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From: Trevor Gross <tmgross@umich.edu>
Date: Mon, 5 Feb 2024 21:57:42 -0500
Message-ID: <CALNs47uVdBhc1bm0VrXacFNasbN9jUnuphGFRgSpX-4eng46+A@mail.gmail.com>
Subject: Re: [PATCH v4 4/9] rust: cred: add Rust abstraction for `struct cred`
To: Alice Ryhl <aliceryhl@google.com>
Cc: Miguel Ojeda <ojeda@kernel.org>, Alex Gaynor <alex.gaynor@gmail.com>, 
	Wedson Almeida Filho <wedsonaf@gmail.com>, Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>, 
	=?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>, 
	Benno Lossin <benno.lossin@proton.me>, Andreas Hindborg <a.hindborg@samsung.com>, 
	Peter Zijlstra <peterz@infradead.org>, Alexander Viro <viro@zeniv.linux.org.uk>, 
	Christian Brauner <brauner@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
	=?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= <arve@android.com>, 
	Todd Kjos <tkjos@android.com>, Martijn Coenen <maco@android.com>, 
	Joel Fernandes <joel@joelfernandes.org>, Carlos Llamas <cmllamas@google.com>, 
	Suren Baghdasaryan <surenb@google.com>, Dan Williams <dan.j.williams@intel.com>, 
	Kees Cook <keescook@chromium.org>, Matthew Wilcox <willy@infradead.org>, 
	Thomas Gleixner <tglx@linutronix.de>, Daniel Xu <dxu@dxuuu.xyz>, linux-kernel@vger.kernel.org, 
	rust-for-linux@vger.kernel.org, linux-fsdevel@vger.kernel.org
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On Fri, Feb 2, 2024 at 5:57=E2=80=AFAM Alice Ryhl <aliceryhl@google.com> wr=
ote:
>
> From: Wedson Almeida Filho <wedsonaf@gmail.com>
>
> Add a wrapper around `struct cred` called `Credential`, and provide
> functionality to get the `Credential` associated with a `File`.
>
> Rust Binder must check the credentials of processes when they attempt to
> perform various operations, and these checks usually take a
> `&Credential` as parameter. The security_binder_set_context_mgr function
> would be one example. This patch is necessary to access these security_*
> methods from Rust.
>
> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
> Co-developed-by: Alice Ryhl <aliceryhl@google.com>
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> ---
> [...]
> diff --git a/rust/kernel/cred.rs b/rust/kernel/cred.rs
> new file mode 100644
> index 000000000000..fabc50e48c9e
> --- /dev/null
> +++ b/rust/kernel/cred.rs
> @@ -0,0 +1,72 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +//! Credentials management.
> +//!
> +//! C header: [`include/linux/cred.h`](srctree/include/linux/cred.h).
> +//!
> +//! Reference: <https://www.kernel.org/doc/html/latest/security/credenti=
als.html>
> +
> +use crate::{
> +    bindings,
> +    types::{AlwaysRefCounted, Opaque},
> +};
> +
> +/// Wraps the kernel's `struct cred`.

Could you add a brief description to the summary line?

> +/// Most fields of credentials are immutable. When things have their cre=
dentials changed, that
> +/// happens by replacing the credential instad of changing an existing c=
redential. See the [kernel

s/instad/instead

> [...]

Reviewed-by: Trevor Gross <tmgross@umich.edu>