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Diffstat (limited to 'pkgs/os-specific/linux/kernel/rust-1.77-6.8.patch')
| -rw-r--r-- | pkgs/os-specific/linux/kernel/rust-1.77-6.8.patch | 799 |
1 files changed, 799 insertions, 0 deletions
diff --git a/pkgs/os-specific/linux/kernel/rust-1.77-6.8.patch b/pkgs/os-specific/linux/kernel/rust-1.77-6.8.patch new file mode 100644 index 0000000000000..4b25d3e60e39d --- /dev/null +++ b/pkgs/os-specific/linux/kernel/rust-1.77-6.8.patch @@ -0,0 +1,799 @@ +From 82a754271336c7736fb0350692be85fecb30e38e Mon Sep 17 00:00:00 2001 +From: Miguel Ojeda <ojeda@kernel.org> +Date: Sat, 17 Feb 2024 01:27:17 +0100 +Subject: [PATCH] rust: upgrade to Rust 1.77.1 + +This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1 +(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 + +The `offset_of` feature (single-field `offset_of!`) that we were using +got stabilized in Rust 1.77.0 [3]. + +Therefore, now the only unstable features allowed to be used outside the +`kernel` crate is `new_uninit`, though other code to be upstreamed may +increase the list. + +Please see [4] for details. + +# Required changes + +Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, +thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc` +complain about the `ThisModule`'s pointer field being never read, but +the previous patch adds the `as_ptr` method to it, needed by Binder [6], +so that we do not need to locally `allow` it. + +# Other changes + +Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there +is a Call for Testing going on [8]. We were requested to test it and +we found it useful [9] -- we will likely enable it in the future. + +# `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-1770-2024-03-21 [1] +Link: https://rust-for-linux.com/rust-version-policy [2] +Link: https://github.com/rust-lang/rust/pull/118799 [3] +Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] +Link: https://github.com/rust-lang/rust/pull/118297 [5] +Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] +Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] +Link: https://github.com/rust-lang/rfcs/pull/3013#issuecomment-1936648479 [8] +Link: https://github.com/rust-lang/rust/issues/82450#issuecomment-1947462977 [9] +Reviewed-by: Alice Ryhl <aliceryhl@google.com> +Tested-by: Boqun Feng <boqun.feng@gmail.com> +Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org +[ Upgraded to 1.77.1. Removed `allow(dead_code)` thanks to the previous + patch. Reworded accordingly. No changes to `alloc` during the beta. ] +Signed-off-by: Miguel Ojeda <ojeda@kernel.org> +Signed-off-by: Alyssa Ross <hi@alyssa.is> + +# Conflicts: +# Documentation/process/changes.rst +# rust/kernel/lib.rs +--- + Documentation/process/changes.rst | 2 +- + rust/alloc/alloc.rs | 6 +- + rust/alloc/boxed.rs | 4 +- + rust/alloc/lib.rs | 7 +- + rust/alloc/raw_vec.rs | 13 ++-- + rust/alloc/slice.rs | 4 +- + rust/alloc/vec/into_iter.rs | 104 +++++++++++++++++++----------- + rust/alloc/vec/mod.rs | 101 ++++++++++++++++++++--------- + rust/kernel/lib.rs | 1 - + scripts/Makefile.build | 2 +- + scripts/min-tool-version.sh | 2 +- + 11 files changed, 158 insertions(+), 88 deletions(-) + +diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst +index c78ecc1e176f..641d67363b92 100644 +--- a/Documentation/process/changes.rst ++++ b/Documentation/process/changes.rst +@@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils. + ====================== =============== ======================================== + GNU C 5.1 gcc --version + Clang/LLVM (optional) 11.0.0 clang --version +-Rust (optional) 1.76.0 rustc --version ++Rust (optional) 1.77.1 rustc --version + bindgen (optional) 0.65.1 bindgen --version + GNU make 3.82 make --version + bash 4.2 bash --version +diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs +index abb791cc2371..b1204f87227b 100644 +--- a/rust/alloc/alloc.rs ++++ b/rust/alloc/alloc.rs +@@ -5,7 +5,7 @@ + #![stable(feature = "alloc_module", since = "1.28.0")] + + #[cfg(not(test))] +-use core::intrinsics; ++use core::hint; + + #[cfg(not(test))] + use core::ptr::{self, NonNull}; +@@ -210,7 +210,7 @@ unsafe fn grow_impl( + let new_size = new_layout.size(); + + // `realloc` probably checks for `new_size >= old_layout.size()` or something similar. +- intrinsics::assume(new_size >= old_layout.size()); ++ hint::assert_unchecked(new_size >= old_layout.size()); + + let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); + let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; +@@ -301,7 +301,7 @@ unsafe fn shrink( + // SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller + new_size if old_layout.align() == new_layout.align() => unsafe { + // `realloc` probably checks for `new_size <= old_layout.size()` or something similar. +- intrinsics::assume(new_size <= old_layout.size()); ++ hint::assert_unchecked(new_size <= old_layout.size()); + + let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size); + let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?; +diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs +index c93a22a5c97f..5fc39dfeb8e7 100644 +--- a/rust/alloc/boxed.rs ++++ b/rust/alloc/boxed.rs +@@ -26,6 +26,7 @@ + //! Creating a recursive data structure: + //! + //! ``` ++//! ##[allow(dead_code)] + //! #[derive(Debug)] + //! enum List<T> { + //! Cons(T, Box<List<T>>), +@@ -194,8 +195,7 @@ + #[fundamental] + #[stable(feature = "rust1", since = "1.0.0")] + // The declaration of the `Box` struct must be kept in sync with the +-// `alloc::alloc::box_free` function or ICEs will happen. See the comment +-// on `box_free` for more details. ++// compiler or ICEs will happen. + pub struct Box< + T: ?Sized, + #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global, +diff --git a/rust/alloc/lib.rs b/rust/alloc/lib.rs +index 36f79c075593..39afd55ec074 100644 +--- a/rust/alloc/lib.rs ++++ b/rust/alloc/lib.rs +@@ -105,7 +105,6 @@ + #![feature(allocator_api)] + #![feature(array_chunks)] + #![feature(array_into_iter_constructors)] +-#![feature(array_methods)] + #![feature(array_windows)] + #![feature(ascii_char)] + #![feature(assert_matches)] +@@ -122,7 +121,6 @@ + #![feature(const_size_of_val)] + #![feature(const_waker)] + #![feature(core_intrinsics)] +-#![feature(core_panic)] + #![feature(deprecated_suggestion)] + #![feature(dispatch_from_dyn)] + #![feature(error_generic_member_access)] +@@ -132,6 +130,7 @@ + #![feature(fmt_internals)] + #![feature(fn_traits)] + #![feature(hasher_prefixfree_extras)] ++#![feature(hint_assert_unchecked)] + #![feature(inline_const)] + #![feature(inplace_iteration)] + #![feature(iter_advance_by)] +@@ -141,6 +140,8 @@ + #![feature(maybe_uninit_slice)] + #![feature(maybe_uninit_uninit_array)] + #![feature(maybe_uninit_uninit_array_transpose)] ++#![feature(non_null_convenience)] ++#![feature(panic_internals)] + #![feature(pattern)] + #![feature(ptr_internals)] + #![feature(ptr_metadata)] +@@ -149,7 +150,6 @@ + #![feature(set_ptr_value)] + #![feature(sized_type_properties)] + #![feature(slice_from_ptr_range)] +-#![feature(slice_group_by)] + #![feature(slice_ptr_get)] + #![feature(slice_ptr_len)] + #![feature(slice_range)] +@@ -182,6 +182,7 @@ + #![feature(const_ptr_write)] + #![feature(const_trait_impl)] + #![feature(const_try)] ++#![feature(decl_macro)] + #![feature(dropck_eyepatch)] + #![feature(exclusive_range_pattern)] + #![feature(fundamental)] +diff --git a/rust/alloc/raw_vec.rs b/rust/alloc/raw_vec.rs +index 98b6abf30af6..1839d1c8ee7a 100644 +--- a/rust/alloc/raw_vec.rs ++++ b/rust/alloc/raw_vec.rs +@@ -4,7 +4,7 @@ + + use core::alloc::LayoutError; + use core::cmp; +-use