Exemplo n.º 1
0
/*
 * pid_for_task
 *
 * Find the BSD process ID for the Mach task associated with the given Mach port 
 * name
 *
 * Parameters:	args		User argument descriptor (see below)
 *
 * Indirect parameters:	args->t		Mach port name
 * 			args->pid	Process ID (returned value; see below)
 *
 * Returns:	KERL_SUCCESS	Success
 * 		KERN_FAILURE	Not success           
 *
 * Implicit returns: args->pid		Process ID
 *
 */
kern_return_t
pid_for_task(
	struct pid_for_task_args *args)
{
	mach_port_name_t	t = args->t;
	user_addr_t		pid_addr  = args->pid;  
	proc_t p;
	task_t		t1;
	int	pid = -1;
	kern_return_t	err = KERN_SUCCESS;

	AUDIT_MACH_SYSCALL_ENTER(AUE_PIDFORTASK);
	AUDIT_ARG(mach_port1, t);

	t1 = port_name_to_task(t);

	if (t1 == TASK_NULL) {
		err = KERN_FAILURE;
		goto pftout;
	} else {
		p = get_bsdtask_info(t1);
		if (p) {
			pid  = proc_pid(p);
			err = KERN_SUCCESS;
		} else {
			err = KERN_FAILURE;
		}
	}
	task_deallocate(t1);
pftout:
	AUDIT_ARG(pid, pid);
	(void) copyout((char *) &pid, pid_addr, sizeof(int));
	AUDIT_MACH_SYSCALL_EXIT(err);
	return(err);
}
Exemplo n.º 2
0
/* USV: No! need to obsolete map_fd()! mmap() already supports 64 bits */
kern_return_t
map_fd(struct map_fd_args *args)
{
	int		fd = args->fd;
	vm_offset_t	offset = args->offset;
	vm_offset_t	*va = args->va;
	boolean_t	findspace = args->findspace;
	vm_size_t	size = args->size;
	kern_return_t ret;

	AUDIT_MACH_SYSCALL_ENTER(AUE_MAPFD);
	AUDIT_ARG(addr, CAST_DOWN(user_addr_t, va));
	AUDIT_ARG(fd, fd);

	ret = map_fd_funneled( fd, (vm_object_offset_t)offset, va, findspace, size);

	AUDIT_MACH_SYSCALL_EXIT(ret);
	return ret;
}
Exemplo n.º 3
0
/*
 *	Routine:	macx_swapoff
 *	Function:
 *		Syscall interface to remove a file from backing store
 */
int
macx_swapoff(
	struct macx_swapoff_args *args)
{
	__unused int	flags = args->flags;
	kern_return_t	kr;
	mach_port_t	backing_store;

	struct vnode		*vp = 0; 
	struct nameidata 	nd, *ndp;
	struct proc		*p =  current_proc();
	int			i;
	int			error;
	boolean_t		funnel_state;
	vfs_context_t ctx = vfs_context_current();

	AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPOFF);

	funnel_state = thread_funnel_set(kernel_flock, TRUE);
	backing_store = NULL;
	ndp = &nd;

	if ((error = suser(kauth_cred_get(), 0)))
		goto swapoff_bailout;

	/*
	 * Get the vnode for the paging area.
	 */
	NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
	       ((IS_64BIT_PROCESS(p)) ? UIO_USERSPACE64 : UIO_USERSPACE32),
	       (user_addr_t) args->filename, ctx);

	if ((error = namei(ndp)))
		goto swapoff_bailout;
	nameidone(ndp);
	vp = ndp->ni_vp;

	if (vp->v_type != VREG) {
		error = EINVAL;
		goto swapoff_bailout;
	}
#if CONFIG_MACF
	vnode_lock(vp);
	error = mac_system_check_swapoff(vfs_context_ucred(ctx), vp);
	vnode_unlock(vp);
	if (error)
		goto swapoff_bailout;
#endif

