linux-kernel - Re: [PATCH v3 1/2] rust: irq: add support for request

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: <D9ZCFH8F2MBK.1J0BC54P9EWN9@kernel.org>
Date: Sun, 18 May 2025 16:07:20 +0200
From: "Benno Lossin" <lossin@...nel.org>
To: "Alexandre Courbot" <acourbot@...dia.com>, "Daniel Almeida"
 <daniel.almeida@...labora.com>, "Miguel Ojeda" <ojeda@...nel.org>, "Alex
 Gaynor" <alex.gaynor@...il.com>, "Boqun Feng" <boqun.feng@...il.com>, "Gary
 Guo" <gary@...yguo.net>, Björn Roy Baron
 <bjorn3_gh@...tonmail.com>, "Benno Lossin" <benno.lossin@...ton.me>,
 "Andreas Hindborg" <a.hindborg@...nel.org>, "Alice Ryhl"
 <aliceryhl@...gle.com>, "Trevor Gross" <tmgross@...ch.edu>, "Danilo
 Krummrich" <dakr@...nel.org>, "Greg Kroah-Hartman"
 <gregkh@...uxfoundation.org>, "Rafael J. Wysocki" <rafael@...nel.org>,
 "Thomas Gleixner" <tglx@...utronix.de>
Cc: <linux-kernel@...r.kernel.org>, <rust-for-linux@...r.kernel.org>
Subject: Re: [PATCH v3 1/2] rust: irq: add support for request_irq()

On Sun May 18, 2025 at 3:24 PM CEST, Alexandre Courbot wrote:
> Hi Daniel,
>
> On Thu May 15, 2025 at 4:20 AM JST, Daniel Almeida wrote:
> <snip>
>> +/// Callbacks for an IRQ handler.
>> +pub trait Handler: Sync {
>> +    /// The actual handler function. As usual, sleeps are not allowed in IRQ
>> +    /// context.
>> +    fn handle_irq(&self) -> IrqReturn;
>> +}
>> +
>> +impl<T: ?Sized + Handler + Send> Handler for Arc<T> {
>> +    fn handle_irq(&self) -> IrqReturn {
>> +        T::handle_irq(self)
>> +    }
>> +}
>> +
>> +impl<T: ?Sized + Handler, A: Allocator> Handler for Box<T, A> {
>> +    fn handle_irq(&self) -> IrqReturn {
>> +        T::handle_irq(self)
>> +    }
>> +}
>
> I see that every smart pointer would have to implement Handler in order
> to be used with this module, but...
>
>> +#[pin_data(PinnedDrop)]
>> +pub struct Registration<T: Handler> {
>> +    irq: u32,
>> +    #[pin]
>> +    handler: T,
>
> ... what if you store another type `U: Borrow<T>` here, and take it as
> the argument of `register`? This way you should be able to use anything
> that implements Borrow<T>, which includes T itself, Arc<T>, Box<T>, and
> more, and can remove the two impl blocks above.

I don't think that this is easily possible, since then the
`Registration` struct will have two generics, which I think is worse.

The impls above are pretty common for these kinds of traits, so I don't
think it's too bad.

---
Cheers,
Benno