xnu-7195.101.1.tar.gz

[apple/xnu.git] / osfmk / kern / ipc_host.c

/*
 * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */

/*
 *      kern/ipc_host.c
 *
 *      Routines to implement host ports.
 */
#include <mach/message.h>
#include <mach/mach_traps.h>
#include <mach/mach_host_server.h>
#include <mach/host_priv_server.h>
#include <kern/host.h>
#include <kern/processor.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/ipc_host.h>
#include <kern/ipc_kobject.h>
#include <kern/misc_protos.h>
#include <kern/spl.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_space.h>

#if CONFIG_MACF
#include <security/mac_mach_internal.h>
#endif

/*
 * Forward declarations
 */

boolean_t
ref_pset_port_locked(
        ipc_port_t port, boolean_t matchn, processor_set_t *ppset);

/*
 *      ipc_host_init: set up various things.
 */

extern lck_grp_t                host_notify_lock_grp;

void
ipc_host_init(void)
{
        ipc_port_t      port;
        int i;

        lck_mtx_init(&realhost.lock, &host_notify_lock_grp, LCK_ATTR_NULL);

        /*
         *      Allocate and set up the two host ports.
         */
        port = ipc_kobject_alloc_port((ipc_kobject_t) &realhost, IKOT_HOST_SECURITY,
            IPC_KOBJECT_ALLOC_MAKE_SEND);
        kernel_set_special_port(&realhost, HOST_SECURITY_PORT, port);

        port = ipc_kobject_alloc_port((ipc_kobject_t) &realhost, IKOT_HOST,
            IPC_KOBJECT_ALLOC_MAKE_SEND);
        kernel_set_special_port(&realhost, HOST_PORT, port);

        port = ipc_kobject_alloc_port((ipc_kobject_t) &realhost, IKOT_HOST_PRIV,
            IPC_KOBJECT_ALLOC_MAKE_SEND);
        kernel_set_special_port(&realhost, HOST_PRIV_PORT, port);

        /* the rest of the special ports will be set up later */

        bzero(&realhost.exc_actions[0], sizeof(realhost.exc_actions[0]));
        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
                realhost.exc_actions[i].port = IP_NULL;
                /* The mac framework is not yet initialized, so we defer
                 * initializing the labels to later, when they are set
                 * for the first time. */
                realhost.exc_actions[i].label = NULL;
                /* initialize the entire exception action struct */
                realhost.exc_actions[i].behavior = 0;
                realhost.exc_actions[i].flavor = 0;
                realhost.exc_actions[i].privileged = FALSE;
        } /* for */

        /*
         *      Set up ipc for default processor set.
         */
        ipc_pset_init(&pset0);
        ipc_pset_enable(&pset0);

        /*
         *      And for master processor
         */
        ipc_processor_init(master_processor);
        ipc_processor_enable(master_processor);
}

/*
 *      Routine:        host_self_trap [mach trap]
 *      Purpose:
 *              Give the caller send rights for his own host port.
 *      Conditions:
 *              Nothing locked.
 *      Returns:
 *              MACH_PORT_NULL if there are any resource failures
 *              or other errors.
 */

mach_port_name_t
host_self_trap(
        __unused struct host_self_trap_args *args)
{
        task_t self = current_task();
        ipc_port_t sright;
        mach_port_name_t name;

        itk_lock(self);
        sright = ipc_port_copy_send(self->itk_host);
        itk_unlock(self);
        name = ipc_port_copyout_send(sright, current_space());
        return name;
}

/*
 *      ipc_processor_init:
 *
 *      Initialize ipc access to processor by allocating port.
 */

void
ipc_processor_init(
        processor_t     processor)
{
        ipc_port_t      port;

        port = ipc_port_alloc_kernel();
        if (port == IP_NULL) {
                panic("ipc_processor_init");
        }
        processor->processor_self = port;
}

/*
 *      ipc_processor_enable:
 *
 *      Enable ipc control of processor by setting port object.
 */
void
ipc_processor_enable(
        processor_t     processor)
{
        ipc_port_t      myport;

        myport = processor->processor_self;
        ipc_kobject_set(myport, (ipc_kobject_t) processor, IKOT_PROCESSOR);
}

/*
 *      ipc_pset_init:
 *
 *      Initialize ipc control of a processor set by allocating its ports.
 */

void
ipc_pset_init(
        processor_set_t         pset)
{
        ipc_port_t      port;

        port = ipc_port_alloc_kernel();
        if (port == IP_NULL) {
                panic("ipc_pset_init");
        }
        pset->pset_self = port;

        port = ipc_port_alloc_kernel();
        if (port == IP_NULL) {
                panic("ipc_pset_init");
        }
        pset->pset_name_self = port;
}

