@@ -5,6 +5,7 @@
#[cfg(not(any(test, testlib)))]
pub mod allocator;
pub mod kbox;
+pub mod kvec;
pub mod layout;
pub mod vec_ext;
@@ -19,6 +20,11 @@
pub use self::kbox::KVBox;
pub use self::kbox::VBox;
+pub use self::kvec::KVVec;
+pub use self::kvec::KVec;
+pub use self::kvec::VVec;
+pub use self::kvec::Vec;
+
/// Indicates an allocation error.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct AllocError;
new file mode 100644
@@ -0,0 +1,650 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Implementation of [`Vec`].
+
+use super::{
+ allocator::{KVmalloc, Kmalloc, Vmalloc},
+ layout::ArrayLayout,
+ AllocError, Allocator, Box, Flags,
+};
+use core::{
+ fmt,
+ marker::PhantomData,
+ mem::{ManuallyDrop, MaybeUninit},
+ ops::Deref,
+ ops::DerefMut,
+ ops::Index,
+ ops::IndexMut,
+ ptr,
+ ptr::NonNull,
+ slice,
+ slice::SliceIndex,
+};
+
+/// Create a [`KVec`] containing the arguments.
+///
+/// New memory is allocated with `GFP_KERNEL`.
+///
+/// # Examples
+///
+/// ```
+/// let mut v = kernel::kvec![];
+/// v.push(1, GFP_KERNEL)?;
+/// assert_eq!(v, [1]);
+///
+/// let mut v = kernel::kvec![1; 3]?;
+/// v.push(4, GFP_KERNEL)?;
+/// assert_eq!(v, [1, 1, 1, 4]);
+///
+/// let mut v = kernel::kvec![1, 2, 3]?;
+/// v.push(4, GFP_KERNEL)?;
+/// assert_eq!(v, [1, 2, 3, 4]);
+///
+/// # Ok::<(), Error>(())
+/// ```
+#[macro_export]
+macro_rules! kvec {
+ () => (
+ $crate::alloc::KVec::new()
+ );
+ ($elem:expr; $n:expr) => (
+ $crate::alloc::KVec::from_elem($elem, $n, GFP_KERNEL)
+ );
+ ($($x:expr),+ $(,)?) => (
+ match $crate::alloc::KBox::new_uninit(GFP_KERNEL) {
+ Ok(b) => Ok($crate::alloc::KVec::from($crate::alloc::KBox::write(b, [$($x),+]))),
+ Err(e) => Err(e),
+ }
+ );
+}
+
+/// The kernel's [`Vec`] type.
+///
+/// A contiguous growable array type with contents allocated with the kernel's allocators (e.g.
+/// [`Kmalloc`], [`Vmalloc`] or [`KVmalloc`]), written `Vec<T, A>`.
+///
+/// For non-zero-sized values, a [`Vec`] will use the given allocator `A` for its allocation. For
+/// the most common allocators the type aliases [`KVec`], [`VVec`] and [`KVVec`] exist.
+///
+/// For zero-sized types the [`Vec`]'s pointer must be `dangling_mut::<T>`; no memory is allocated.
+///
+/// Generally, [`Vec`] consists of a pointer that represents the vector's backing buffer, the
+/// capacity of the vector (the number of elements that currently fit into the vector), it's length
+/// (the number of elements that are currently stored in the vector) and the `Allocator` type used
+/// to allocate (and free) the backing buffer.
+///
+/// A [`Vec`] can be deconstructed into and (re-)constructed from it's previously named raw parts
+/// and manually modified.
+///
+/// [`Vec`]'s backing buffer gets, if required, automatically increased (re-allocated) when elements
+/// are added to the vector.
+///
+/// # Invariants
+///
+/// - `self.ptr` is always properly aligned and either points to memory allocated with `A` or, for
+/// zero-sized types, is a dangling, well aligned pointer.
+///
+/// - `self.len` always represents the exact number of elements stored in the vector.
+///
+/// - `self.layout` represents the absolute number of elements that can be stored within the vector
+/// without re-allocation. For ZSTs `self.layout`'s capacity is zero. However, it is legal for the
+/// backing buffer to be larger than `layout`.
