linux-kernel - Re: [PATCH v5 3/7] rust: alloc: add Vec::push_within

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: <CAH5fLggG7Af0ZBjhMLuSOX8FNGepeo8eEO77dcN3JSohog0XtA@mail.gmail.com>
Date: Fri, 2 May 2025 16:25:01 +0200
From: Alice Ryhl <aliceryhl@...gle.com>
To: Greg KH <gregkh@...uxfoundation.org>
Cc: Danilo Krummrich <dakr@...nel.org>, Matthew Maurer <mmaurer@...gle.com>, rust-for-linux@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 3/7] rust: alloc: add Vec::push_within_capacity

On Fri, May 2, 2025 at 4:07 PM Greg KH <gregkh@...uxfoundation.org> wrote:
>
> On Fri, May 02, 2025 at 01:19:31PM +0000, Alice Ryhl wrote:
> > This introduces a new method called `push_within_capacity` for appending
> > to a vector without attempting to allocate if the capacity is full. Rust
> > Binder will use this in various places to safely push to a vector while
> > holding a spinlock.
> >
> > The implementation is moved to a push_within_capacity_unchecked method.
> > This is preferred over having push() call push_within_capacity()
> > followed by an unwrap_unchecked() for simpler unsafe.
> >
> > Panics in the kernel are best avoided when possible, so an error is
> > returned if the vector does not have sufficient capacity. An error type
> > is used rather than just returning Result<(),T> to make it more
> > convenient for callers (i.e. they can use ? or unwrap).
> >
> > Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
> > +    /// Appends an element to the back of the [`Vec`] instance without reallocating.
> > +    ///
> > +    /// # Safety
> > +    ///
> > +    /// The length must be less than the capacity.
> > +    pub unsafe fn push_within_capacity_unchecked(&mut self, v: T) {
>
> Why does this have to be public?  Does binder need to call this instead
> of just push_within_capacity()?

It does not need to be public.

Alice