Fix build for Linux 6.1

[rnestler]

I tried building the kernel module for the Linux 6.1 kernel and these were the changes that were needed. I'm not sure if it makes sense to merge this, since it is probably due to changes in https://github.com/Rust-for-Linux/linux which were not yet up-streamed, but if anyone tries something similar this diff might be helpful.

[ojeda]

Yeah, this template was intended to match the rust branch in the other repo, but soon it will make sense to move it to match mainline. Thanks for the PR, I am sure it will be useful for somebody!

[ojeda]

Raphael, could you please rebase it for the current mainline? The b change is not needed anymore. Thanks!

[rnestler]

Raphael, could you please rebase it for the current mainline? The b change is not needed anymore. Thanks!

It fails without the b changes for 6.1.7 which is the latest release in the 6.1 series.

Or do you mean I should update it for 6.2-rc4?

[ojeda]

Yeah, I meant to the latest Linus' tag (the change is there since -rc1), 6.2 should be out in a few weeks.

[ojeda]

Or we can put this in, and you can send another PR for the b change and we merge it a bit later.

[rnestler]

Or we can put this in, and you can send another PR for the b change and we merge it a bit later.

Sounds good to me 🙂

[rnestler]

Btw. my adventures with Rust Linux kernel modules are documented here:

• https://blog.rnstlr.ch/building-an-out-of-tree-rust-kernel-module.html
• https://blog.rnstlr.ch/building-an-out-of-tree-rust-kernel-module-part-two.html

[ojeda]

Nice! Thanks for documenting it! :)

By the way, on:

I'm also considering reporting this to the ArchLinux developers, but I'm not sure how much priority Rust kernel modules should have, given the early stage. I'll probably wait until Linux 6.2 is released before investigating further.

I would say it is indeed a bit too early to put things in distros -- many pieces will need to arrive into mainline to make it useful for end users and to make it production ready. But, of course, playing with it and starting to see how it could be eventually bundled in distros is great :)

As for the metadata files etc.: everything must be compiled with the exact same toolchain. In any case, for playing around with Rust modules, it is easier to do so in-tree, since as you have seen, you have to compile the kernel with Rust support enabled anyway (and currently to do anything useful you will need to add extra abstractions to the kernel crate, too), thus I recommend to just add your module to the kernel tree directly instead of dealing with two folders/repos.