/*
 *      ipc_pset_enable:
 *
 *      Enable ipc access to a processor set.
 */
void
ipc_pset_enable(
        processor_set_t         pset)
{
        ipc_kobject_set(pset->pset_self, (ipc_kobject_t) pset, IKOT_PSET);
        ipc_kobject_set(pset->pset_name_self, (ipc_kobject_t) pset, IKOT_PSET_NAME);
}

/*
 *      processor_set_default:
 *
 *      Return ports for manipulating default_processor set.
 */
kern_return_t
processor_set_default(
        host_t                  host,
        processor_set_t         *pset)
{
        if (host == HOST_NULL) {
                return KERN_INVALID_ARGUMENT;
        }

        *pset = &pset0;

        return KERN_SUCCESS;
}

/*
 *      Routine:        convert_port_to_host
 *      Purpose:
 *              Convert from a port to a host.
 *              Doesn't consume the port ref; the host produced may be null.
 *      Conditions:
 *              Nothing locked.
 */

host_t
convert_port_to_host(
        ipc_port_t      port)
{
        host_t host = HOST_NULL;

        if (IP_VALID(port)) {
                if (ip_kotype(port) == IKOT_HOST ||
                    ip_kotype(port) == IKOT_HOST_PRIV) {
                        host = (host_t) ip_get_kobject(port);
                        require_ip_active(port);
                }
        }
        return host;
}

/*
 *      Routine:        convert_port_to_host_priv
 *      Purpose:
 *              Convert from a port to a host.
 *              Doesn't consume the port ref; the host produced may be null.
 *      Conditions:
 *              Nothing locked.
 */

host_t
convert_port_to_host_priv(
        ipc_port_t      port)
{
        host_t host = HOST_NULL;

        /* reject translation if itk_host is not host_priv */
        if (port != current_task()->itk_host) {
                return HOST_NULL;
        }

        if (IP_VALID(port)) {
                ip_lock(port);
                if (ip_active(port) &&
                    (ip_kotype(port) == IKOT_HOST_PRIV)) {
                        assert(ip_get_kobject(port) == &realhost);
                        host = &realhost;
                }
                ip_unlock(port);
        }

        return host;
}

/*
 *      Routine:        convert_port_to_processor
 *      Purpose:
 *              Convert from a port to a processor.
 *              Doesn't consume the port ref;
 *              the processor produced may be null.
 *      Conditions:
 *              Nothing locked.
 */

processor_t
convert_port_to_processor(
        ipc_port_t      port)
{
        processor_t processor = PROCESSOR_NULL;

        if (IP_VALID(port)) {
                ip_lock(port);
                if (ip_active(port) &&
                    (ip_kotype(port) == IKOT_PROCESSOR)) {
                        processor = (processor_t) ip_get_kobject(port);
                }
                ip_unlock(port);
        }

        return processor;
}

/*
 *      Routine:        convert_port_to_pset
 *      Purpose:
 *              Convert from a port to a pset.
 *              Doesn't consume the port ref; produces a pset ref,
 *              which may be null.
 *      Conditions:
 *              Nothing locked.
 */

processor_set_t
convert_port_to_pset(
        ipc_port_t      port)
{
        boolean_t r;
        processor_set_t pset = PROCESSOR_SET_NULL;

        r = FALSE;
        while (!r && IP_VALID(port)) {
                ip_lock(port);
                r = ref_pset_port_locked(port, FALSE, &pset);
                /* port unlocked */
        }
        return pset;
}

/*
 *      Routine:        convert_port_to_pset_name
 *      Purpose:
 *              Convert from a port to a pset.
 *              Doesn't consume the port ref; produces a pset ref,
 *              which may be null.
 *      Conditions:
 *              Nothing locked.
 */

processor_set_name_t
convert_port_to_pset_name(
        ipc_port_t      port)
{
        boolean_t r;
        processor_set_t pset = PROCESSOR_SET_NULL;

        r = FALSE;
        while (!r && IP_VALID(port)) {
                ip_lock(port);
                r = ref_pset_port_locked(port, TRUE, &pset);
                /* port unlocked */
        }
        return pset;
}

boolean_t
ref_pset_port_locked(ipc_port_t port, boolean_t matchn, processor_set_t *ppset)
{
        processor_set_t pset;

        pset = PROCESSOR_SET_NULL;
        if (ip_active(port) &&
            ((ip_kotype(port) == IKOT_PSET) ||
            (matchn && (ip_kotype(port) == IKOT_PSET_NAME)))) {
                pset = (processor_set_t) ip_get_kobject(port);
        }

