diff --git a/src/drivers/nulldrv/main.cpp b/src/drivers/nulldrv/main.cpp
index e7abda6..d778bbe 100644
--- a/src/drivers/nulldrv/main.cpp
+++ b/src/drivers/nulldrv/main.cpp
@@ -131,7 +131,7 @@ main(int argc, const char **argv)
 
 	_syscall_system_log("main thread closing endpoint");
 
-	result = _syscall_endpoint_close(endp);
+	result = _syscall_object_close(endp);
 	if (result != j6_status_ok)
 		return result;
 
diff --git a/src/include/j6/signals.h b/src/include/j6/signals.h
index 9e5aa51..8eff049 100644
--- a/src/include/j6/signals.h
+++ b/src/include/j6/signals.h
@@ -4,24 +4,21 @@
 
 // Signals 0-15 are common to all types
 #define j6_signal_no_handles		(1ull << 0)
+#define j6_signal_closed			(1ull << 1)
 
 // Signals 16-47 are defined per-object-type
 
 // Process signals
-#define j6_signal_process_exit		(1ull << 16)
 
 // Thread signals
-#define j6_signal_thread_exit		(1ull << 16)
 
 // Channel signals
-#define j6_signal_channel_closed	(1ull << 16)
-#define j6_signal_channel_can_send	(1ull << 17)
-#define j6_signal_channel_can_recv	(1ull << 18)
+#define j6_signal_channel_can_send	(1ull << 16)
+#define j6_signal_channel_can_recv	(1ull << 17)
 
 // Endpoint signals
-#define j6_signal_endpoint_closed	(1ull << 16)
-#define j6_signal_endpoint_can_send	(1ull << 17)
-#define j6_signal_endpoint_can_recv	(1ull << 18)
+#define j6_signal_endpoint_can_send	(1ull << 16)
+#define j6_signal_endpoint_can_recv	(1ull << 17)
 
 // Signals 48-63 are user-defined signals
 #define j6_signal_user0				(1ull << 48)
diff --git a/src/include/syscalls.inc b/src/include/syscalls.inc
index b2a94b2..d483835 100644
--- a/src/include/syscalls.inc
+++ b/src/include/syscalls.inc
@@ -1,33 +1,30 @@
 SYSCALL(0x00, system_log,        const char *)
 SYSCALL(0x01, system_noop,       void)
 
+SYSCALL(0x08, object_koid,       j6_handle_t, j6_koid_t *)
 SYSCALL(0x09, object_wait,       j6_handle_t, j6_signal_t, j6_signal_t *)
 SYSCALL(0x0a, object_signal,     j6_handle_t, j6_signal_t)
+SYSCALL(0x0b, object_close,      j6_handle_t)
 
-SYSCALL(0x10, process_koid,      j6_koid_t *)
-SYSCALL(0x11, process_exit,      int64_t)
+SYSCALL(0x10, process_exit,      int64_t)
 
-SYSCALL(0x18, thread_koid,       j6_koid_t *)
-SYSCALL(0x19, thread_create,     void *, j6_handle_t *)
-SYSCALL(0x1a, thread_exit,       int64_t)
-SYSCALL(0x1b, thread_pause,      void)
-SYSCALL(0x1c, thread_sleep,      uint64_t)
+SYSCALL(0x18, thread_create,     void *, j6_handle_t *)
+SYSCALL(0x19, thread_exit,       int64_t)
+SYSCALL(0x1a, thread_pause,      void)
+SYSCALL(0x1b, thread_sleep,      uint64_t)
 
 SYSCALL(0x20, channel_create,    j6_handle_t *)
-SYSCALL(0x21, channel_close,     j6_handle_t)
-SYSCALL(0x22, channel_send,      j6_handle_t, size_t *, void *)
-SYSCALL(0x23, channel_receive,   j6_handle_t, size_t *, void *)
+SYSCALL(0x21, channel_send,      j6_handle_t, size_t *, void *)
+SYSCALL(0x22, channel_receive,   j6_handle_t, size_t *, void *)
 
