@@ -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) 1.75.0 rustc --version
+Rust (optional) 1.76.0 rustc --version
bindgen (optional) 0.65.1 bindgen --version
GNU make 3.82 make --version
bash 4.2 bash --version
@@ -425,12 +425,14 @@ pub unsafe fn __rdl_oom(size: usize, _align: usize) -> ! {
}
}
+#[cfg(not(no_global_oom_handling))]
/// Specialize clones into pre-allocated, uninitialized memory.
/// Used by `Box::clone` and `Rc`/`Arc::make_mut`.
pub(crate) trait WriteCloneIntoRaw: Sized {
unsafe fn write_clone_into_raw(&self, target: *mut Self);
}
+#[cfg(not(no_global_oom_handling))]
impl<T: Clone> WriteCloneIntoRaw for T {
#[inline]
default unsafe fn write_clone_into_raw(&self, target: *mut Self) {
@@ -440,6 +442,7 @@ impl<T: Clone> WriteCloneIntoRaw for T {
}
}
+#[cfg(not(no_global_oom_handling))]
impl<T: Copy> WriteCloneIntoRaw for T {
#[inline]
unsafe fn write_clone_into_raw(&self, target: *mut Self) {
@@ -1042,10 +1042,18 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
/// use std::ptr;
///
/// let x = Box::new(String::from("Hello"));
- /// let p = Box::into_raw(x);
+ /// let ptr = Box::into_raw(x);
/// unsafe {
- /// ptr::drop_in_place(p);
- /// dealloc(p as *mut u8, Layout::new::<String>());
+ /// ptr::drop_in_place(ptr);
+ /// dealloc(ptr as *mut u8, Layout::new::<String>());
+ /// }
+ /// ```
+ /// Note: This is equivalent to the following:
+ /// ```
+ /// let x = Box::new(String::from("Hello"));
+ /// let ptr = Box::into_raw(x);
+ /// unsafe {
+ /// drop(Box::from_raw(ptr));
/// }
/// ```
///
@@ -150,6 +150,7 @@ fn fmt(
/// An intermediate trait for specialization of `Extend`.
#[doc(hidden)]
+#[cfg(not(no_global_oom_handling))]
trait SpecExtend<I: IntoIterator> {
/// Extends `self` with the contents of the given iterator.
fn spec_extend(&mut self, iter: I);
@@ -80,8 +80,8 @@
not(no_sync),
target_has_atomic = "ptr"
))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![doc(rust_logo)]
+#![feature(rustdoc_internals)]
#![no_std]
#![needs_allocator]
// Lints:
@@ -142,7 +142,6 @@
#![feature(maybe_uninit_uninit_array)]
#![feature(maybe_uninit_uninit_array_transpose)]
#![feature(pattern)]
-#![feature(ptr_addr_eq)]
#![feature(ptr_internals)]
#![feature(ptr_metadata)]
#![feature(ptr_sub_ptr)]
@@ -157,6 +156,7 @@
#![feature(std_internals)]
#![feature(str_internals)]
#![feature(strict_provenance)]
+#![feature(trusted_fused)]
#![feature(trusted_len)]
#![feature(trusted_random_access)]
#![feature(try_trait_v2)]
@@ -277,7 +277,7 @@ pub(crate) mod test_helpers {
/// seed not being the same for every RNG invocation too.
pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
use std::hash::{BuildHasher, Hash, Hasher};
- let mut hasher = std::collections::hash_map::RandomState::new().build_hasher();
+ let mut hasher = std::hash::RandomState::new().build_hasher();
std::panic::Location::caller().hash(&mut hasher);
let hc64 = hasher.finish();
let seed_vec =
@@ -27,6 +27,16 @@ enum AllocInit {
Zeroed,
}
+#[repr(transparent)]
+#[cfg_attr(target_pointer_width = "16", rustc_layout_scalar_valid_range_end(0x7fff))]
+#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0x7fff_ffff))]
+#[cfg_attr(target_pointer_width = "64", rustc_layout_scalar_valid_range_end(0x7fff_ffff_ffff_ffff))]
+struct Cap(usize);
+
+impl Cap {
+ const ZERO: Cap = unsafe { Cap(0) };
+}
+
/// A low-level utility for more ergonomically allocating, reallocating, and deallocating
/// a buffer of memory on the heap without having to worry about all the corner cases
/// involved. This type is excellent for building your own data structures like Vec and VecDeque.
