read;
                fnv = file->f_op->aio_read;
        } else {
                fn = (io_fn_t)file->f_op->write;
                fnv = file->f_op->aio_write;
        }

        if (fnv)
                ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
                                                pos, fnv);
        else
                ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);

out:
        if (iov != iovstack)
                kfree(iov);
        if ((ret + (type == READ)) > 0) {
                struct dentry *dentry = file->f_path.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->aio_read && !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->aio_write && !file->f_op->write))
                goto out;

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

out:
        fput(file);
        return ret;
}

asmlinkage long
compat_sys_vmsplice(int fd, const struct compat_iovec __user *iov32,
                    unsigned int nr_segs, unsigned int flags)
{
        unsigned i;
        struct iovec __user *iov;
        if (nr_segs > UIO_MAXIOV)
                return -EINVAL;
        iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec));
        for (i = 0; i < nr_segs; i++) {
                struct compat_iovec v;
                if (get_user(v.iov_base, &iov32[i].iov_base) ||
                    get_user(v.iov_len, &iov32[i].iov_len) ||
                    put_user(compat_ptr(v.iov_base), &iov[i].iov_base) ||
                    put_user(v.iov_len, &iov[i].iov_len))
                        return -EFAULT;
        }
        return sys_vmsplice(fd, iov, nr_segs, flags);
}

/*
 * Exactly like fs/open.c:sys_open(), except that it doesn't set the
 * O_LARGEFILE flag.
 */
asmlinkage long
compat_sys_open(const char __user *filename, int flags, int mode)
{
        return do_sys_open(AT_FDCWD, filename, flags, mode);
}

/*
 * Exactly like fs/open.c:sys_openat(), except that it doesn't set the
 * O_LARGEFILE flag.
 */
asmlinkage long
compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int mode)
{
        return do_sys_open(dfd, filename, flags, mode);
}

/*
 * 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;
        unsigned long kpos = 0;
        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), MAX_ARG_STRLEN))) {
                        ret = -EFAULT;
                        goto out;
                }

                if (len > MAX_ARG_STRLEN) {
                        ret = -E2BIG;
                        goto out;
                }

                /* We're going to work our way backwords. */
                pos = bprm->p;
                str += len;
                bprm->p -= len;

                while (len > 0) {
                        int offset, bytes_to_copy;

                        offset = pos % PAGE_SIZE;
                        if (offset == 0)
                                offset = PAGE_SIZE;

                        bytes_to_copy = offset;
                        if (bytes_to_copy > len)
                                bytes_to_copy = len;

                        offset -= bytes_to_copy;
                        pos -= bytes_to_copy;
                        str -= bytes_to_copy;
                        len -= bytes_to_copy;

                        if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
                                struct page *page;

#ifdef CONFIG_STACK_GROWSUP
                                ret = expand_stack_downwards(bprm->vma, pos);
                                if (ret < 0) {
                                        /* We've exceed the stack rlimit. */
                                        ret = -E2BIG;
                                        goto out;
                                }
#endif
                                ret = get_user_pages(current, bprm->mm, pos,
                                                     1, 1, 1, &page, NULL);
                                if (ret <= 0) {
                                        /* We've exceed the stack rlimit. */
                                        ret = -E2BIG;
                                        goto out;
                                }

                                if (kmapped_page) {
                                        flush_kernel_dcache_page(kmapped_page);
                                        kunmap(kmapped_page);
                                        put_page(kmapped_page);
                                }
                                kmapped_page = page;
                                kaddr = kmap(kmapped_page);
                                kpos = pos & PAGE_MASK;
                                flush_cache_page(bprm->vma, kpos,
                                                 page_to_pfn(kmapped_page));
                        }
                        if (copy_from_user(kaddr+offset, compat_ptr(str),
                                                bytes_to_copy)) {
                                ret = -EFAULT;
                                goto out;
                        }
                }
        }
        ret = 0;
out:
        if (kmapped_page) {
                flush_kernel_dcache_page(kmapped_page);
                kunmap(kmapped_page);
                put_page(kmapped_page);
        }
        return ret;
}

/*
 * 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;

