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-rw-r--r--rust/kernel/alloc/allocator.rs30
-rw-r--r--rust/kernel/alloc/allocator_test.rs13
-rw-r--r--rust/kernel/alloc/kbox.rs98
-rw-r--r--rust/kernel/alloc/kvec.rs59
4 files changed, 166 insertions, 34 deletions
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index aa2dfa9dca4c..2692cf90c948 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -43,17 +43,6 @@ pub struct Vmalloc;
/// For more details see [self].
pub struct KVmalloc;
-/// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment.
-fn aligned_size(new_layout: Layout) -> usize {
- // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
- let layout = new_layout.pad_to_align();
-
- // Note that `layout.size()` (after padding) is guaranteed to be a multiple of `layout.align()`
- // which together with the slab guarantees means the `krealloc` will return a properly aligned
- // object (see comments in `kmalloc()` for more information).
- layout.size()
-}
-
/// # Invariants
///
/// One of the following: `krealloc`, `vrealloc`, `kvrealloc`.
@@ -88,7 +77,7 @@ impl ReallocFunc {
old_layout: Layout,
flags: Flags,
) -> Result<NonNull<[u8]>, AllocError> {
- let size = aligned_size(layout);
+ let size = layout.size();
let ptr = match ptr {
Some(ptr) => {
if old_layout.size() == 0 {
@@ -123,6 +112,17 @@ impl ReallocFunc {
}
}
+impl Kmalloc {
+ /// Returns a [`Layout`] that makes [`Kmalloc`] fulfill the requested size and alignment of
+ /// `layout`.
+ pub fn aligned_layout(layout: Layout) -> Layout {
+ // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
+ // `layout.align()` which together with the slab guarantees means that `Kmalloc` will return
+ // a properly aligned object (see comments in `kmalloc()` for more information).
+ layout.pad_to_align()
+ }
+}
+
// SAFETY: `realloc` delegates to `ReallocFunc::call`, which guarantees that
// - memory remains valid until it is explicitly freed,
// - passing a pointer to a valid memory allocation is OK,
@@ -135,6 +135,8 @@ unsafe impl Allocator for Kmalloc {
old_layout: Layout,
flags: Flags,
) -> Result<NonNull<[u8]>, AllocError> {
+ let layout = Kmalloc::aligned_layout(layout);
+
// SAFETY: `ReallocFunc::call` has the same safety requirements as `Allocator::realloc`.
unsafe { ReallocFunc::KREALLOC.call(ptr, layout, old_layout, flags) }
}
@@ -176,6 +178,10 @@ unsafe impl Allocator for KVmalloc {
old_layout: Layout,
flags: Flags,
) -> Result<NonNull<[u8]>, AllocError> {
+ // `KVmalloc` may use the `Kmalloc` backend, hence we have to enforce a `Kmalloc`
+ // compatible layout.
+ let layout = Kmalloc::aligned_layout(layout);
+
// TODO: Support alignments larger than PAGE_SIZE.
if layout.align() > bindings::PAGE_SIZE {
pr_warn!("KVmalloc does not support alignments larger than PAGE_SIZE yet.\n");
diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs
index d19c06ef0498..90dd987d40e4 100644
--- a/rust/kernel/alloc/allocator_test.rs
+++ b/rust/kernel/alloc/allocator_test.rs
@@ -22,6 +22,17 @@ pub type Kmalloc = Cmalloc;
pub type Vmalloc = Kmalloc;
pub type KVmalloc = Kmalloc;
+impl Cmalloc {
+ /// Returns a [`Layout`] that makes [`Kmalloc`] fulfill the requested size and alignment of
+ /// `layout`.
+ pub fn aligned_layout(layout: Layout) -> Layout {
+ // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
+ // `layout.align()` which together with the slab guarantees means that `Kmalloc` will return
+ // a properly aligned object (see comments in `kmalloc()` for more information).
+ layout.pad_to_align()
+ }
+}
+
extern "C" {
#[link_name = "aligned_alloc"]
fn libc_aligned_alloc(align: usize, size: usize) -> *mut crate::ffi::c_void;
@@ -82,7 +93,7 @@ unsafe impl Allocator for Cmalloc {
// SAFETY: Returns either NULL or a pointer to a memory allocation that satisfies or
// exceeds the given size and alignment requirements.