@@ -52,7 +62,12 @@ enum AllocInit {
#[allow(missing_debug_implementations)]
pub(crate) struct RawVec<T, A: Allocator = Global> {
ptr: Unique<T>,
- cap: usize,
+ /// Never used for ZSTs; it's `capacity()`'s responsibility to return usize::MAX in that case.
+ ///
+ /// # Safety
+ ///
+ /// `cap` must be in the `0..=isize::MAX` range.
+ cap: Cap,
alloc: A,
}
@@ -121,7 +136,7 @@ impl<T, A: Allocator> RawVec<T, A> {
/// the returned `RawVec`.
pub const fn new_in(alloc: A) -> Self {
// `cap: 0` means "unallocated". zero-sized types are ignored.
- Self { ptr: Unique::dangling(), cap: 0, alloc }
+ Self { ptr: Unique::dangling(), cap: Cap::ZERO, alloc }
}
/// Like `with_capacity`, but parameterized over the choice of
@@ -203,7 +218,7 @@ fn allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Self {
// here should change to `ptr.len() / mem::size_of::<T>()`.
Self {
ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) },
- cap: capacity,
+ cap: unsafe { Cap(capacity) },
alloc,
}
}
@@ -228,7 +243,7 @@ fn try_allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Result<Self, T
// here should change to `ptr.len() / mem::size_of::<T>()`.
Ok(Self {
ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) },
- cap: capacity,
+ cap: unsafe { Cap(capacity) },
alloc,
})
}
@@ -240,12 +255,13 @@ fn try_allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Result<Self, T
/// The `ptr` must be allocated (via the given allocator `alloc`), and with the given
/// `capacity`.
/// The `capacity` cannot exceed `isize::MAX` for sized types. (only a concern on 32-bit
- /// systems). ZST vectors may have a capacity up to `usize::MAX`.
+ /// systems). For ZSTs capacity is ignored.
/// If the `ptr` and `capacity` come from a `RawVec` created via `alloc`, then this is
/// guaranteed.
#[inline]
pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, alloc: A) -> Self {
- Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap: capacity, alloc }
+ let cap = if T::IS_ZST { Cap::ZERO } else { unsafe { Cap(capacity) } };
+ Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap, alloc }
}
/// Gets a raw pointer to the start of the allocation. Note that this is
@@ -261,7 +277,7 @@ pub fn ptr(&self) -> *mut T {
/// This will always be `usize::MAX` if `T` is zero-sized.
#[inline(always)]
pub fn capacity(&self) -> usize {
- if T::IS_ZST { usize::MAX } else { self.cap }
+ if T::IS_ZST { usize::MAX } else { self.cap.0 }
}
/// Returns a shared reference to the allocator backing this `RawVec`.
@@ -270,7 +286,7 @@ pub fn allocator(&self) -> &A {
}
fn current_memory(&self) -> Option<(NonNull<u8>, Layout)> {
- if T::IS_ZST || self.cap == 0 {
+ if T::IS_ZST || self.cap.0 == 0 {
None
} else {
// We could use Layout::array here which ensures the absence of isize and usize overflows
@@ -280,7 +296,7 @@ fn current_memory(&self) -> Option<(NonNull<u8>, Layout)> {
let _: () = const { assert!(mem::size_of::<T>() % mem::align_of::<T>() == 0) };
unsafe {
let align = mem::align_of::<T>();
- let size = mem::size_of::<T>().unchecked_mul(self.cap);
+ let size = mem::size_of::<T>().unchecked_mul(self.cap.0);
let layout = Layout::from_size_align_unchecked(size, align);
Some((self.ptr.cast().into(), layout))
}
@@ -414,12 +430,15 @@ fn needs_to_grow(&self, len: usize, additional: usize) -> bool {
additional > self.capacity().wrapping_sub(len)
}
- fn set_ptr_and_cap(&mut self, ptr: NonNull<[u8]>, cap: usize) {
+ /// # Safety:
+ ///
+ /// `cap` must not exceed `isize::MAX`.
