Rust CI wanted features & bugfixes

[ojeda]

Note: the policy for the Rust for Linux CI job in upstream Rust is at https://rustc-dev-guide.rust-lang.org/tests/rust-for-linux.html.

Features that we would like to see

Required (we almost certainly want them)

• Run objtool to detect CFI violations.

Nice to have (not critical, we could workaround if needed, etc.)

Low priority (we will likely not use them in the end)

Done (stabilized, fixed, not needed anymore, etc.)

• The kernel in the Rust CI.

  • Ideally in the pre-merge CI.
  • Draft policy from RustNL: https://hackmd.io/@rustnl-2024-unconf/HkutiwyQR.
  • PR: Add Rust for Linux auto CI job rust-lang/rust#125209 (2024-06-10).
  • PR (Rust for Linux ping group - initial marker team to list members): Add a Rust for Linux marker team rust-lang/team#1457.
  • PR (Rust for Linux ping group - actual ping group): Create a triagebot ping group for Rust for Linux rust-lang/rust#125375.
  • PR (Rust for Linux ping group - docs on dev guide): Add Rust for Linux notification group entry rust-lang/rustc-dev-guide#1984.
  • PR (Rust for Linux ping group - fill marker team): Fill the Rust for Linux ping group rust-lang/team#1465.
  • PR (Rust for Linux ping group - fill marker team 2): Add Vincenzo to Rust for Linux ping group rust-lang/team#1466.
  • PR (Renamed CI job): CI: rename Rust for Linux CI job rust-lang/rust#127023.
  • PR (Documentation about policy): Add Rust for Linux integration tests documentation rust-lang/rustc-dev-guide#2004.
  • Zulip: https://rust-lang.zulipchat.com/#narrow/stream/242791-t-infra/topic/Testing.20Rust.20for.20Linux.20in.20our.20CI.
  • Zulip (question about process, long after it was added): https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/RFL.20CI.20Job.

• Move RFL job forward to v6.11-rc1.

  • PR: CI: move RFL job forward to v6.11-rc1 rust-lang/rust#128322.

• Build the generated doctests and documentation.

  • PR: CI: rfl: build the generated doctests and documentation rust-lang/rust#128367.

• Add a few more tools and steps (Clippy, rustfmt, -Zunpretty=expanded).

  • PR: CI: rfl: add more tools and steps rust-lang/rust#128928.

• Move RFL job forward to v6.12-rc2.

  • PR: CI: rfl: move job forward to Linux v6.12-rc2 rust-lang/rust#131378.

• Move RFL job forward to rust-next (i.e. to a commit, temporarily) to avoid using feature(receiver_trait).

  • PR: CI: rfl: use rust-next temporary commit rust-lang/rust#132058.
  • Needed for: Rename Receiver -> LegacyReceiver rust-lang/rust#130225.

• Update and make the policy official.

  • PR: update rfl ci job policy rust-lang/rustc-dev-guide#2108.

• Move RFL job forward to v6.13-rc1.

  • PR: CI: rfl: move job forward to Linux v6.13-rc1 rust-lang/rust#133827.

• Move RFL job forward to v6.14-rc3.

  • PR: CI: rfl: move job forward to Linux v6.14-rc3 rust-lang/rust#137169.

• Ping group: remove Wedson.

  • PR: Rust for Linux: remove Wedson rust-lang/team#1658.

• Ping group: add Danilo.

  • PR: Rust for Linux: add Danilo rust-lang/team#1659.

• Re-enable the Rust for Linux job using PATH.

  • PR: Do not install rustup on Rust for Linux job rust-lang/rust#137947.

• Move RFL job forward to v6.15-rc4.

  • PR: CI: rfl: move job forward to Linux v6.15-rc4 rust-lang/rust#140470.

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Bugs that we would like to see fixed

Required (we almost certainly want them)

Nice to have (probably not critical, we could workaround if needed, etc.)

Low priority (we will likely not use them in the end)

Done (stabilized, fixed, or not needed anymore, etc.)

[keys-i]

is this done?

[ojeda]

These are meta-issues to hold live lists, i.e. they can grow over time. We could close on 0 and reopen if something gets added, but I am not sure how that would be useful.

[Conan-Kudo]

Do we test Clang + LTO alongside the other modes (Clang without LTO, GCC, etc.)?

[ojeda]

Only a single, basic built-test is done, and only for the Rust side of the kernel, at least so far. It is mainly meant to catch unintentional changes around unstable features that would break the kernel's build.

[davidtwco]

In the 23/10/2024 Project-RfL meeting, we discussed wanting the compiler team to come up with an official policy on what we'll do when the CI job breaks, but I think what you've already got in the dev guide is pretty good and I'm happy for us to stick with that. If we end up finding out that policy doesn't work then we can change it but it seems like a very sensible starting point to me. I'll update the dev guide to remove "unofficial".

cc @wesleywiser

[ojeda]

Thanks for taking a look David. That is great -- if we can help with something or something needs changing in the instructions/guidelines, please of course ping us, we are happy to adjust. The CI job has worked great so far for both Rust and the kernel, as far as I can tell.