core::intrinsics; ++use core::hint; + use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties}; + use core::ptr::{self, NonNull, Unique}; + use core::slice; +@@ -317,7 +317,7 @@ fn current_memory(&self) -> Option<(NonNull<u8>, Layout)> { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Aborts + /// +@@ -358,7 +358,7 @@ pub fn try_reserve(&mut self, len: usize, additional: usize) -> Result<(), TryRe + } + unsafe { + // Inform the optimizer that the reservation has succeeded or wasn't needed +- core::intrinsics::assume(!self.needs_to_grow(len, additional)); ++ hint::assert_unchecked(!self.needs_to_grow(len, additional)); + } + Ok(()) + } +@@ -381,7 +381,7 @@ pub fn try_reserve_for_push(&mut self, len: usize) -> Result<(), TryReserveError + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Aborts + /// +@@ -402,7 +402,7 @@ pub fn try_reserve_exact( + } + unsafe { + // Inform the optimizer that the reservation has succeeded or wasn't needed +- core::intrinsics::assume(!self.needs_to_grow(len, additional)); ++ hint::assert_unchecked(!self.needs_to_grow(len, additional)); + } + Ok(()) + } +@@ -553,7 +553,7 @@ fn finish_grow<A>( + debug_assert_eq!(old_layout.align(), new_layout.align()); + unsafe { + // The allocator checks for alignment equality +- intrinsics::assume(old_layout.align() == new_layout.align()); ++ hint::assert_unchecked(old_layout.align() == new_layout.align()); + alloc.grow(ptr, old_layout, new_layout) + } + } else { +@@ -591,7 +591,6 @@ fn handle_reserve(result: Result<(), TryReserveError>) { + // `> isize::MAX` bytes will surely fail. On 32-bit and 16-bit we need to add + // an extra guard for this in case we're running on a platform which can use + // all 4GB in user-space, e.g., PAE or x32. +- + #[inline] + fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> { + if usize::BITS < 64 && alloc_size > isize::MAX as usize { +diff --git a/rust/alloc/slice.rs b/rust/alloc/slice.rs +index 1181836da5f4..a36b072c9519 100644 +--- a/rust/alloc/slice.rs ++++ b/rust/alloc/slice.rs +@@ -53,14 +53,14 @@ + pub use core::slice::{from_mut_ptr_range, from_ptr_range}; + #[stable(feature = "rust1", since = "1.0.0")] + pub use core::slice::{from_raw_parts, from_raw_parts_mut}; ++#[stable(feature = "slice_group_by", since = "1.77.0")] ++pub use core::slice::{ChunkBy, ChunkByMut}; + #[stable(feature = "rust1", since = "1.0.0")] + pub use core::slice::{Chunks, Windows}; + #[stable(feature = "chunks_exact", since = "1.31.0")] + pub use core::slice::{ChunksExact, ChunksExactMut}; + #[stable(feature = "rust1", since = "1.0.0")] + pub use core::slice::{ChunksMut, Split, SplitMut}; +-#[unstable(feature = "slice_group_by", issue = "80552")] +-pub use core::slice::{GroupBy, GroupByMut}; + #[stable(feature = "rust1", since = "1.0.0")] + pub use core::slice::{Iter, IterMut}; + #[stable(feature = "rchunks", since = "1.31.0")] +diff --git a/rust/alloc/vec/into_iter.rs b/rust/alloc/vec/into_iter.rs +index 136bfe94af6c..0f11744c44b3 100644 +--- a/rust/alloc/vec/into_iter.rs ++++ b/rust/alloc/vec/into_iter.rs +@@ -20,6 +20,17 @@ + use core::ptr::{self, NonNull}; + use core::slice::{self}; + ++macro non_null { ++ (mut $place:expr, $t:ident) => {{ ++ #![allow(unused_unsafe)] // we're sometimes used within an unsafe block ++ unsafe { &mut *(ptr::addr_of_mut!($place) as *mut NonNull<$t>) } ++ }}, ++ ($place:expr, $t:ident) => {{ ++ #![allow(unused_unsafe)] // we're sometimes used within an unsafe block ++ unsafe { *(ptr::addr_of!