[kernel] Consolodate koid and close syscalls

A number of object types had _close or _koid syscalls. Moved those to be
generic for kobject.

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

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;

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);

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); }

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()
 {

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.

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();

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);
 }

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)
 {

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)
 {

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)
 {

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

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)
 {

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)
 {

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)
 {