diff --git a/include/mach/debug.defs b/include/mach/debug.defs
new file mode 100644
index 0000000..49959ba
--- /dev/null
+++ b/include/mach/debug.defs
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2014 Free Software Foundation.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _KERN_DEBUG_DEFS_
+#define _KERN_DEBUG_DEFS_
+
+type kernel_debug_name_t = c_string[*: 64];
+
+#endif /* _KERN_DEBUG_DEFS_ */
diff --git a/include/mach/debug.h b/include/mach/debug.h
new file mode 100644
index 0000000..149d800
--- /dev/null
+++ b/include/mach/debug.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2014 Free Software Foundation.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _KERN_DEBUG_H_
+#define _KERN_DEBUG_H_
+
+/*
+ *	A fixed-length string data type intended for names given to
+ *	kernel objects.
+ *
+ *	Note that it is not guaranteed that the in-kernel data
+ *	structure will hold KERNEL_DEBUG_NAME_MAX bytes.  The given
+ *	name will be truncated to fit into the target data structure.
+ */
+#define KERNEL_DEBUG_NAME_MAX (64)
+typedef char	kernel_debug_name_t[KERNEL_DEBUG_NAME_MAX];
+
+#endif /* _KERN_DEBUG_H_ */
diff --git a/include/mach/gnumach.defs b/include/mach/gnumach.defs
index 12c4e99..273e30b 100644
--- a/include/mach/gnumach.defs
+++ b/include/mach/gnumach.defs
@@ -27,6 +27,7 @@ subsystem
 
 #include <mach/std_types.defs>
 #include <mach/mach_types.defs>
+#include <mach/debug.defs>
 
 type vm_cache_statistics_data_t = struct[11] of integer_t;
 
@@ -63,3 +64,11 @@ simpleroutine thread_terminate_release(
 		reply_port	: mach_port_name_t;
 		address		: vm_address_t;
 		size		: vm_size_t);
+
+/*
+ *	Set the name of task TASK to NAME.  This is a debugging aid.
+ *	NAME will be used in error messages printed by the kernel.
+ */
+simpleroutine task_set_name(
+		task	: task_t;
+		name	: kernel_debug_name_t);
diff --git a/ipc/mach_port.c b/ipc/mach_port.c
index fbc5e69..891d2f2 100644
--- a/ipc/mach_port.c
+++ b/ipc/mach_port.c
@@ -571,7 +571,7 @@ mach_port_destroy(
 	kr = ipc_right_lookup_write(space, name, &entry);
 	if (kr != KERN_SUCCESS) {
 		if (name != MACH_PORT_NULL && name != MACH_PORT_DEAD && space == current_space()) {
-			printf("task %p destroying an invalid port %lu, most probably a bug.\n", current_task(), name);
+			printf("task %.*s destroying an invalid port %lu, most probably a bug.\n", TASK_NAME_SIZE, current_task()->name, name);
 			if (mach_port_deallocate_debug)
 				SoftDebugger("mach_port_deallocate");
 		}
@@ -615,7 +615,7 @@ mach_port_deallocate(
 	kr = ipc_right_lookup_write(space, name, &entry);
 	if (kr != KERN_SUCCESS) {
 		if (name != MACH_PORT_NULL && name != MACH_PORT_DEAD && space == current_space()) {
-			printf("task %p deallocating an invalid port %lu, most probably a bug.\n", current_task(), name);
+			printf("task %.*s deallocating an invalid port %lu, most probably a bug.\n", TASK_NAME_SIZE, current_task()->name, name);
 			if (mach_port_deallocate_debug)
 				SoftDebugger("mach_port_deallocate");
 		}
diff --git a/kern/printf.c b/kern/printf.c
index af59d5a..ea78d48 100644
--- a/kern/printf.c
+++ b/kern/printf.c
@@ -615,6 +615,16 @@ vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
   return cookie.index;
 }
 
