On Sat, Jul 12, 2025 at 08:04:48PM +0200, Benno Lossin wrote:
On Sat Jul 12, 2025 at 7:10 PM CEST, Miguel Ojeda wrote:
Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler may warn:
error: trait `MustNotImplDrop` is never used --> rust/kernel/init/macros.rs:927:15 | 927 | trait MustNotImplDrop {} | ^^^^^^^^^^^^^^^ | ::: rust/kernel/sync/arc.rs:133:1 | 133 | #[pin_data] | ----------- in this procedural macro expansion | = note: `-D dead-code` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(dead_code)]` = note: this error originates in the macro `$crate::__pin_data` which comes from the expansion of the attribute macro `pin_data` (in Nightly builds, run with -Z macro-backtrace for more info)Thus `allow` it to clean it up.
This is a bit strange, I can't directly reproduce the issue... I already get this warning in 1.88:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=465f71a848e77ac3f7a96a0af6bc9e2aThis does not happen in mainline nor 6.15.y, because there the macro was moved out of the `kernel` crate, and `dead_code` warnings are not emitted if the macro is foreign to the crate. Thus this patch is directly sent to stable and intended for 6.12.y only.
Similarly, it is not needed in previous LTSs, because there the Rust version is pinned.
Cc: Benno Lossin lossin@kernel.org Signed-off-by: Miguel Ojeda ojeda@kernel.org
Anyways the patch itself looks fine, nobody should care about the dead-code warning (since it is in fact used to prevent `Drop` being implemented).
Acked-by: Benno Lossin lossin@kernel.org
Thanks, now queued up.
greg k-h