Message ID | 20230630150216.109789-1-benno.lossin@proton.me |
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State | New |
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[2620:137:e000::1:20]) by mx.google.com with ESMTP id j190-20020a6380c7000000b00553c4551a08si2979138pgd.887.2023.06.30.08.10.41; Fri, 30 Jun 2023 08:10:55 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@proton.me header.s=protonmail header.b=NrF664B6; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=proton.me Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232893AbjF3PDm (ORCPT <rfc822;nicolai.engesland@gmail.com> + 99 others); Fri, 30 Jun 2023 11:03:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232883AbjF3PDk (ORCPT <rfc822;linux-kernel@vger.kernel.org>); Fri, 30 Jun 2023 11:03:40 -0400 Received: from mail-40133.protonmail.ch (mail-40133.protonmail.ch [185.70.40.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4618F171E for <linux-kernel@vger.kernel.org>; Fri, 30 Jun 2023 08:03:36 -0700 (PDT) Date: Fri, 30 Jun 2023 15:03:23 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1688137413; x=1688396613; bh=GOuPFgT87znF0ebWMyLwXo4ofXzgfLkd6vzl1Y3CfqA=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=NrF664B6Yj0S5v0K2a8SBUlj4tguRpmjCqdIi0VDecC5Af+oGs8Jow/Z7UlUxgpU6 sr/lRkn5WLpKUuwrJ28b9xhWvtVm92iXjHoqHgWwALy5WJK8wMWigXQKzq1J9YbtoY uVH5+0WMMG8zV1uDUJTmaUnY8YJ+2i+atSwnmEPX3gyffdh+XdnG+oPAq8RegM1QH+ oayFkKeYdKuzUUuBX30Zi8Cq1uFdEhbv/o0k0GnPqXGRIPHirt2o3vNMtQIAcGGof+ trOWTeMVgrocDBf+d+8C2bakHzV+avyR/N5Pe+Zj8MW4uCaACwlW5L00vXRO8abiIz EQVCjKMpULetA== To: Miguel Ojeda <ojeda@kernel.org>, Wedson Almeida Filho <wedsonaf@gmail.com>, Alex Gaynor <alex.gaynor@gmail.com> From: Benno Lossin <benno.lossin@proton.me> Cc: 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>, Alice Ryhl <aliceryhl@google.com>, Andreas Hindborg <nmi@metaspace.dk>, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev Subject: [PATCH] rust: types: make `Opaque` be `!Unpin` Message-ID: <20230630150216.109789-1-benno.lossin@proton.me> Feedback-ID: 71780778:user:proton MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: <linux-kernel.vger.kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1770140840485918299?= X-GMAIL-MSGID: =?utf-8?q?1770140840485918299?= |
Series |
rust: types: make `Opaque` be `!Unpin`
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Commit Message
Benno Lossin
June 30, 2023, 3:03 p.m. UTC
Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust
guarantee: the assumption that the type `T` can be freely moved. This is
not the case for many types from the C side (e.g. if they contain a
`struct list_head`). This change removes the need to add a
`PhantomPinned` field manually to Rust structs that contain C structs
which must not be moved.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
---
This patch depends on the patch that swaps `UnsafeCell` with
`MaybeUninit` inside `Opaque` [1].
[1]: https://lore.kernel.org/rust-for-linux/20230614115328.2825961-1-aliceryhl@google.com/
---
rust/kernel/types.rs | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
Comments
On 6/30/23 17:03, Benno Lossin wrote: > Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust > guarantee: the assumption that the type `T` can be freely moved. This is > not the case for many types from the C side (e.g. if they contain a > `struct list_head`). This change removes the need to add a > `PhantomPinned` field manually to Rust structs that contain C structs > which must not be moved. > > Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
On Fri, 30 Jun 2023 15:03:23 +0000 Benno Lossin <benno.lossin@proton.me> wrote: > Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust > guarantee: the assumption that the type `T` can be freely moved. This is > not the case for many types from the C side (e.g. if they contain a > `struct list_head`). This change removes the need to add a > `PhantomPinned` field manually to Rust structs that contain C structs > which must not be moved. > > Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> > --- > This patch depends on the patch that swaps `UnsafeCell` with > `MaybeUninit` inside `Opaque` [1]. > > [1]: https://lore.kernel.org/rust-for-linux/20230614115328.2825961-1-aliceryhl@google.com/ > --- > rust/kernel/types.rs | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs > index fb41635f1e1f..e664a2beef30 100644 > --- a/rust/kernel/types.rs > +++ b/rust/kernel/types.rs > @@ -6,7 +6,7 @@ > use alloc::boxed::Box; > use core::{ > cell::UnsafeCell, > - marker::PhantomData, > + marker::{PhantomData, PhantomPinned}, > mem::MaybeUninit, > ops::{Deref, DerefMut}, > ptr::NonNull, > @@ -224,17 +224,26 @@ fn drop(&mut self) { > /// > /// This is meant to be used with FFI objects that are never interpreted by Rust code. > #[repr(transparent)] > -pub struct Opaque<T>(UnsafeCell<MaybeUninit<T>>); > +pub struct Opaque<T> { > + value: UnsafeCell<MaybeUninit<T>>, > + _pin: PhantomPinned, > +} > > impl<T> Opaque<T> { > /// Creates a new opaque value. > pub const fn new(value: T) -> Self { > - Self(UnsafeCell::new(MaybeUninit::new(value))) > + Self { > + value: UnsafeCell::new(MaybeUninit::new(value)), > + _pin: PhantomPinned, > + } > } > > /// Creates an uninitialised value. > pub const fn uninit() -> Self { > - Self(UnsafeCell::new(MaybeUninit::uninit())) > + Self { > + value: UnsafeCell::new(MaybeUninit::uninit()), > + _pin: PhantomPinned, > + } > } > > /// Creates a pin-initializer from the given initializer closure. > @@ -258,7 +267,7 @@ pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> { > > /// Returns a raw pointer to the opaque data. > pub fn get(&self) -> *mut T { > - UnsafeCell::get(&self.0).cast::<T>() > + UnsafeCell::get(&self.value).cast::<T>() > } > > /// Gets the value behind `this`.
