kernel/object: Amend handle types to distinguish between readable and writable events

Two kernel object should absolutely never have the same handle ID type.
This can cause incorrect behavior when it comes to retrieving object
types from the handle table. In this case it allows converting a
WritableEvent into a ReadableEvent and vice-versa, which is undefined
behavior, since the object types are not the same.

This also corrects ClearEvent() to check both kernel types like the
kernel itself does.

src/core/hle/kernel/object.cpp

@@ -13,7 +13,7 @@ Object::~Object() = default;
 
 bool Object::IsWaitable() const {
     switch (GetHandleType()) {
-    case HandleType::Event:
+    case HandleType::ReadableEvent:
     case HandleType::Thread:
     case HandleType::Timer:
     case HandleType::ServerPort:
@@ -21,6 +21,7 @@ bool Object::IsWaitable() const {
         return true;
 
     case HandleType::Unknown:
+    case HandleType::WritableEvent:
     case HandleType::SharedMemory:
     case HandleType::Process:
     case HandleType::AddressArbiter:

src/core/hle/kernel/object.h

@@ -19,7 +19,8 @@ using Handle = u32;
 
 enum class HandleType : u32 {
     Unknown,
-    Event,
+    WritableEvent,
+    ReadableEvent,
     SharedMemory,
     Thread,
     Process,

src/core/hle/kernel/readable_event.h

@@ -29,7 +29,7 @@ public:
         return reset_type;
     }
 
-    static const HandleType HANDLE_TYPE = HandleType::Event;
+    static const HandleType HANDLE_TYPE = HandleType::ReadableEvent;
     HandleType GetHandleType() const override {
         return HANDLE_TYPE;
     }

src/core/hle/kernel/svc.cpp

@@ -1575,16 +1575,23 @@ static ResultCode ClearEvent(Handle handle) {
     LOG_TRACE(Kernel_SVC, "called, event=0x{:08X}", handle);
 
     const auto& handle_table = Core::CurrentProcess()->GetHandleTable();
-    SharedPtr<ReadableEvent> evt = handle_table.Get<ReadableEvent>(handle);
-    if (evt == nullptr) {
-        LOG_ERROR(Kernel_SVC, "Event handle does not exist, handle=0x{:08X}", handle);
-        return ERR_INVALID_HANDLE;
+
+    auto writable_event = handle_table.Get<WritableEvent>(handle);
+    if (writable_event) {
+        writable_event->Clear();
+        return RESULT_SUCCESS;
     }
 
-    evt->Clear();
+    auto readable_event = handle_table.Get<ReadableEvent>(handle);
+    if (readable_event) {
+        readable_event->Clear();
         return RESULT_SUCCESS;
     }
 
+    LOG_ERROR(Kernel_SVC, "Event handle does not exist, handle=0x{:08X}", handle);
+    return ERR_INVALID_HANDLE;
+}
+
 static ResultCode GetProcessInfo(u64* out, Handle process_handle, u32 type) {
     LOG_DEBUG(Kernel_SVC, "called, handle=0x{:08X}, type=0x{:X}", process_handle, type);
 

src/core/hle/kernel/writable_event.h

@@ -39,7 +39,7 @@ public:
         return name;
     }
 
-    static const HandleType HANDLE_TYPE = HandleType::Event;
+    static const HandleType HANDLE_TYPE = HandleType::WritableEvent;
     HandleType GetHandleType() const override {
         return HANDLE_TYPE;
     }

src/yuzu/debugger/wait_tree.cpp

@@ -153,7 +153,7 @@ QString WaitTreeWaitObject::GetText() const {
 
 std::unique_ptr<WaitTreeWaitObject> WaitTreeWaitObject::make(const Kernel::WaitObject& object) {
     switch (object.GetHandleType()) {
-    case Kernel::HandleType::Event:
+    case Kernel::HandleType::ReadableEvent:
         return std::make_unique<WaitTreeEvent>(static_cast<const Kernel::ReadableEvent&>(object));
     case Kernel::HandleType::Timer:
         return std::make_unique<WaitTreeTimer>(static_cast<const Kernel::Timer&>(object));