	for(i = 0; i < MAX_BACKING_STORE; i++) {
		if(bs_port_table[i].vp == vp) {
			break;
		}
	}
	if (i == MAX_BACKING_STORE) {
		error = EINVAL;
		goto swapoff_bailout;
	}
	backing_store = (mach_port_t)bs_port_table[i].bs;

	kr = default_pager_backing_store_delete(backing_store);
	switch (kr) {
		case KERN_SUCCESS:
			error = 0;
			bs_port_table[i].vp = 0;
			/* This vnode is no longer used for swapfile */
			vnode_lock_spin(vp);
			CLR(vp->v_flag, VSWAP);
			vnode_unlock(vp);

			/* get rid of macx_swapon() "long term" reference */
			vnode_rele(vp);

			break;
		case KERN_FAILURE:
			error = EAGAIN;
			break;
		default:
			error = EAGAIN;
			break;
	}

swapoff_bailout:
	/* get rid of macx_swapoff() namei() reference */
	if (vp)
		vnode_put(vp);

	(void) thread_funnel_set(kernel_flock, FALSE);
	AUDIT_MACH_SYSCALL_EXIT(error);
	return(error);
}
Exemplo n.º 4
0
/*
 *	Routine:	macx_swapon
 *	Function:
 *		Syscall interface to add a file to backing store
 */
int
macx_swapon(
	struct macx_swapon_args *args)
{
	int			size = args->size;
	vnode_t			vp = (vnode_t)NULL; 
	struct nameidata 	nd, *ndp;
	register int		error;
	kern_return_t		kr;
	mach_port_t		backing_store;
	memory_object_default_t	default_pager;
	int			i;
	boolean_t		funnel_state;
	off_t			file_size;
	vfs_context_t		ctx = vfs_context_current();
	struct proc		*p =  current_proc();
	int			dp_cluster_size;


	AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
	AUDIT_ARG(value32, args->priority);

	funnel_state = thread_funnel_set(kernel_flock, TRUE);
	ndp = &nd;

	if ((error = suser(kauth_cred_get(), 0)))
		goto swapon_bailout;

	/*
	 * Get a vnode for the paging area.
	 */
	NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
	       ((IS_64BIT_PROCESS(p)) ? UIO_USERSPACE64 : UIO_USERSPACE32),
	       (user_addr_t) args->filename, ctx);

	if ((error = namei(ndp)))
		goto swapon_bailout;
	nameidone(ndp);
	vp = ndp->ni_vp;

	if (vp->v_type != VREG) {
		error = EINVAL;
		goto swapon_bailout;
	}

	/* get file size */
	if ((error = vnode_size(vp, &file_size, ctx)) != 0)
		goto swapon_bailout;
#if CONFIG_MACF
	vnode_lock(vp);
	error = mac_system_check_swapon(vfs_context_ucred(ctx), vp);
	vnode_unlock(vp);
	if (error)
		goto swapon_bailout;
#endif

	/* resize to desired size if it's too small */
	if ((file_size < (off_t)size) && ((error = vnode_setsize(vp, (off_t)size, 0, ctx)) != 0))
		goto swapon_bailout;

	if (default_pager_init_flag == 0) {
		start_def_pager(NULL);
		default_pager_init_flag = 1;
	}

	/* add new backing store to list */
	i = 0;
	while(bs_port_table[i].vp != 0) {
		if(i == MAX_BACKING_STORE)
			break;
		i++;
	}
	if(i == MAX_BACKING_STORE) {
	   	error = ENOMEM;
		goto swapon_bailout;
	}

	/* remember the vnode. This vnode has namei() reference */
	bs_port_table[i].vp = vp;
	
