]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/ipc/ipc_mqueue.c
xnu-1504.15.3.tar.gz
[apple/xnu.git] / osfmk / ipc / ipc_mqueue.c
index 0c7502e6afa0efbb3ce6a46884c99daa9d4fe0b3..9d17b81b9455e3cc09c97f3a4de030b3ebe1d412 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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 OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * 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_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_FREE_COPYRIGHT@
  *
  *     Functions to manipulate IPC message queues.
  */
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
+ * support for mandatory and extensible security protections.  This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
+    
 
 #include <mach/port.h>
 #include <mach/message.h>
@@ -65,6 +78,7 @@
 #include <kern/counters.h>
 #include <kern/sched_prim.h>
 #include <kern/ipc_kobject.h>
+#include <kern/ipc_mig.h>      /* XXX - for mach_msg_receive_continue */
 #include <kern/misc_protos.h>
 #include <kern/task.h>
 #include <kern/thread.h>
 #include <ipc/ipc_pset.h>
 #include <ipc/ipc_space.h>
 
-#include <ddb/tr.h>
+#ifdef __LP64__
+#include <vm/vm_map.h>
+#endif
+
+#if CONFIG_MACF_MACH
+#include <security/mac_mach_internal.h>
+#endif
 
 int ipc_mqueue_full;           /* address is event for queue space */
 int ipc_mqueue_rcv;            /* address is event for message arrival */
 
-#define TR_ENABLE 0
+/* forward declarations */
+void ipc_mqueue_receive_results(wait_result_t result);
 
 /*
  *     Routine:        ipc_mqueue_init
@@ -94,7 +115,7 @@ ipc_mqueue_init(
        boolean_t       is_set)
 {
        if (is_set) {
-               wait_queue_sub_init(&mqueue->imq_set_queue, SYNC_POLICY_FIFO);
+               wait_queue_set_init(&mqueue->imq_set_queue, SYNC_POLICY_FIFO|SYNC_POLICY_PREPOST);
        } else {
                wait_queue_init(&mqueue->imq_wait_queue, SYNC_POLICY_FIFO);
                ipc_kmsg_queue_init(&mqueue->imq_messages);
@@ -119,11 +140,11 @@ ipc_mqueue_init(
 
 boolean_t
 ipc_mqueue_member(
-       ipc_mqueue_t    port_mqueue,
-       ipc_mqueue_t    set_mqueue)
+       ipc_mqueue_t            port_mqueue,
+       ipc_mqueue_t            set_mqueue)
 {
        wait_queue_t    port_waitq = &port_mqueue->imq_wait_queue;
-       wait_queue_t    set_waitq = &set_mqueue->imq_wait_queue;
+       wait_queue_set_t set_waitq = &set_mqueue->imq_set_queue;
 
        return (wait_queue_member(port_waitq, set_waitq));
 
@@ -133,39 +154,51 @@ ipc_mqueue_member(
  *     Routine:        ipc_mqueue_remove
  *     Purpose:
  *             Remove the association between the queue and the specified
- *             subordinate message queue.
+ *             set message queue.
  */
 
 kern_return_t
 ipc_mqueue_remove(
        ipc_mqueue_t     mqueue,
-       ipc_mqueue_t     sub_mqueue)
+       ipc_mqueue_t     set_mqueue)
 {
        wait_queue_t     mq_waitq = &mqueue->imq_wait_queue;
-       wait_queue_sub_t sub_waitq = &sub_mqueue->imq_set_queue;
+       wait_queue_set_t set_waitq = &set_mqueue->imq_set_queue;
 
-       if (wait_queue_member(mq_waitq, sub_waitq)) {
-           wait_queue_unlink(mq_waitq, sub_waitq);
-           return KERN_SUCCESS;
-       }
-       return KERN_NOT_IN_SET;    
+       return wait_queue_unlink(mq_waitq, set_waitq);
 }
 
 /*
- *     Routine:        ipc_mqueue_remove_one
+ *     Routine:        ipc_mqueue_remove_from_all
  *     Purpose:
- *             Find and remove one subqueue from the queue.
+ *             Remove the mqueue from all the sets it is a member of
  *     Conditions:
- *             Will return the set mqueue that was removed
+ *             Nothing locked.
  */
 void
-ipc_mqueue_remove_one(
-       ipc_mqueue_t    mqueue,
-       ipc_mqueue_t    *sub_queuep)
+ipc_mqueue_remove_from_all(
+       ipc_mqueue_t    mqueue)
 {
        wait_queue_t    mq_waitq = &mqueue->imq_wait_queue;
 
