Re: linux-next: build failure after merge of the rust tree

Danilo Krummrich
2025-06-24T11:12:44Z

On Tue, Jun 24, 2025 at 12:31:52PM +0200, Miguel Ojeda wrote:
> By the way, I also noticed a Clippy warning in `nova-next` (on its
> own, i.e. without merging anything) -- please see below [1].

How do I get this warning to trigger? I did run my usual tests with rustc 1.78
and 1.87.

> [1]
>
> error: mutable borrow from immutable input(s)
> --> rust/kernel/dma.rs:297:78
> |
> 297 | pub unsafe fn as_slice_mut(&self, offset: usize, count:
> usize) -> Result<&mut [T]> {

I think the method isn't wrong, it is unsafe and the safety requirement
explicitly covers this part.

However, we should consider changing it anyways.

> |
> ^^^^^^^^
> |
> note: immutable borrow here
> --> rust/kernel/dma.rs:297:32
> |
> 297 | pub unsafe fn as_slice_mut(&self, offset: usize, count:
> usize) -> Result<&mut [T]> {
> | ^^^^^
> = help: for further information visit
> https://rust-lang.github.io/rust-clippy/master/index.html#mut_from_ref
> = note: `-D clippy::mut-from-ref` implied by `-D warnings`
> = help: to override `-D warnings` add `#[allow(clippy::mut_from_ref)]`