Re: Rust kernel policy

[Boqun Feng <boqun.feng@gmail.com>]

On Tue, Feb 18, 2025 at 04:58:27PM -0800, H. Peter Anvin wrote:
[...]
> > > David Howells did a patch set in 2018 (I believe) to clean up the C code in the kernel so it could be compiled with either C or C++; the patchset wasn't particularly big and mostly mechanical in nature, something that would be impossible with Rust. Even without moving away from the common subset of C and C++ we would immediately gain things like type safe linkage.
> > 
> > That is great, but that does not give you memory safety and everyone
> > would still need to learn C++.
> 
> The point is that C++ is a superset of C, and we would use a subset of C++
> that is more "C+"-style. That is, most changes would occur in header files,
> especially early on. Since the kernel uses a *lot* of inlines and macros,
> the improvements would still affect most of the *existing* kernel code,
> something you simply can't do with Rust.
> 

I don't think that's the point of introducing a new language, the
problem we are trying to resolve is when writing a driver or some kernel
component, due to the complexity, memory safety issues (and other
issues) are likely to happen. So using a language providing type safety
can help that. Replacing inlines and macros with neat template tricks is
not the point, at least from what I can tell, inlines and macros are not
the main source of bugs (or are they any source of bugs in production?).
Maybe you have an example?

Regards,
Boqun

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