What is the name of novel (or author of it) where the world is a seemlingly endless vertical cliff?

This is a long shot, but wondering if anyone can help - trying to recall a sic fi author, one of his books was about a world that was all vertical , people lived on this eternal cliff ( I think they caught up-draughts and down-draughts to go up and down the cliff). Another story by the same author was about a criminal who was imprisoned in a giant, inescapable structure in distant space (I think that had a red cover)…