As a Malaysian, do I have to apply for visa beforehand or can I apply for it upon arrival at Pudong?

I will be fliying from Singapore to Jeju via Pudong Shanghai. The transit is less than 24 hours but I would like to enter Shanghai for some sightseeing. The same applies on the returning flights from Jeju to Singapore via Pudong. That is, I will like to enter on the returning flight as well.