($place) as *const NonNull<$t>) } ++ }}, ++} ++ + /// An iterator that moves out of a vector. + /// + /// This `struct` is created by the `into_iter` method on [`Vec`](super::Vec) +@@ -43,10 +54,12 @@ pub struct IntoIter< + // the drop impl reconstructs a RawVec from buf, cap and alloc + // to avoid dropping the allocator twice we need to wrap it into ManuallyDrop + pub(super) alloc: ManuallyDrop<A>, +- pub(super) ptr: *const T, +- pub(super) end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that +- // ptr == end is a quick test for the Iterator being empty, that works +- // for both ZST and non-ZST. ++ pub(super) ptr: NonNull<T>, ++ /// If T is a ZST, this is actually ptr+len. This encoding is picked so that ++ /// ptr == end is a quick test for the Iterator being empty, that works ++ /// for both ZST and non-ZST. ++ /// For non-ZSTs the pointer is treated as `NonNull<T>` ++ pub(super) end: *const T, + } + + #[stable(feature = "vec_intoiter_debug", since = "1.13.0")] +@@ -70,7 +83,7 @@ impl<T, A: Allocator> IntoIter<T, A> { + /// ``` + #[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")] + pub fn as_slice(&self) -> &[T] { +- unsafe { slice::from_raw_parts(self.ptr, self.len()) } ++ unsafe { slice::from_raw_parts(self.ptr.as_ptr(), self.len()) } + } + + /// Returns the remaining items of this iterator as a mutable slice. +@@ -99,7 +112,7 @@ pub fn allocator(&self) -> &A { + } + + fn as_raw_mut_slice(&mut self) -> *mut [T] { +- ptr::slice_from_raw_parts_mut(self.ptr as *mut T, self.len()) ++ ptr::slice_from_raw_parts_mut(self.ptr.as_ptr(), self.len()) + } + + /// Drops remaining elements and relinquishes the backing allocation. +@@ -126,7 +139,7 @@ pub(super) fn forget_allocation_drop_remaining(&mut self) { + // this creates less assembly + self.cap = 0; + self.buf = unsafe { NonNull::new_unchecked(RawVec::NEW.ptr()) }; +- self.ptr = self.buf.as_ptr(); ++ self.ptr = self.buf; + self.end = self.buf.as_ptr(); + + // Dropping the remaining elements can panic, so this needs to be +@@ -138,9 +151,9 @@ pub(super) fn forget_allocation_drop_remaining(&mut self) { + + /// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed. + pub(crate) fn forget_remaining_elements(&mut self) { +- // For th ZST case, it is crucial that we mutate `end` here, not `ptr`. ++ // For the ZST case, it is crucial that we mutate `end` here, not `ptr`. + // `ptr` must stay aligned, while `end` may be unaligned. +- self.end = self.ptr; ++ self.end = self.ptr.as_ptr(); + } + + #[cfg(not(no_global_oom_handling))] +@@ -162,7 +175,7 @@ pub(crate) fn into_vecdeque(self) -> VecDeque<T, A> { + // say that they're all at the beginning of the "allocation". + 0..this.len() + } else { +- this.ptr.sub_ptr(buf)..this.end.sub_ptr(buf) ++ this.ptr.sub_ptr(this.buf)..this.end.sub_ptr(buf) + }; + let cap = this.cap; + let alloc = ManuallyDrop::take(&mut this.alloc); +@@ -189,29 +202,35 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { + + #[inline] + fn next(&mut self) -> Option<T> { +- if self.ptr == self.end { +- None +- } else if T::IS_ZST { +- // `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by +- // reducing the `end`. +- self.end = self.end.wrapping_byte_sub(1); ++ if T::IS_ZST { ++ if self.ptr.as_ptr() == self.end as *mut _ { ++ None ++ } else { ++ // `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by ++ // reducing the `end`. ++ self.end = self.end.wrapping_byte_sub(1); + +- // Make up a value of this ZST. +- Some(unsafe { mem::zeroed() }) ++ // Make up a value of this ZST. ++ Some(unsafe { mem::zeroed() }) ++ } + } else { +- let old = self.ptr; +- self.ptr = unsafe { self.ptr.add(1) }; ++ if self.ptr == non_null!(self.end, T) { ++ None ++ } else { ++ let old = self.ptr; ++ self.ptr = unsafe { old.add(1) }; + +- Some(unsafe { ptr::read(old) }) ++ Some(unsafe { ptr::read(old.as_ptr()) }) ++ } + } + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + let exact = if T::IS_ZST { +- self.end.addr().wrapping_sub(self.ptr.addr()) ++ self.end.addr().wrapping_sub(self.ptr.as_ptr().addr()) + } else { +- unsafe { self.end.sub_ptr(self.ptr) } ++ unsafe { non_null!