- let dst = unsafe { libc_aligned_alloc(layout.align(), layout.size()) } as *mut u8;
+ let dst = unsafe { libc_aligned_alloc(layout.align(), layout.size()) }.cast::<u8>();
let dst = NonNull::new(dst).ok_or(AllocError)?;
if flags.contains(__GFP_ZERO) {
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
index c386ff771d50..856d05aa60f1 100644
--- a/rust/kernel/alloc/kbox.rs
+++ b/rust/kernel/alloc/kbox.rs
@@ -6,6 +6,7 @@
use super::allocator::{KVmalloc, Kmalloc, Vmalloc};
use super::{AllocError, Allocator, Flags};
use core::alloc::Layout;
+use core::borrow::{Borrow, BorrowMut};
use core::fmt;
use core::marker::PhantomData;
use core::mem::ManuallyDrop;
@@ -15,6 +16,7 @@ use core::pin::Pin;
use core::ptr::NonNull;
use core::result::Result;
+use crate::ffi::c_void;
use crate::init::InPlaceInit;
use crate::types::ForeignOwnable;
use pin_init::{InPlaceWrite, Init, PinInit, ZeroableOption};
@@ -398,70 +400,74 @@ where
}
}
-// SAFETY: The `into_foreign` function returns a pointer that is well-aligned.
+// SAFETY: The pointer returned by `into_foreign` comes from a well aligned
+// pointer to `T`.
unsafe impl<T: 'static, A> ForeignOwnable for Box<T, A>
where
A: Allocator,
{
- type PointedTo = T;
+ const FOREIGN_ALIGN: usize = core::mem::align_of::<T>();
type Borrowed<'a> = &'a T;
type BorrowedMut<'a> = &'a mut T;
- fn into_foreign(self) -> *mut Self::PointedTo {
- Box::into_raw(self)
+ fn into_foreign(self) -> *mut c_void {
+ Box::into_raw(self).cast()
}
- unsafe fn from_foreign(ptr: *mut Self::PointedTo) -> Self {
+ unsafe fn from_foreign(ptr: *mut c_void) -> Self {
// SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
// call to `Self::into_foreign`.
- unsafe { Box::from_raw(ptr) }
+ unsafe { Box::from_raw(ptr.cast()) }
}
- unsafe fn borrow<'a>(ptr: *mut Self::PointedTo) -> &'a T {
+ unsafe fn borrow<'a>(ptr: *mut c_void) -> &'a T {
// SAFETY: The safety requirements of this method ensure that the object remains alive and
// immutable for the duration of 'a.
- unsafe { &*ptr }
+ unsafe { &*ptr.cast() }
}
- unsafe fn borrow_mut<'a>(ptr: *mut Self::PointedTo) -> &'a mut T {
+ unsafe fn borrow_mut<'a>(ptr: *mut c_void) -> &'a mut T {
+ let ptr = ptr.cast();
// SAFETY: The safety requirements of this method ensure that the pointer is valid and that
// nothing else will access the value for the duration of 'a.
unsafe { &mut *ptr }
}
}
-// SAFETY: The `into_foreign` function returns a pointer that is well-aligned.
+// SAFETY: The pointer returned by `into_foreign` comes from a well aligned
+// pointer to `T`.
unsafe impl<T: 'static, A> ForeignOwnable for Pin<Box<T, A>>
where
A: Allocator,
{
- type PointedTo = T;
+ const FOREIGN_ALIGN: usize = core::mem::align_of::<T>();
type Borrowed<'a> = Pin<&'a T>;
type BorrowedMut<'a> = Pin<&'a mut T>;
- fn into_foreign(self) -> *mut Self::PointedTo {
+ fn into_foreign(self) -> *mut c_void {
// SAFETY: We are still treating the box as pinned.
- Box::into_raw(unsafe { Pin::into_inner_unchecked(self) })
+ Box::into_raw(unsafe { Pin::into_inner_unchecked(self) }).cast()
}
- unsafe fn from_foreign(ptr: *mut Self::PointedTo) -> Self {
+ unsafe fn from_foreign(ptr: *mut c_void) -> Self {
// SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
// call to `Self::into_foreign`.
- unsafe { Pin::new_unchecked(Box::from_raw(ptr)) }
+ unsafe { Pin::new_unchecked(Box::from_raw(ptr.cast())) }
}
- unsafe fn borrow<'a>(ptr: *mut Self::PointedTo) -> Pin<&'a T> {
+ unsafe fn borrow<'a>(ptr: *mut c_void) -> Pin<&'a T> {
// SAFETY: The safety requirements for this function ensure that the object is still alive,
// so it is safe to dereference the raw pointer.
// The safety requirements of `from_foreign` also ensure that the object remains alive for
// the lifetime of the returned value.
- let r = unsafe { &*ptr };
+ let r = unsafe { &*ptr.cast() };
// SAFETY: This pointer originates from a `Pin<Box<T>>`.
unsafe { Pin::new_unchecked(r) }
}
- unsafe fn borrow_mut<'a>(ptr: *mut Self::PointedTo) -> Pin<&'a mut T> {
+ unsafe fn borrow_mut<'a>(ptr: *mut c_void) -> Pin<&'a mut T> {
+ let ptr = ptr.cast();
// SAFETY: The safety requirements for this function ensure that the object is still alive,
// so it is safe to dereference the raw pointer.
