6.12-stable review patch. If anyone has any objections, please let me know.
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From: Miguel Ojeda ojeda@kernel.org
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 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.
Acked-by: Benno Lossin lossin@kernel.org Signed-off-by: Miguel Ojeda ojeda@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- rust/kernel/init/macros.rs | 2 ++ 1 file changed, 2 insertions(+)
--- a/rust/kernel/init/macros.rs +++ b/rust/kernel/init/macros.rs @@ -924,6 +924,7 @@ macro_rules! __pin_data { // We prevent this by creating a trait that will be implemented for all types implementing // `Drop`. Additionally we will implement this trait for the struct leading to a conflict, // if it also implements `Drop` + #[allow(dead_code)] trait MustNotImplDrop {} #[expect(drop_bounds)] impl<T: ::core::ops::Drop> MustNotImplDrop for T {} @@ -932,6 +933,7 @@ macro_rules! __pin_data { // We also take care to prevent users from writing a useless `PinnedDrop` implementation. // They might implement `PinnedDrop` correctly for the struct, but forget to give // `PinnedDrop` as the parameter to `#[pin_data]`. + #[allow(dead_code)] #[expect(non_camel_case_types)] trait UselessPinnedDropImpl_you_need_to_specify_PinnedDrop {} impl<T: $crate::init::PinnedDrop>