6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Miguel Ojeda ojeda@kernel.org
commit e08ff622c91af997cb89bc47e90a1a383e938bd0 upstream.
This is the next upgrade to the Rust toolchain, from 1.72.1 to 1.73.0 (i.e. the latest) [1].
See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2").
# Unstable features
No unstable features (that we use) were stabilized.
Therefore, the only unstable feature allowed to be used outside the `kernel` crate is still `new_uninit`, though other code to be upstreamed may increase the list.
Please see [3] for details.
# Required changes
For the upgrade, the following changes are required:
- Allow `internal_features` for `feature(compiler_builtins)` since now Rust warns about using internal compiler and standard library features (similar to how it also warns about incomplete ones) [4].
- A cleanup for a documentation link thanks to a new `rustdoc` lint. See previous commits for details.
- A need to make an intra-doc link to a macro explicit, due to a change in behavior in `rustdoc`. See previous commits for details.
# `alloc` upgrade and reviewing
The vast majority of changes are due to our `alloc` fork being upgraded at once.
There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream.
Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream.
Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions.
To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch:
# Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc
# Apply this patch. git -C linux am rust-upgrade.patch
# Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc
Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended.
Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1730-2023-... [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/Rust-for-Linux/linux/issues/2 [3] Link: https://github.com/rust-lang/compiler-team/issues/596 [4] Reviewed-by: Martin Rodriguez Reboredo yakoyoku@gmail.com Reviewed-by: Vincenzo Palazzo vincenzopalazzodev@gmail.com Reviewed-by: Alice Ryhl aliceryhl@google.com Link: https://lore.kernel.org/r/20231005210556.466856-4-ojeda@kernel.org Signed-off-by: Miguel Ojeda ojeda@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Documentation/process/changes.rst | 2 - rust/alloc/alloc.rs | 22 ----------------- rust/alloc/boxed.rs | 48 ++++++++++++++++++++++++-------------- rust/alloc/lib.rs | 5 ++- rust/alloc/raw_vec.rs | 30 +++++++++++++++-------- rust/alloc/vec/mod.rs | 4 +-- rust/alloc/vec/spec_extend.rs | 8 +++--- rust/compiler_builtins.rs | 1 scripts/min-tool-version.sh | 2 - 9 files changed, 63 insertions(+), 59 deletions(-)
--- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -31,7 +31,7 @@ you probably needn't concern yourself wi ====================== =============== ======================================== GNU C 5.1 gcc --version Clang/LLVM (optional) 11.0.0 clang --version -Rust (optional) 1.72.1 rustc --version +Rust (optional) 1.73.0 rustc --version bindgen (optional) 0.65.1 bindgen --version GNU make 3.82 make --version bash 4.2 bash --version --- a/rust/alloc/alloc.rs +++ b/rust/alloc/alloc.rs @@ -6,11 +6,7 @@
#[cfg(not(test))] use core::intrinsics; -#[cfg(all(bootstrap, not(test)))] -use core::intrinsics::{min_align_of_val, size_of_val};
-#[cfg(all(bootstrap, not(test)))] -use core::ptr::Unique; #[cfg(not(test))] use core::ptr::{self, NonNull};
@@ -339,23 +335,6 @@ unsafe fn exchange_malloc(size: usize, a } }
-#[cfg(all(bootstrap, not(test)))] -#[lang = "box_free"] -#[inline] -// This signature has to be the same as `Box`, otherwise an ICE will happen. -// When an additional parameter to `Box` is added (like `A: Allocator`), this has to be added here as -// well. -// For example if `Box` is changed to `struct Box<T: ?Sized, A: Allocator>(Unique<T>, A)`, -// this function has to be changed to `fn box_free<T: ?Sized, A: Allocator>(Unique<T>, A)` as well. -unsafe fn box_free<T: ?Sized, A: Allocator>(ptr: Unique<T>, alloc: A) { - unsafe { - let size = size_of_val(ptr.as_ref()); - let align = min_align_of_val(ptr.as_ref()); - let layout = Layout::from_size_align_unchecked(size, align); - alloc.deallocate(From::from(ptr.cast()), layout) - } -} - // # Allocation error handler