// The safety requirements of `from_foreign` also ensure that the object remains alive for
@@ -499,6 +505,62 @@ where
}
}
+/// # Examples
+///
+/// ```
+/// # use core::borrow::Borrow;
+/// # use kernel::alloc::KBox;
+/// struct Foo<B: Borrow<u32>>(B);
+///
+/// // Owned instance.
+/// let owned = Foo(1);
+///
+/// // Owned instance using `KBox`.
+/// let owned_kbox = Foo(KBox::new(1, GFP_KERNEL)?);
+///
+/// let i = 1;
+/// // Borrowed from `i`.
+/// let borrowed = Foo(&i);
+/// # Ok::<(), Error>(())
+/// ```
+impl<T, A> Borrow<T> for Box<T, A>
+where
+ T: ?Sized,
+ A: Allocator,
+{
+ fn borrow(&self) -> &T {
+ self.deref()
+ }
+}
+
+/// # Examples
+///
+/// ```
+/// # use core::borrow::BorrowMut;
+/// # use kernel::alloc::KBox;
+/// struct Foo<B: BorrowMut<u32>>(B);
+///
+/// // Owned instance.
+/// let owned = Foo(1);
+///
+/// // Owned instance using `KBox`.
+/// let owned_kbox = Foo(KBox::new(1, GFP_KERNEL)?);
+///
+/// let mut i = 1;
+/// // Borrowed from `i`.
+/// let borrowed = Foo(&mut i);
+/// # Ok::<(), Error>(())
+/// ```
+impl<T, A> BorrowMut<T> for Box<T, A>
+where
+ T: ?Sized,
+ A: Allocator,
+{
+ fn borrow_mut(&mut self) -> &mut T {
+ self.deref_mut()
+ }
+}
+
impl<T, A> fmt::Display for Box<T, A>
where
T: ?Sized + fmt::Display,
diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index 1a0dd852a468..3c72e0bdddb8 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -8,6 +8,7 @@ use super::{
AllocError, Allocator, Box, Flags,
};
use core::{
+ borrow::{Borrow, BorrowMut},
fmt,
marker::PhantomData,
mem::{ManuallyDrop, MaybeUninit},
@@ -288,7 +289,7 @@ where
// - `self.len` is smaller than `self.capacity` by the type invariant 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>;
+ let ptr = unsafe { self.as_mut_ptr().add(self.len) }.cast::<MaybeUninit<T>>();
// SAFETY: The memory between `self.len` and `self.capacity` is guaranteed to be allocated
// and valid, but uninitialized.
@@ -847,11 +848,11 @@ where
// - `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) }
+ unsafe { Vec::from_raw_parts(ptr.cast(), len, len) }
}
}
-impl<T> Default for KVec<T> {
+impl<T, A: Allocator> Default for Vec<T, A> {
#[inline]
fn default() -> Self {
Self::new()
@@ -890,6 +891,58 @@ where
}
}
+/// # Examples
+///
+/// ```
+/// # use core::borrow::Borrow;
+/// struct Foo<B: Borrow<[u32]>>(B);
+///
+/// // Owned array.
+/// let owned_array = Foo([1, 2, 3]);
+///
+/// // Owned vector.
+/// let owned_vec = Foo(KVec::from_elem(0, 3, GFP_KERNEL)?);
+///
+/// let arr = [1, 2, 3];
+/// // Borrowed slice from `arr`.
+/// let borrowed_slice = Foo(&arr[..]);
+/// # Ok::<(), Error>(())
+/// ```
+impl<T, A> Borrow<[T]> for Vec<T, A>
+where
+ A: Allocator,
+{
+ fn borrow(&self) -> &[T] {
+ self.as_slice()
+ }
+}
+
+/// # Examples
+///
+/// ```
+/// # use core::borrow::BorrowMut;
+/// struct Foo<B: BorrowMut<[u32]>>(B);
+///
+/// // Owned array.
+/// let owned_array = Foo([1, 2, 3]);
+///
+/// // Owned vector.
+/// let owned_vec = Foo(KVec::from_elem(0, 3, GFP_KERNEL)?);
+///
+/// let mut arr = [1, 2, 3];
+/// // Borrowed slice from `arr`.
+/// let borrowed_slice = Foo(&mut arr[..]);
+/// # Ok::<(), Error>(())
+/// ```
+impl<T, A> BorrowMut<[T]> for Vec<T, A>
+where
+ A: Allocator,
+{
+ fn borrow_mut(&mut self) -> &mut [T] {
+ self.as_mut_slice()
+ }
+}
+
impl<T: Eq, A> Eq for Vec<T, A> where A: Allocator {}
impl<T, I: SliceIndex<[T]>, A> Index<I> for Vec<T, A>
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-30 11:24:06 +0000