Re: [PATCH v2 2/7] rust: cred: add Rust abstraction for `struct cred`

From: Alice Ryhl
Date: Mon Dec 11 2023 - 10:34:37 EST


Benno Lossin <benno.lossin@xxxxxxxxx> writes:
> On 12/6/23 12:59, Alice Ryhl wrote:
> > +/// Wraps the kernel's `struct cred`.
> > +///
> > +/// # Invariants
> > +///
> > +/// Instances of this type are always ref-counted, that is, a call to `get_cred` ensures that the
> > +/// allocation remains valid at least until the matching call to `put_cred`.
> > +#[repr(transparent)]
> > +pub struct Credential(pub(crate) Opaque<bindings::cred>);
>
> Why is the field `pub(crate)`?

Historical accident. It isn't needed anymore. I'll remove it.

> > + unsafe fn dec_ref(obj: core::ptr::NonNull<Self>) {
> > + // SAFETY: The safety requirements guarantee that the refcount is nonzero.
>
> Can you also justify the `cast()`?

Will do.

Alice