 SYSCALL(0x28, endpoint_create,   j6_handle_t *)
-SYSCALL(0x29, endpoint_close,    j6_handle_t)
-SYSCALL(0x2a, endpoint_send,     j6_handle_t, j6_tag_t, size_t, void *)
-SYSCALL(0x2b, endpoint_receive,  j6_handle_t, j6_tag_t *, size_t *, void *)
-SYSCALL(0x2c, endpoint_sendrecv, j6_handle_t, j6_tag_t *, size_t *, void *)
-SYSCALL(0x2d, endpoint_bind_irq, j6_handle_t, unsigned)
+SYSCALL(0x29, endpoint_send,     j6_handle_t, j6_tag_t, size_t, void *)
+SYSCALL(0x2a, endpoint_receive,  j6_handle_t, j6_tag_t *, size_t *, void *)
+SYSCALL(0x2b, endpoint_sendrecv, j6_handle_t, j6_tag_t *, size_t *, void *)
+SYSCALL(0x2c, endpoint_bind_irq, j6_handle_t, unsigned)
 
 SYSCALL(0x30, vma_create,        j6_handle_t *, size_t, uint32_t)
 SYSCALL(0x31, vma_create_map,    j6_handle_t *, size_t, uintptr_t, uint32_t)
-SYSCALL(0x32, vma_close,         j6_handle_t)
-SYSCALL(0x33, vma_map,           j6_handle_t, uintptr_t)
-SYSCALL(0x34, vma_unmap,         j6_handle_t)
+SYSCALL(0x32, vma_map,           j6_handle_t, uintptr_t)
+SYSCALL(0x33, vma_unmap,         j6_handle_t)
 SYSCALL(0x34, vma_resize,        j6_handle_t, size_t *)
diff --git a/src/kernel/objects/channel.cpp b/src/kernel/objects/channel.cpp
index de34cf9..5f4fbdc 100644
--- a/src/kernel/objects/channel.cpp
+++ b/src/kernel/objects/channel.cpp
@@ -78,8 +78,8 @@ channel::dequeue(size_t *len, void *data)
 void
 channel::close()
 {
+	kobject::close();
 	g_kernel_buffers.return_buffer(m_data);
-	assert_signal(j6_signal_channel_closed);
 }
 
 void
diff --git a/src/kernel/objects/channel.h b/src/kernel/objects/channel.h
index 26d3529..5ce949f 100644
--- a/src/kernel/objects/channel.h
+++ b/src/kernel/objects/channel.h
@@ -37,10 +37,7 @@ public:
 
 	/// Mark this channel as closed, all future calls to enqueue or
 	/// dequeue messages will fail with j6_status_closed.
-	void close();
-
-	/// Check if this channel has been closed
-	inline bool closed() { return check_signal(j6_signal_channel_closed); }
+	virtual void close() override;
 
 protected:
 	virtual void on_no_handles() override;
diff --git a/src/kernel/objects/endpoint.cpp b/src/kernel/objects/endpoint.cpp
index c3ac58f..bb232a9 100644
--- a/src/kernel/objects/endpoint.cpp
+++ b/src/kernel/objects/endpoint.cpp
@@ -10,14 +10,15 @@ endpoint::endpoint() :
 
 endpoint::~endpoint()
 {
-	if (!check_signal(j6_signal_endpoint_closed))
+	if (!check_signal(j6_signal_closed))
 		close();
 }
 
 void
 endpoint::close()
 {
-	assert_signal(j6_signal_endpoint_closed);
+	kobject::close();
+
 	for (auto &data : m_blocked) {
 		if (data.th)
 			data.th->wake_on_result(this, j6_status_closed);
diff --git a/src/kernel/objects/endpoint.h b/src/kernel/objects/endpoint.h
index 690672b..99c910d 100644
--- a/src/kernel/objects/endpoint.h
+++ b/src/kernel/objects/endpoint.h
@@ -16,7 +16,7 @@ public:
 	static constexpr kobject::type type = kobject::type::endpoint;
 
 	/// Close the endpoint, waking all waiting processes with an error
-	void close();
+	virtual void close() override;
 
 	/// Check if the endpoint has space for a message to be sent
 	inline bool can_send() const { return check_signal(j6_signal_endpoint_can_send); }
diff --git a/src/kernel/objects/kobject.cpp b/src/kernel/objects/kobject.cpp
index 017d940..b401ccf 100644
--- a/src/kernel/objects/kobject.cpp
+++ b/src/kernel/objects/kobject.cpp
@@ -61,6 +61,12 @@ kobject::notify_signal_observers()
 	}
 }
 
+void
+kobject::close()
+{
+	assert_signal(j6_signal_closed);
+}
+
 void
 kobject::on_no_handles()
 {
diff --git a/src/kernel/objects/kobject.h b/src/kernel/objects/kobject.h
index 446d75c..852a741 100644
--- a/src/kernel/objects/kobject.h
+++ b/src/kernel/objects/kobject.h
@@ -3,6 +3,7 @@
 /// Definition of base type for user-interactable kernel objects
 