+ unsafe fn set_ptr_and_cap(&mut self, ptr: NonNull<[u8]>, cap: usize) {
// Allocators currently return a `NonNull<[u8]>` whose length matches
// the size requested. If that ever changes, the capacity here should
// change to `ptr.len() / mem::size_of::<T>()`.
self.ptr = unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) };
- self.cap = cap;
+ self.cap = unsafe { Cap(cap) };
}
// This method is usually instantiated many times. So we want it to be as
@@ -444,14 +463,15 @@ fn grow_amortized(&mut self, len: usize, additional: usize) -> Result<(), TryRes
// This guarantees exponential growth. The doubling cannot overflow
// because `cap <= isize::MAX` and the type of `cap` is `usize`.
- let cap = cmp::max(self.cap * 2, required_cap);
+ let cap = cmp::max(self.cap.0 * 2, required_cap);
let cap = cmp::max(Self::MIN_NON_ZERO_CAP, cap);
let new_layout = Layout::array::<T>(cap);
// `finish_grow` is non-generic over `T`.
let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
- self.set_ptr_and_cap(ptr, cap);
+ // SAFETY: finish_grow would have resulted in a capacity overflow if we tried to allocate more than isize::MAX items
+ unsafe { self.set_ptr_and_cap(ptr, cap) };
Ok(())
}
@@ -470,7 +490,10 @@ fn grow_exact(&mut self, len: usize, additional: usize) -> Result<(), TryReserve
// `finish_grow` is non-generic over `T`.
let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
- self.set_ptr_and_cap(ptr, cap);
+ // SAFETY: finish_grow would have resulted in a capacity overflow if we tried to allocate more than isize::MAX items
+ unsafe {
+ self.set_ptr_and_cap(ptr, cap);
+ }
Ok(())
}
@@ -488,7 +511,7 @@ fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> {
if cap == 0 {
unsafe { self.alloc.deallocate(ptr, layout) };
self.ptr = Unique::dangling();
- self.cap = 0;
+ self.cap = Cap::ZERO;
} else {
let ptr = unsafe {
// `Layout::array` cannot overflow here because it would have
@@ -499,7 +522,10 @@ fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> {
.shrink(ptr, layout, new_layout)
.map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })?
};
- self.set_ptr_and_cap(ptr, cap);
+ // SAFETY: if the allocation is valid, then the capacity is too
+ unsafe {
+ self.set_ptr_and_cap(ptr, cap);
+ }
}
Ok(())
}
@@ -9,7 +9,8 @@
use core::array;
use core::fmt;
use core::iter::{
- FusedIterator, InPlaceIterable, SourceIter, TrustedLen, TrustedRandomAccessNoCoerce,
+ FusedIterator, InPlaceIterable, SourceIter, TrustedFused, TrustedLen,
+ TrustedRandomAccessNoCoerce,
};
use core::marker::PhantomData;
use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
@@ -287,9 +288,7 @@ 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 { ptr::read(self.ptr.add(i)) } }
}
}
@@ -341,6 +340,10 @@ fn is_empty(&self) -> bool {
#[stable(feature = "fused", since = "1.26.0")]
impl<T, A: Allocator> FusedIterator for IntoIter<T, A> {}
+#[doc(hidden)]
+#[unstable(issue = "none", feature = "trusted_fused")]
+unsafe impl<T, A: Allocator> TrustedFused for IntoIter<T, A> {}
+
#[unstable(feature = "trusted_len", issue = "37572")]
unsafe impl<T, A: Allocator> TrustedLen for IntoIter<T, A> {}
@@ -425,7 +428,10 @@ fn drop(&mut self) {
// also refer to the vec::in_place_collect module documentation to get an overview
#[unstable(issue = "none", feature = "inplace_iteration")]
#[doc(hidden)]
-unsafe impl<T, A: Allocator> InPlaceIterable for IntoIter<T, A> {}
+unsafe impl<T, A: Allocator> InPlaceIterable for IntoIter<T, A> {
+ const EXPAND_BY: Option<NonZeroUsize> = NonZeroUsize::new(1);
+ const MERGE_BY: Option<NonZeroUsize> = NonZeroUsize::new(1);
+}
#[unstable(issue = "none", feature = "inplace_iteration")]
#[doc(hidden)]
@@ -105,6 +105,7 @@
#[cfg(not(no_global_oom_handling))]
use self::is_zero::IsZero;
+#[cfg(not(no_global_oom_handling))]
mod is_zero;
#[cfg(not(no_global_oom_handling))]
@@ -123,7 +124,7 @@
mod set_len_on_drop;
#[cfg(not(no_global_oom_handling))]
-use self::in_place_drop::{InPlaceDrop, InPlaceDstBufDrop};
+use self::in_place_drop::{InPlaceDrop, InPlaceDstDataSrcBufDrop};
#[cfg(not(no_global_oom_handling))]
mod in_place_drop;
@@ -1893,7 +1894,32 @@ pub fn dedup_by<F>(&mut self, mut same_bucket: F)
return;
}
- /* INVARIANT: vec.len() > read >= write > write-1 >= 0 */
+ // Check if we ever want to remove anything.
