diff -ur -x 'Makefile*' -x debian -x configure -x config.sub -x config.guess gnumach-1.8+git20171101/include/mach/task_special_ports.h mnt/root/gnumach-1.8+git20171101/include/mach/task_special_ports.h
--- gnumach-1.8+git20171101/include/mach/task_special_ports.h	2014-03-17 14:29:32.000000000 -0400
+++ mnt/root/gnumach-1.8+git20171101/include/mach/task_special_ports.h	2018-03-06 22:31:19.000000000 -0500
@@ -40,6 +40,8 @@
 #define TASK_EXCEPTION_PORT	3	/* Exception messages for task are
 					   sent to this port. */
 #define TASK_BOOTSTRAP_PORT	4	/* Bootstrap environment for task. */
+#define TASK_TRACE_PORT		5	/* Trace port that receives a copy
+                                           of all messages sent to/from task. */
 
 /*
  *	Definitions for ease of use
@@ -63,4 +65,10 @@
 #define task_set_bootstrap_port(task, port)	\
 		(task_set_special_port((task), TASK_BOOTSTRAP_PORT, (port)))
 
+#define task_get_trace_port(task, port)	\
+		(task_get_special_port((task), TASK_TRACE_PORT, (port)))
+
+#define task_set_trace_port(task, port)	\
+		(task_set_special_port((task), TASK_TRACE_PORT, (port)))
+
 #endif	/* _MACH_TASK_SPECIAL_PORTS_H_ */
diff -ur -x 'Makefile*' -x debian -x configure -x config.sub -x config.guess gnumach-1.8+git20171101/ipc/ipc_kmsg.c mnt/root/gnumach-1.8+git20171101/ipc/ipc_kmsg.c
--- gnumach-1.8+git20171101/ipc/ipc_kmsg.c	2016-12-19 09:53:33.000000000 -0500
+++ mnt/root/gnumach-1.8+git20171101/ipc/ipc_kmsg.c	2018-03-07 00:08:16.000000000 -0500
@@ -2627,6 +2627,73 @@
 	}
 }
 
+/*
+ *	Routine:	ipc_kmsg_trace
+ *	Purpose:
+ *		If the current task has a trace port set, send a duplicate
+ *		copy of the message to the trace port.
+ *	Conditions:
+ *		Nothing locked.
+ */
+
+typedef struct {
+	mach_msg_header_t     header;
+	mach_msg_type_t       retval_type;
+	mach_msg_return_t     retval;
+	mach_msg_type_long_t  trace_message_type;
+} mach_trace_message_t;
+
+static mach_trace_message_t trace_template = {
+	.header.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_PORT_SEND, 0),
+
+	.retval_type.msgt_name = MACH_MSG_TYPE_INTEGER_32,
+	.retval_type.msgt_size = 32,
+	.retval_type.msgt_number = 1,
+	.retval_type.msgt_inline = TRUE,
+	.retval_type.msgt_longform = FALSE,
+
+	.trace_message_type.msgtl_header.msgt_inline = TRUE,
+	.trace_message_type.msgtl_header.msgt_longform = TRUE,
+	.trace_message_type.msgtl_name = MACH_MSG_TYPE_BYTE,
+	.trace_message_type.msgtl_size = 8
+};
+
+void
+ipc_kmsg_trace(
+	ipc_kmsg_t 		kmsg,
+	mach_msg_size_t 	size,
+	mach_msg_return_t	retval)
+{
+	if (current_task()->itk_trace != MACH_PORT_NULL) {
+
+		/* XXX: check to make sure trace port doesn't belong to current_task, or we'll loop endlessly */
+
+		ipc_kmsg_t trace_kmsg;
+
+		trace_kmsg = ikm_alloc(size + sizeof(mach_trace_message_t));
+
+		if (trace_kmsg == IKM_NULL) {
+			printf("dropped trace message (alloc failed)\n");
+			return;
+		}
+
+		mach_trace_message_t * trace_msg = (mach_trace_message_t *) & trace_kmsg->ikm_header;
+
+		memcpy(trace_msg, & trace_template, sizeof(mach_trace_message_t));
+
+		trace_msg->header.msgh_size = size + sizeof(mach_trace_message_t);
+		trace_msg->header.msgh_remote_port = (mach_port_t) current_task()->itk_trace;
+		trace_msg->trace_message_type.msgtl_number = size;
+
+		memcpy(trace_msg + 1, & kmsg->ikm_header, size);
+
+		if (ipc_mqueue_send(trace_kmsg, 0, 0) != MACH_MSG_SUCCESS) {
+			printf("dropped trace message (send failed)\n");
+			ikm_free(trace_kmsg);
+		}
+	}
+}
+
 #if	MACH_KDB
 