-       wait_queue_unlink_one(mq_waitq, (wait_queue_sub_t *)sub_queuep);
+       wait_queue_unlink_all(mq_waitq);
+       return;
+}
+
+/*
+ *     Routine:        ipc_mqueue_remove_all
+ *     Purpose:
+ *             Remove all the member queues from the specified set.
+ *     Conditions:
+ *             Nothing locked.
+ */
+void
+ipc_mqueue_remove_all(
+       ipc_mqueue_t    mqueue)
+{
+       wait_queue_set_t        mq_setq = &mqueue->imq_set_queue;
+
+       wait_queue_set_unlink_all(mq_setq);
        return;
 }
 
@@ -187,7 +220,7 @@ ipc_mqueue_add(
        ipc_mqueue_t     set_mqueue)
 {
        wait_queue_t     port_waitq = &port_mqueue->imq_wait_queue;
-       wait_queue_sub_t set_waitq = &set_mqueue->imq_set_queue;
+       wait_queue_set_t set_waitq = &set_mqueue->imq_set_queue;
        ipc_kmsg_queue_t kmsgq;
        ipc_kmsg_t       kmsg, next;
        kern_return_t    kr;
@@ -212,16 +245,29 @@ ipc_mqueue_add(
 
                for (;;) {
                        thread_t th;
+                       mach_msg_size_t msize;
 
-                       th = wait_queue_wakeup_identity_locked(port_waitq,
-                                                                                                  IPC_MQUEUE_RECEIVE,
-                                                                                                  THREAD_AWAKENED,
-                                                                                                  FALSE);
+                       th = wait_queue_wakeup64_identity_locked(
+                                               port_waitq,
+                                               IPC_MQUEUE_RECEIVE,
+                                               THREAD_AWAKENED,
+                                               FALSE);
                        /* waitq/mqueue still locked, thread locked */
 
                        if (th == THREAD_NULL)
                                goto leave;
 
+                       /*
+                        * If the receiver waited with a facility not directly
+                        * related to Mach messaging, then it isn't prepared to get
+                        * handed the message directly.  Just set it running, and
+                        * go look for another thread that can.
+                        */
+                       if (th->ith_state != MACH_RCV_IN_PROGRESS) {
+                                 thread_unlock(th);
+                                 continue;
+                       }
+
                        /*
                         * Found a receiver. see if they can handle the message
                         * correctly (the message is not too large for them, or
@@ -230,15 +276,16 @@ ipc_mqueue_add(
                         * the list and let them go back and figure it out and
                         * just move onto the next.
                         */
+                       msize = ipc_kmsg_copyout_size(kmsg, th->map);
                        if (th->ith_msize <
-                           kmsg->ikm_header.msgh_size +
-                           REQUESTED_TRAILER_SIZE(th->ith_option)) {
+                                       (msize + REQUESTED_TRAILER_SIZE(th->ith_option))) {
                                th->ith_state = MACH_RCV_TOO_LARGE;
-                               th->ith_msize = kmsg->ikm_header.msgh_size;
+                               th->ith_msize = msize;
                                if (th->ith_option & MACH_RCV_LARGE) {
                                        /*
                                         * let him go without message
                                         */
+                                       th->ith_receiver_name = port_mqueue->imq_receiver_name;
                                        th->ith_kmsg = IKM_NULL;
                                        th->ith_seqno = 0;
                                        thread_unlock(th);
@@ -252,8 +299,9 @@ ipc_mqueue_add(
                         * This thread is going to take this message,
                         * so give it to him.
                         */
-                       ipc_mqueue_release_msgcount(port_mqueue);
                        ipc_kmsg_rmqueue(kmsgq, kmsg);
+                       ipc_mqueue_release_msgcount(port_mqueue);
+
                        th->ith_kmsg = kmsg;
                        th->ith_seqno = port_mqueue->imq_seqno++;
                        thread_unlock(th);
@@ -279,10 +327,11 @@ void
 ipc_mqueue_changed(
        ipc_mqueue_t            mqueue)
 {
-       wait_queue_wakeup_all_locked(&mqueue->imq_wait_queue,
-                                                                IPC_MQUEUE_RECEIVE,
-                                                                THREAD_RESTART,
-                                                                FALSE);                /* unlock waitq? */
+       wait_queue_wakeup64_all_locked(
+                               &mqueue->imq_wait_queue,
+                               IPC_MQUEUE_RECEIVE,
+                               THREAD_RESTART,
+                               FALSE);         /* unlock waitq? */
 }
 