 #include "j6/errors.h"
+#include "j6/signals.h"
 #include "j6/types.h"
 #include "kutil/vector.h"
 
@@ -76,6 +77,12 @@ public:
 	/// Remove the given thread from the list of threads waiting on this object.
 	inline void remove_blocked_thread(thread *t) { m_blocked_threads.remove_swap(t); }
 
+	/// Perform any cleanup actions necessary to mark this object closed
+	virtual void close();
+
+	/// Check if this object has been closed
+	inline bool closed() const { return check_signal(j6_signal_closed); }
+
 protected:
 	/// Interface for subclasses to handle when all handles are closed. Subclasses
 	/// should either call the base version, or assert j6_signal_no_handles.
diff --git a/src/kernel/objects/process.cpp b/src/kernel/objects/process.cpp
index cc61d6f..7cdf6a3 100644
--- a/src/kernel/objects/process.cpp
+++ b/src/kernel/objects/process.cpp
@@ -1,4 +1,3 @@
-#include "j6/signals.h"
 #include "kutil/assert.h"
 #include "kutil/no_construct.h"
 #include "cpu.h"
@@ -62,7 +61,7 @@ process::exit(unsigned code)
 		thread->exit(code);
 	}
 	m_return_code = code;
-	assert_signal(j6_signal_process_exit);
+	close();
 
 	if (this == bsp_cpu_data.p)
 		scheduler::get().schedule();
diff --git a/src/kernel/objects/thread.cpp b/src/kernel/objects/thread.cpp
index 8c3528d..6a5b1ca 100644
--- a/src/kernel/objects/thread.cpp
+++ b/src/kernel/objects/thread.cpp
@@ -139,7 +139,7 @@ thread::exit(uint32_t code)
 	m_return_code = code;
 	set_state(state::exited);
 	clear_state(state::ready);
-	assert_signal(j6_signal_thread_exit);
+	close();
 
 	schedule_if_current(this);
 }
diff --git a/src/kernel/syscalls/channel.cpp b/src/kernel/syscalls/channel.cpp
index b056c9d..9a5aedf 100644
--- a/src/kernel/syscalls/channel.cpp
+++ b/src/kernel/syscalls/channel.cpp
@@ -13,15 +13,6 @@ channel_create(j6_handle_t *handle)
 	return j6_status_ok;
 }
 
-j6_status_t
-channel_close(j6_handle_t handle)
-{
-	channel *c = remove_handle<channel>(handle);
-	if (!c) return j6_err_invalid_arg;
-	c->close();
-	return j6_status_ok;
-}
-
 j6_status_t
 channel_send(j6_handle_t handle, size_t *len, void *data)
 {
diff --git a/src/kernel/syscalls/endpoint.cpp b/src/kernel/syscalls/endpoint.cpp
index d07c3d4..6f83bc5 100644
--- a/src/kernel/syscalls/endpoint.cpp
+++ b/src/kernel/syscalls/endpoint.cpp
@@ -15,15 +15,6 @@ endpoint_create(j6_handle_t *handle)
 	return j6_status_ok;
 }
 
-j6_status_t
-endpoint_close(j6_handle_t handle)
-{
-	endpoint *e = remove_handle<endpoint>(handle);
-	if (!e) return j6_err_invalid_arg;
-	e->close();
-	return j6_status_ok;
-}
-
 j6_status_t
 endpoint_send(j6_handle_t handle, j6_tag_t tag, size_t len, void *data)
 {
diff --git a/src/kernel/syscalls/helpers.h b/src/kernel/syscalls/helpers.h
index 11cadb6..ff5caa3 100644
--- a/src/kernel/syscalls/helpers.h
+++ b/src/kernel/syscalls/helpers.h
@@ -3,6 +3,7 @@
 /// Utility functions for use in syscall handler implementations
 
 #include "j6/types.h"
+#include "objects/kobject.h"
 #include "objects/process.h"
 
 namespace syscalls {
@@ -26,6 +27,13 @@ T * get_handle(j6_handle_t handle)
 	return static_cast<T*>(o);
 }
 