+ // This allows to use copy_non_overlapping in next cycle.
+ // And avoids any memory writes if we don't need to remove anything.
+ let mut first_duplicate_idx: usize = 1;
+ let start = self.as_mut_ptr();
+ while first_duplicate_idx != len {
+ let found_duplicate = unsafe {
+ // SAFETY: first_duplicate always in range [1..len)
+ // Note that we start iteration from 1 so we never overflow.
+ let prev = start.add(first_duplicate_idx.wrapping_sub(1));
+ let current = start.add(first_duplicate_idx);
+ // We explicitly say in docs that references are reversed.
+ same_bucket(&mut *current, &mut *prev)
+ };
+ if found_duplicate {
+ break;
+ }
+ first_duplicate_idx += 1;
+ }
+ // Don't need to remove anything.
+ // We cannot get bigger than len.
+ if first_duplicate_idx == len {
+ return;
+ }
+
+ /* INVARIANT: vec.len() > read > write > write-1 >= 0 */
struct FillGapOnDrop<'a, T, A: core::alloc::Allocator> {
/* Offset of the element we want to check if it is duplicate */
read: usize,
@@ -1939,31 +1965,39 @@ fn drop(&mut self) {
}
}
- let mut gap = FillGapOnDrop { read: 1, write: 1, vec: self };
- let ptr = gap.vec.as_mut_ptr();
-
/* Drop items while going through Vec, it should be more efficient than
* doing slice partition_dedup + truncate */
+ // Construct gap first and then drop item to avoid memory corruption if `T::drop` panics.
+ let mut gap =
+ FillGapOnDrop { read: first_duplicate_idx + 1, write: first_duplicate_idx, vec: self };
+ unsafe {
+ // SAFETY: we checked that first_duplicate_idx in bounds before.
+ // If drop panics, `gap` would remove this item without drop.
+ ptr::drop_in_place(start.add(first_duplicate_idx));
+ }
+
/* SAFETY: Because of the invariant, read_ptr, prev_ptr and write_ptr
* are always in-bounds and read_ptr never aliases prev_ptr */
unsafe {
while gap.read < len {
- let read_ptr = ptr.add(gap.read);
- let prev_ptr = ptr.add(gap.write.wrapping_sub(1));
+ let read_ptr = start.add(gap.read);
+ let prev_ptr = start.add(gap.write.wrapping_sub(1));
- if same_bucket(&mut *read_ptr, &mut *prev_ptr) {
+ // We explicitly say in docs that references are reversed.
+ let found_duplicate = same_bucket(&mut *read_ptr, &mut *prev_ptr);
+ if found_duplicate {
// Increase `gap.read` now since the drop may panic.
gap.read += 1;
/* We have found duplicate, drop it in-place */
ptr::drop_in_place(read_ptr);
} else {
- let write_ptr = ptr.add(gap.write);
+ let write_ptr = start.add(gap.write);
- /* Because `read_ptr` can be equal to `write_ptr`, we either
- * have to use `copy` or conditional `copy_nonoverlapping`.