+///
+/// - The `Allocator` type `A` of the vector is the exact same `Allocator` type the backing buffer
+/// was allocated with (and must be freed with).
+pub struct Vec<T, A: Allocator> {
+ ptr: NonNull<T>,
+ /// Represents the actual buffer size as `cap` times `size_of::<T>` bytes.
+ ///
+ /// Note: This isn't quite the same as `Self::capacity`, which in contrast returns the number of
+ /// elements we can still store without reallocating.
+ layout: ArrayLayout<T>,
+ len: usize,
+ _p: PhantomData<A>,
+}
+
+/// Type alias for [`Vec`] with a [`Kmalloc`] allocator.
+///
+/// # Examples
+///
+/// ```
+/// let mut v = KVec::new();
+/// v.push(1, GFP_KERNEL)?;
+/// assert_eq!(&v, &[1]);
+///
+/// # Ok::<(), Error>(())
+/// ```
+pub type KVec<T> = Vec<T, Kmalloc>;
+
+/// Type alias for [`Vec`] with a [`Vmalloc`] allocator.
+///
+/// # Examples
+///
+/// ```
+/// let mut v = VVec::new();
+/// v.push(1, GFP_KERNEL)?;
+/// assert_eq!(&v, &[1]);
+///
+/// # Ok::<(), Error>(())
+/// ```
+pub type VVec<T> = Vec<T, Vmalloc>;
+
+/// Type alias for [`Vec`] with a [`KVmalloc`] allocator.
+///
+/// # Examples
+///
+/// ```
+/// let mut v = KVVec::new();
+/// v.push(1, GFP_KERNEL)?;
+/// assert_eq!(&v, &[1]);
+///
+/// # Ok::<(), Error>(())
+/// ```
+pub type KVVec<T> = Vec<T, KVmalloc>;
+
+// SAFETY: `Vec` is `Send` if `T` is `Send` because `Vec` owns its elements.
+unsafe impl<T, A> Send for Vec<T, A>
+where
+ T: Send,
+ A: Allocator,
+{
+}
+
+// SAFETY: `Vec` is `Sync` if `T` is `Sync` because `Vec` owns its elements.
+unsafe impl<T, A> Sync for Vec<T, A>
+where
+ T: Sync,
+ A: Allocator,
+{
+}
+
+impl<T, A> Vec<T, A>
+where
+ A: Allocator,
+{
+ #[inline]
+ const fn is_zst() -> bool {
+ core::mem::size_of::<T>() == 0
+ }
+
+ /// Returns the number of elements that can be stored within the vector without allocating
+ /// additional memory.
+ pub fn capacity(&self) -> usize {
+ if const { Self::is_zst() } {
+ usize::MAX
+ } else {
+ self.layout.len()
+ }
+ }
+
+ /// Returns the number of elements stored within the vector.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.len
+ }
+
+ /// Forcefully sets `self.len` to `new_len`.
+ ///
+ /// # Safety
+ ///
+ /// - `new_len` must be less than or equal to [`Self::capacity`].
+ /// - If `new_len` is greater than `self.len`, all elements within the interval
+ /// [`self.len`,`new_len`) must be initialized.
+ #[inline]
+ pub unsafe fn set_len(&mut self, new_len: usize) {
+ debug_assert!(new_len <= self.capacity());
+ self.len = new_len;
+ }
+
+ /// Returns a slice of the entire vector.
+ #[inline]
+ pub fn as_slice(&self) -> &[T] {
+ self
+ }
+
+ /// Returns a mutable slice of the entire vector.
+ #[inline]
+ pub fn as_mut_slice(&mut self) -> &mut [T] {
+ self
+ }
+
+ /// Returns a mutable raw pointer to the vector's backing buffer, or, if `T` is a ZST, a
+ /// dangling raw pointer.
+ #[inline]
+ pub fn as_mut_ptr(&mut self) -> *mut T {
+ self.ptr.as_ptr()
+ }
+
+ /// Returns a raw pointer to the vector's backing buffer, or, if `T` is a ZST, a dangling raw
+ /// pointer.