Benno Lossin <benno.lossin@proton.me> writes: > Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust > guarantee: the assumption that the type `T` can be freely moved. This is > not the case for many types from the C side (e.g. if they contain a > `struct list_head`). This change removes the need to add a > `PhantomPinned` field manually to Rust structs that contain C structs > which must not be moved. > > Signed-off-by: Benno Lossin <benno.lossin@proton.me> > --- Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> > This patch depends on the patch that swaps `UnsafeCell` with > `MaybeUninit` inside `Opaque` [1]. > > [1]: https://lore.kernel.org/rust-for-linux/20230614115328.2825961-1-aliceryhl@google.com/ > --- > rust/kernel/types.rs | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs > index fb41635f1e1f..e664a2beef30 100644 > --- a/rust/kernel/types.rs > +++ b/rust/kernel/types.rs > @@ -6,7 +6,7 @@ > use alloc::boxed::Box; > use core::{ > cell::UnsafeCell, > - marker::PhantomData, > + marker::{PhantomData, PhantomPinned}, > mem::MaybeUninit, > ops::{Deref, DerefMut}, > ptr::NonNull, > @@ -224,17 +224,26 @@ fn drop(&mut self) { > /// > /// This is meant to be used with FFI objects that are never interpreted by Rust code. > #[repr(transparent)] > -pub struct Opaque<T>(UnsafeCell<MaybeUninit<T>>); > +pub struct Opaque<T> { > + value: UnsafeCell<MaybeUninit<T>>, > + _pin: PhantomPinned, > +} > > impl<T> Opaque<T> { > /// Creates a new opaque value. > pub const fn new(value: T) -> Self { > - Self(UnsafeCell::new(MaybeUninit::new(value))) > + Self { > + value: UnsafeCell::new(MaybeUninit::new(value)), > + _pin: PhantomPinned, > + } > } > > /// Creates an uninitialised value. > pub const fn uninit() -> Self { > - Self(UnsafeCell::new(MaybeUninit::uninit())) > + Self { > + value: UnsafeCell::new(MaybeUninit::uninit()), > + _pin: PhantomPinned, > + } > } > > /// Creates a pin-initializer from the given initializer closure. > @@ -258,7 +267,7 @@ pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> { > > /// Returns a raw pointer to the opaque data. > pub fn get(&self) -> *mut T { > - UnsafeCell::get(&self.0).cast::<T>() > + UnsafeCell::get(&self.value).cast::<T>() > } > > /// Gets the value behind `this`.
On Fri, Jun 30, 2023 at 5:03 PM Benno Lossin <benno.lossin@proton.me> wrote: > > Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust > guarantee: the assumption that the type `T` can be freely moved. This is > not the case for many types from the C side (e.g. if they contain a > `struct list_head`). This change removes the need to add a > `PhantomPinned` field manually to Rust structs that contain C structs > which must not be moved. > > Signed-off-by: Benno Lossin <benno.lossin@proton.me> Applied to `rust-next` -- thanks everyone! Cheers, Miguel
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index fb41635f1e1f..e664a2beef30 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -6,7 +6,7 @@ use alloc::boxed::Box; use core::{ cell::UnsafeCell, - marker::PhantomData, + marker::{PhantomData, PhantomPinned}, mem::MaybeUninit, ops::{Deref, DerefMut}, ptr::NonNull, @@ -224,17 +224,26 @@ fn drop(&mut self) { /// /// This is meant to be used with FFI objects that are never interpreted by Rust code. #[repr(transparent)] -pub struct Opaque<T>(UnsafeCell<MaybeUninit<T>>); +pub struct Opaque<T> { + value: UnsafeCell<MaybeUninit<T>>, + _pin: PhantomPinned, +} impl<T> Opaque<T> { /// Creates a new opaque value. pub const fn new(value: T) -> Self { - Self(UnsafeCell::new(MaybeUninit::new(value))) + Self { + value: UnsafeCell::new(MaybeUninit::new(value)), + _pin: PhantomPinned, + } } /// Creates an uninitialised value. pub const fn uninit() -> Self { - Self(UnsafeCell::new(MaybeUninit::uninit())) + Self { + value: UnsafeCell::new(MaybeUninit::uninit()), + _pin: PhantomPinned, + } } /// Creates a pin-initializer from the given initializer closure. @@ -258,7 +267,7 @@ pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> { /// Returns a raw pointer to the opaque data. pub fn get(&self) -> *mut T { - UnsafeCell::get(&self.0).cast::<T>() + UnsafeCell::get(&self.value).cast::<T>() } /// Gets the value behind `this`.