	/*
	 * Look to see if we are already paging to this file.
	 */
	/* make certain the copy send of kernel call will work */
	default_pager = MEMORY_OBJECT_DEFAULT_NULL;
	kr = host_default_memory_manager(host_priv_self(), &default_pager, 0);
	if(kr != KERN_SUCCESS) {
	   error = EAGAIN;
	   bs_port_table[i].vp = 0;
	   goto swapon_bailout;
	}

	if (vp->v_mount->mnt_kern_flag & MNTK_SSD) {
		/*
		 * keep the cluster size small since the
		 * seek cost is effectively 0 which means
		 * we don't care much about fragmentation
		 */
		dp_isssd = TRUE;
		dp_cluster_size = 2 * PAGE_SIZE;
	} else {
		/*
		 * use the default cluster size
		 */
		dp_isssd = FALSE;
		dp_cluster_size = 0;
	}
	kr = default_pager_backing_store_create(default_pager, 
					-1, /* default priority */
					dp_cluster_size,
					&backing_store);
	memory_object_default_deallocate(default_pager);

	if(kr != KERN_SUCCESS) {
	   error = ENOMEM;
	   bs_port_table[i].vp = 0;
	   goto swapon_bailout;
	}

	/* Mark this vnode as being used for swapfile */
	vnode_lock_spin(vp);
	SET(vp->v_flag, VSWAP);
	vnode_unlock(vp);

	/*
	 * NOTE: we are able to supply PAGE_SIZE here instead of
	 *	an actual record size or block number because:
	 *	a: we do not support offsets from the beginning of the
	 *		file (allowing for non page size/record modulo offsets.
	 *	b: because allow paging will be done modulo page size
	 */

	kr = default_pager_add_file(backing_store, (vnode_ptr_t) vp,
				PAGE_SIZE, (int)(file_size/PAGE_SIZE));
	if(kr != KERN_SUCCESS) {
	   bs_port_table[i].vp = 0;
	   if(kr == KERN_INVALID_ARGUMENT)
		error = EINVAL;
	   else 
		error = ENOMEM;

	   /* This vnode is not to be used for swapfile */
	   vnode_lock_spin(vp);
	   CLR(vp->v_flag, VSWAP);
	   vnode_unlock(vp);

	   goto swapon_bailout;
	}
	bs_port_table[i].bs = (void *)backing_store;
	error = 0;

	ubc_setthreadcred(vp, p, current_thread());

	/*
	 * take a long term reference on the vnode to keep
	 * vnreclaim() away from this vnode.
	 */
	vnode_ref(vp);

swapon_bailout:
	if (vp) {
		vnode_put(vp);
	}
	(void) thread_funnel_set(kernel_flock, FALSE);
	AUDIT_MACH_SYSCALL_EXIT(error);
	return(error);
}
Exemplo n.º 5
0
kern_return_t
task_name_for_pid(
	struct task_name_for_pid_args *args)
{
	mach_port_name_t	target_tport = args->target_tport;
	int			pid = args->pid;
	user_addr_t		task_addr = args->t;
	proc_t		p = PROC_NULL;
	task_t		t1;
	mach_port_name_t	tret;
	void * sright;
	int error = 0, refheld = 0;
	kauth_cred_t target_cred;

	AUDIT_MACH_SYSCALL_ENTER(AUE_TASKNAMEFORPID);
	AUDIT_ARG(pid, pid);
	AUDIT_ARG(mach_port1, target_tport);

	t1 = port_name_to_task(target_tport);
	if (t1 == TASK_NULL) {
		(void) copyout((char *)&t1, task_addr, sizeof(mach_port_name_t));
		AUDIT_MACH_SYSCALL_EXIT(KERN_FAILURE);
		return(KERN_FAILURE);
	} 

	p = proc_find(pid);
	if (p != PROC_NULL) {
		AUDIT_ARG(process, p);
		target_cred = kauth_cred_proc_ref(p);
		refheld = 1;

		if ((p->p_stat != SZOMB)
		    && ((current_proc() == p)
			|| kauth_cred_issuser(kauth_cred_get()) 
			|| ((kauth_cred_getuid(target_cred) == kauth_cred_getuid(kauth_cred_get())) && 
			    ((kauth_cred_getruid(target_cred) == kauth_getruid()))))) {

