Re: linux-next: manual merge of the rust tree with the driver-core tree

[Danilo Krummrich <dakr@kernel.org>]

On Fri, Jul 18, 2025 at 08:46:53PM +1000, Stephen Rothwell wrote:
> Hi all,
> 
> Today's linux-next merge of the rust tree got a conflict in:
> 
>   rust/kernel/device_id.rs
> 
> between commit:
> 
>   8d84b32075fb ("rust: device_id: split out index support into a separate trait")
> 
> from the driver-core tree and commit:
> 
>   5e30550558b1 ("rust: enable `clippy::as_underscore` lint")
> 
> from the rust tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.

Thanks, the diff looks good!

> -- 
> Cheers,
> Stephen Rothwell
> 
> diff --cc rust/kernel/device_id.rs
> index 8ed2c946144c,3dc72ca8cfc2..000000000000
> --- a/rust/kernel/device_id.rs
> +++ b/rust/kernel/device_id.rs
> @@@ -94,16 -77,14 +94,16 @@@ impl<T: RawDeviceId, U, const N: usize
>               // SAFETY: by the safety requirement of `RawDeviceId`, we're guaranteed that `T` is
>               // layout-wise compatible with `RawType`.
>               raw_ids[i] = unsafe { core::mem::transmute_copy(&ids[i].0) };
>  -            // SAFETY: by the safety requirement of `RawDeviceId`, this would be effectively
>  -            // `raw_ids[i].driver_data = i;`.
>  -            unsafe {
>  -                raw_ids[i]
>  -                    .as_mut_ptr()
>  -                    .byte_add(T::DRIVER_DATA_OFFSET)
>  -                    .cast::<usize>()
>  -                    .write(i);
>  +            if let Some(data_offset) = data_offset {
>  +                // SAFETY: by the safety requirement of this function, this would be effectively
>  +                // `raw_ids[i].driver_data = i;`.
>  +                unsafe {
>  +                    raw_ids[i]
>  +                        .as_mut_ptr()
> -                         .byte_offset(data_offset as _)
> ++                        .byte_add(data_offset)
>  +                        .cast::<usize>()
>  +                        .write(i);
>  +                }
>               }
>   
>               // SAFETY: this is effectively a move: `infos[i] = ids[i].1`. We make a copy here but