5.5 Merge window, part 1

It seems great for testing simple "library" functions where the code to be tested is already exposed as public functions with no or few external dependencies.

But how do you use it to test a driver for example? There's typically a lot of subsystem / bus stuff that would have to be mocked.

And, if you want to unittest the internal helper functions of your driver they can't be static. I guess a macro could be written for that but then, seeing as all the unittests are built into a single kernel running under UML how would you handle naming collisions that could occur if previously static symbols become public in a testing context?