(self.end, T).sub_ptr(self.ptr) } + }; + (exact, Some(exact)) + } +@@ -219,7 +238,7 @@ fn size_hint(&self) -> (usize, Option<usize>) { + #[inline] + fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { + let step_size = self.len().min(n); +- let to_drop = ptr::slice_from_raw_parts_mut(self.ptr as *mut T, step_size); ++ let to_drop = ptr::slice_from_raw_parts_mut(self.ptr.as_ptr(), step_size); + if T::IS_ZST { + // See `next` for why we sub `end` here. + self.end = self.end.wrapping_byte_sub(step_size); +@@ -261,7 +280,7 @@ fn count(self) -> usize { + // Safety: `len` indicates that this many elements are available and we just checked that + // it fits into the array. + unsafe { +- ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, len); ++ ptr::copy_nonoverlapping(self.ptr.as_ptr(), raw_ary.as_mut_ptr() as *mut T, len); + self.forget_remaining_elements(); + return Err(array::IntoIter::new_unchecked(raw_ary, 0..len)); + } +@@ -270,7 +289,7 @@ fn count(self) -> usize { + // Safety: `len` is larger than the array size. Copy a fixed amount here to fully initialize + // the array. + return unsafe { +- ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, N); ++ ptr::copy_nonoverlapping(self.ptr.as_ptr(), raw_ary.as_mut_ptr() as *mut T, N); + self.ptr = self.ptr.add(N); + Ok(raw_ary.transpose().assume_init()) + }; +@@ -288,7 +307,7 @@ unsafe fn __iterator_get_unchecked(&mut self, i: usize) -> Self::Item + // Also note the implementation of `Self: TrustedRandomAccess` requires + // that `T: Copy` so reading elements from the buffer doesn't invalidate + // them for `Drop`. +- unsafe { if T::IS_ZST { mem::zeroed() } else { ptr::read(self.ptr.add(i)) } } ++ unsafe { if T::IS_ZST { mem::zeroed() } else { self.ptr.add(i).read() } } + } + } + +@@ -296,18 +315,25 @@ unsafe fn __iterator_get_unchecked(&mut self, i: usize) -> Self::Item + impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> { + #[inline] + fn next_back(&mut self) -> Option<T> { +- if self.end == self.ptr { +- None +- } else if T::IS_ZST { +- // See above for why 'ptr.offset' isn't used +- self.end = self.end.wrapping_byte_sub(1); ++ if T::IS_ZST { ++ if self.end as *mut _ == self.ptr.as_ptr() { ++ None ++ } else { ++ // See above for why 'ptr.offset' isn't used ++ self.end = self.end.wrapping_byte_sub(1); + +- // Make up a value of this ZST. +- Some(unsafe { mem::zeroed() }) ++ // Make up a value of this ZST. ++ Some(unsafe { mem::zeroed() }) ++ } + } else { +- self.end = unsafe { self.end.sub(1) }; ++ if non_null!(self.end, T) == self.ptr { ++ None ++ } else { ++ let new_end = unsafe { non_null!(self.end, T).sub(1) }; ++ *non_null!(mut self.end, T) = new_end; + +- Some(unsafe { ptr::read(self.end) }) ++ Some(unsafe { ptr::read(new_end.as_ptr()) }) ++ } + } + } + +@@ -333,7 +359,11 @@ fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { + #[stable(feature = "rust1", since = "1.0.0")] + impl<T, A: Allocator> ExactSizeIterator for IntoIter<T, A> { + fn is_empty(&self) -> bool { +- self.ptr == self.end ++ if T::IS_ZST { ++ self.ptr.as_ptr() == self.end as *mut _ ++ } else { ++ self.ptr == non_null!(self.end, T) ++ } + } + } + +diff --git a/rust/alloc/vec/mod.rs b/rust/alloc/vec/mod.rs +index 220fb9d6f45b..0be27fff4554 100644 +--- a/rust/alloc/vec/mod.rs ++++ b/rust/alloc/vec/mod.rs +@@ -360,7 +360,7 @@ + /// + /// `vec![x; n]`, `vec![a, b, c, d]`, and + /// [`Vec::with_capacity(n)`][`Vec::with_capacity`], will all produce a `Vec` +-/// with exactly the requested capacity. If <code>[len] == [capacity]</code>, ++/// with at least the requested capacity. If <code>[len] == [capacity]</code>, + /// (as is the case for the [`vec!