			if (p->task != TASK_NULL) {
				task_reference(p->task);
#if CONFIG_MACF
				error = mac_proc_check_get_task_name(kauth_cred_get(),  p);
				if (error) {
					task_deallocate(p->task);
					goto noperm;
				}
#endif
				sright = (void *)convert_task_name_to_port(p->task);
				tret = ipc_port_copyout_send(sright, 
						get_task_ipcspace(current_task()));
			} else
				tret  = MACH_PORT_NULL;

			AUDIT_ARG(mach_port2, tret);
			(void) copyout((char *)&tret, task_addr, sizeof(mach_port_name_t));
			task_deallocate(t1);
			error = KERN_SUCCESS;
			goto tnfpout;
		}
	}

#if CONFIG_MACF
noperm:
#endif
    task_deallocate(t1);
	tret = MACH_PORT_NULL;
	(void) copyout((char *) &tret, task_addr, sizeof(mach_port_name_t));
	error = KERN_FAILURE;
tnfpout:
	if (refheld != 0)
		kauth_cred_unref(&target_cred);
	if (p != PROC_NULL)
		proc_rele(p);
	AUDIT_MACH_SYSCALL_EXIT(error);
	return(error);
}
Exemplo n.º 6
0
/*
 *	Routine:	task_for_pid
 *	Purpose:
 *		Get the task port for another "process", named by its
 *		process ID on the same host as "target_task".
 *
 *		Only permitted to privileged processes, or processes
 *		with the same user ID.
 *
 *		Note: if pid == 0, an error is return no matter who is calling.
 *
 * XXX This should be a BSD system call, not a Mach trap!!!
 */
kern_return_t
task_for_pid(
	struct task_for_pid_args *args)
{
	mach_port_name_t	target_tport = args->target_tport;
	int			pid = args->pid;
	user_addr_t		task_addr = args->t;
	proc_t 			p = PROC_NULL;
	task_t			t1 = TASK_NULL;
	mach_port_name_t	tret = MACH_PORT_NULL;
 	ipc_port_t 		tfpport;
	void * sright;
	int error = 0;

	AUDIT_MACH_SYSCALL_ENTER(AUE_TASKFORPID);
	AUDIT_ARG(pid, pid);
	AUDIT_ARG(mach_port1, target_tport);

	/* Always check if pid == 0 */
	if (pid == 0) {
		(void ) copyout((char *)&t1, task_addr, sizeof(mach_port_name_t));
		AUDIT_MACH_SYSCALL_EXIT(KERN_FAILURE);
		return(KERN_FAILURE);
	}

	t1 = port_name_to_task(target_tport);
	if (t1 == TASK_NULL) {
		(void) copyout((char *)&t1, task_addr, sizeof(mach_port_name_t));
		AUDIT_MACH_SYSCALL_EXIT(KERN_FAILURE);
		return(KERN_FAILURE);
	} 


	p = proc_find(pid);
	if (p == PROC_NULL) {
		error = KERN_FAILURE;
		goto tfpout;
	}

#if CONFIG_AUDIT
	AUDIT_ARG(process, p);
#endif

	if (!(task_for_pid_posix_check(p))) {
		error = KERN_FAILURE;
		goto tfpout;
	}

	if (p->task != TASK_NULL) {
		/* If we aren't root and target's task access port is set... */
		if (!kauth_cred_issuser(kauth_cred_get()) &&
			p != current_proc() &&
			(task_get_task_access_port(p->task, &tfpport) == 0) &&
			(tfpport != IPC_PORT_NULL)) {

			if (tfpport == IPC_PORT_DEAD) {
				error = KERN_PROTECTION_FAILURE;
				goto tfpout;
			}

