From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C165621D2BD; Fri, 4 Oct 2024 15:43:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728056597; cv=none; b=JURRgsTNRIw/J0E5+T0m5FdEFOi2fL/yEmDBXQc8NHEpIQ6+WP/37fOKKgKvvKFaE6TPRveAzxdo6f4QZrcSRqf5qRqVq3ARIHlh461+p5leFrCXC2v/7rFe2ZTuTINr16EiJp7dzUmr/qIlsOq2+yAZEIJOz45rdoDdOwTKfjU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728056597; c=relaxed/simple; bh=kazRakNrpHOowneaJN4zcTb6ci/LaZH4uk5yeLlVimc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ucjDObFmAPebfPDKDpauW8TfuVunpyEXkf7hkxSdlZ3/L5PQrGmJASQ66TfOc+YIUhSq/SQPXbA6ZfbjoFloxC0e7JvFk1hcP5XRRBjjXWK9wJr+ScAw0VoTcP+WWhjmLvs3Npq4uUIc64LdpE2MtL5wmekI86sRQ3aqIr8SAkk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PY60yaBL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PY60yaBL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4582BC4CECE; Fri, 4 Oct 2024 15:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728056596; bh=kazRakNrpHOowneaJN4zcTb6ci/LaZH4uk5yeLlVimc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PY60yaBLX5FkWroGne2wbiRf3YOduSZVZm5AHgfyk3WHkfWbM3EuOrVqXycz4PQq+ L7kLm6ETYxc6+1xIy6vIEplED3xtKssri1U63By0v6Aprb3PO7CD48G/KQPD32sgtJ vci/dSKvPyxY601jRKNuA/LQ03a7e2hPiAZLWPQqRQUms6VALZyIA9L5y8jP4wxwV7 O+XD4vvvKldAUaErm99zXSSYqGHqSfxaJm+IqSE2EyH5k/x7lOfsO7Gdrk0RwSzZXs UZB3fpr7e5dFB5csBMAGxrOWgFIN4xCvRqYtAUB2d6YvLLzFf1UgIPk0KrpdD0lUdG 7FqY3nKH27GTg== From: Danilo Krummrich To: ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, aliceryhl@google.com, akpm@linux-foundation.org Cc: daniel.almeida@collabora.com, faith.ekstrand@collabora.com, boris.brezillon@collabora.com, lina@asahilina.net, mcanal@igalia.com, zhiw@nvidia.com, cjia@nvidia.com, jhubbard@nvidia.com, airlied@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-mm@kvack.org, Danilo Krummrich Subject: [PATCH v9 13/29] rust: alloc: remove extension of std's `Box` Date: Fri, 4 Oct 2024 17:41:17 +0200 Message-ID: <20241004154149.93856-14-dakr@kernel.org> X-Mailer: git-send-email 2.46.1 In-Reply-To: <20241004154149.93856-1-dakr@kernel.org> References: <20241004154149.93856-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Now that all existing `Box` users were moved to the kernel `Box` type, remove the `BoxExt` extension and all other related extensions. Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Signed-off-by: Danilo Krummrich --- rust/kernel/alloc.rs | 1 - rust/kernel/alloc/box_ext.rs | 89 ------------------------------------ rust/kernel/init.rs | 46 +------------------ rust/kernel/lib.rs | 1 - rust/kernel/prelude.rs | 4 +- rust/kernel/types.rs | 50 -------------------- 6 files changed, 3 insertions(+), 188 deletions(-) delete mode 100644 rust/kernel/alloc/box_ext.rs diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 12cd52f83222..ebe58247504f 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -4,7 +4,6 @@ #[cfg(not(any(test, testlib)))] pub mod allocator; -pub mod box_ext; pub mod kbox; pub mod vec_ext; diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs deleted file mode 100644 index 7009ad78d4e0..000000000000 --- a/rust/kernel/alloc/box_ext.rs +++ /dev/null @@ -1,89 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -//! Extensions to [`Box`] for fallible allocations. - -use super::{AllocError, Flags}; -use alloc::boxed::Box; -use core::{mem::MaybeUninit, ptr, result::Result}; - -/// Extensions to [`Box`]. -pub trait BoxExt: Sized { - /// Allocates a new box. - /// - /// The allocation may fail, in which case an error is returned. - fn new(x: T, flags: Flags) -> Result; - - /// Allocates a new uninitialised box. - /// - /// The allocation may fail, in which case an error is returned. - fn new_uninit(flags: Flags) -> Result>, AllocError>; - - /// Drops the contents, but keeps the allocation. - /// - /// # Examples - /// - /// ``` - /// use kernel::alloc::{flags, box_ext::BoxExt}; - /// let value = Box::new([0; 32], flags::GFP_KERNEL)?; - /// assert_eq!