        *ppset = pset;
        ip_unlock(port);

        return TRUE;
}

/*
 *      Routine:        convert_host_to_port
 *      Purpose:
 *              Convert from a host to a port.
 *              Produces a naked send right which may be invalid.
 *      Conditions:
 *              Nothing locked.
 */

ipc_port_t
convert_host_to_port(
        host_t          host)
{
        ipc_port_t port;

        host_get_host_port(host, &port);
        return port;
}

/*
 *      Routine:        convert_processor_to_port
 *      Purpose:
 *              Convert from a processor to a port.
 *              Produces a naked send right which may be invalid.
 *              Processors are not reference counted, so nothing to release.
 *      Conditions:
 *              Nothing locked.
 */

ipc_port_t
convert_processor_to_port(
        processor_t             processor)
{
        ipc_port_t port = processor->processor_self;

        if (port != IP_NULL) {
                port = ipc_port_make_send(port);
        }
        return port;
}

/*
 *      Routine:        convert_pset_to_port
 *      Purpose:
 *              Convert from a pset to a port.
 *              Produces a naked send right which may be invalid.
 *              Processor sets are not reference counted, so nothing to release.
 *      Conditions:
 *              Nothing locked.
 */

ipc_port_t
convert_pset_to_port(
        processor_set_t         pset)
{
        ipc_port_t port = pset->pset_self;

        if (port != IP_NULL) {
                port = ipc_port_make_send(port);
        }

        return port;
}

/*
 *      Routine:        convert_pset_name_to_port
 *      Purpose:
 *              Convert from a pset to a port.
 *              Produces a naked send right which may be invalid.
 *              Processor sets are not reference counted, so nothing to release.
 *      Conditions:
 *              Nothing locked.
 */

ipc_port_t
convert_pset_name_to_port(
        processor_set_name_t            pset)
{
        ipc_port_t port = pset->pset_name_self;

        if (port != IP_NULL) {
                port = ipc_port_make_send(port);
        }

        return port;
}

/*
 *      Routine:        convert_port_to_host_security
 *      Purpose:
 *              Convert from a port to a host security.
 *              Doesn't consume the port ref; the port produced may be null.
 *      Conditions:
 *              Nothing locked.
 */

host_t
convert_port_to_host_security(
        ipc_port_t port)
{
        host_t host = HOST_NULL;

        if (IP_VALID(port)) {
                ip_lock(port);
                if (ip_active(port) &&
                    (ip_kotype(port) == IKOT_HOST_SECURITY)) {
                        host = (host_t) ip_get_kobject(port);
                }
                ip_unlock(port);
        }

        return host;
}

/*
 *      Routine:        host_set_exception_ports [kernel call]
 *      Purpose:
 *                      Sets the host exception port, flavor and
 *                      behavior for the exception types specified by the mask.
 *                      There will be one send right per exception per valid
 *                      port.
 *      Conditions:
 *              Nothing locked.  If successful, consumes
 *              the supplied send right.
 *      Returns:
 *              KERN_SUCCESS            Changed the special port.
 *              KERN_INVALID_ARGUMENT   The host_priv is not valid,
 *                                      Illegal mask bit set.
 *                                      Illegal exception behavior
 */
kern_return_t
host_set_exception_ports(
        host_priv_t                     host_priv,
        exception_mask_t                exception_mask,
        ipc_port_t                      new_port,
        exception_behavior_t            new_behavior,
        thread_state_flavor_t           new_flavor)
{
        int     i;
        ipc_port_t      old_port[EXC_TYPES_COUNT];

#if CONFIG_MACF
        struct label *deferred_labels[EXC_TYPES_COUNT];
        struct label *new_label;
#endif

        if (host_priv == HOST_PRIV_NULL) {
                return KERN_INVALID_ARGUMENT;
        }

        if (exception_mask & ~EXC_MASK_VALID) {
                return KERN_INVALID_ARGUMENT;
        }

        if (IP_VALID(new_port)) {
                switch (new_behavior & ~MACH_EXCEPTION_MASK) {
                case EXCEPTION_DEFAULT:
                case EXCEPTION_STATE:
                case EXCEPTION_STATE_IDENTITY:
                        break;
                default:
                        return KERN_INVALID_ARGUMENT;
                }
        }