 
@@ -308,12 +357,12 @@ ipc_mqueue_changed(
 mach_msg_return_t
 ipc_mqueue_send(
        ipc_mqueue_t            mqueue,
-       ipc_kmsg_t                      kmsg,
+       ipc_kmsg_t              kmsg,
        mach_msg_option_t       option,
-       mach_msg_timeout_t      timeout)
+       mach_msg_timeout_t      send_timeout,
+       spl_t                   s)
 {
-       int save_wait_result;
-       spl_t s;
+       int wresult;
 
        /*
         *  Don't block if:
@@ -321,57 +370,68 @@ ipc_mqueue_send(
         *      2) Caller used the MACH_SEND_ALWAYS internal option.
         *      3) Message is sent to a send-once right.
         */
-       s = splsched();
-       imq_lock(mqueue);
-
        if (!imq_full(mqueue) ||
-               (option & MACH_SEND_ALWAYS) ||
-               (MACH_MSGH_BITS_REMOTE(kmsg->ikm_header.msgh_bits) ==
-                MACH_MSG_TYPE_PORT_SEND_ONCE)) {
+           (!imq_full_kernel(mqueue) && 
+            ((option & MACH_SEND_ALWAYS) ||
+             (MACH_MSGH_BITS_REMOTE(kmsg->ikm_header->msgh_bits) ==
+              MACH_MSG_TYPE_PORT_SEND_ONCE)))) {
                mqueue->imq_msgcount++;
+               assert(mqueue->imq_msgcount > 0);
                imq_unlock(mqueue);
                splx(s);
        } else {
+               thread_t cur_thread = current_thread();
+               uint64_t deadline;
 
                /* 
                 * We have to wait for space to be granted to us.
                 */
-               if ((option & MACH_SEND_TIMEOUT) && (timeout == 0)) {
+               if ((option & MACH_SEND_TIMEOUT) && (send_timeout == 0)) {
                        imq_unlock(mqueue);
                        splx(s);
                        return MACH_SEND_TIMED_OUT;
                }
+               if (imq_full_kernel(mqueue)) {
+                       imq_unlock(mqueue);
+                       splx(s);
+                       return MACH_SEND_NO_BUFFER;
+               }
                mqueue->imq_fullwaiters = TRUE;
-               wait_queue_assert_wait_locked(&mqueue->imq_wait_queue,
-                                                                         IPC_MQUEUE_FULL,
-                                                                         THREAD_ABORTSAFE,
-                                                                         TRUE); /* unlock? */
-               /* wait/mqueue is unlocked */
+               thread_lock(cur_thread);
+               if (option & MACH_SEND_TIMEOUT)
+                       clock_interval_to_deadline(send_timeout, 1000*NSEC_PER_USEC, &deadline);
+               else
+                       deadline = 0;
+               wresult = wait_queue_assert_wait64_locked(
+                                               &mqueue->imq_wait_queue,
+                                               IPC_MQUEUE_FULL,
+                                               THREAD_ABORTSAFE, deadline,
+                                               cur_thread);
+               thread_unlock(cur_thread);
+               imq_unlock(mqueue);
                splx(s);
                
-               if (option & MACH_SEND_TIMEOUT)
-                       thread_set_timer(timeout, 1000*NSEC_PER_USEC);
-
-               counter(c_ipc_mqueue_send_block++);
-               save_wait_result = thread_block((void (*)(void)) 0);
+               if (wresult == THREAD_WAITING) {
+                       wresult = thread_block(THREAD_CONTINUE_NULL);
+                       counter(c_ipc_mqueue_send_block++);
+               }
                
-               switch (save_wait_result) {
+               switch (wresult) {
                case THREAD_TIMED_OUT:
                        assert(option & MACH_SEND_TIMEOUT);
                        return MACH_SEND_TIMED_OUT;
                        
                case THREAD_AWAKENED:
                        /* we can proceed - inherited msgcount from waker */
-                       if (option & MACH_SEND_TIMEOUT)
-                               thread_cancel_timer();
+                       assert(mqueue->imq_msgcount > 0);
                        break;
                        
                case THREAD_INTERRUPTED:
-                       if (option & MACH_SEND_TIMEOUT)
-                               thread_cancel_timer();
                        return MACH_SEND_INTERRUPTED;
                        
                case THREAD_RESTART:
+                       /* mqueue is being destroyed */
+                       return MACH_SEND_INVALID_DEST;
                default:
                        panic("ipc_mqueue_send");
                }
@@ -388,24 +448,28 @@ ipc_mqueue_send(
  *             found a waiter.
  *
  *     Conditions:
- *             The message queue is locked
+ *             The message queue is locked.
+ *             The message corresponding to this reference is off the queue.
  */
 void
 ipc_mqueue_release_msgcount(
        ipc_mqueue_t mqueue)    
 {
        assert(imq_held(mqueue));
-       assert(mqueue->imq_msgcount > 0);
+       assert(mqueue->imq_msgcount > 1 || ipc_kmsg_queue_empty(&mqueue->imq_messages));
 
