[$] How to write Rust in the kernel: part 1

The Linux kernel is seeing a steady accumulation of Rust code. As it becomes
more prevalent, maintainers may want to know how to read, review, and test the
Rust code that relates to their areas of expertise. Just as kernel C code is
different from user-space C code, so too is kernel Rust code somewhat different
from user-space Rust code. That fact makes Rust's

extensive documentation of
less use than it otherwise would be, and means that potential contributors with
user-space experience will need some additional instruction.
This article is the first in a multi-part series aimed at helping existing
kernel contributors become familiar with Rust, and helping existing Rust
programmers become familiar with what the kernel does differently from the
typical Rust project.