+ #[inline]
+ pub fn as_ptr(&self) -> *const T {
+ self.ptr.as_ptr()
+ }
+
+ /// Returns `true` if the vector contains no elements, `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let mut v = KVec::new();
+ /// assert!(v.is_empty());
+ ///
+ /// v.push(1, GFP_KERNEL);
+ /// assert!(!v.is_empty());
+ /// ```
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ self.len() == 0
+ }
+
+ /// Creates a new, empty Vec<T, A>.
+ ///
+ /// This method does not allocate by itself.
+ #[inline]
+ pub const fn new() -> Self {
+ // INVARIANT: Since this is a new, empty `Vec` with no backing memory yet,
+ // - `ptr` is a properly aligned dangling pointer for type `T`,
+ // - `layout` is an empty `ArrayLayout` (zero capacity)
+ // - `len` is zero, since no elements can be or have been stored,
+ // - `A` is always valid.
+ Self {
+ ptr: NonNull::dangling(),
+ layout: ArrayLayout::empty(),
+ len: 0,
+ _p: PhantomData::<A>,
+ }
+ }
+
+ /// Returns a slice of `MaybeUninit<T>` for the remaining spare capacity of the vector.
+ pub fn spare_capacity_mut(&mut self) -> &mut [MaybeUninit<T>] {
+ // SAFETY:
+ // - `self.len` is smaller than `self.capacity` and hence, the resulting pointer is
+ // guaranteed to be part of the same allocated object.
+ // - `self.len` can not overflow `isize`.
+ let ptr = unsafe { self.as_mut_ptr().add(self.len) } as *mut MaybeUninit<T>;
+
+ // SAFETY: The memory between `self.len` and `self.capacity` is guaranteed to be allocated
+ // and valid, but uninitialized.
+ unsafe { slice::from_raw_parts_mut(ptr, self.capacity() - self.len) }
+ }
+
+ /// Appends an element to the back of the [`Vec`] instance.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let mut v = KVec::new();
+ /// v.push(1, GFP_KERNEL)?;
+ /// assert_eq!(&v, &[1]);
+ ///
+ /// v.push(2, GFP_KERNEL)?;
+ /// assert_eq!(&v, &[1, 2]);
+ /// # Ok::<(), Error>(())
+ /// ```
+ pub fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError> {
+ self.reserve(1, flags)?;
+
+ // SAFETY:
+ // - `self.len` is smaller than `self.capacity` and hence, the resulting pointer is
+ // guaranteed to be part of the same allocated object.
+ // - `self.len` can not overflow `isize`.
+ let ptr = unsafe { self.as_mut_ptr().add(self.len) };
+
+ // SAFETY:
+ // - `ptr` is properly aligned and valid for writes.
+ unsafe { core::ptr::write(ptr, v) };
+
+ // SAFETY: We just initialised the first spare entry, so it is safe to increase the length
+ // by 1. We also know that the new length is <= capacity because of the previous call to
+ // `reserve` above.
+ unsafe { self.set_len(self.len() + 1) };
+ Ok(())
+ }
+
+ /// Creates a new [`Vec`] instance with at least the given capacity.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let v = KVec::<u32>::with_capacity(20, GFP_KERNEL)?;
+ ///
+ /// assert!(v.capacity() >= 20);
+ /// # Ok::<(), Error>(())
+ /// ```
+ pub fn with_capacity(capacity: usize, flags: Flags) -> Result<Self, AllocError> {
+ let mut v = Vec::new();
+
+ v.reserve(capacity, flags)?;
+
+ Ok(v)
+ }
+
+ /// Creates a Vec<T, A> from a pointer, a length and a capacity using the allocator `A`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let mut v = kernel::kvec![1, 2, 3]?;
+ /// v.reserve(1, GFP_KERNEL)?;
+ ///
+ /// let (mut ptr, mut len, cap) = v.into_raw_parts();
+ ///
+ /// // SAFETY: We've just reserved memory for another element.