        mqueue->imq_msgcount--;
+
        if (!imq_full(mqueue) && mqueue->imq_fullwaiters) {
-               if (wait_queue_wakeup_one_locked(&mqueue->imq_wait_queue,
-                                                                                IPC_MQUEUE_FULL,
-                                                                                THREAD_AWAKENED,
-                                                                                FALSE) != KERN_SUCCESS) {
+               if (wait_queue_wakeup64_one_locked(
+                                               &mqueue->imq_wait_queue,
+                                               IPC_MQUEUE_FULL,
+                                               THREAD_AWAKENED,
+                                               FALSE) != KERN_SUCCESS) {
                        mqueue->imq_fullwaiters = FALSE;
                } else {
-                       mqueue->imq_msgcount++;  /* gave it away */
+                       /* gave away our slot - add reference back */
+                       mqueue->imq_msgcount++; 
                }
        }
 }
@@ -425,7 +489,6 @@ ipc_mqueue_post(
        register ipc_mqueue_t   mqueue,
        register ipc_kmsg_t             kmsg)
 {
-
        spl_t s;
 
        /*
@@ -439,11 +502,13 @@ ipc_mqueue_post(
        for (;;) {
                wait_queue_t waitq = &mqueue->imq_wait_queue;
                thread_t receiver;
+               mach_msg_size_t msize;
 
-               receiver = wait_queue_wakeup_identity_locked(waitq,
-                                                                                                        IPC_MQUEUE_RECEIVE,
-                                                                                                        THREAD_AWAKENED,
-                                                                                                        FALSE);
+               receiver = wait_queue_wakeup64_identity_locked(
+                                                       waitq,
+                                                       IPC_MQUEUE_RECEIVE,
+                                                       THREAD_AWAKENED,
+                                                       FALSE);
                /* waitq still locked, thread locked */
 
                if (receiver == THREAD_NULL) {
@@ -454,16 +519,28 @@ ipc_mqueue_post(
                        ipc_kmsg_enqueue_macro(&mqueue->imq_messages, kmsg);
                        break;
                }
-               
+       
+               /*
+                * If the receiver waited with a facility not directly
+                * related to Mach messaging, then it isn't prepared to get
+                * handed the message directly.  Just set it running, and
+                * go look for another thread that can.
+                */
+               if (receiver->ith_state != MACH_RCV_IN_PROGRESS) {
+                                 thread_unlock(receiver);
+                                 continue;
+               }
+
+       
                /*
                 * We found a waiting thread.
                 * If the message is too large or the scatter list is too small
                 * the thread we wake up will get that as its status.
                 */
+               msize = ipc_kmsg_copyout_size(kmsg, receiver->map);
                if (receiver->ith_msize <
-                   (kmsg->ikm_header.msgh_size) +
-                   REQUESTED_TRAILER_SIZE(receiver->ith_option)) {
-                       receiver->ith_msize = kmsg->ikm_header.msgh_size;
+                               (msize + REQUESTED_TRAILER_SIZE(receiver->ith_option))) {
+                       receiver->ith_msize = msize;
                        receiver->ith_state = MACH_RCV_TOO_LARGE;
                } else {
                        receiver->ith_state = MACH_MSG_SUCCESS;
@@ -504,13 +581,11 @@ ipc_mqueue_post(
 }
 
 
-kern_return_t
-ipc_mqueue_receive_results(void)
+/* static */ void
+ipc_mqueue_receive_results(wait_result_t saved_wait_result)
 {
        thread_t                self = current_thread();
        mach_msg_option_t       option = self->ith_option;
-       kern_return_t           saved_wait_result = self->wait_result;
-       kern_return_t           mr;
 
        /*
         * why did we wake up?
@@ -521,15 +596,11 @@ ipc_mqueue_receive_results(void)
                return;
 
        case THREAD_INTERRUPTED:
-               if (option & MACH_RCV_TIMEOUT)
-                       thread_cancel_timer();
                self->ith_state = MACH_RCV_INTERRUPTED;
                return;
 
        case THREAD_RESTART:
                /* something bad happened to the port/set */
-               if (option & MACH_RCV_TIMEOUT)
-                       thread_cancel_timer();
                self->ith_state = MACH_RCV_PORT_CHANGED;
                return;
 
