From 057b8d2571071da05d06810ca70f26c6316f6ea7 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 3 Jul 2021 17:02:21 +0200 Subject: rust: adapt `alloc` crate to the kernel This customizes the subset of the Rust standard library `alloc` that was just imported as-is, mainly by: - Adding SPDX license identifiers. - Skipping modules (e.g. `rc` and `sync`) via new `cfg`s. - Adding fallible (`try_*`) versions of existing infallible methods (i.e. returning a `Result` instead of panicking). Since the standard library requires stable/unstable attributes, these additions are annotated with: #[stable(feature = "kernel", since = "1.0.0")] Using "kernel" as the feature allows to have the additions clearly marked. The "1.0.0" version is just a placeholder. (At the moment, only one is needed, but in the future more fallible methods will be added). Reviewed-by: Greg Kroah-Hartman Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Matthew Bakhtiari Signed-off-by: Matthew Bakhtiari Signed-off-by: Miguel Ojeda --- rust/alloc/README.md | 33 +++++++++++++++++++++++++++++++++ rust/alloc/alloc.rs | 2 ++ rust/alloc/borrow.rs | 4 +++- rust/alloc/boxed.rs | 4 ++++ rust/alloc/collections/mod.rs | 2 ++ rust/alloc/lib.rs | 8 ++++++++ rust/alloc/raw_vec.rs | 9 +++++++++ rust/alloc/slice.rs | 2 ++ rust/alloc/vec/drain.rs | 2 ++ rust/alloc/vec/drain_filter.rs | 2 ++ rust/alloc/vec/into_iter.rs | 4 ++++ rust/alloc/vec/is_zero.rs | 2 ++ rust/alloc/vec/mod.rs | 25 +++++++++++++++++++++++++ rust/alloc/vec/partial_eq.rs | 2 ++ 14 files changed, 100 insertions(+), 1 deletion(-) create mode 100644 rust/alloc/README.md (limited to 'rust') diff --git a/rust/alloc/README.md b/rust/alloc/README.md new file mode 100644 index 000000000000..c89c753720b5 --- /dev/null +++ b/rust/alloc/README.md @@ -0,0 +1,33 @@ +# `alloc` + +These source files come from the Rust standard library, hosted in +the repository, licensed under +"Apache-2.0 OR MIT" and adapted for kernel use. For copyright details, +see . + +Please note that these files should be kept as close as possible to +upstream. In general, only additions should be performed (e.g. new +methods). Eventually, changes should make it into upstream so that, +at some point, this fork can be dropped from the kernel tree. + + +## Rationale + +On one hand, kernel folks wanted to keep `alloc` in-tree to have more +freedom in both workflow and actual features if actually needed +(e.g. receiver types if we ended up using them), which is reasonable. + +On the other hand, Rust folks wanted to keep `alloc` as close as +upstream as possible and avoid as much divergence as possible, which +is also reasonable. + +We agreed on a middle-ground: we would keep a subset of `alloc` +in-tree that would be as small and as close as possible to upstream. +Then, upstream can start adding the functions that we add to `alloc` +etc., until we reach a point where the kernel already knows exactly +what it needs in `alloc` and all the new methods are merged into +upstream, so that we can drop `alloc` from the kernel tree and go back +to using the upstream one. + +By doing this, the kernel can go a bit faster now, and Rust can +slowly incorporate and discuss the changes as needed. diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs index 6162b5c6d4c9..ca224a541770 100644 --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! Memory allocation APIs #![stable(feature = "alloc_module", since = "1.28.0")] diff --git a/rust/alloc/borrow.rs b/rust/alloc/borrow.rs index cb4e438f8bea..dde4957200d4 100644 --- a/rust/alloc/borrow.rs +++ b/rust/alloc/borrow.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A module for working with borrowed data. #![stable(feature = "rust1", since = "1.0.0")] @@ -11,7 +13,7 @@ use core::ops::{Add, AddAssign}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::borrow::{Borrow, BorrowMut}; -use crate::fmt; +use core::fmt; #[cfg(not(no_global_oom_handling))] use crate::string::String; diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs index c07536f0d0ce..dcfe87b14f3a 100644 --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A pointer type for heap allocation. //! //! [`Box`], casually referred to as a 'box', provides the simplest form of @@ -163,9 +165,11 @@ use crate::str::from_boxed_utf8_unchecked; #[cfg(not(no_global_oom_handling))] use crate::vec::Vec; +#[cfg(not(no_thin))] #[unstable(feature = "thin_box", issue = "92791")] pub use thin::ThinBox; +#[cfg(not(no_thin))] mod thin; /// A pointer type for heap allocation. diff --git a/rust/alloc/collections/mod.rs b/rust/alloc/collections/mod.rs index 628a5b155673..1eec265b28f8 100644 --- a/rust/alloc/collections/mod.rs +++ b/rust/alloc/collections/mod.