Re: [PATCH v6 05/26] rust: alloc: add module `allocator_test`

[Gary Guo <gary@garyguo.net>]

On Fri, 16 Aug 2024 02:10:47 +0200
Danilo Krummrich <dakr@kernel.org> wrote:

> `Allocator`s, such as `Kmalloc`, will be used by e.g. `Box` and `Vec` in
> subsequent patches, and hence this dependency propagates throughout the
> whole kernel.
> 
> Add the `allocator_test` module that provides an empty implementation
> for all `Allocator`s in the kernel, such that we don't break the
> `rusttest` make target in subsequent patches.
> 
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> Reviewed-by: Benno Lossin <benno.lossin@proton.me>
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/alloc.rs                |  9 +++++++--
>  rust/kernel/alloc/allocator_test.rs | 19 +++++++++++++++++++
>  2 files changed, 26 insertions(+), 2 deletions(-)
>  create mode 100644 rust/kernel/alloc/allocator_test.rs
> 
> diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
> index 477dbe3c5a2f..91a367a58f36 100644
> --- a/rust/kernel/alloc.rs
> +++ b/rust/kernel/alloc.rs
> @@ -2,12 +2,17 @@
>  
>  //! Extensions to the [`alloc`] crate.
>  
> -#[cfg(not(test))]
> -#[cfg(not(testlib))]
> +#[cfg(not(any(test, testlib)))]
>  pub mod allocator;
>  pub mod box_ext;
>  pub mod vec_ext;
>  
> +#[cfg(any(test, testlib))]
> +pub mod allocator_test;
> +
> +#[cfg(any(test, testlib))]
> +pub use self::allocator_test as allocator;
> +
>  /// Indicates an allocation error.
>  #[derive(Copy, Clone, PartialEq, Eq, Debug)]
>  pub struct AllocError;
> diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs
> new file mode 100644
> index 000000000000..4785efc474a7
> --- /dev/null
> +++ b/rust/kernel/alloc/allocator_test.rs
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#![allow(missing_docs)]
> +
> +use super::{AllocError, Allocator, Flags};
> +use core::alloc::Layout;
> +use core::ptr::NonNull;
> +
> +pub struct Kmalloc;
> +
> +unsafe impl Allocator for Kmalloc {
> +    unsafe fn realloc(
> +        _ptr: Option<NonNull<u8>>,
> +        _layout: Layout,
> +        _flags: Flags,
> +    ) -> Result<NonNull<[u8]>, AllocError> {
> +        panic!();
> +    }
> +}