@@ -538,11 +609,6 @@ ipc_mqueue_receive_results(void)
                 * We do not need to go select a message, somebody
                 * handed us one (or a too-large indication).
                 */
-               if (option & MACH_RCV_TIMEOUT)
-                       thread_cancel_timer();
-               
-               mr = MACH_MSG_SUCCESS;
-
                switch (self->ith_state) {
                case MACH_RCV_SCATTER_SMALL:
                case MACH_RCV_TOO_LARGE:
@@ -570,9 +636,11 @@ ipc_mqueue_receive_results(void)
 }
 
 void
-ipc_mqueue_receive_continue(void)
+ipc_mqueue_receive_continue(
+       __unused void *param,
+       wait_result_t wresult)
 {
-       ipc_mqueue_receive_results();
+       ipc_mqueue_receive_results(wresult);
        mach_msg_receive_continue();  /* hard-coded for now */
 }
 
@@ -606,79 +674,139 @@ ipc_mqueue_receive_continue(void)
 
 void
 ipc_mqueue_receive(
-       ipc_mqueue_t            mqueue,
-       mach_msg_option_t       option,
-       mach_msg_size_t         max_size,
-       mach_msg_timeout_t      timeout,
-       int                     interruptible)
+       ipc_mqueue_t            mqueue,
+       mach_msg_option_t       option,
+       mach_msg_size_t         max_size,
+       mach_msg_timeout_t      rcv_timeout,
+       int                     interruptible)
 {
-       ipc_port_t port;
-       mach_msg_return_t mr, mr2;
-       ipc_kmsg_queue_t kmsgs;
-       kern_return_t   save_wait_result;
-       thread_t self;
-       ipc_kmsg_t              *kmsgp;
-       mach_port_seqno_t       *seqnop;
-       spl_t s;
+       wait_result_t           wresult;
+        thread_t                self = current_thread();
+        
+        wresult = ipc_mqueue_receive_on_thread(mqueue, option, max_size,
+                                               rcv_timeout, interruptible,
+                                               self);
+        if (wresult == THREAD_NOT_WAITING)
+                return;
+
+       if (wresult == THREAD_WAITING) {
+               counter((interruptible == THREAD_ABORTSAFE) ? 
+                       c_ipc_mqueue_receive_block_user++ :
+                       c_ipc_mqueue_receive_block_kernel++);
+
+               if (self->ith_continuation)
+                       thread_block(ipc_mqueue_receive_continue);
+                       /* NOTREACHED */
+
+               wresult = thread_block(THREAD_CONTINUE_NULL);
+       }
+       ipc_mqueue_receive_results(wresult);
+}
+
+wait_result_t
+ipc_mqueue_receive_on_thread(
+        ipc_mqueue_t            mqueue,
+       mach_msg_option_t       option,
+       mach_msg_size_t         max_size,
+       mach_msg_timeout_t      rcv_timeout,
+       int                     interruptible,
+       thread_t                thread)
+{
+       ipc_kmsg_queue_t        kmsgs;
+       wait_result_t           wresult;
+       uint64_t                deadline;
+       spl_t                   s;
+#if CONFIG_MACF_MACH
+       ipc_labelh_t lh;
+       task_t task;
+       int rc;
+#endif
 
        s = splsched();
        imq_lock(mqueue);
        
        if (imq_is_set(mqueue)) {
-               wait_queue_link_t wql;
-               ipc_mqueue_t port_mq;
                queue_t q;
 
-               q = &mqueue->imq_setlinks;
+               q = &mqueue->imq_preposts;
 
                /*
                 * If we are waiting on a portset mqueue, we need to see if
-                * any of the member ports have work for us.  If so, try to
-                * deliver one of those messages. By holding the portset's
+                * any of the member ports have work for us.  Ports that
+                * have (or recently had) messages will be linked in the
+                * prepost queue for the portset. By holding the portset's
                 * mqueue lock during the search, we tie up any attempts by
                 * mqueue_deliver or portset membership changes that may
-                * cross our path. But this is a lock order violation, so we
-                * have to do it "softly."  If we don't find a message waiting
-                * for us, we will assert our intention to wait while still
-                * holding that lock.  When we release the lock, the deliver/
-                * change will succeed and find us.
+                * cross our path.
                 */
        search_set:
-               queue_iterate(q, wql, wait_queue_link_t, wql_sublinks) {
+               while(!queue_empty(q)) {
+                       wait_queue_link_t wql;
+                       ipc_mqueue_t port_mq;
+
+                       queue_remove_first(q, wql, wait_queue_link_t, wql_preposts);
+                       assert(!wql_is_preposted(wql));
+
+                       /*
+                        * This is a lock order violation, so we have to do it
+                        * "softly," putting the link back on the prepost list
+                        * if it fails (at the tail is fine since the order of
+                        * handling messages from different sources in a set is
+                        * not guaranteed and we'd like to skip to the next source
+                        * if one is available).
+                        */
                        port_mq = (ipc_mqueue_t)wql->wql_queue;
-                       kmsgs = &port_mq->imq_messages;
-                       
                        if (!imq_lock_try(port_mq)) {
+                               queue_enter(q, wql, wait_queue_link_t, wql_preposts);
                                imq_unlock(mqueue);
                                splx(s);
-                               delay(1);
+                               mutex_pause(0);
                                s = splsched();
                                imq_lock(mqueue);
                                goto search_set; /* start again at beginning - SMP */
                        }
 