+template <>
+inline kobject * get_handle<kobject>(j6_handle_t handle)
+{
+	process &p = process::current();
+	return p.lookup_handle(handle);
+}
+
 template <typename T>
 T * remove_handle(j6_handle_t handle)
 {
diff --git a/src/kernel/syscalls/object.cpp b/src/kernel/syscalls/object.cpp
index fcdf7cb..4431302 100644
--- a/src/kernel/syscalls/object.cpp
+++ b/src/kernel/syscalls/object.cpp
@@ -3,18 +3,29 @@
 #include "j6/types.h"
 
 #include "log.h"
-#include "objects/process.h"
 #include "objects/thread.h"
+#include "syscalls/helpers.h"
 
 namespace syscalls {
 
+j6_status_t
+object_koid(j6_handle_t handle, j6_koid_t *koid)
+{
+	if (koid == nullptr)
+		return j6_err_invalid_arg;
+
+	kobject *obj = get_handle<kobject>(handle);
+	if (!obj)
+		return j6_err_invalid_arg;
+
+	*koid = obj->koid();
+	return j6_status_ok;
+}
+
 j6_status_t
 object_wait(j6_handle_t handle, j6_signal_t mask, j6_signal_t *sigs)
 {
-	thread &th = thread::current();
-	process &p = process::current();
-
-	kobject *obj = p.lookup_handle(handle);
+	kobject *obj = get_handle<kobject>(handle);
 	if (!obj)
 		return j6_err_invalid_arg;
 
@@ -24,6 +35,7 @@ object_wait(j6_handle_t handle, j6_signal_t mask, j6_signal_t *sigs)
 		return j6_status_ok;
 	}
 
+	thread &th = thread::current();
 	obj->add_blocked_thread(&th);
 	th.wait_on_signals(obj, mask);
 
@@ -40,8 +52,7 @@ object_signal(j6_handle_t handle, j6_signal_t signals)
 	if ((signals & j6_signal_user_mask) != signals)
 		return j6_err_invalid_arg;
 
-	process &p = process::current();
-	kobject *obj = p.lookup_handle(handle);
+	kobject *obj = get_handle<kobject>(handle);
 	if (!obj)
 		return j6_err_invalid_arg;
 
@@ -49,4 +60,15 @@ object_signal(j6_handle_t handle, j6_signal_t signals)
 	return j6_status_ok;
 }
 
+j6_status_t
+object_close(j6_handle_t handle)
+{
+	kobject *obj = get_handle<kobject>(handle);
+	if (!obj)
+		return j6_err_invalid_arg;
+
+	obj->close();
+	return j6_status_ok;
+}
+
 } // namespace syscalls
diff --git a/src/kernel/syscalls/process.cpp b/src/kernel/syscalls/process.cpp
index 3cf1884..ca49d4f 100644
--- a/src/kernel/syscalls/process.cpp
+++ b/src/kernel/syscalls/process.cpp
@@ -6,16 +6,6 @@
 
 namespace syscalls {
 
-j6_status_t
-process_koid(j6_koid_t *koid)
-{
-	if (koid == nullptr)
-		return j6_err_invalid_arg;
-
-	*koid = process::current().koid();
-	return j6_status_ok;
-}
-
 j6_status_t
 process_exit(int64_t status)
 {
diff --git a/src/kernel/syscalls/thread.cpp b/src/kernel/syscalls/thread.cpp
index 0b2f859..f1a0cad 100644
--- a/src/kernel/syscalls/thread.cpp
+++ b/src/kernel/syscalls/thread.cpp
@@ -7,16 +7,6 @@
 
 namespace syscalls {
 
-j6_status_t
-thread_koid(j6_koid_t *koid)
-{
-	if (koid == nullptr)
-		return j6_err_invalid_arg;
-
-	*koid =  thread::current().koid();
-	return j6_status_ok;
-}
-
 j6_status_t
 thread_create(void *rip, j6_handle_t *handle)
 {
diff --git a/src/kernel/syscalls/vm_area.cpp b/src/kernel/syscalls/vm_area.cpp
index b61eb59..8fa22c4 100644
--- a/src/kernel/syscalls/vm_area.cpp
+++ b/src/kernel/syscalls/vm_area.cpp
@@ -47,17 +47,6 @@ vma_unmap(j6_handle_t handle)
 	return j6_status_ok;
 }
 
-j6_status_t
-vma_close(j6_handle_t handle)
-{
-	j6_status_t status = vma_unmap(handle);
-	if (status != j6_status_ok)
-		return status;
-
-	remove_handle<vm_area>(handle);
-	return j6_status_ok;
-}
-
 j6_status_t
 vma_resize(j6_handle_t handle, size_t *size)
 {