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

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

        sched_exec();

        bprm->file = file;
        bprm->filename = filename;
        bprm->interp = filename;

        retval = bprm_mm_init(bprm);
        if (retval)
                goto out_file;

        bprm->argc = compat_count(argv, MAX_ARG_STRINGS);
        if ((retval = bprm->argc) < 0)
                goto out_mm;

        bprm->envc = compat_count(envp, MAX_ARG_STRINGS);
        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) {
                /* execve success */
                security_bprm_free(bprm);
                acct_update_integrals(current);
                free_bprm(bprm);
                return retval;
        }

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

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

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

out_kfree:
        free_bprm(bprm);

out_ret:
        return retval;
}

#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))

static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
                                      int timeval, int ret)
{
        struct timespec ts;

        if (!p)
                return ret;

        if (current->personality & STICKY_TIMEOUTS)
                goto sticky;

        /* No update for zero timeout */
        if (!end_time->tv_sec && !end_time->tv_nsec)
                return ret;

        ktime_get_ts(&ts);
        ts = timespec_sub(*end_time, ts);
        if (ts.tv_sec < 0)
                ts.tv_sec = ts.tv_nsec = 0;

        if (timeval) {
                struct compat_timeval rtv;

                rtv.tv_sec = ts.tv_sec;
                rtv.tv_usec = ts.tv_nsec / NSEC_PER_USEC;

                if (!copy_to_user(p, &rtv, sizeof(rtv)))
                        return ret;
        } else {
                struct compat_timespec rts;

                rts.tv_sec = ts.tv_sec;
                rts.tv_nsec = ts.tv_nsec;

                if (!copy_to_user(p, &rts, sizeof(rts)))
                        return ret;
        }
        /*
         * If an application puts its timeval in read-only memory, we
         * don't want the Linux-specific update to the timeval to
         * cause a fault after the select has completed
         * successfully. However, because we're not updating the
         * timeval, we can't restart the system call.
         */

sticky:
        if (ret == -ERESTARTNOHAND)
                ret = -EINTR;
        return ret;
}

/*
 * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
 * 64-bit unsigned longs.
 */
static
int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
                        unsigned long *fdset)
{
        nr = DIV_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;
                        if (__get_user(l, ufdset) || __get_user(h, ufdset+1))
                                return -EFAULT;
                        ufdset += 2;
                        *fdset++ = h << 32 | l;
                        nr -= 2;
                }
                if (odd && __get_user(*fdset, ufdset))
                        return -EFAULT;
        } 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
int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
                      unsigned long *fdset)
{
        unsigned long odd;
        nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS);

        if (!ufdset)
                return 0;

        odd = nr & 1UL;
        nr &= ~1UL;
        while (nr) {
                unsigned long h, l;
                l = *fdset++;
                h = l >> 32;
                if (__put_user(l, ufdset) || __put_user(h, ufdset+1))
                        return -EFAULT;
                ufdset += 2;
                nr -= 2;
        }
        if (odd && __put_user(*fdset, ufdset))
                return -EFAULT;
        return 0;
}


/*
 * This is a virtual copy of sys_select from fs/select.c and probably
 * should be compared to it from time to time
 */

/*
 * 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)

int compat_core_sys_select(int n, compat_ulong_t __user *inp,
        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
        struct timespec *end_time)
{
        fd_set_bits fds;
        void *bits;
        int size, max_fds, ret = -EINVAL;
        struct fdtable *fdt;
        long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];

        if (n < 0)
                goto out_nofds;

        /* max_fds can increase, so grab it once to avoid race */
        rcu_read_lock();
        fdt = files_fdtable(current->files);
        max_fds = fdt->max_fds;
        rcu_read_unlock();
        if (n > max_fds)
                n = max_fds;

        /*
         * 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.
         */
        size = FDS_BYTES(n);
        bits = stack_fds;
        if (size > sizeof(stack_fds) / 6) {
                bits = kmalloc(6 * size, GFP_KERNEL);
                ret = -ENOMEM;
                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, end_time);

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

        if (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))
                ret = -EFAULT;
out:
        if (bits != stack_fds)
                kfree(bits);
out_nofds:
        return ret;
}

