Re: [PATCH v2] rust: transmute: add `as_bytes` method for `AsBytes` trait

[Danilo Krummrich <dakr@kernel.org>]

On 7/25/25 3:08 PM, Alexandre Courbot wrote:
> diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs
> index 1c7d43771a37b90150de86699f114a2ffb84db91..d4036986a3d7fb97e5da3e121e9590ad23b784e9 100644
> --- a/rust/kernel/transmute.rs
> +++ b/rust/kernel/transmute.rs
> @@ -47,7 +47,16 @@ macro_rules! impl_frombytes {
>   ///
>   /// Values of this type may not contain any uninitialized bytes. This type must not have interior
>   /// mutability.
> -pub unsafe trait AsBytes {}
> +pub unsafe trait AsBytes {
> +    /// Returns `self` as a slice of bytes.
> +    fn as_bytes(&self) -> &[u8] {
> +        let data = (self as *const Self).cast::<u8>();

I'd probably use from_ref() instead. With that,

	Reviewed-by: Danilo Krummrich <dakr@kernel.org>

> +        let len = size_of_val(self);
> +
> +        // SAFETY: `data` is non-null and valid for `len * sizeof::<u8>()` bytes.
> +        unsafe { core::slice::from_raw_parts(data, len) }
> +    }
> +}