        /*
         * Check the validity of the thread_state_flavor by calling the
         * VALID_THREAD_STATE_FLAVOR architecture dependent macro defined in
         * osfmk/mach/ARCHITECTURE/thread_status.h
         */
        if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) {
                return KERN_INVALID_ARGUMENT;
        }

#if CONFIG_MACF
        if (mac_task_check_set_host_exception_ports(current_task(), exception_mask) != 0) {
                return KERN_NO_ACCESS;
        }

        new_label = mac_exc_create_label_for_current_proc();

        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
                if (host_priv->exc_actions[i].label == NULL) {
                        deferred_labels[i] = mac_exc_create_label();
                } else {
                        deferred_labels[i] = NULL;
                }
        }
#endif

        host_lock(host_priv);

        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
#if CONFIG_MACF
                if (host_priv->exc_actions[i].label == NULL) {
                        // Lazy initialization (see ipc_port_init).
                        mac_exc_associate_action_label(&host_priv->exc_actions[i], deferred_labels[i]);
                        deferred_labels[i] = NULL; // Label is used, do not free.
                }
#endif

                if ((exception_mask & (1 << i))
#if CONFIG_MACF
                    && mac_exc_update_action_label(&host_priv->exc_actions[i], new_label) == 0
#endif
                    ) {
                        old_port[i] = host_priv->exc_actions[i].port;

                        host_priv->exc_actions[i].port =
                            ipc_port_copy_send(new_port);
                        host_priv->exc_actions[i].behavior = new_behavior;
                        host_priv->exc_actions[i].flavor = new_flavor;
                } else {
                        old_port[i] = IP_NULL;
                }
        }/* for */

        /*
         * Consume send rights without any lock held.
         */
        host_unlock(host_priv);

#if CONFIG_MACF
        mac_exc_free_label(new_label);
#endif

        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
                if (IP_VALID(old_port[i])) {
                        ipc_port_release_send(old_port[i]);
                }
#if CONFIG_MACF
                if (deferred_labels[i] != NULL) {
                        /* Deferred label went unused: Another thread has completed the lazy initialization. */
                        mac_exc_free_label(deferred_labels[i]);
                }
#endif
        }
        if (IP_VALID(new_port)) {        /* consume send right */
                ipc_port_release_send(new_port);
        }

        return KERN_SUCCESS;
}

/*
 *      Routine:        host_get_exception_ports [kernel call]
 *      Purpose:
 *              Clones a send right for each of the host's exception
 *              ports specified in the mask and returns the behaviour
 *              and flavor of said port.
 *
 *              Returns upto [in} CountCnt elements.
 *
 *      Conditions:
 *              Nothing locked.
 *      Returns:
 *              KERN_SUCCESS            Extracted a send right.
 *              KERN_INVALID_ARGUMENT   Invalid host_priv specified,
 *                                      Invalid special port,
 *                                      Illegal mask bit set.
 *              KERN_FAILURE            The thread is dead.
 */
kern_return_t
host_get_exception_ports(
        host_priv_t                     host_priv,
        exception_mask_t                exception_mask,
        exception_mask_array_t          masks,
        mach_msg_type_number_t          * CountCnt,
        exception_port_array_t          ports,
        exception_behavior_array_t      behaviors,
        thread_state_flavor_array_t     flavors         )
{
        unsigned int    i, j, count;

        if (host_priv == HOST_PRIV_NULL) {
                return KERN_INVALID_ARGUMENT;
        }

        if (exception_mask & ~EXC_MASK_VALID) {
                return KERN_INVALID_ARGUMENT;
        }

        host_lock(host_priv);

        count = 0;

        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
                if (exception_mask & (1 << i)) {
                        for (j = 0; j < count; j++) {
/*
 *                              search for an identical entry, if found
 *                              set corresponding mask for this exception.
 */
                                if (host_priv->exc_actions[i].port == ports[j] &&
                                    host_priv->exc_actions[i].behavior == behaviors[j]
                                    && host_priv->exc_actions[i].flavor == flavors[j]) {
                                        masks[j] |= (1 << i);
                                        break;
                                }
                        }/* for */
                        if (j == count && count < *CountCnt) {
                                masks[j] = (1 << i);
                                ports[j] =
                                    ipc_port_copy_send(host_priv->exc_actions[i].port);
                                behaviors[j] = host_priv->exc_actions[i].behavior;
                                flavors[j] = host_priv->exc_actions[i].flavor;
                                count++;
                        }
                }
        }/* for */
        host_unlock(host_priv);

