[loeg]

All bets go out the window with adversarial multi-process shared memory mutexes. The other process may not even be running the same locking code.

[gsliepen]

That's an easy answer, but multi-process mutexes are supported on Linux (and perhaps other OSes as well), and it would be nice if this could also be safely handled by something like Surelock. If it would, then it couldn't rely on VM addresses to order locks.