#[cfg(not(no_global_oom_handling))] @@ -415,7 +394,6 @@ pub mod __alloc_error_handler { static __rust_alloc_error_handler_should_panic: u8; }
- #[allow(unused_unsafe)] if unsafe { __rust_alloc_error_handler_should_panic != 0 } { panic!("memory allocation of {size} bytes failed") } else { --- a/rust/alloc/boxed.rs +++ b/rust/alloc/boxed.rs @@ -159,12 +159,12 @@ use core::hash::{Hash, Hasher}; use core::iter::FusedIterator; use core::marker::Tuple; use core::marker::Unsize; -use core::mem; +use core::mem::{self, SizedTypeProperties}; use core::ops::{ CoerceUnsized, Deref, DerefMut, DispatchFromDyn, Generator, GeneratorState, Receiver, }; use core::pin::Pin; -use core::ptr::{self, Unique}; +use core::ptr::{self, NonNull, Unique}; use core::task::{Context, Poll};
#[cfg(not(no_global_oom_handling))] @@ -483,8 +483,12 @@ impl<T, A: Allocator> Box<T, A> { where A: Allocator, { - let layout = Layout::new::<mem::MaybeUninit<T>>(); - let ptr = alloc.allocate(layout)?.cast(); + let ptr = if T::IS_ZST { + NonNull::dangling() + } else { + let layout = Layout::new::<mem::MaybeUninit<T>>(); + alloc.allocate(layout)?.cast() + }; unsafe { Ok(Box::from_raw_in(ptr.as_ptr(), alloc)) } }
@@ -553,8 +557,12 @@ impl<T, A: Allocator> Box<T, A> { where A: Allocator, { - let layout = Layout::new::<mem::MaybeUninit<T>>(); - let ptr = alloc.allocate_zeroed(layout)?.cast(); + let ptr = if T::IS_ZST { + NonNull::dangling() + } else { + let layout = Layout::new::<mem::MaybeUninit<T>>(); + alloc.allocate_zeroed(layout)?.cast() + }; unsafe { Ok(Box::from_raw_in(ptr.as_ptr(), alloc)) } }
@@ -679,14 +687,16 @@ impl<T> Box<[T]> { #[unstable(feature = "allocator_api", issue = "32838")] #[inline] pub fn try_new_uninit_slice(len: usize) -> Result<Box<[mem::MaybeUninit<T>]>, AllocError> { - unsafe { + let ptr = if T::IS_ZST || len == 0 { + NonNull::dangling() + } else { let layout = match Layout::array::<mem::MaybeUninit<T>>(len) { Ok(l) => l, Err(_) => return Err(AllocError), }; - let ptr = Global.allocate(layout)?; - Ok(RawVec::from_raw_parts_in(ptr.as_mut_ptr() as *mut _, len, Global).into_box(len)) - } + Global.allocate(layout)?.cast() + }; + unsafe { Ok(RawVec::from_raw_parts_in(ptr.as_ptr(), len, Global).into_box(len)) } }
/// Constructs a new boxed slice with uninitialized contents, with the memory @@ -711,14 +721,16 @@ impl<T> Box<[T]> { #[unstable(feature = "allocator_api", issue = "32838")] #[inline] pub fn try_new_zeroed_slice(len: usize) -> Result<Box<[mem::MaybeUninit<T>]>, AllocError> { - unsafe { + let ptr = if T::IS_ZST || len == 0 { + NonNull::dangling() + } else { let layout = match Layout::array::<mem::MaybeUninit<T>>(len) { Ok(l) => l, Err(_) => return Err(AllocError), }; - let ptr = Global.allocate_zeroed(layout)?; - Ok(RawVec::from_raw_parts_in(ptr.as_mut_ptr() as *mut _, len, Global).into_box(len)) - } + Global.allocate_zeroed(layout)?.cast() + }; + unsafe { Ok(RawVec::from_raw_parts_in(ptr.as_ptr(), len, Global).into_box(len)) } } }
@@ -1223,7 +1235,9 @@ unsafe impl<#[may_dangle] T: ?Sized, A:
unsafe { let layout = Layout::for_value_raw(ptr.as_ptr()); - self.1.deallocate(From::from(ptr.cast()), layout) + if layout.size() != 0 { + self.1.deallocate(From::from(ptr.cast()), layout); + } } } } @@ -2173,7 +2187,7 @@ impl dyn Error + Send { let err: Box<dyn Error> = self; <dyn Error>::downcast(err).map_err(|s| unsafe { // Reapply the `Send` marker. - mem::transmute::<Box<dyn Error>, Box<dyn Error + Send>>(s) + Box::from_raw(Box::into_raw(s) as *mut (dyn Error + Send)) }) } } @@ -2187,7 +2201,7 @@ impl dyn Error + Send + Sync { let err: Box<dyn Error> = self; <dyn Error>::downcast(err).map_err(|s| unsafe { // Reapply the `Send + Sync` marker. - mem::transmute::<Box<dyn Error>, Box<dyn Error + Send + Sync>>(s) + Box::from_raw(Box::into_raw(s) as *mut (dyn Error + Send + Sync)) }) } } --- a/rust/alloc/lib.rs +++ b/rust/alloc/lib.rs @@ -60,7 +60,7 @@