 char *
diff -ur -x 'Makefile*' -x debian -x configure -x config.sub -x config.guess gnumach-1.8+git20171101/kern/ipc_tt.c mnt/root/gnumach-1.8+git20171101/kern/ipc_tt.c
--- gnumach-1.8+git20171101/kern/ipc_tt.c	2016-10-02 13:45:20.000000000 -0400
+++ mnt/root/gnumach-1.8+git20171101/kern/ipc_tt.c	2018-03-06 22:29:11.000000000 -0500
@@ -89,6 +89,7 @@
 	if (parent == TASK_NULL) {
 		task->itk_exception = IP_NULL;
 		task->itk_bootstrap = IP_NULL;
+		task->itk_trace = IP_NULL;
 		for (i = 0; i < TASK_PORT_REGISTER_MAX; i++)
 			task->itk_registered[i] = IP_NULL;
 	} else {
@@ -101,12 +102,14 @@
 			task->itk_registered[i] =
 				ipc_port_copy_send(parent->itk_registered[i]);
 
-		/* inherit exception and bootstrap ports */
+		/* inherit exception, bootstrap, and trace ports */
 
 		task->itk_exception =
 			ipc_port_copy_send(parent->itk_exception);
 		task->itk_bootstrap =
 			ipc_port_copy_send(parent->itk_bootstrap);
+		task->itk_trace =
+			ipc_port_copy_send(parent->itk_trace);
 
 		itk_unlock(parent);
 	}
@@ -190,6 +193,8 @@
 		ipc_port_release_send(task->itk_exception);
 	if (IP_VALID(task->itk_bootstrap))
 		ipc_port_release_send(task->itk_bootstrap);
+	if (IP_VALID(task->itk_trace))
+		ipc_port_release_send(task->itk_trace);
 
 	for (i = 0; i < TASK_PORT_REGISTER_MAX; i++)
 		if (IP_VALID(task->itk_registered[i]))
@@ -609,6 +614,10 @@
 		whichp = &task->itk_bootstrap;
 		break;
 
+	    case TASK_TRACE_PORT:
+		whichp = &task->itk_trace;
+		break;
+
 	    default:
 		return KERN_INVALID_ARGUMENT;
 	}
@@ -666,6 +675,10 @@
 		whichp = &task->itk_bootstrap;
 		break;
 
+	    case TASK_TRACE_PORT:
+		whichp = &task->itk_trace;
+		break;
+
 	    default:
 		return KERN_INVALID_ARGUMENT;
 	}
diff -ur -x 'Makefile*' -x debian -x configure -x config.sub -x config.guess gnumach-1.8+git20171101/kern/task.h mnt/root/gnumach-1.8+git20171101/kern/task.h
--- gnumach-1.8+git20171101/kern/task.h	2017-10-31 14:03:02.000000000 -0400
+++ mnt/root/gnumach-1.8+git20171101/kern/task.h	2018-03-06 22:27:28.000000000 -0500
@@ -94,6 +94,7 @@
 	struct ipc_port *itk_sself;	/* a send right */
 	struct ipc_port *itk_exception;	/* a send right */
 	struct ipc_port *itk_bootstrap;	/* a send right */
+	struct ipc_port *itk_trace;	/* a send right */
 	struct ipc_port *itk_registered[TASK_PORT_REGISTER_MAX];
 					/* all send rights */