+int
+snprintf(char *buf, size_t size, const char *fmt, ...)
+{
+	int written;
+	va_list	listp;
+	va_start(listp, fmt);
+	written = vsnprintf(buf, size, fmt, listp);
+	va_end(listp);
+	return written;
+}
 
 void safe_gets(str, maxlen)
 	char *str;
diff --git a/kern/printf.h b/kern/printf.h
index 8b4e760..0f8b328 100644
--- a/kern/printf.h
+++ b/kern/printf.h
@@ -40,6 +40,7 @@ extern void printnum (unsigned long u, int base,
                       vm_offset_t putc_arg);
 
 extern int sprintf (char *buf, const char *fmt, ...);
+extern int snprintf (char *buf, size_t size, const char *fmt, ...);
 extern int vsnprintf (char *buf, size_t size, const char *fmt, va_list args);
 
 extern int printf (const char *fmt, ...);
diff --git a/kern/slab.c b/kern/slab.c
index d1e3632..3fc95b6 100644
--- a/kern/slab.c
+++ b/kern/slab.c
@@ -662,7 +662,8 @@ static void kmem_cache_error(struct kmem_cache *cache, void *buf, int error,
 {
     struct kmem_buftag *buftag;
 
-    kmem_error("cache: %s, buffer: %p", cache->name, (void *)buf);
+    kmem_error("cache: %.*s, buffer: %p", KMEM_CACHE_NAME_SIZE, cache->name,
+               (void *)buf);
 
     switch(error) {
     case KMEM_ERR_INVALID:
diff --git a/kern/task.c b/kern/task.c
index 13b3c76..0c45d43 100644
--- a/kern/task.c
+++ b/kern/task.c
@@ -37,6 +37,7 @@
 #include <mach/vm_param.h>
 #include <mach/task_info.h>
 #include <mach/task_special_ports.h>
+#include <mach/debug.h>
 #include <ipc/ipc_space.h>
 #include <ipc/ipc_types.h>
 #include <kern/debug.h>
@@ -45,6 +46,7 @@
 #include <kern/slab.h>
 #include <kern/kalloc.h>
 #include <kern/processor.h>
+#include <kern/printf.h>
 #include <kern/sched_prim.h>	/* for thread_wakeup */
 #include <kern/ipc_tt.h>
 #include <kern/syscall_emulation.h>
@@ -164,6 +166,8 @@ kern_return_t task_create(
 	}
 #endif	/* FAST_TAS */
 
+	snprintf (new_task->name, TASK_NAME_SIZE, "%p", new_task);
+
 	ipc_task_enable(new_task);
 
 	*child_task = new_task;
@@ -1068,6 +1072,21 @@ task_priority(
 }
 
 /*
+ *	task_set_name
+ *
+ *	Set the name of task TASK to NAME.  This is a debugging aid.
+ *	NAME will be used in error messages printed by the kernel.
+ */
+kern_return_t
+task_set_name(
+	task_t			task,
+	kernel_debug_name_t	name)
+{
+	strncpy(task->name, name, sizeof task->name);
+	return KERN_SUCCESS;
+}
+
+/*
  *	task_collect_scan:
  *
  *	Attempt to free resources owned by tasks.
diff --git a/kern/task.h b/kern/task.h
index e852033..bf5bb53 100644
--- a/kern/task.h
+++ b/kern/task.h
@@ -39,6 +39,7 @@
 #include <mach/time_value.h>
 #include <mach/mach_param.h>
 #include <mach/task_info.h>
+#include <mach/debug.h>
 #include <kern/kern_types.h>
 #include <kern/lock.h>
 #include <kern/queue.h>
@@ -48,6 +49,13 @@
 #include <vm/vm_types.h>
 #include <machine/task.h>
 
+/*
+ * Task name buffer size.  The size is chosen so that struct task fits
+ * into three cache lines.  The size of a cache line on a typical CPU
+ * is 64 bytes.
+ */
+#define TASK_NAME_SIZE 32
+
 struct task {
 	/* Synchronization/destruction information */
 	decl_simple_lock_data(,lock)	/* Task's lock */
@@ -113,6 +121,8 @@ struct task {
 	natural_t	cow_faults;	/* copy-on-write faults counter */
 	natural_t	messages_sent;	/* messages sent counter */
 	natural_t	messages_received; /* messages received counter */
+
+	char	name[TASK_NAME_SIZE];
 };
 
 #define task_lock(task)		simple_lock(&(task)->lock)
@@ -160,6 +170,9 @@ extern kern_return_t	task_assign(
 extern kern_return_t	task_assign_default(
 	task_t		task,
 	boolean_t	assign_threads);
+extern kern_return_t	task_set_name(
+	task_t			task,
+	kernel_debug_name_t	name);
 extern void consider_task_collect(void);
 
 /*