			/* Call up to the task access server */
			error = check_task_access(tfpport, proc_selfpid(), kauth_getgid(), pid);

			if (error != MACH_MSG_SUCCESS) {
				if (error == MACH_RCV_INTERRUPTED)
					error = KERN_ABORTED;
				else
					error = KERN_FAILURE;
				goto tfpout;
			}
		}
#if CONFIG_MACF
		error = mac_proc_check_get_task(kauth_cred_get(), p);
		if (error) {
			error = KERN_FAILURE;
			goto tfpout;
		}
#endif

		/* Grant task port access */
		task_reference(p->task);
		extmod_statistics_incr_task_for_pid(p->task);

		sright = (void *) convert_task_to_port(p->task);
		tret = ipc_port_copyout_send(
				sright, 
				get_task_ipcspace(current_task()));
	} 
	error = KERN_SUCCESS;

tfpout:
	task_deallocate(t1);
	AUDIT_ARG(mach_port2, tret);
	(void) copyout((char *) &tret, task_addr, sizeof(mach_port_name_t));
	if (p != PROC_NULL)
		proc_rele(p);
	AUDIT_MACH_SYSCALL_EXIT(error);
	return(error);
}
Exemplo n.º 7
0
/*
 *	Routine:	task_for_pid
 *	Purpose:
 *		Get the task port for another "process", named by its
 *		process ID on the same host as "target_task".
 *
 *		Only permitted to privileged processes, or processes
 *		with the same user ID.
 *
 * XXX This should be a BSD system call, not a Mach trap!!!
 */
kern_return_t
task_for_pid(
	struct task_for_pid_args *args)
{
	mach_port_name_t	target_tport = args->target_tport;
	int			pid = args->pid;
	user_addr_t		task_addr = args->t;
	struct uthread		*uthread;
	proc_t 			p = PROC_NULL;
	task_t			t1 = TASK_NULL;
	mach_port_name_t	tret = MACH_PORT_NULL;
 	ipc_port_t 		tfpport;
	void * sright;
	int error = 0;

	AUDIT_MACH_SYSCALL_ENTER(AUE_TASKFORPID);
	AUDIT_ARG(pid, pid);
	AUDIT_ARG(mach_port1, target_tport);

#if defined(SECURE_KERNEL)
	if (0 == pid) {
		(void ) copyout((char *)&t1, task_addr, sizeof(mach_port_name_t));
		AUDIT_MACH_SYSCALL_EXIT(KERN_FAILURE);
		return(KERN_FAILURE);
	}
#endif

	t1 = port_name_to_task(target_tport);
	if (t1 == TASK_NULL) {
		(void) copyout((char *)&t1, task_addr, sizeof(mach_port_name_t));
		AUDIT_MACH_SYSCALL_EXIT(KERN_FAILURE);
		return(KERN_FAILURE);
	} 


	/*
	 * Delayed binding of thread credential to process credential, if we
	 * are not running with an explicitly set thread credential.
	 */
	uthread = get_bsdthread_info(current_thread());
	kauth_cred_uthread_update(uthread, current_proc());

	p = proc_find(pid);
	AUDIT_ARG(process, p);

	if (!(task_for_pid_posix_check(p))) {
		error = KERN_FAILURE;
		goto tfpout;
	}

	if (p->task != TASK_NULL) {
		/* If we aren't root and target's task access port is set... */
		if (!kauth_cred_issuser(kauth_cred_get()) &&
			p != current_proc() &&
			(task_get_task_access_port(p->task, &tfpport) == 0) &&
			(tfpport != IPC_PORT_NULL)) {

			if (tfpport == IPC_PORT_DEAD) {
				error = KERN_PROTECTION_FAILURE;
				goto tfpout;
			}

			/* Call up to the task access server */
			error = check_task_access(tfpport, proc_selfpid(), kauth_getgid(), pid);

			if (error != MACH_MSG_SUCCESS) {
				if (error == MACH_RCV_INTERRUPTED)
					error = KERN_ABORTED;
				else
					error = KERN_FAILURE;
				goto tfpout;
			}
		}
#if CONFIG_MACF
		error = mac_proc_check_get_task(kauth_cred_get(), p);
		if (error) {
			error = KERN_FAILURE;
			goto tfpout;
		}
#endif

