U.S.A. - Hong Kong - Shanghai - U.S.A?

Hello,
I need to go to Shanghai to help a friend come back to America. I don't have time to get a visa. I would like to travel from the U.S.A. to Hong Kong, then from Hong Kong to Shanghai, stay in Shanghai for one day, and then fly back to the U.S.A? Do I need an entry permit for this? Does this qualify for the transit stay in China?