The interfaces between C and Rust in the kernel have grown over time; any non-trivial Rust driver will use a number of these. Tasks like allocating memory, dealing with immovable structures, and interacting with locks are necessary for handling most devices. There are also many subsystem-specific bindings, but the focus of this third item in our series on writing Rust in the kernel will be on an overview of the bindings that all kernel Rust code can be expected to use. Rust code can call C using...