/*
   *	Wrapper functions for 16bit uid back compatibility. All nicely tied
   *	together in the faint hope we can take the out in five years time.
   */
  
  #include <linux/mm.h>

  #include <linux/mman.h>

  #include <linux/notifier.h>
  #include <linux/reboot.h>
  #include <linux/prctl.h>

  #include <linux/capability.h>

  #include <linux/init.h>
  #include <linux/highuid.h>
  #include <linux/security.h>
  #include <linux/syscalls.h>
  
  #include <asm/uaccess.h>

  SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)

  {

  	long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(3, ret, filename, user, group);

  	return ret;

  }

  SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)

  {

  	long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(3, ret, filename, user, group);

  	return ret;

  }

  SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)

  {

  	long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(3, ret, fd, user, group);

  	return ret;

  }

  SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)

  {

  	long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(2, ret, rgid, egid);

  	return ret;

  }

  SYSCALL_DEFINE1(setgid16, old_gid_t, gid)

  {

  	long ret = sys_setgid(low2highgid(gid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(1, ret, gid);

  	return ret;

  }

  SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)

  {

  	long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(2, ret, ruid, euid);

  	return ret;

  }

  SYSCALL_DEFINE1(setuid16, old_uid_t, uid)

  {

  	long ret = sys_setuid(low2highuid(uid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(1, ret, uid);

  	return ret;

  }

  SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)

  {

  	long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
  				 low2highuid(suid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(3, ret, ruid, euid, suid);

  	return ret;

  }

  SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruid, old_uid_t __user *, euid, old_uid_t __user *, suid)

  {

  	const struct cred *cred = current_cred();

  	int retval;

  	if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
  	    !(retval   = put_user(high2lowuid(cred->euid), euid)))
  		retval = put_user(high2lowuid(cred->suid), suid);

  
  	return retval;
  }

  SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)

  {

  	long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
  				 low2highgid(sgid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(3, ret, rgid, egid, sgid);

  	return ret;

  }

  
  SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgid, old_gid_t __user *, egid, old_gid_t __user *, sgid)

  {

  	const struct cred *cred = current_cred();

  	int retval;

  	if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
  	    !(retval   = put_user(high2lowgid(cred->egid), egid)))
  		retval = put_user(high2lowgid(cred->sgid), sgid);

  
  	return retval;
  }

  SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)

  {

  	long ret = sys_setfsuid(low2highuid(uid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(1, ret, uid);

  	return ret;

  }

  SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)

  {

  	long ret = sys_setfsgid(low2highgid(gid));
  	/* avoid REGPARM breakage on x86: */

  	asmlinkage_protect(1, ret, gid);

  	return ret;

  }
  
  static int groups16_to_user(old_gid_t __user *grouplist,
      struct group_info *group_info)
  {
  	int i;
  	old_gid_t group;
  
  	for (i = 0; i < group_info->ngroups; i++) {
  		group = high2lowgid(GROUP_AT(group_info, i));
  		if (put_user(group, grouplist+i))
  			return -EFAULT;
  	}
  
  	return 0;
  }
  
  static int groups16_from_user(struct group_info *group_info,
      old_gid_t __user *grouplist)
  {
  	int i;
  	old_gid_t group;
  
  	for (i = 0; i < group_info->ngroups; i++) {
  		if (get_user(group, grouplist+i))
  			return  -EFAULT;
  		GROUP_AT(group_info, i) = low2highgid(group);
  	}
  
  	return 0;
  }

  SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)

  {

  	const struct cred *cred = current_cred();
  	int i;

  
  	if (gidsetsize < 0)
  		return -EINVAL;

  	i = cred->group_info->ngroups;

  	if (gidsetsize) {
  		if (i > gidsetsize) {
  			i = -EINVAL;
  			goto out;
  		}

  		if (groups16_to_user(grouplist, cred->group_info)) {

  			i = -EFAULT;
  			goto out;
  		}
  	}
  out:

  	return i;
  }

  SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)

  {
  	struct group_info *group_info;
  	int retval;

  	if (!nsown_capable(CAP_SETGID))

  		return -EPERM;
  	if ((unsigned)gidsetsize > NGROUPS_MAX)
  		return -EINVAL;
  
  	group_info = groups_alloc(gidsetsize);
  	if (!group_info)
  		return -ENOMEM;
  	retval = groups16_from_user(group_info, grouplist);
  	if (retval) {
  		put_group_info(group_info);
  		return retval;
  	}
  
  	retval = set_current_groups(group_info);
  	put_group_info(group_info);
  
  	return retval;
  }

  SYSCALL_DEFINE0(getuid16)

  {

  	return high2lowuid(current_uid());

  }

  SYSCALL_DEFINE0(geteuid16)

  {

  	return high2lowuid(current_euid());

  }

  SYSCALL_DEFINE0(getgid16)

  {

  	return high2lowgid(current_gid());

  }

  SYSCALL_DEFINE0(getegid16)

  {

  	return high2lowgid(current_egid());

  }