linux-kernel - Re: [PATCH v2 2/4] rust: xarray: abstract `xa

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aOZhS9nTDnH3Zh7N@google.com>
Date: Wed, 8 Oct 2025 13:04:11 +0000
From: Alice Ryhl <aliceryhl@...gle.com>
To: "Onur Özkan" <work@...rozkan.dev>
Cc: rust-for-linux@...r.kernel.org, ojeda@...nel.org, alex.gaynor@...il.com, 
	boqun.feng@...il.com, gary@...yguo.net, bjorn3_gh@...tonmail.com, 
	lossin@...nel.org, tmgross@...ch.edu, dakr@...nel.org, 
	linux-kernel@...r.kernel.org, acourbot@...dia.com, airlied@...il.com, 
	simona@...ll.ch, maarten.lankhorst@...ux.intel.com, mripard@...nel.org, 
	tzimmermann@...e.de, corbet@....net, lyude@...hat.com, 
	linux-doc@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH v2 2/4] rust: xarray: abstract `xa_alloc`

On Wed, Oct 08, 2025 at 03:46:17PM +0300, Onur Özkan wrote:
> Implements `alloc` function to `XArray<T>` that wraps
> `xa_alloc` safely, which will be used to generate the
> auxiliary device IDs.
> 
> Resolves a task from the nova/core task list under the "XArray
> bindings [XARR]" section in "Documentation/gpu/nova/core/todo.rst"
> file.
> 
> Signed-off-by: Onur Özkan <work@...rozkan.dev>
> ---
>  rust/kernel/xarray.rs | 41 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 40 insertions(+), 1 deletion(-)
> 
> diff --git a/rust/kernel/xarray.rs b/rust/kernel/xarray.rs
> index 90e27cd5197e..0711ccf99fb4 100644
> --- a/rust/kernel/xarray.rs
> +++ b/rust/kernel/xarray.rs
> @@ -10,7 +10,7 @@
>      ffi::c_void,
>      types::{ForeignOwnable, NotThreadSafe, Opaque},
>  };
> -use core::{iter, marker::PhantomData, pin::Pin, ptr::NonNull};
> +use core::{iter, marker::PhantomData, ops::Range, pin::Pin, ptr::NonNull};
>  use pin_init::{pin_data, pin_init, pinned_drop, PinInit};
> 
>  /// An array which efficiently maps sparse integer indices to owned objects.
> @@ -268,6 +268,45 @@ pub fn store(
>              Ok(unsafe { T::try_from_foreign(old) })
>          }
>      }
> +
> +    /// Allocates an empty slot within the given `limit` and stores `value` there.
> +    ///
> +    /// May drop the lock if needed to allocate memory, and then reacquire it afterwards.
> +    ///
> +    /// On success, returns the allocated index.
> +    ///
> +    /// On failure, returns the element which was attempted to be stored.
> +    pub fn alloc(
> +        &mut self,
> +        limit: Range<u32>,

The Range type is inclusive/exclusive but xa_limit is
inclusive/inclusive. They should match to avoid confusion.

Alice