kernel: resolving a handle now increments the refcount of the corresponding object

sched/task.c

@@ -326,7 +326,7 @@ kern_status_t task_resolve_handle(
 	}
 
 	if (out_obj) {
-		*out_obj = handle_data->h_object;
+		*out_obj = object_ref(handle_data->h_object);
 	}
 
 	if (out_flags) {

syscall/msg.c

@@ -92,9 +92,6 @@ kern_status_t sys_port_connect(
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(port_obj);
 	struct port *port = port_cast(port_obj);
 	task_unlock_irqrestore(self, flags);
 
@@ -117,7 +114,6 @@ kern_status_t sys_port_connect(
 	port_lock_irqsave(port, &flags);
 	status = port_connect(port, remote);
 	port_unlock_irqrestore(port, flags);
-	object_unref(port_obj);
 	object_unref(&remote->c_base);
 
 	return KERN_OK;
@@ -141,9 +137,6 @@ kern_status_t sys_port_disconnect(kern_handle_t port_handle)
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(port_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct port *port = port_cast(port_obj);
@@ -251,9 +244,6 @@ kern_status_t sys_msg_send(
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(port_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct port *port = port_cast(port_obj);
@@ -293,9 +283,6 @@ kern_status_t sys_msg_recv(kern_handle_t channel_handle, kern_msg_t *out_msg)
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(channel_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct channel *channel = channel_cast(channel_obj);
@@ -338,9 +325,6 @@ kern_status_t sys_msg_reply(
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(channel_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct channel *channel = channel_cast(channel_obj);
@@ -390,9 +374,6 @@ kern_status_t sys_msg_read(
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(channel_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct channel *channel = channel_cast(channel_obj);
@@ -450,9 +431,6 @@ kern_status_t sys_msg_write(
 		return status;
 	}
 
-	/* add a reference to the port object to make sure it isn't deleted
-	 * while we're using it */
-	object_ref(channel_obj);
 	task_unlock_irqrestore(self, flags);
 
 	struct channel *channel = channel_cast(channel_obj);

syscall/task.c

@@ -84,7 +84,6 @@ kern_status_t sys_task_create(
 		return status;
 	}
 
-	object_ref(parent_obj);
 	struct task *parent = task_cast(parent_obj);
 
 	struct handle *child_handle_slot = NULL, *space_handle_slot = NULL;
@@ -94,6 +93,7 @@ kern_status_t sys_task_create(
 		&child_handle_slot,
 		&child_handle);
 	if (status != KERN_OK) {
+		object_unref(parent_obj);
 		task_unlock_irqrestore(self, flags);
 		return status;
 	}
@@ -103,6 +103,7 @@ kern_status_t sys_task_create(
 		&space_handle_slot,
 		&space_handle);
 	if (status != KERN_OK) {
+		object_unref(parent_obj);
 		handle_table_free_handle(self->t_handles, child_handle);
 		task_unlock_irqrestore(self, flags);
 		return status;
@@ -169,7 +170,6 @@ kern_status_t sys_task_create_thread(
 		return status;
 	}
 
-	object_ref(target_obj);
 	struct task *target = task_cast(target_obj);
 
 	struct handle *target_handle = NULL;
@@ -238,6 +238,7 @@ kern_status_t sys_task_get_address_space(
 		&handle_slot,
 		&handle);
 	if (status != KERN_OK) {
+		object_unref(task_obj);
 		task_unlock_irqrestore(self, flags);
 		return status;
 	}
@@ -245,6 +246,7 @@ kern_status_t sys_task_get_address_space(
 	struct task *task = task_cast(task_obj);
 
 	if (!task) {
+		object_unref(task_obj);
 		handle_table_free_handle(self->t_handles, handle);
 		task_unlock_irqrestore(self, flags);
 		return KERN_INVALID_ARGUMENT;
@@ -253,6 +255,7 @@ kern_status_t sys_task_get_address_space(
 	handle_slot->h_object = &task->t_address_space->vr_base;
 	object_add_handle(&task->t_address_space->vr_base);
 	task_unlock_irqrestore(self, flags);
+	object_unref(task_obj);
 
 	*out = handle;
 	return KERN_OK;
@@ -276,11 +279,11 @@ kern_status_t sys_thread_start(kern_handle_t thread_handle)
 		return status;
 	}
 
-	object_ref(thread_obj);
 	struct thread *thread = thread_cast(thread_obj);
 	task_unlock_irqrestore(self, flags);
 
 	schedule_thread_on_cpu(thread);
+	object_unref(thread_obj);
 
 	return KERN_OK;
 }

syscall/vm-object.c

@@ -144,9 +144,6 @@ kern_status_t sys_vm_object_copy(
 		return status;
 	}
 
-	object_ref(src_obj);
-	object_ref(dst_obj);
-
 	task_unlock_irqrestore(self, flags);
 
 	struct vm_object *dst_vmo = vm_object_cast(dst_obj);

syscall/vm-region.c

@@ -61,7 +61,6 @@ kern_status_t sys_vm_region_create(
 		return status;
 	}
 
-	object_ref(obj);
 	task_unlock_irqrestore(self, flags);
 	vm_region_lock_irqsave(parent_region, &flags);
 
@@ -116,7 +115,6 @@ kern_status_t sys_vm_region_kill(kern_handle_t region_handle)
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(obj);
 	task_unlock_irqrestore(self, flags);
 
 	vm_region_lock_irqsave(region, &flags);
@@ -162,7 +160,6 @@ kern_status_t sys_vm_region_read(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(obj);
 	task_unlock_irqrestore(self, flags);
 
 	virt_addr_t src_address = vm_region_get_base_address(region) + offset;
@@ -214,7 +211,6 @@ kern_status_t sys_vm_region_write(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(obj);
 	task_unlock_irqrestore(self, flags);
 
 	virt_addr_t dst_address = vm_region_get_base_address(region) + offset;
@@ -283,8 +279,6 @@ kern_status_t sys_vm_region_map_absolute(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(vmo_obj);
-	object_ref(region_obj);
 	task_unlock_irqrestore(self, flags);
 
 	off_t region_offset = VM_REGION_ANY_OFFSET;
@@ -369,8 +363,6 @@ kern_status_t sys_vm_region_map_relative(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(vmo_obj);
-	object_ref(region_obj);
 	task_unlock_irqrestore(self, flags);
 
 	status = vm_region_map_object(
@@ -418,7 +410,6 @@ kern_status_t sys_vm_region_unmap_absolute(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(region_obj);
 	task_unlock_irqrestore(self, flags);
 
 	off_t region_offset = address - vm_region_get_base_address(region);
@@ -458,7 +449,6 @@ kern_status_t sys_vm_region_unmap_relative(
 		return KERN_INVALID_ARGUMENT;
 	}
 
-	object_ref(region_obj);
 	task_unlock_irqrestore(self, flags);
 
 	status = vm_region_unmap(region, offset, length);