                        /*
-                        * If there is still a message to be had, we will
-                        * try to select it (may not succeed because of size
-                        * and options).  In any case, we deliver those
-                        * results back to the user.
-                        *
-                        * We also move the port's linkage to the tail of the
-                        * list for this set (fairness). Future versions will
-                        * sort by timestamp or priority.
+                        * If there are no messages on this queue, just skip it
+                        * (we already removed the link from the set's prepost queue).
                         */
+                       kmsgs = &port_mq->imq_messages;
                        if (ipc_kmsg_queue_first(kmsgs) == IKM_NULL) {
                                imq_unlock(port_mq);
                                continue;
                        }
-                       queue_remove(q, wql, wait_queue_link_t, wql_sublinks);
-                       queue_enter(q, wql, wait_queue_link_t, wql_sublinks);
+
+                       /*
+                        * There are messages, so reinsert the link back
+                        * at the tail of the preposted queue (for fairness)
+                        * while we still have the portset mqueue locked.
+                        */
+                       queue_enter(q, wql, wait_queue_link_t, wql_preposts);
                        imq_unlock(mqueue);
 
-                       ipc_mqueue_select(port_mq, option, max_size);
+                       /*
+                        * Continue on to handling the message with just
+                        * the port mqueue locked.
+                        */
+                       ipc_mqueue_select_on_thread(port_mq, option, max_size, thread);
                        imq_unlock(port_mq);
+#if CONFIG_MACF_MACH
+                       if (thread->task != TASK_NULL &&
+                           thread->ith_kmsg != NULL &&
+                           thread->ith_kmsg->ikm_sender != NULL) {
+                               lh = thread->ith_kmsg->ikm_sender->label;
+                               tasklabel_lock(thread->task);
+                               ip_lock(lh->lh_port);
+                               rc = mac_port_check_receive(&thread->task->maclabel,
+                                                            &lh->lh_label);
+                               ip_unlock(lh->lh_port);
+                               tasklabel_unlock(thread->task);
+                               if (rc)
+                                       thread->ith_state = MACH_RCV_INVALID_DATA;
+                       }
+#endif
                        splx(s);
-                       return;
+                       return THREAD_NOT_WAITING;
                        
                }
 
@@ -689,127 +817,178 @@ ipc_mqueue_receive(
                 */
                kmsgs = &mqueue->imq_messages;
                if (ipc_kmsg_queue_first(kmsgs) != IKM_NULL) {
-                       ipc_mqueue_select(mqueue, option, max_size);
+                       ipc_mqueue_select_on_thread(mqueue, option, max_size, thread);
                        imq_unlock(mqueue);
+#if CONFIG_MACF_MACH
+                       if (thread->task != TASK_NULL &&
+                           thread->ith_kmsg != NULL &&
+                           thread->ith_kmsg->ikm_sender != NULL) {
+                               lh = thread->ith_kmsg->ikm_sender->label;
+                               tasklabel_lock(thread->task);
+                               ip_lock(lh->lh_port);
+                               rc = mac_port_check_receive(&thread->task->maclabel,
+                                                            &lh->lh_label);
+                               ip_unlock(lh->lh_port);
+                               tasklabel_unlock(thread->task);
+                               if (rc)
+                                       thread->ith_state = MACH_RCV_INVALID_DATA;
+                       }
+#endif
                        splx(s);
-                       return;
+                       return THREAD_NOT_WAITING;
                }
        }
-               
+       
        /*
         * Looks like we'll have to block.  The mqueue we will
         * block on (whether the set's or the local port's) is
         * still locked.
         */
-       self = current_thread();
        if (option & MACH_RCV_TIMEOUT) {
-               if (timeout == 0) {
+               if (rcv_timeout == 0) {
                        imq_unlock(mqueue);
                        splx(s);
-                       self->ith_state = MACH_RCV_TIMED_OUT;
-                       return;
+                       thread->ith_state = MACH_RCV_TIMED_OUT;
+                       return THREAD_NOT_WAITING;
                }
        }
 