`] macro), then a `Vec<T>` can be converted to + /// and from a [`Box<[T]>`][owned slice] without reallocating or moving the elements. + /// +@@ -447,7 +447,7 @@ pub const fn new() -> Self { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -690,7 +690,7 @@ pub const fn new_in(alloc: A) -> Self { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -1013,7 +1013,7 @@ pub fn capacity(&self) -> usize { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -1043,7 +1043,7 @@ pub fn reserve(&mut self, additional: usize) { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -1140,8 +1140,11 @@ pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveE + + /// Shrinks the capacity of the vector as much as possible. + /// +- /// It will drop down as close as possible to the length but the allocator +- /// may still inform the vector that there is space for a few more elements. ++ /// The behavior of this method depends on the allocator, which may either shrink the vector ++ /// in-place or reallocate. The resulting vector might still have some excess capacity, just as ++ /// is the case for [`with_capacity`]. See [`Allocator::shrink`] for more details. ++ /// ++ /// [`with_capacity`]: Vec::with_capacity + /// + /// # Examples + /// +@@ -1191,10 +1194,10 @@ pub fn shrink_to(&mut self, min_capacity: usize) { + + /// Converts the vector into [`Box<[T]>`][owned slice]. + /// +- /// If the vector has excess capacity, its items will be moved into a +- /// newly-allocated buffer with exactly the right capacity. ++ /// Before doing the conversion, this method discards excess capacity like [`shrink_to_fit`]. + /// + /// [owned slice]: Box ++ /// [`shrink_to_fit`]: Vec::shrink_to_fit + /// + /// # Examples + /// +@@ -2017,7 +2020,7 @@ fn drop(&mut self) { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -2133,7 +2136,7 @@ pub fn pop(&mut self) -> Option<T> { + } else { + unsafe { + self.len -= 1; +- core::intrinsics::assume(self.len < self.capacity()); ++ core::hint::assert_unchecked(self.len < self.capacity()); + Some(ptr::read(self.as_ptr().add(self.len()))) + } + } +@@ -2143,7 +2146,7 @@ pub fn pop(&mut self) -> Option<T> { + /// + /// # Panics + /// +- /// Panics if the new capacity exceeds `isize::MAX` bytes. ++ /// Panics if the new capacity exceeds `isize::MAX` _bytes_. + /// + /// # Examples + /// +@@ -2315,6 +2318,12 @@ pub fn is_empty(&self) -> bool { + /// `[at, len)`. After the call, the original vector will be left containing + /// the elements `[0, at)` with its previous capacity unchanged. + /// ++ /// - If you want to take ownership of the entire contents and capacity of ++ /// the vector, see [`mem::take`] or [`mem::replace`]. ++ /// - If you don't need the returned vector at all, see [`Vec::truncate`]. ++ /// - If you want to take ownership of an arbitrary subslice, or you don't ++ /// necessarily want to store the removed items in a vector, see [`Vec::drain`]. ++ /// + /// # Panics + /// + /// Panics if `at > len`. +@@ -2346,14 +2355,6 @@ fn assert_failed(at: usize, len: usize) -> ! { + assert_failed(at, self.len()); + } + +- if at == 0 { +- // the new vector can take over the original buffer and avoid the copy +- return mem::replace( +- self, +- Vec::with_capacity_in(self.capacity(), self.allocator().clone()), +- ); +- } +- + let other_len = self.len - at; + let mut other = Vec::with_capacity_in(other_len, self.allocator().clone()); + +@@ -3027,6 +3028,50 @@ fn index_mut(&mut self, index: I) -> &mut Self::Output { + } + } + ++/// Collects an iterator into a Vec, commonly called via [`Iterator::collect()`] ++/// ++/// # Allocation behavior ++/// ++/// In general `Vec` does not guarantee any particular growth or allocation strategy. ++/// That also applies to this trait impl. ++/// ++/// **Note:** This section covers implementation details and is therefore exempt from ++/// stability guarantees. ++/// ++/// Vec may use any or none of the following strategies, ++/// depending on the supplied iterator: ++/// ++/// * preallocate based on [`Iterator::size_hint()`] ++/// * and