        *CountCnt = count;
        return KERN_SUCCESS;
}

kern_return_t
host_swap_exception_ports(
        host_priv_t                     host_priv,
        exception_mask_t                exception_mask,
        ipc_port_t                      new_port,
        exception_behavior_t            new_behavior,
        thread_state_flavor_t           new_flavor,
        exception_mask_array_t          masks,
        mach_msg_type_number_t          * CountCnt,
        exception_port_array_t          ports,
        exception_behavior_array_t      behaviors,
        thread_state_flavor_array_t     flavors         )
{
        unsigned int    i,
            j,
            count;
        ipc_port_t      old_port[EXC_TYPES_COUNT];

#if CONFIG_MACF
        struct label *deferred_labels[EXC_TYPES_COUNT];
        struct label *new_label;
#endif

        if (host_priv == HOST_PRIV_NULL) {
                return KERN_INVALID_ARGUMENT;
        }

        if (exception_mask & ~EXC_MASK_VALID) {
                return KERN_INVALID_ARGUMENT;
        }

        if (IP_VALID(new_port)) {
                switch (new_behavior) {
                case EXCEPTION_DEFAULT:
                case EXCEPTION_STATE:
                case EXCEPTION_STATE_IDENTITY:
                        break;
                default:
                        return KERN_INVALID_ARGUMENT;
                }
        }

        if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) {
                return KERN_INVALID_ARGUMENT;
        }

#if CONFIG_MACF
        if (mac_task_check_set_host_exception_ports(current_task(), exception_mask) != 0) {
                return KERN_NO_ACCESS;
        }

        new_label = mac_exc_create_label_for_current_proc();

        for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) {
                if (host_priv->exc_actions[i].label == NULL) {
                        deferred_labels[i] = mac_exc_create_label();
                } else {
                        deferred_labels[i] = NULL;
                }
        }
#endif /* CONFIG_MACF */

        host_lock(host_priv);

        assert(EXC_TYPES_COUNT > FIRST_EXCEPTION);
        for (count = 0, i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT && count < *CountCnt; i++) {
#if CONFIG_MACF
                if (host_priv->exc_actions[i].label == NULL) {
                        // Lazy initialization (see ipc_port_init).
                        mac_exc_associate_action_label(&host_priv->exc_actions[i], deferred_labels[i]);
                        deferred_labels[i] = NULL; // Label is used, do not free.
                }
#endif

                if ((exception_mask & (1 << i))
#if CONFIG_MACF
                    && mac_exc_update_action_label(&host_priv->exc_actions[i], new_label) == 0
#endif
                    ) {
                        for (j = 0; j < count; j++) {
/*
 *                              search for an identical entry, if found
 *                              set corresponding mask for this exception.
 */
                                if (host_priv->exc_actions[i].port == ports[j] &&
                                    host_priv->exc_actions[i].behavior == behaviors[j]
                                    && host_priv->exc_actions[i].flavor == flavors[j]) {
                                        masks[j] |= (1 << i);
                                        break;
                                }
                        }/* for */
                        if (j == count) {
                                masks[j] = (1 << i);
                                ports[j] =
                                    ipc_port_copy_send(host_priv->exc_actions[i].port);
                                behaviors[j] = host_priv->exc_actions[i].behavior;
                                flavors[j] = host_priv->exc_actions[i].flavor;
                                count++;
                        }
                        old_port[i] = host_priv->exc_actions[i].port;
                        host_priv->exc_actions[i].port =
                            ipc_port_copy_send(new_port);
                        host_priv->exc_actions[i].behavior = new_behavior;
                        host_priv->exc_actions[i].flavor = new_flavor;
                } else {
                        old_port[i] = IP_NULL;
                }
        }/* for */
        host_unlock(host_priv);

#if CONFIG_MACF
        mac_exc_free_label(new_label);
#endif

        /*
         * Consume send rights without any lock held.
         */
        while (--i >= FIRST_EXCEPTION) {
                if (IP_VALID(old_port[i])) {
                        ipc_port_release_send(old_port[i]);
                }
#if CONFIG_MACF
                if (deferred_labels[i] != NULL) {
                        mac_exc_free_label(deferred_labels[i]); // Label unused.
                }
#endif
        }

        if (IP_VALID(new_port)) {        /* consume send right */
                ipc_port_release_send(new_port);
        }
        *CountCnt = count;

        return KERN_SUCCESS;
}