Re: [PATCH v3 1/4] rust: types: implement ForeignOwnable for ARef<T>

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Missing `#[inline]` annotations on small abstraction functions in `ForeignOwnable for ARef<T>`.
--

commit 4199b74db0ae4068188998ff9452d6df8acb7816
Author: Danilo Krummrich <dakr@kernel.org>

rust: types: implement ForeignOwnable for ARef<T>

Implement ForeignOwnable for ARef<T>, making it possible for C code to
own an ARef<T>.

> diff --git a/rust/kernel/sync/aref.rs b/rust/kernel/sync/aref.rs
> --- a/rust/kernel/sync/aref.rs
> +++ b/rust/kernel/sync/aref.rs

[ ... ]

> +unsafe impl<T: AlwaysRefCounted + 'static> ForeignOwnable for ARef<T> {
> +    const FOREIGN_ALIGN: usize = core::mem::align_of::<T>();
> +
> +    type Borrowed<'a> = &'a T;
> +    type BorrowedMut<'a> = &'a T;
> +
> +    fn into_foreign(self) -> *mut c_void {
> +        ARef::into_raw(self).as_ptr().cast()
> +    }
> +
> +    unsafe fn from_foreign(ptr: *mut c_void) -> Self {
> +        // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
> +        // call to `Self::into_foreign`.
> +        let ptr = unsafe { NonNull::new_unchecked(ptr.cast()) };
> +
> +        // SAFETY: `ptr` came from `into_foreign`, which consumed an `ARef` without decrementing
> +        // the refcount, so we can transfer the ownership to the new `ARef`.
> +        unsafe { ARef::from_raw(ptr) }
> +    }

[Severity: Low]
This isn't a bug, but should into_foreign() and from_foreign() be annotated 
with #[inline]? 

Since aref.rs is a core abstraction, the Rust coding guidelines suggest adding 
the inline annotation to small or forwarding functions to help with cross-crate 
inlining optimizations. Would it make sense to add this to borrow() and 
borrow_mut() in this block as well?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260618132628.3811068-2-phasta@kernel.org?part=1