Package for development of out-of-tree kernel modules written in Rust

From	NoisyCoil <noisycoil@disroot.org>
Newsgroups	linux.debian.kernel
Subject	Package for development of out-of-tree kernel modules written in Rust
Date	2025-02-26 01:30 +0100
Message-ID	<Kkdtf-1ZKL-1@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

Hi kernel team!


I know this is early to say the least, but I would like to ask your 
opinion on the naming of a package that could eventually end up in the 
official Debian kernel packaging.

As is the case for C, building out-of-tree kernel modules written in 
Rust [1] requires some extra files to be installed alongside the kernel. 
For C modules this is covered by linux-headers and dependencies. For 
Rust, one needs to have installed the *.rmeta and *.so files which are 
generated in the rust/ directory during the build. The first of these 
contain metadata like the version of rustc used for the build, 
information on exported types/items/etc., bindings and so on [2][3]. 
They do not contain compiled code but are ultimately dependent (among 
other things such as the compiler) on the .config used to build them, so 
they are arch- and flavor-specific. The only *.so file generated at this 
time is a proc macro, and that, to my understanding, is a regular shared 
library.

Needless to say, Rust must be enabled in the kernel for these files to 
be generated, meaning the Debian kernel cannot currently support this. 
However, there is at least one fork of the Debian kernel being built 
with Rust enabled at present, namely, the Asahi kernel which we are 
maintaining in the Bananas Team [4] (which needs Rust for the Apple AGX 
GPU driver), so I started experimenting with the idea of having a 
package to provide these files. Following the scheme of having a 
metapackage + an actual versioned package I added two packages, 
linux-librust@source_suffix@@localversion@-dev [5] and 
linux-librust-@abiname@ [6], the first of which has the second as a 
dependency, while the second contains the actual files and links needed 
to build out-of-tree Rust modules. I tested it with [1] and it worked 
(modulo a small change needed to build [1] outside of mainline). You can 
find a draft at [7].

I would like to include the new linux-librust-* packages in the next 
version of our fork (6.13), but first I would like to ask your opinion 
on the naming I chose, whether you have suggestions (beyond the naming 
too!) and so on. If (when? ;-)) Rust is enabled in the Debian kernel, it 
would be nice to have a package like this to go with linux-headers, so I 
thought I could as well start this conversation to see if I can work on 
something that can eventually end up in src:linux.


One disclaimer: Miguel Ojeda (whom I cc'ed in case something interesting 
comes out of this discussion) told me he wouldn't recommend people to do 
out-of-tree Rust development e.g. because the kernel crate (which lives 
in rust/kernel) may need to be rebuilt to enable or accommodate new 
abstractions. I use this recommendation to clarify that general 
development is not what a linux-librust package aims to enable. The 
problem it tries to solve is "how do I build out-of-tree kernel modules 
written in Rust that work with the kernel installed by my distribution?" 
(this is why it's packaged from the same source!) If your distribution 
does not provide the abstractions you need then your distribution's 
kernel is not good enough for your use-case and you need to rebuild the 
kernel from source, in which case you don't need a linux-librust package 
(you already have the files you need). On the other hand, if your 
distribution does not provide those files, you will not be able to build 
such modules even if your distribution's kernel is good enough for you.


Cheers!


P.S.: Also cc'ing waldi personally since he recently expressed interest 
in enabling Rust in the Debian kernel, and the Rust Team in case someone 
is interested.



[1] https://github.com/Rust-for-Linux/rust-out-of-tree-module
[2] 
https://rustc-dev-guide.rust-lang.org/backend/libs-and-metadata.html#rmeta
[3] 
https://rustc-dev-guide.rust-lang.org/backend/libs-and-metadata.html#metadata
[4] https://salsa.debian.org/bananas-team/wip/linux-asahi
[5] For us this would be linux-librust-asahi-dev, since we renamed our 
source as linux-asahi. For src:linux this would be linux-librust-dev. 
I've been consistent with metapackages such as 
linux-headers@source_suffix@@localversion@ and 
linux-image@source_suffix@@localversion@-dbg and kept @source_suffix@ in 
the package's name.
[6] For us this is linux-librust-$version-asahi, where "asahi" here is 
the flavour name (src:linux-asahi contains an additional asahi flavour 
to enable the configs needed for apple silicon and make it clear to 
users they have to install the -asahi packages instead of the -arm64 
ones). For src:linux this would be linux-librust-$version-amd64, -arm64, 
-arm64-16k, etc.
[7] 
https://salsa.debian.org/bananas-team/wip/linux-asahi/-/commit/7a3873463600bc85781e4683a38d6e510c154937

Back to linux.debian.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Package for development of out-of-tree kernel modules written in Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 01:30 +0100
  Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-02-26 12:50 +0100
    Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 13:20 +0100
      Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-26 14:00 +0100
        Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 15:20 +0100
          Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-26 19:30 +0100
            Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 22:00 +0100
              Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-27 18:40 +0100
        Re: Package for development of out-of-tree kernel modules written  in Rust Ben Hutchings <ben@decadent.org.uk> - 2025-02-26 19:20 +0100
          Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 19:30 +0100
            Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-26 20:10 +0100
              Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 20:20 +0100
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-27 18:40 +0100
              Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-02 23:00 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-02 23:30 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-02 23:40 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-03 00:50 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-03 16:50 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-03 19:30 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-03 21:00 +0200
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-04-03 23:30 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-03 23:40 +0200
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-04-06 23:40 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-12 18:50 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-13 13:40 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-13 17:40 +0200
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-04-13 18:40 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-04-13 20:30 +0200
                Re: Package for development of out-of-tree kernel modules written  in Rust Ben Hutchings <ben@decadent.org.uk> - 2025-04-16 17:40 +0200
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-05-03 17:10 +0200
                Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-04-04 11:20 +0200
                Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-04-06 23:40 +0200
          Re: Package for development of out-of-tree kernel modules written in Rust Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> - 2025-02-26 19:40 +0100
      Re: Package for development of out-of-tree kernel modules written in  Rust NoisyCoil <noisycoil@disroot.org> - 2025-02-26 14:40 +0100
      Re: Package for development of out-of-tree kernel modules written in  Rust Bastian Blank <waldi@debian.org> - 2025-02-26 14:40 +0100

csiph-web