Kernel/LibC/Userspace: Implement chown and set tty owner on login

kernel/kernel/Terminal/Serial.cpp

@@ -179,7 +179,7 @@ namespace Kernel
 	}
 
 	SerialTTY::SerialTTY(Serial serial)
-		: TTY(0660, 0, 0)
+		: TTY(0600, 0, 0)
 		, m_serial(serial)
 		, m_rdev(next_rdev())
 	{

kernel/kernel/Terminal/TTY.cpp

@@ -105,6 +105,21 @@ namespace Kernel
 		initialized = true;
 	}
 
+	BAN::ErrorOr<void> TTY::chmod_impl(mode_t mode)
+	{
+		ASSERT((mode & Inode::Mode::TYPE_MASK) == 0);
+		m_inode_info.mode &= Inode::Mode::TYPE_MASK;
+		m_inode_info.mode |= mode;
+		return {};
+	}
+
+	BAN::ErrorOr<void> TTY::chown_impl(uid_t uid, gid_t gid)
+	{
+		m_inode_info.uid = uid;
+		m_inode_info.gid = gid;
+		return {};
+	}
+
 	void TTY::on_key_event(Input::KeyEvent event)
 	{
 		LockGuard _(m_lock);

kernel/kernel/Terminal/VirtualTTY.cpp

@@ -42,7 +42,7 @@ namespace Kernel
 	}
 
 	VirtualTTY::VirtualTTY(TerminalDriver* driver)
-		: TTY(0666, 0, 0)
+		: TTY(0600, 0, 0)
 		, m_terminal_driver(driver)
 		, m_rdev(next_rdev())
 	{