+ /// unsafe { ptr.add(len).write(4) };
+ /// len += 1;
+ ///
+ /// // SAFETY: We only wrote an additional element at the end of the `KVec`'s buffer and
+ /// // correspondingly increased the length of the `KVec` by one. Otherwise, we construct it
+ /// // from the exact same raw parts.
+ /// let v = unsafe { KVec::from_raw_parts(ptr, len, cap) };
+ ///
+ /// assert_eq!(v, [1, 2, 3, 4]);
+ ///
+ /// # Ok::<(), Error>(())
+ /// ```
+ ///
+ /// # Safety
+ ///
+ /// If `T` is a ZST:
+ ///
+ /// - `ptr` must be a dangling, well aligned pointer.
+ ///
+ /// Otherwise:
+ ///
+ /// - `ptr` must have been allocated with the allocator `A`.
+ /// - `ptr` must satisfy or exceed the alignment requirements of `T`.
+ /// - `ptr` must point to memory with a size of at least `size_of::<T>() * capacity`.
+ /// bytes.
+ /// - The allocated size in bytes must not be larger than `isize::MAX`.
+ /// - `length` must be less than or equal to `capacity`.
+ /// - The first `length` elements must be initialized values of type `T`.
+ ///
+ /// It is also valid to create an empty `Vec` passing a dangling pointer for `ptr` and zero for
+ /// `cap` and `len`.
+ pub unsafe fn from_raw_parts(ptr: *mut T, length: usize, capacity: usize) -> Self {
+ let layout = if Self::is_zst() {
+ ArrayLayout::empty()
+ } else {
+ // SAFETY: By the safety requirements of this function, `capacity * size_of::<T>()` is
+ // smaller than `isize::MAX`.
+ unsafe { ArrayLayout::new_unchecked(capacity) }
+ };
+
+ // INVARIANT: For ZSTs, we store an empty `ArrayLayout`, all other type invariants are
+ // covered by the safety requirements of this function.
+ Self {
+ // SAFETY: By the safety requirements, `ptr` is either dangling or pointing to a valid
+ // memory allocation, allocated with `A`.
+ ptr: unsafe { NonNull::new_unchecked(ptr) },
+ layout,
+ len: length,
+ _p: PhantomData::<A>,
+ }
+ }
+
+ /// Consumes the `Vec<T, A>` and returns its raw components `pointer`, `length` and `capacity`.
+ ///
+ /// This will not run the destructor of the contained elements and for non-ZSTs the allocation
+ /// will stay alive indefinitely. Use [`Vec::from_raw_parts`] to recover the [`Vec`], drop the
+ /// elements and free the allocation, if any.
+ pub fn into_raw_parts(self) -> (*mut T, usize, usize) {
+ let mut me = ManuallyDrop::new(self);
+ let len = me.len();
+ let capacity = me.capacity();
+ let ptr = me.as_mut_ptr();
+ (ptr, len, capacity)
+ }
+
+ /// Ensures that the capacity exceeds the length by at least `additional`
+ /// elements.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let mut v = KVec::new();
+ /// v.push(1, GFP_KERNEL)?;
+ ///
+ /// v.reserve(10, GFP_KERNEL)?;
+ /// let cap = v.capacity();
+ /// assert!(cap >= 10);
+ ///
+ /// v.reserve(10, GFP_KERNEL)?;
+ /// let new_cap = v.capacity();
+ /// assert_eq!(new_cap, cap);
+ ///
+ /// # Ok::<(), Error>(())
+ /// ```
+ pub fn reserve(&mut self, additional: usize, flags: Flags) -> Result<(), AllocError> {
+ let len = self.len();
+ let cap = self.capacity();
+
+ if cap - len >= additional {
+ return Ok(());
+ }
+
+ if Self::is_zst() {
+ // The capacity is already `usize::MAX` for ZSTs, we can't go higher.
+ return Err(AllocError);
+ }
+
+ // We know that `cap <= isize::MAX` because of the type invariants of `Self`. So the
+ // multiplication by two won't overflow.