// To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be // able to "empty" this crate. See https://github.com/rust-lang/miri-test-libstd/issues/4. -// rustc itself never sets the feature, so this line has no affect there. +// rustc itself never sets the feature, so this line has no effect there. #![cfg(any(not(feature = "miri-test-libstd"), test, doctest))] // #![allow(unused_attributes)] @@ -90,6 +90,8 @@ #![warn(missing_docs)] #![allow(explicit_outlives_requirements)] #![warn(multiple_supertrait_upcastable)] +#![cfg_attr(not(bootstrap), allow(internal_features))] +#![cfg_attr(not(bootstrap), allow(rustdoc::redundant_explicit_links))] // // Library features: // tidy-alphabetical-start @@ -139,7 +141,6 @@ #![feature(maybe_uninit_uninit_array_transpose)] #![feature(pattern)] #![feature(pointer_byte_offsets)] -#![feature(provide_any)] #![feature(ptr_internals)] #![feature(ptr_metadata)] #![feature(ptr_sub_ptr)] --- a/rust/alloc/raw_vec.rs +++ b/rust/alloc/raw_vec.rs @@ -471,16 +471,26 @@ impl<T, A: Allocator> RawVec<T, A> { let (ptr, layout) = if let Some(mem) = self.current_memory() { mem } else { return Ok(()) }; // See current_memory() why this assert is here let _: () = const { assert!(mem::size_of::<T>() % mem::align_of::<T>() == 0) }; - let ptr = unsafe { - // `Layout::array` cannot overflow here because it would have - // overflowed earlier when capacity was larger. - let new_size = mem::size_of::<T>().unchecked_mul(cap); - let new_layout = Layout::from_size_align_unchecked(new_size, layout.align()); - self.alloc - .shrink(ptr, layout, new_layout) - .map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })? - }; - self.set_ptr_and_cap(ptr, cap); + + // If shrinking to 0, deallocate the buffer. We don't reach this point + // for the T::IS_ZST case since current_memory() will have returned + // None. + if cap == 0 { + unsafe { self.alloc.deallocate(ptr, layout) }; + self.ptr = Unique::dangling(); + self.cap = 0; + } else { + let ptr = unsafe { + // `Layout::array` cannot overflow here because it would have + // overflowed earlier when capacity was larger. + let new_size = mem::size_of::<T>().unchecked_mul(cap); + let new_layout = Layout::from_size_align_unchecked(new_size, layout.align()); + self.alloc + .shrink(ptr, layout, new_layout) + .map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })? + }; + self.set_ptr_and_cap(ptr, cap); + } Ok(()) } } --- a/rust/alloc/vec/mod.rs +++ b/rust/alloc/vec/mod.rs @@ -216,7 +216,7 @@ mod spec_extend; /// /// # Indexing /// -/// The `Vec` type allows to access values by index, because it implements the +/// The `Vec` type allows access to values by index, because it implements the /// [`Index`] trait. An example will be more explicit: /// /// ``` @@ -3263,7 +3263,7 @@ impl<T, A: Allocator> Vec<T, A> { /// [`copy_from_slice`]: slice::copy_from_slice #[cfg(not(no_global_oom_handling))] #[stable(feature = "extend_ref", since = "1.2.0")] -impl<'a, T: Copy + 'a, A: Allocator + 'a> Extend<&'a T> for Vec<T, A> { +impl<'a, T: Copy + 'a, A: Allocator> Extend<&'a T> for Vec<T, A> { fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { self.spec_extend(iter.into_iter()) } --- a/rust/alloc/vec/spec_extend.rs +++ b/rust/alloc/vec/spec_extend.rs @@ -77,7 +77,7 @@ impl<T, A: Allocator> TrySpecExtend<T, I }
#[cfg(not(no_global_oom_handling))] -impl<'a, T: 'a, I, A: Allocator + 'a> SpecExtend<&'a T, I> for Vec<T, A> +impl<'a, T: 'a, I, A: Allocator> SpecExtend<&'a T, I> for Vec<T, A> where I: Iterator<Item = &'a T>, T: Clone, @@ -87,7 +87,7 @@ where } }
-impl<'a, T: 'a, I, A: Allocator + 'a> TrySpecExtend<&'a T, I> for Vec<T, A> +impl<'a, T: 'a, I, A: Allocator> TrySpecExtend<&'a T, I> for Vec<T, A> where I: Iterator<Item = &'a T>, T: Clone, @@ -98,7 +98,7 @@ where }
#[cfg(not(no_global_oom_handling))] -impl<'a, T: 'a, A: Allocator + 'a> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A> +impl<'a, T: 'a, A: Allocator> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A> where T: Copy, { @@ -108,7 +108,7 @@ where } }
-impl<'a, T: 'a, A: Allocator + 'a> TrySpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A> +impl<'a, T: 'a, A: Allocator> TrySpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A> where T: Copy, { --- a/rust/compiler_builtins.rs +++ b/rust/compiler_builtins.rs @@ -19,6 +19,7 @@ //! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins //! [`compiler-rt`]: https://compiler-rt.llvm.org/
+#![allow(internal_features)] #![feature(compiler_builtins)] #![compiler_builtins] #![no_builtins] --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -31,7 +31,7 @@ llvm) fi ;; rustc) - echo 1.72.1 + echo 1.73.0 ;; bindgen) echo 0.65.1