-       self->ith_state = MACH_RCV_IN_PROGRESS;
-       self->ith_option = option;
-       self->ith_msize = max_size;
-               
-       wait_queue_assert_wait_locked(&mqueue->imq_wait_queue,
-                                                                 IPC_MQUEUE_RECEIVE,
-                                                                 interruptible,
-                                                                 TRUE); /* unlock? */
-       /* mqueue/waitq is unlocked */
+       thread_lock(thread);
+       thread->ith_state = MACH_RCV_IN_PROGRESS;
+       thread->ith_option = option;
+       thread->ith_msize = max_size;
+
+       if (option & MACH_RCV_TIMEOUT)
+               clock_interval_to_deadline(rcv_timeout, 1000*NSEC_PER_USEC, &deadline);
+       else
+               deadline = 0;
+
+       wresult = wait_queue_assert_wait64_locked(&mqueue->imq_wait_queue,
+                                                 IPC_MQUEUE_RECEIVE,
+                                                 interruptible, deadline,
+                                                 thread);
+       /* preposts should be detected above, not here */
+       if (wresult == THREAD_AWAKENED)
+               panic("ipc_mqueue_receive_on_thread: sleep walking");
+
+       thread_unlock(thread);
+       imq_unlock(mqueue);
        splx(s);
-
-       if (option & MACH_RCV_TIMEOUT) {
-               thread_set_timer(timeout, 1000*NSEC_PER_USEC);
-       }
-
-       if (interruptible == THREAD_ABORTSAFE) {
-               counter(c_ipc_mqueue_receive_block_user++);
-       } else {
-               counter(c_ipc_mqueue_receive_block_kernel++);
-       }
-
-#if defined (__i386__)
-       thread_block((void (*)(void))0);
-#else
-       if (self->ith_continuation) {
-               thread_block(ipc_mqueue_receive_continue);
-       } else {
-               thread_block((void (*)(void))0);
-       }
-#endif
-
-       ipc_mqueue_receive_results();  /* if we fell thru */
+       return wresult;
 }
 
 
 /*
- *     Routine:        ipc_mqueue_select
+ *     Routine:        ipc_mqueue_select_on_thread
  *     Purpose:
  *             A receiver discovered that there was a message on the queue
  *             before he had to block.  Pick the message off the queue and
- *             "post" it to himself.
+ *             "post" it to thread.
  *     Conditions:
  *             mqueue locked.
+ *              thread not locked.
  *             There is a message.
  *     Returns:
  *             MACH_MSG_SUCCESS        Actually selected a message for ourselves.
  *             MACH_RCV_TOO_LARGE  May or may not have pull it, but it is large
  */
 void
-ipc_mqueue_select(
+ipc_mqueue_select_on_thread(
        ipc_mqueue_t            mqueue,
        mach_msg_option_t       option,
-       mach_msg_size_t         max_size)
+       mach_msg_size_t         max_size,
+       thread_t                thread)
 {
-       thread_t self = current_thread();
        ipc_kmsg_t kmsg;
-       mach_port_seqno_t seqno;
-       mach_msg_return_t mr;
-
-       mr = MACH_MSG_SUCCESS;
-
+       mach_msg_return_t mr = MACH_MSG_SUCCESS;
+       mach_msg_size_t rcv_size;
 
        /*
         * Do some sanity checking of our ability to receive
         * before pulling the message off the queue.
         */
        kmsg = ipc_kmsg_queue_first(&mqueue->imq_messages);
-
        assert(kmsg != IKM_NULL);
 
-       if (kmsg->ikm_header.msgh_size + 
-               REQUESTED_TRAILER_SIZE(option) > max_size) {
-               mr = MACH_RCV_TOO_LARGE;
-       } 
-
        /*
         * If we really can't receive it, but we had the
         * MACH_RCV_LARGE option set, then don't take it off
         * the queue, instead return the appropriate error
         * (and size needed).
         */
-       if ((mr == MACH_RCV_TOO_LARGE) && (option & MACH_RCV_LARGE)) {
-               self->ith_kmsg = IKM_NULL;
-               self->ith_msize = kmsg->ikm_header.msgh_size;
-               self->ith_seqno = 0;
-               self->ith_state = mr;
-               return;
+       rcv_size = ipc_kmsg_copyout_size(kmsg, thread->map);
+       if (rcv_size + REQUESTED_TRAILER_SIZE(option) > max_size) {
+               mr = MACH_RCV_TOO_LARGE;
+               if (option & MACH_RCV_LARGE) {
+                       thread->ith_receiver_name = mqueue->imq_receiver_name;
+                       thread->ith_kmsg = IKM_NULL;
+                       thread->ith_msize = rcv_size;
+                       thread->ith_seqno = 0;
+                       thread->ith_state = mr;
+                       return;
+               }
        }
 