+ let new_cap = core::cmp::max(cap * 2, len.checked_add(additional).ok_or(AllocError)?);
+ let layout = ArrayLayout::new(new_cap).map_err(|_| AllocError)?;
+
+ // SAFETY:
+ // - `ptr` is valid because it's either `None` or comes from a previous call to
+ // `A::realloc`.
+ // - `self.layout` matches the `ArrayLayout` of the preceeding allocation.
+ let ptr = unsafe {
+ A::realloc(
+ Some(self.ptr.cast()),
+ layout.into(),
+ self.layout.into(),
+ flags,
+ )?
+ };
+
+ // INVARIANT:
+ // - `layout` is some `ArrayLayout::<T>`,
+ // - `ptr` has been created by `A::realloc` from `layout`.
+ self.ptr = ptr.cast();
+ self.layout = layout;
+
+ Ok(())
+ }
+}
+
+impl<T: Clone, A: Allocator> Vec<T, A> {
+ /// Extend the vector by `n` clones of `value`.
+ pub fn extend_with(&mut self, n: usize, value: T, flags: Flags) -> Result<(), AllocError> {
+ if n == 0 {
+ return Ok(());
+ }
+
+ self.reserve(n, flags)?;
+
+ let spare = self.spare_capacity_mut();
+
+ for item in spare.iter_mut().take(n - 1) {
+ item.write(value.clone());
+ }
+
+ // We can write the last element directly without cloning needlessly.
+ spare[n - 1].write(value);
+
+ // SAFETY:
+ // - `self.len() + n < self.capacity()` due to the call to reserve above,
+ // - the loop and the line above initialized the next `n` elements.
+ unsafe { self.set_len(self.len() + n) };
+
+ Ok(())
+ }
+
+ /// Pushes clones of the elements of slice into the [`Vec`] instance.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let mut v = KVec::new();
+ /// v.push(1, GFP_KERNEL)?;
+ ///
+ /// v.extend_from_slice(&[20, 30, 40], GFP_KERNEL)?;
+ /// assert_eq!(&v, &[1, 20, 30, 40]);
+ ///
+ /// v.extend_from_slice(&[50, 60], GFP_KERNEL)?;
+ /// assert_eq!(&v, &[1, 20, 30, 40, 50, 60]);
+ /// # Ok::<(), Error>(())
+ /// ```
+ pub fn extend_from_slice(&mut self, other: &[T], flags: Flags) -> Result<(), AllocError> {
+ self.reserve(other.len(), flags)?;
+ for (slot, item) in core::iter::zip(self.spare_capacity_mut(), other) {
+ slot.write(item.clone());
+ }
+
+ // SAFETY:
+ // - `other.len()` spare entries have just been initialized, so it is safe to increase
+ // the length by the same number.
+ // - `self.len() + other.len() <= self.capacity()` is guaranteed by the preceding `reserve`
+ // call.
+ unsafe { self.set_len(self.len() + other.len()) };
+ Ok(())
+ }
+
+ /// Create a new `Vec<T, A> and extend it by `n` clones of `value`.
+ pub fn from_elem(value: T, n: usize, flags: Flags) -> Result<Self, AllocError> {
+ let mut v = Self::with_capacity(n, flags)?;
+
+ v.extend_with(n, value, flags)?;
+
+ Ok(v)
+ }
+}
+
+impl<T, A> Drop for Vec<T, A>
+where
+ A: Allocator,
+{
+ fn drop(&mut self) {
+ // SAFETY: `self.as_mut_ptr` is guaranteed to be valid by the type invariant.
+ unsafe {
+ ptr::drop_in_place(core::ptr::slice_from_raw_parts_mut(
+ self.as_mut_ptr(),
+ self.len,
+ ))
+ };
+
+ // SAFETY:
+ // - `self.ptr` was previously allocated with `A`.
+ // - `self.layout` matches the `ArrayLayout` of the preceeding allocation.