- * Looks like the first option is faster. */
- ptr::copy(read_ptr, write_ptr, 1);
+ /* read_ptr cannot be equal to write_ptr because at this point
+ * we guaranteed to skip at least one element (before loop starts).
+ */
+ ptr::copy_nonoverlapping(read_ptr, write_ptr, 1);
/* We have filled that place, so go further */
gap.write += 1;
@@ -2844,6 +2878,7 @@ pub fn from_elem_in<T: Clone, A: Allocator>(elem: T, n: usize, alloc: A) -> Vec<
<T as SpecFromElem>::from_elem(elem, n, alloc)
}
+#[cfg(not(no_global_oom_handling))]
trait ExtendFromWithinSpec {
/// # Safety
///
@@ -2852,6 +2887,7 @@ trait ExtendFromWithinSpec {
unsafe fn spec_extend_from_within(&mut self, src: Range<usize>);
}
+#[cfg(not(no_global_oom_handling))]
impl<T: Clone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
default unsafe fn spec_extend_from_within(&mut self, src: Range<usize>) {
// SAFETY:
@@ -2871,6 +2907,7 @@ impl<T: Clone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
}
}
+#[cfg(not(no_global_oom_handling))]
impl<T: Copy, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
unsafe fn spec_extend_from_within(&mut self, src: Range<usize>) {
let count = src.len();
@@ -2951,7 +2988,7 @@ fn clone_from(&mut self, other: &Self) {
/// ```
/// use std::hash::BuildHasher;
///
-/// let b = std::collections::hash_map::RandomState::new();
+/// let b = std::hash::RandomState::new();
/// let v: Vec<u8> = vec![0xa8, 0x3c, 0x09];
/// let s: &[u8] = &[0xa8, 0x3c, 0x09];
/// assert_eq!(b.hash_one(v), b.hash_one(s));
@@ -33,7 +33,7 @@ llvm)
fi
;;
rustc)
- echo 1.75.0
+ echo 1.76.0
;;
bindgen)
echo 0.65.1
This is the next upgrade to the Rust toolchain, from 1.75.0 to 1.76.0 (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 in Rust 1.76.0. The only unstable features allowed to be used outside the `kernel` crate are still `new_uninit,offset_of`, though other code to be upstreamed may increase the list. Please see [3] for details. # Required changes `rustc` (and others) now warns when it cannot connect to the Make jobserver, thus mark those invocations as recursive as needed. Please see the previous commit for details. # Other changes Rust 1.76.0 does not emit the `.debug_pub{names,types}` sections anymore for DWARFv4 [4][5]. For instance, in the uncompressed debug info case, this debug information took: samples/rust/rust_minimal.o ~64 KiB (~18% of total object size) rust/kernel.o ~92 KiB (~15%) rust/core.o ~114 KiB ( ~5%) In the compressed debug info (zlib) case: samples/rust/rust_minimal.o ~11 KiB (~6%) rust/kernel.o ~17 KiB (~5%) rust/core.o ~21 KiB (~1.5%) In addition, the `rustc_codegen_gcc` backend now does not emit the `.eh_frame` section when compiling under `-Cpanic=abort` [6], thus removing the need for the patch in the CI to compile the kernel [7]. Moreover, it also now emits the `.comment` section too [6]. # `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-1760-2024-02-08 [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/688 [4] Link: https://github.com/rust-lang/rust/pull/117962 [5] Link: https://github.com/rust-lang/rust/pull/118068 [6] Link: https://github.com/Rust-for-Linux/ci-rustc_codegen_gcc [7] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> --- Documentation/process/changes.rst | 2 +- rust/alloc/alloc.rs | 3 ++ rust/alloc/boxed.rs | 14 +++++-- rust/alloc/collections/mod.rs | 1 + rust/alloc/lib.rs | 8 ++-- rust/alloc/raw_vec.rs | 58 +++++++++++++++++++-------- rust/alloc/vec/into_iter.rs | 16 +++++--- rust/alloc/vec/mod.rs | 65 ++++++++++++++++++++++++------- scripts/min-tool-version.sh | 2 +- 9 files changed, 125 insertions(+), 44 deletions(-) -- 2.43.0