		/* Grant task port access */
		task_reference(p->task);
		sright = (void *) convert_task_to_port(p->task);
		tret = ipc_port_copyout_send(
				sright, 
				get_task_ipcspace(current_task()));
	} 
	error = KERN_SUCCESS;

tfpout:
	task_deallocate(t1);
	AUDIT_ARG(mach_port2, tret);
	(void) copyout((char *) &tret, task_addr, sizeof(mach_port_name_t));
	if (p != PROC_NULL)
		proc_rele(p);
	AUDIT_MACH_SYSCALL_EXIT(error);
	return(error);
}
Exemplo n.º 8
0
/*
 *	Routine:	macx_swapoff
 *	Function:
 *		Syscall interface to remove a file from backing store
 */
int
macx_swapoff(
    char 	*filename,
    int	flags)
{
    kern_return_t	kr;
    mach_port_t	backing_store;

    struct vnode		*vp = 0;
    struct nameidata 	nd, *ndp;
    struct proc		*p =  current_proc();
    int			i;
    int			error;
    boolean_t		funnel_state;

    AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPOFF);
    funnel_state = thread_funnel_set(kernel_flock, TRUE);
    backing_store = NULL;
    ndp = &nd;

    if ((error = suser(p->p_ucred, &p->p_acflag)))
        goto swapoff_bailout;

    /*
     * Get the vnode for the paging area.
     */
    NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1, UIO_USERSPACE,
           filename, p);

    if ((error = namei(ndp)))
        goto swapoff_bailout;
    vp = ndp->ni_vp;

    if (vp->v_type != VREG) {
        error = EINVAL;
        VOP_UNLOCK(vp, 0, p);
        goto swapoff_bailout;
    }

    for(i = 0; i < MAX_BACKING_STORE; i++) {
        if(bs_port_table[i].vp == vp) {
            backing_store;
            break;
        }
    }
    if (i == MAX_BACKING_STORE) {
        error = EINVAL;
        VOP_UNLOCK(vp, 0, p);
        goto swapoff_bailout;
    }
    backing_store = (mach_port_t)bs_port_table[i].bs;

    VOP_UNLOCK(vp, 0, p);
    kr = default_pager_backing_store_delete(backing_store);
    switch (kr) {
    case KERN_SUCCESS:
        error = 0;
        bs_port_table[i].vp = 0;
        ubc_rele(vp);
        /* This vnode is no longer used for swapfile */
        CLR(vp->v_flag, VSWAP);

        /* get rid of macx_swapon() namei() reference */
        vrele(vp);

        /* get rid of macx_swapon() "extra" reference */
        vrele(vp);
        break;
    case KERN_FAILURE:
        error = EAGAIN;
        break;
    default:
        error = EAGAIN;
        break;
    }

swapoff_bailout:
    /* get rid of macx_swapoff() namei() reference */
    if (vp)
        vrele(vp);

    (void) thread_funnel_set(kernel_flock, FALSE);
    AUDIT_MACH_SYSCALL_EXIT(error);
    return(error);
}
Exemplo n.º 9
0
/*
 *	Routine:	macx_swapon
 *	Function:
 *		Syscall interface to add a file to backing store
 */
int
macx_swapon(
    char 	*filename,
    int	flags,
    long	size,
    long	priority)
{
    struct vnode		*vp = 0;
    struct nameidata 	nd, *ndp;
    struct proc		*p =  current_proc();
    pager_file_t		pf;
    register int		error;
    kern_return_t		kr;
    mach_port_t		backing_store;
    memory_object_default_t	default_pager;
    int			i;
    boolean_t		funnel_state;

    struct vattr	vattr;

    AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
    AUDIT_ARG(value, priority);

    funnel_state = thread_funnel_set(kernel_flock, TRUE);
    ndp = &nd;

    if ((error = suser(p->p_ucred, &p->p_acflag)))
        goto swapon_bailout;

    if(default_pager_init_flag == 0) {
        start_def_pager(NULL);
        default_pager_init_flag = 1;
    }

    /*
     * Get a vnode for the paging area.
     */
    NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1, UIO_USERSPACE,
           filename, p);

    if ((error = namei(ndp)))
        goto swapon_bailout;
    vp = ndp->ni_vp;

    if (vp->v_type != VREG) {
        error = EINVAL;
        VOP_UNLOCK(vp, 0, p);
        goto swapon_bailout;
    }
    UBCINFOCHECK("macx_swapon", vp);

    if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) {
        VOP_UNLOCK(vp, 0, p);
        goto swapon_bailout;
    }

    if (vattr.va_size < (u_quad_t)size) {
        vattr_null(&vattr);
        vattr.va_size = (u_quad_t)size;
        error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
        if (error) {
            VOP_UNLOCK(vp, 0, p);
            goto swapon_bailout;
        }
    }

    /* add new backing store to list */
    i = 0;
    while(bs_port_table[i].vp != 0) {
        if(i == MAX_BACKING_STORE)
            break;
        i++;
    }
    if(i == MAX_BACKING_STORE) {
        error = ENOMEM;
        VOP_UNLOCK(vp, 0, p);
        goto swapon_bailout;
    }

    /* remember the vnode. This vnode has namei() reference */
    bs_port_table[i].vp = vp;

    /*
     * Look to see if we are already paging to this file.
     */
    /* make certain the copy send of kernel call will work */
    default_pager = MEMORY_OBJECT_DEFAULT_NULL;
    kr = host_default_memory_manager(host_priv_self(), &default_pager, 0);
    if(kr != KERN_SUCCESS) {
        error = EAGAIN;
        VOP_UNLOCK(vp, 0, p);
        bs_port_table[i].vp = 0;
        goto swapon_bailout;
    }

    kr = default_pager_backing_store_create(default_pager,
                                            -1, /* default priority */
                                            0, /* default cluster size */
                                            &backing_store);
    memory_object_default_deallocate(default_pager);

    if(kr != KERN_SUCCESS) {
        error = ENOMEM;
        VOP_UNLOCK(vp, 0, p);
        bs_port_table[i].vp = 0;
        goto swapon_bailout;
    }

    /*
     * NOTE: we are able to supply PAGE_SIZE here instead of
     *	an actual record size or block number because:
     *	a: we do not support offsets from the beginning of the
     *		file (allowing for non page size/record modulo offsets.
     *	b: because allow paging will be done modulo page size
     */

    VOP_UNLOCK(vp, 0, p);
    kr = default_pager_add_file(backing_store, vp, PAGE_SIZE,
                                ((int)vattr.va_size)/PAGE_SIZE);
    if(kr != KERN_SUCCESS) {
        bs_port_table[i].vp = 0;
        if(kr == KERN_INVALID_ARGUMENT)
            error = EINVAL;
        else
            error = ENOMEM;
        goto swapon_bailout;
    }
    bs_port_table[i].bs = (void *)backing_store;
    error = 0;
    if (!ubc_hold(vp))
        panic("macx_swapon: hold");

    /* Mark this vnode as being used for swapfile */
    SET(vp->v_flag, VSWAP);

    ubc_setcred(vp, p);

    /*
     * take an extra reference on the vnode to keep
     * vnreclaim() away from this vnode.
     */
    VREF(vp);

    /* Hold on to the namei  reference to the paging file vnode */
    vp = 0;

swapon_bailout:
    if (vp) {
        vrele(vp);
    }
    (void) thread_funnel_set(kernel_flock, FALSE);
    AUDIT_MACH_SYSCALL_EXIT(error);
    return(error);
}