Re: [PATCH 6.12.y 00/60] `alloc`, `#[expect]` and "Custom FFI"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Mar 07, 2025 at 11:49:07PM +0100, Miguel Ojeda wrote:
> Hi Greg, Sasha,
> 
> Please consider this series for 6.12.y. It should apply cleanly on top
> of v6.12.18.
> 
> These are the patches to backport the `alloc` series for Rust, which
> will be useful for Rust Android Binder and others. It also means that,
> with this applied, we will not rely on the standard library `alloc` (and
> the unstable `cfg` option we used) anymore in any stable kernel that
> supports several Rust versions, so e.g. upstream Rust could consider
> removing that `cfg` if they needed.
> 
> The entire series of cherry-picks apply almost cleanly (only 2 trivial
> conflicts) -- to achieve that, I included the `#[expect]` support, which
> will make future backports that use that feature easier anyway. That
> series also enabled some Clippy warnings. We could reduce the series,
> but the end result is warning-free and Clippy is opt-in anyway.
> Out-of-tree code could, of course, see some warnings if they use it.
> 
> I also included a bunch of Clippy warnings cleanups for the DRM QR Code
> to have this series clean up to Rust 1.85.0 (the latest stable), but
> I could send them separately if needed.
> 
> Finally, I included the "Custom FFI" series backport, which in turn
> solves the arm64 + Rust 1.85.0 + `CONFIG_RUST_FW_LOADER_ABSTRACTIONS=y`
> issue. It will also make future patches easier to backport, since we
> will have the same `ffi::` types.
> 
> I tested that the entire series builds between every commit for x86_64
> `LLVM=1` with the latest stable and minimum supported Rust compiler
> versions. I also ran my usual stable kernel tests on the end result;
> that is, boot-tested in QEMU for several architectures etc. In v6.12.18
> for loongarch there is an unrelated error that was not there in v6.12.17
> when I did a previous test run -- reported separately.
> 
> Things could still break, so extra tests on the next -rc from users in
> Cc here would be welcome -- thanks!

All queued up now, thanks!

greg k-h