(*value, [0; 32]); - /// let mut value = Box::drop_contents(value); - /// // Now we can re-use `value`: - /// value.write([1; 32]); - /// // SAFETY: We just wrote to it. - /// let value = unsafe { value.assume_init() }; - /// assert_eq!(*value, [1; 32]); - /// # Ok::<(), Error>(()) - /// ``` - fn drop_contents(this: Self) -> Box>; -} - -impl BoxExt for Box { - fn new(x: T, flags: Flags) -> Result { - let mut b = >::new_uninit(flags)?; - b.write(x); - // SAFETY: We just wrote to it. - Ok(unsafe { b.assume_init() }) - } - - #[cfg(any(test, testlib))] - fn new_uninit(_flags: Flags) -> Result>, AllocError> { - Ok(Box::new_uninit()) - } - - #[cfg(not(any(test, testlib)))] - fn new_uninit(flags: Flags) -> Result>, AllocError> { - let ptr = if core::mem::size_of::>() == 0 { - core::ptr::NonNull::<_>::dangling().as_ptr() - } else { - let layout = core::alloc::Layout::new::>(); - - // SAFETY: Memory is being allocated (first arg is null). The only other source of - // safety issues is sleeping on atomic context, which is addressed by klint. Lastly, - // the type is not a SZT (checked above). - let ptr = - unsafe { super::allocator::krealloc_aligned(core::ptr::null_mut(), layout, flags) }; - if ptr.is_null() { - return Err(AllocError); - } - - ptr.cast::>() - }; - - // SAFETY: For non-zero-sized types, we allocate above using the global allocator. For - // zero-sized types, we use `NonNull::dangling`. - Ok(unsafe { Box::from_raw(ptr) }) - } - - fn drop_contents(this: Self) -> Box> { - let ptr = Box::into_raw(this); - // SAFETY: `ptr` is valid, because it came from `Box::into_raw`. - unsafe { ptr::drop_in_place(ptr) }; - - // CAST: `MaybeUninit` is a transparent wrapper of `T`. - let ptr = ptr.cast::>(); - - // SAFETY: `ptr` is valid for writes, because it came from `Box::into_raw` and it is valid for - // reads, since the pointer came from `Box::into_raw` and the type is `MaybeUninit`. - unsafe { Box::from_raw(ptr) } - } -} diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index c889f2640b56..c9919ba0b683 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -211,13 +211,12 @@ //! [`pin_init!`]: crate::pin_init! use crate::{ - alloc::{box_ext::BoxExt, AllocError, Flags, KBox}, + alloc::{AllocError, Flags, KBox}, error::{self, Error}, sync::Arc, sync::UniqueArc, types::{Opaque, ScopeGuard}, }; -use alloc::boxed::Box; use core::{ cell::UnsafeCell, convert::Infallible, @@ -588,7 +587,6 @@ macro_rules! pin_init { /// # Examples /// /// ```rust -/// # #![feature(new_uninit)] /// use kernel::{init::{self, PinInit}, error::Error}; /// #[pin_data] /// struct BigBuf { @@ -1245,26 +1243,6 @@ fn try_init(init: impl Init, flags: Flags) -> Result } } -impl InPlaceInit for Box { - type PinnedSelf = Pin; - - #[inline] - fn try_pin_init(init: impl PinInit, flags: Flags) -> Result - where - E: From, - { - as BoxExt<_>>::new_uninit(flags)?.write_pin_init(init) - } - - #[inline] - fn try_init(init: impl Init, flags: Flags) -> Result - where - E: From, - { - as BoxExt<_>>::new_uninit(flags)?.write_init(init) - } -} - impl InPlaceInit for UniqueArc { type PinnedSelf = Pin; @@ -1301,28 +1279,6 @@ pub trait InPlaceWrite { fn write_pin_init(self, init: impl PinInit) -> Result, E>; } -impl InPlaceWrite for Box> { - type Initialized = Box; - - fn write_init(mut self, init: impl Init) -> Result { - let slot = self.as_mut_ptr(); - // SAFETY: When init errors/panics, slot will get deallocated but not dropped, - // slot is valid. - unsafe { init.