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)
{
        struct timespec end_time, *to = NULL;
        struct compat_timeval tv;
        int ret;

        if (tvp) {
                if (copy_from_user(&tv, tvp, sizeof(tv)))
                        return -EFAULT;

                to = &end_time;
                if (poll_select_set_timeout(to,
                                tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
                                (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
                        return -EINVAL;
        }

        ret = compat_core_sys_select(n, inp, outp, exp, to);
        ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);

        return ret;
}

#ifdef HAVE_SET_RESTORE_SIGMASK
asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
        struct compat_timespec __user *tsp, compat_sigset_t __user *sigmask,
        compat_size_t sigsetsize)
{
        compat_sigset_t ss32;
        sigset_t ksigmask, sigsaved;
        struct compat_timespec ts;
        struct timespec end_time, *to = NULL;
        int ret;

        if (tsp) {
                if (copy_from_user(&ts, tsp, sizeof(ts)))
                        return -EFAULT;

                to = &end_time;
                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
                        return -EINVAL;
        }

        if (sigmask) {
                if (sigsetsize != sizeof(compat_sigset_t))
                        return -EINVAL;
                if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
                        return -EFAULT;
                sigset_from_compat(&ksigmask, &ss32);

                sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
                sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
        }

        ret = compat_core_sys_select(n, inp, outp, exp, to);
        ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

        if (ret == -ERESTARTNOHAND) {
                /*
                 * Don't restore the signal mask yet. Let do_signal() deliver
                 * the signal on the way back to userspace, before the signal
                 * mask is restored.
                 */
                if (sigmask) {
                        memcpy(&current->saved_sigmask, &sigsaved,
                                        sizeof(sigsaved));
                        set_restore_sigmask();
                }
        } else if (sigmask)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);

        return ret;
}

asmlinkage long compat_sys_pselect6(int n, compat_ulong_t __user *inp,
        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
        struct compat_timespec __user *tsp, void __user *sig)
{
        compat_size_t sigsetsize = 0;
        compat_uptr_t up = 0;

        if (sig) {
                if (!access_ok(VERIFY_READ, sig,
                                sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||
                        __get_user(up, (compat_uptr_t __user *)sig) ||
                        __get_user(sigsetsize,
                                (compat_size_t __user *)(sig+sizeof(up))))
                        return -EFAULT;
        }
        return compat_sys_pselect7(n, inp, outp, exp, tsp, compat_ptr(up),
                                        sigsetsize);
}

asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
        unsigned int nfds, struct compat_timespec __user *tsp,
        const compat_sigset_t __user *sigmask, compat_size_t sigsetsize)
{
        compat_sigset_t ss32;
        sigset_t ksigmask, sigsaved;
        struct compat_timespec ts;
        struct timespec end_time, *to = NULL;
        int ret;

        if (tsp) {
                if (copy_from_user(&ts, tsp, sizeof(ts)))
                        return -EFAULT;

                to = &end_time;
                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
                        return -EINVAL;
        }

        if (sigmask) {
                if (sigsetsize != sizeof(compat_sigset_t))
                        return -EINVAL;
                if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
                        return -EFAULT;
                sigset_from_compat(&ksigmask, &ss32);

                sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
                sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
        }

        ret = do_sys_poll(ufds, nfds, to);

        /* We can restart this syscall, usually */
        if (ret == -EINTR) {
                /*
                 * Don't restore the signal mask yet. Let do_signal() deliver
                 * the signal on the way back to userspace, before the signal
                 * mask is restored.
                 */
                if (sigmask) {
                        memcpy(&current->saved_sigmask, &sigsaved,
                                sizeof(sigsaved));
                        set_restore_sigmask();
                }
                ret = -ERESTARTNOHAND;
        } else if (sigmask)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);

        ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

        return ret;
}
#endif /* HAVE_SET_RESTORE_SIGMASK */

#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)
{
        if (!access_ok(VERIFY_READ, &arg->ca32_svc, sizeof(arg->ca32_svc)) ||
                get_user(karg->ca_version, &arg->ca32_version) ||
                __get_user(karg->ca_svc.svc_port, &arg->ca32_svc.svc32_port) ||
                __get_user(karg->ca_svc.svc_nthreads,
                                &arg->ca32_svc.svc32_nthreads))
                return -EFAULT;
        return 0;
}

static int compat_nfs_clnt_trans(struct nfsctl_arg *karg,
                                struct compat_nfsctl_arg __user *arg)
{
        if (!access_ok(VERIFY_READ, &arg->ca32_client,
                        sizeof(arg->ca32_client)) ||
                get_user(karg->ca_version, &arg->ca32_version) ||
                __copy_from_user(&karg->ca_client.cl_ident[0],
                                &arg->ca32_client.cl32_ident[0],
                                NFSCLNT_IDMAX) ||
                __get_user(karg->ca_client.cl_naddr,
                                &arg->ca32_client.cl32_naddr) ||
                __copy_from_user(&karg->ca_client.cl_addrlist[0],
                                &arg->ca32_client.cl32_addrlist[0],
                                (sizeof(struct in_addr) * NFSCLNT_ADDRMAX)) ||
                __get_user(karg->ca_client.cl_fhkeytype,
                                &arg->ca32_client.cl32_fhkeytype) ||
                __get_user(karg->ca_client.cl_fhkeylen,
                                &arg->ca32_client.cl32_fhkeylen) ||
                __copy_from_user(&karg->ca_client.cl_fhkey[0],
                                &arg->ca32_client.cl32_fhkey[0],
                                NFSCLNT_KEYMAX))
                return -EFAULT;

        return 0;
}

static int compat_nfs_exp_trans(struct nfsctl_arg *karg,
                                struct compat_nfsctl_arg __user *arg)
{
        if (!access_ok(VERIFY_READ, &arg->ca32_export,
                                sizeof(arg->ca32_export)) ||
                get_user(karg->ca_version, &arg->ca32_version) ||
                __copy_from_user(&karg->ca_export.ex_client[0],
                                &arg->ca32_export.ex32_client[0],
                                NFSCLNT_IDMAX) ||
                __copy_from_user(&karg->ca_export.ex_path[0],
                                &arg->ca32_export.ex32_path[0],
                                NFS_MAXPATHLEN) ||
                __get_user(karg->ca_export.ex_dev,
                                &arg->ca32_export.ex32_dev) ||
                __get_user(karg->ca_export.ex_ino,
                                &arg->ca32_export.ex32_ino) ||
                __get_user(karg->ca_export.ex_flags,
                                &arg->ca32_export.ex32_flags) ||
                __get_user(karg->ca_export.ex_anon_uid,
                                &arg->ca32_export.ex32_anon_uid) ||
                __get_user(karg->ca_export.ex_anon_gid,
                                &arg->ca32_export.ex32_anon_gid))
                return -EFAULT;
        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 0;
}

static int compat_nfs_getfd_trans(struct nfsctl_arg *karg,
                                struct compat_nfsctl_arg __user *arg)
{
        if (!access_ok(VERIFY_READ, &arg->ca32_getfd,
                        sizeof(arg->ca32_getfd)) ||
                get_user(karg->ca_version, &arg->ca32_version) ||
                __copy_from_user(&karg->ca_getfd.gd_addr,
                                &arg->ca32_getfd.gd32_addr,
                                (sizeof(struct sockaddr))) ||
                __copy_from_user(&karg->ca_getfd.gd_path,
                                &arg->ca32_getfd.gd32_path,
                                (NFS_MAXPATHLEN+1)) ||
                __get_user(karg->ca_getfd.gd_version,
                                &arg->ca32_getfd.gd32_version))
                return -EFAULT;

        return 0;
}

static int compat_nfs_getfs_trans(struct nfsctl_arg *karg,
                                struct compat_nfsctl_arg __user *arg)
{
        if (!access_ok(VERIFY_READ,&arg->ca32_getfs,sizeof(arg->ca32_getfs)) ||
                get_user(karg->ca_version, &arg->ca32_version) ||
                __copy_from_user(&karg->ca_getfs.gd_addr,
                                &arg->ca32_getfs.gd32_addr,
                                (sizeof(struct sockaddr))) ||
                __copy_from_user(&karg->ca_getfs.gd_path,
                                &arg->ca32_getfs.gd32_path,
                                (NFS_MAXPATHLEN+1)) ||
                __get_user(karg->ca_getfs.gd_maxlen,
                                &arg->ca32_getfs.gd32_maxlen))
                return -EFAULT;

        return 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;
                break;
        }

        if (err)
                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

#ifdef CONFIG_EPOLL

#ifdef HAVE_SET_RESTORE_SIGMASK
asmlinkage long compat_sys_epoll_pwait(int epfd,
                        struct compat_epoll_event __user *events,
                        int maxevents, int timeout,
                        const compat_sigset_t __user *sigmask,
                        compat_size_t sigsetsize)
{
        long err;
        compat_sigset_t csigmask;
        sigset_t ksigmask, sigsaved;