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! Collection types. #![stable(feature = "rust1", since = "1.0.0")] diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs index fd21b3671182..233bcd5e4654 100644 --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! # The Rust core allocation and collections library //! //! This library provides smart pointers and collections for managing @@ -192,6 +194,7 @@ extern crate std; extern crate test; // Module with internal macros used by other modules (needs to be included before other modules). +#[cfg(not(no_macros))] #[macro_use] mod macros; @@ -216,11 +219,16 @@ pub mod borrow; pub mod collections; #[cfg(not(no_global_oom_handling))] pub mod ffi; +#[cfg(not(no_fmt))] pub mod fmt; +#[cfg(not(no_rc))] pub mod rc; pub mod slice; +#[cfg(not(no_str))] pub mod str; +#[cfg(not(no_string))] pub mod string; +#[cfg(not(no_sync))] #[cfg(target_has_atomic = "ptr")] pub mod sync; #[cfg(all(not(no_global_oom_handling), target_has_atomic = "ptr"))] diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs index 4be5f6cf9ca5..daf5f2da7168 100644 --- a/rust/alloc/raw_vec.rs +++ b/rust/alloc/raw_vec.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + #![unstable(feature = "raw_vec_internals", reason = "unstable const warnings", issue = "none")] use core::alloc::LayoutError; @@ -307,6 +309,12 @@ impl RawVec { } } + /// The same as `reserve_for_push`, but returns on errors instead of panicking or aborting. + #[inline(never)] + pub fn try_reserve_for_push(&mut self, len: usize) -> Result<(), TryReserveError> { + self.grow_amortized(len, 1) + } + /// Ensures that the buffer contains at least enough space to hold `len + /// additional` elements. If it doesn't already, will reallocate the /// minimum possible amount of memory necessary. Generally this will be @@ -421,6 +429,7 @@ impl RawVec { Ok(()) } + #[allow(dead_code)] fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> { assert!(cap <= self.capacity(), "Tried to shrink to a larger capacity"); diff --git a/rust/alloc/slice.rs b/rust/alloc/slice.rs index 199b3c9d0290..e444e97fa145 100644 --- a/rust/alloc/slice.rs +++ b/rust/alloc/slice.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A dynamically-sized view into a contiguous sequence, `[T]`. //! //! *[See also the slice primitive type](slice).* diff --git a/rust/alloc/vec/drain.rs b/rust/alloc/vec/drain.rs index 5cdee0bd4da4..b6a5f98e4fcd 100644 --- a/rust/alloc/vec/drain.rs +++ b/rust/alloc/vec/drain.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::{Allocator, Global}; use core::fmt; use core::iter::{FusedIterator, TrustedLen}; diff --git a/rust/alloc/vec/drain_filter.rs b/rust/alloc/vec/drain_filter.rs index 3c37c92ae44b..b04fce041622 100644 --- a/rust/alloc/vec/drain_filter.rs +++ b/rust/alloc/vec/drain_filter.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::{Allocator, Global}; use core::ptr::{self}; use core::slice::{self}; diff --git a/rust/alloc/vec/into_iter.rs b/rust/alloc/vec/into_iter.rs index 9b84a1d9b4b6..f7a50e76691e 100644 --- a/rust/alloc/vec/into_iter.rs +++ b/rust/alloc/vec/into_iter.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + #[cfg(not(no_global_oom_handling))] use super::AsVecIntoIter; use crate::alloc::{Allocator, Global}; @@ -9,6 +11,7 @@ use core::iter::{ }; use core::marker::PhantomData; use core::mem::{self, ManuallyDrop}; +#[cfg(not(no_global_oom_handling))] use core::ops::Deref; use core::ptr::{self, NonNull}; use core::slice::{self}; @@ -123,6 +126,7 @@ impl IntoIter { } /// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed. + #[allow(dead_code)] pub(crate) fn forget_remaining_elements(&mut self) { self.ptr = self.end; } diff --git a/rust/alloc/vec/is_zero.rs b/rust/alloc/vec/is_zero.rs index edf270db81d4..377f3d172777 100644 --- a/rust/alloc/vec/is_zero.rs +++ b/rust/alloc/vec/is_zero.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::boxed::Box; #[rustc_specialization_trait] diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs index 3dc8a4fbba86..540787804cc2 100644 --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + //! A contiguous growable array type with heap-allocated contents, written //! `Vec`. //! @@ -1739,6 +1741,29 @@ impl Vec { } } + /// Tries to append an element to the back of a collection. + /// + /// # Examples + /// + /// ``` + /// let mut vec = vec![1, 2]; + /// vec.try_push(3).unwrap(); + /// assert_eq!(vec, [1, 2, 3]); + /// ``` + #[inline] + #[stable(feature = "kernel", since = "1.0.0")] + pub fn try_push(&mut self, value: T) -> Result<(), TryReserveError> { + if self.len == self.buf.capacity() { + self.buf.try_reserve_for_push(self.len)?; + } + unsafe { + let end = self.as_mut_ptr().add(self.len); + ptr::write(end, value); + self.len += 1; + } + Ok(()) + } + /// Removes the last element from a vector and returns it, or [`None`] if it /// is empty. /// diff --git a/rust/alloc/vec/partial_eq.rs b/rust/alloc/vec/partial_eq.rs index b0cf72577a1b..10ad4e492287 100644 --- a/rust/alloc/vec/partial_eq.rs +++ b/rust/alloc/vec/partial_eq.rs @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + use crate::alloc::Allocator; #[cfg(not(no_global_oom_handling))] use crate::borrow::Cow; -- cgit v1.2.3-70-g09d2