__init(slot)? }; - // SAFETY: All fields have been initialized. - Ok(unsafe { self.assume_init() }) - } - - fn write_pin_init(mut self, init: impl PinInit) -> Result, E> { - let slot = self.as_mut_ptr(); - // SAFETY: When init errors/panics, slot will get deallocated but not dropped, - // slot is valid and will not be moved, because we pin it later. - unsafe { init.__pinned_init(slot)? }; - // SAFETY: All fields have been initialized. - Ok(unsafe { self.assume_init() }.into()) - } -} - impl InPlaceWrite for UniqueArc> { type Initialized = UniqueArc; diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index d59639e36db5..c9fb478f03b2 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -16,7 +16,6 @@ #![feature(coerce_unsized)] #![feature(dispatch_from_dyn)] #![feature(lint_reasons)] -#![feature(new_uninit)] #![feature(unsize)] // Ensure conditional compilation based on the kernel configuration works; diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index a9210634a8c3..c1f8e5c832e2 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -14,10 +14,10 @@ #[doc(no_inline)] pub use core::pin::Pin; -pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt, KBox, KVBox, VBox}; +pub use crate::alloc::{flags::*, vec_ext::VecExt, KBox, KVBox, VBox}; #[doc(no_inline)] -pub use alloc::{boxed::Box, vec::Vec}; +pub use alloc::vec::Vec; #[doc(no_inline)] pub use macros::{module, pin_data, pinned_drop, vtable, Zeroable}; diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index 28d9e5ea3df4..f567494d4e54 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -3,13 +3,11 @@ //! Kernel types. use crate::init::{self, PinInit}; -use alloc::boxed::Box; use core::{ cell::UnsafeCell, marker::{PhantomData, PhantomPinned}, mem::{ManuallyDrop, MaybeUninit}, ops::{Deref, DerefMut}, - pin::Pin, ptr::NonNull, }; @@ -71,54 +69,6 @@ unsafe fn try_from_foreign(ptr: *const core::ffi::c_void) -> Option { } } -impl ForeignOwnable for Box { - type Borrowed<'a> = &'a T; - - fn into_foreign(self) -> *const core::ffi::c_void { - Box::into_raw(self) as _ - } - - unsafe fn borrow<'a>(ptr: *const core::ffi::c_void) -> &'a T { - // SAFETY: The safety requirements for this function ensure that the object is still alive, - // so it is safe to dereference the raw pointer. - // The safety requirements of `from_foreign` also ensure that the object remains alive for - // the lifetime of the returned value. - unsafe { &*ptr.cast() } - } - - unsafe fn from_foreign(ptr: *const core::ffi::c_void) -> Self { - // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous - // call to `Self::into_foreign`. - unsafe { Box::from_raw(ptr as _) } - } -} - -impl ForeignOwnable for Pin> { - type Borrowed<'a> = Pin<&'a T>; - - fn into_foreign(self) -> *const core::ffi::c_void { - // SAFETY: We are still treating the box as pinned. - Box::into_raw(unsafe { Pin::into_inner_unchecked(self) }) as _ - } - - unsafe fn borrow<'a>(ptr: *const core::ffi::c_void) -> Pin<&'a T> { - // SAFETY: The safety requirements for this function ensure that the object is still alive, - // so it is safe to dereference the raw pointer. - // The safety requirements of `from_foreign` also ensure that the object remains alive for - // the lifetime of the returned value. - let r = unsafe { &*ptr.cast() }; - - // SAFETY: This pointer originates from a `Pin>`. - unsafe { Pin::new_unchecked(r) } - } - - unsafe fn from_foreign(ptr: *const core::ffi::c_void) -> Self { - // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous - // call to `Self::into_foreign`. - unsafe { Pin::new_unchecked(Box::from_raw(ptr as _)) } - } -} - impl ForeignOwnable for () { type Borrowed<'a> = (); -- 2.46.1