        /*
         * If the caller wants a certain signal mask to be set during the wait,
         * we apply it here.
         */
        if (sigmask) {
                if (sigsetsize != sizeof(compat_sigset_t))
                        return -EINVAL;
                if (copy_from_user(&csigmask, sigmask, sizeof(csigmask)))
                        return -EFAULT;
                sigset_from_compat(&ksigmask, &csigmask);
                sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
                sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
        }

        err = sys_epoll_wait(epfd, events, maxevents, timeout);

        /*
         * If we changed the signal mask, we need to restore the original one.
         * In case we've got a signal while waiting, we do not restore the
         * signal mask yet, and we allow do_signal() to deliver the signal on
         * the way back to userspace, before the signal mask is restored.
         */
        if (sigmask) {
                if (err == -EINTR) {
                        memcpy(&current->saved_sigmask, &sigsaved,
                               sizeof(sigsaved));
                        set_restore_sigmask();
                } else
                        sigprocmask(SIG_SETMASK, &sigsaved, NULL);
        }

        return err;
}
#endif /* HAVE_SET_RESTORE_SIGMASK */

#endif /* CONFIG_EPOLL */

#ifdef CONFIG_SIGNALFD

asmlinkage long compat_sys_signalfd4(int ufd,
                                     const compat_sigset_t __user *sigmask,
                                     compat_size_t sigsetsize, int flags)
{
        compat_sigset_t ss32;
        sigset_t tmp;
        sigset_t __user *ksigmask;

        if (sigsetsize != sizeof(compat_sigset_t))
                return -EINVAL;
        if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
                return -EFAULT;
        sigset_from_compat(&tmp, &ss32);
        ksigmask = compat_alloc_user_space(sizeof(sigset_t));
        if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
                return -EFAULT;

        return sys_signalfd4(ufd, ksigmask, sizeof(sigset_t), flags);
}

asmlinkage long compat_sys_signalfd(int ufd,
                                    const compat_sigset_t __user *sigmask,
                                    compat_size_t sigsetsize)
{
        return compat_sys_signalfd4(ufd, sigmask, sigsetsize, 0);
}
#endif /* CONFIG_SIGNALFD */

#ifdef CONFIG_TIMERFD

asmlinkage long compat_sys_timerfd_settime(int ufd, int flags,
                                   const struct compat_itimerspec __user *utmr,
                                   struct compat_itimerspec __user *otmr)
{
        int error;
        struct itimerspec t;
        struct itimerspec __user *ut;

        if (get_compat_itimerspec(&t, utmr))
                return -EFAULT;
        ut = compat_alloc_user_space(2 * sizeof(struct itimerspec));
        if (copy_to_user(&ut[0], &t, sizeof(t)))
                return -EFAULT;
        error = sys_timerfd_settime(ufd, flags, &ut[0], &ut[1]);
        if (!error && otmr)
                error = (copy_from_user(&t, &ut[1], sizeof(struct itimerspec)) ||
                         put_compat_itimerspec(otmr, &t)) ? -EFAULT: 0;

        return error;
}

asmlinkage long compat_sys_timerfd_gettime(int ufd,
                                   struct compat_itimerspec __user *otmr)
{
        int error;
        struct itimerspec t;
        struct itimerspec __user *ut;

        ut = compat_alloc_user_space(sizeof(struct itimerspec));
        error = sys_timerfd_gettime(ufd, ut);
        if (!error)
                error = (copy_from_user(&t, ut, sizeof(struct itimerspec)) ||
                         put_compat_itimerspec(otmr, &t)) ? -EFAULT: 0;

        return error;
}

#endif /* CONFIG_TIMERFD */