panic if the number of items is outside the provided lower/upper bounds ++/// * use an amortized growth strategy similar to `pushing` one item at a time ++/// * perform the iteration in-place on the original allocation backing the iterator ++/// ++/// The last case warrants some attention. It is an optimization that in many cases reduces peak memory ++/// consumption and improves cache locality. But when big, short-lived allocations are created, ++/// only a small fraction of their items get collected, no further use is made of the spare capacity ++/// and the resulting `Vec` is moved into a longer-lived structure, then this can lead to the large ++/// allocations having their lifetimes unnecessarily extended which can result in increased memory ++/// footprint. ++/// ++/// In cases where this is an issue, the excess capacity can be discarded with [`Vec::shrink_to()`], ++/// [`Vec::shrink_to_fit()`] or by collecting into [`Box<[T]>`][owned slice] instead, which additionally reduces ++/// the size of the long-lived struct. ++/// ++/// [owned slice]: Box ++/// ++/// ```rust ++/// # use std::sync::Mutex; ++/// static LONG_LIVED: Mutex<Vec<Vec<u16>>> = Mutex::new(Vec::new()); ++/// ++/// for i in 0..10 { ++/// let big_temporary: Vec<u16> = (0..1024).collect(); ++/// // discard most items ++/// let mut result: Vec<_> = big_temporary.into_iter().filter(|i| i % 100 == 0).collect(); ++/// // without this a lot of unused capacity might be moved into the global ++/// result.shrink_to_fit(); ++/// LONG_LIVED.lock().unwrap().push(result); ++/// } ++/// ``` + #[cfg(not(no_global_oom_handling))] + #[stable(feature = "rust1", since = "1.0.0")] + impl<T> FromIterator<T> for Vec<T> { +@@ -3069,14 +3114,8 @@ fn into_iter(self) -> Self::IntoIter { + begin.add(me.len()) as *const T + }; + let cap = me.buf.capacity(); +- IntoIter { +- buf: NonNull::new_unchecked(begin), +- phantom: PhantomData, +- cap, +- alloc, +- ptr: begin, +- end, +- } ++ let buf = NonNull::new_unchecked(begin); ++ IntoIter { buf, phantom: PhantomData, cap, alloc, ptr: buf, end } + } + } + } +@@ -3598,8 +3637,10 @@ fn from(s: Box<[T], A>) -> Self { + impl<T, A: Allocator> From<Vec<T, A>> for Box<[T], A> { + /// Convert a vector into a boxed slice. + /// +- /// If `v` has excess capacity, its items will be moved into a +- /// newly-allocated buffer with exactly the right capacity. ++ /// Before doing the conversion, this method discards excess capacity like [`Vec::shrink_to_fit`]. ++ /// ++ /// [owned slice]: Box ++ /// [`Vec::shrink_to_fit`]: Vec::shrink_to_fit + /// + /// # Examples + /// +diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs +index 75efe47522e4..f07bc5a2c6b4 100644 +--- a/rust/kernel/lib.rs ++++ b/rust/kernel/lib.rs +@@ -17,7 +17,6 @@ + #![feature(const_maybe_uninit_zeroed)] + #![feature(dispatch_from_dyn)] + #![feature(new_uninit)] +-#![feature(offset_of)] + #![feature(ptr_metadata)] + #![feature(receiver_trait)] + #![feature(unsize)] +diff --git a/scripts/Makefile.build b/scripts/Makefile.build +index 1633175846df..0bc7c5fe64b1 100644 +--- a/scripts/Makefile.build ++++ b/scripts/Makefile.build +@@ -262,7 +262,7 @@ $(obj)/%.lst: $(src)/%.c FORCE + # Compile Rust sources (.rs) + # --------------------------------------------------------------------------- + +-rust_allowed_features := new_uninit,offset_of ++rust_allowed_features := new_uninit + + # `--out-dir` is required to avoid temporaries being created by `rustc` in the + # current working directory, which may be not accessible in the out-of-tree +diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh +index e217683b10d6..db2b0bc5866b 100755 +--- a/scripts/min-tool-version.sh ++++ b/scripts/min-tool-version.sh +@@ -33,7 +33,7 @@ llvm) + fi + ;; + rustc) +- echo 1.76.0 ++ echo 1.77.1 + ;; + bindgen) + echo 0.65.1 +-- +2.44.0 + |