        ipc_kmsg_rmqueue_first_macro(&mqueue->imq_messages, kmsg);
        ipc_mqueue_release_msgcount(mqueue);
-       self->ith_seqno = mqueue->imq_seqno++;
-       self->ith_kmsg = kmsg;
-       self->ith_state = mr;
+       thread->ith_seqno = mqueue->imq_seqno++;
+       thread->ith_kmsg = kmsg;
+       thread->ith_state = mr;
 
        current_task()->messages_received++;
        return;
 }
 
+/*
+ *     Routine:        ipc_mqueue_peek
+ *     Purpose:
+ *             Peek at a message queue to see if it has any messages
+ *             (in it or contained message queues for a set).
+ *
+ *     Conditions:
+ *             Locks may be held by callers, so this routine cannot block.
+ *             Caller holds reference on the message queue.
+ */
+int
+ipc_mqueue_peek(ipc_mqueue_t mq)
+{
+       wait_queue_link_t       wql;
+       queue_t                 q;
+       spl_t s;
+
+       if (!imq_is_set(mq))
+               return (ipc_kmsg_queue_first(&mq->imq_messages) != IKM_NULL);
+
+       /*
+        * Don't block trying to get the lock.
+        */
+       s = splsched();
+       if (!imq_lock_try(mq)) {
+               splx(s);
+               return -1;
+       }
+
+       /* 
+        * peek at the contained port message queues, return as soon as
+        * we spot a message on one of the message queues linked on the
+        * prepost list.
+        */
+       q = &mq->imq_preposts;
+       queue_iterate(q, wql, wait_queue_link_t, wql_preposts) {
+               ipc_mqueue_t port_mq = (ipc_mqueue_t)wql->wql_queue;
+               ipc_kmsg_queue_t kmsgs = &port_mq->imq_messages;
+                       
+               if (ipc_kmsg_queue_first(kmsgs) != IKM_NULL) {
+                       imq_unlock(mq);
+                       splx(s);
+                       return 1;
+               }
+       }
+       imq_unlock(mq);
+       splx(s);
+       return 0;
+}
+
 /*
  *     Routine:        ipc_mqueue_destroy
  *     Purpose:
@@ -834,10 +1013,11 @@ ipc_mqueue_destroy(
         *      rouse all blocked senders
         */
        mqueue->imq_fullwaiters = FALSE;
-       wait_queue_wakeup_all_locked(&mqueue->imq_wait_queue,
-                                                                IPC_MQUEUE_FULL,
-                                                                THREAD_AWAKENED,
-                                                                FALSE);
+       wait_queue_wakeup64_all_locked(
+                               &mqueue->imq_wait_queue,
+                               IPC_MQUEUE_FULL,
+                               THREAD_RESTART,
+                               FALSE);
 
        kmqueue = &mqueue->imq_messages;
 
@@ -870,6 +1050,8 @@ ipc_mqueue_set_qlimit(
 {
         spl_t s;
 
+        assert(qlimit <= MACH_PORT_QLIMIT_MAX);
+
         /* wake up senders allowed by the new qlimit */
         s = splsched();
         imq_lock(mqueue);
@@ -880,13 +1062,15 @@ ipc_mqueue_set_qlimit(
                 wakeup = qlimit - mqueue->imq_qlimit;
 
                 for (i = 0; i < wakeup; i++) {
-                        if (wait_queue_wakeup_one_locked(&mqueue->imq_wait_queue,
-                                                                                         IPC_MQUEUE_FULL,
-                                                                                         THREAD_AWAKENED,
-                                                                                         FALSE) == KERN_NOT_WAITING) {
+                        if (wait_queue_wakeup64_one_locked(
+                                                       &mqueue->imq_wait_queue,
+                                                       IPC_MQUEUE_FULL,
+                                                       THREAD_AWAKENED,
+                                                       FALSE) == KERN_NOT_WAITING) {
                                         mqueue->imq_fullwaiters = FALSE;
                                         break;
                         }
+                        mqueue->imq_msgcount++;  /* give it to the awakened thread */
                 }
         }
        mqueue->imq_qlimit = qlimit;
@@ -960,7 +1144,6 @@ ipc_mqueue_copyin(
 
        if (entry->ie_bits & MACH_PORT_TYPE_RECEIVE) {
                ipc_port_t port;
-               ipc_pset_t pset;
 
                port = (ipc_port_t) object;
                assert(port != IP_NULL);