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

Danilo Krummrich
2025-07-18T16:43:36Z

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