On Wed, Jan 28, 2026 at 08:28:33PM -0600, Timur Tabi wrote:
> [PATCH v6 3/7] gpu: nova-core: implement BinaryWriter for
> CoherentAllocation<u8>
The commit title says 'gpu: nova-core:' but this is primarily a change
to rust/kernel/dma.rs, so it should say 'rust: dma:' or similar.
> +// SAFETY: Sharing `&CoherentAllocation` across threads is safe if `T` is
> `Sync`, because all
> +// methods that access the buffer contents (`field_read`, `field_write`,
> `as_slice`,
> +// `as_slice_mut`) are `unsafe`, and callers are responsible for ensuring no
> data races occur.
> +// The safe methods only return metadata or raw pointers whose use requires
> `unsafe`.
> +unsafe impl<T: AsBytes + FromBytes + Sync> Sync for CoherentAllocation<T> {}
This change is unrelated to implementing BinaryWriter for
CoherentAllocation.
> +impl debugfs::BinaryWriter for CoherentAllocation<u8> {
> + fn write_to_slice(
> + &self,
> + writer: &mut UserSliceWriter,
> + offset: &mut file::Offset,
> + ) -> Result<usize> {
> + if offset.is_negative() {
> + return Err(EINVAL);
> + }
> +
> + let offset_val: usize = (*offset).try_into().map_err(|_| EINVAL)?;
If the user seeks to a large offset, this leads to EINVAL. But the
correct behavior for a file is to simply return Ok(0) in such case.
Alice