+ unsafe { A::free(self.ptr.cast(), self.layout.into()) };
+ }
+}
+
+impl<T, A, const N: usize> From<Box<[T; N], A>> for Vec<T, A>
+where
+ A: Allocator,
+{
+ fn from(b: Box<[T; N], A>) -> Vec<T, A> {
+ let len = b.len();
+ let ptr = Box::into_raw(b);
+
+ // SAFETY:
+ // - `b` has been allocated with `A`,
+ // - `ptr` fulfills the alignment requirements for `T`,
+ // - `ptr` points to memory with at least a size of `size_of::<T>() * len`,
+ // - all elements within `b` are initialized values of `T`,
+ // - `len` does not exceed `isize::MAX`.
+ unsafe { Vec::from_raw_parts(ptr as _, len, len) }
+ }
+}
+
+impl<T> Default for KVec<T> {
+ #[inline]
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl<T: fmt::Debug, A: Allocator> fmt::Debug for Vec<T, A> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
+impl<T, A> Deref for Vec<T, A>
+where
+ A: Allocator,
+{
+ type Target = [T];
+
+ #[inline]
+ fn deref(&self) -> &[T] {
+ // SAFETY: The memory behind `self.as_ptr()` is guaranteed to contain `self.len`
+ // initialized elements of type `T`.
+ unsafe { slice::from_raw_parts(self.as_ptr(), self.len) }
+ }
+}
+
+impl<T, A> DerefMut for Vec<T, A>
+where
+ A: Allocator,
+{
+ #[inline]
+ fn deref_mut(&mut self) -> &mut [T] {
+ // SAFETY: The memory behind `self.as_ptr()` is guaranteed to contain `self.len`
+ // initialized elements of type `T`.
+ unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), self.len) }
+ }
+}
+
+impl<T: Eq, A> Eq for Vec<T, A> where A: Allocator {}
+
+impl<T, I: SliceIndex<[T]>, A> Index<I> for Vec<T, A>
+where
+ A: Allocator,
+{
+ type Output = I::Output;
+
+ #[inline]
+ fn index(&self, index: I) -> &Self::Output {
+ Index::index(&**self, index)
+ }
+}
+
+impl<T, I: SliceIndex<[T]>, A> IndexMut<I> for Vec<T, A>
+where
+ A: Allocator,
+{
+ #[inline]
+ fn index_mut(&mut self, index: I) -> &mut Self::Output {
+ IndexMut::index_mut(&mut **self, index)
+ }
+}
+
+macro_rules! impl_slice_eq {
+ ($([$($vars:tt)*] $lhs:ty, $rhs:ty,)*) => {
+ $(
+ impl<T, U, $($vars)*> PartialEq<$rhs> for $lhs
+ where
+ T: PartialEq<U>,
+ {
+ #[inline]
+ fn eq(&self, other: &$rhs) -> bool { self[..] == other[..] }
+ }
+ )*
+ }
+}
+
+impl_slice_eq! {
+ [A1: Allocator, A2: Allocator] Vec<T, A1>, Vec<U, A2>,
+ [A: Allocator] Vec<T, A>, &[U],
+ [A: Allocator] Vec<T, A>, &mut [U],
+ [A: Allocator] &[T], Vec<U, A>,
+ [A: Allocator] &mut [T], Vec<U, A>,
+ [A: Allocator] Vec<T, A>, [U],
+ [A: Allocator] [T], Vec<U, A>,
+ [A: Allocator, const N: usize] Vec<T, A>, [U; N],
+ [A: Allocator, const N: usize] Vec<T, A>, &[U; N],
+}
@@ -17,6 +17,7 @@
#![feature(dispatch_from_dyn)]
#![feature(lint_reasons)]
#![feature(unsize)]
+#![feature(inline_const)]
// Ensure conditional compilation based on the kernel configuration works;
// otherwise we may silently break things like initcall handling.
@@ -14,7 +14,7 @@
#[doc(no_inline)]
pub use core::pin::Pin;
-pub use crate::alloc::{flags::*, vec_ext::VecExt, Box, KBox, KVBox, VBox};
+pub use crate::alloc::{flags::*, vec_ext::VecExt, Box, KBox, KVBox, KVVec, KVec, VBox, VVec};
#[doc(no_inline)]
pub use alloc::vec::Vec;