compat.c

{
	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 */