You would also need to comprehensively annotate the Linux C headers in order to provide the information that Rust expects (e.g. for each ptr instance whether it's a "raw" pointer, a shared/exclusive reference or a piece of "owned" data, whether it can be NULL etc. etc.). This might actually get accepted upstream though. Having the kernel-build itself depend on Rust could be far more problematic, given e.g. the variety of hardware that Linux must support.