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authorLinus Torvalds <torvalds@linux-foundation.org>2025-09-30 19:12:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-09-30 19:12:49 -0700
commitf4e0ff7e45c30f4665cfbbe2f0538e9c5789bebc (patch)
tree6703541ef1fec9d20dafc751d2e971879c429884 /rust/kernel/alloc/allocator_test.rs
parentae28ed4578e6d5a481e39c5a9827f27048661fdd (diff)
parentf3f6b3664302e16ef1c6b91034a72df5564d6b8a (diff)
Merge tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Derive 'Zeroable' for all structs and unions generated by 'bindgen' where possible and corresponding cleanups. To do so, add the 'pin-init' crate as a dependency to 'bindings' and 'uapi'. It also includes its first use in the 'cpufreq' module, with more to come in the next cycle. - Add warning to the 'rustdoc' target to detect broken 'srctree/' links and fix existing cases. - Remove support for unused (since v6.16) host '#[test]'s, simplifying the 'rusttest' target. Tests should generally run within KUnit. 'kernel' crate: - Add 'ptr' module with a new 'Alignment' type, which is always a power of two and is used to validate that a given value is a valid alignment and to perform masking and alignment operations: // Checked at build time. assert_eq!(Alignment::new::<16>().as_usize(), 16); // Checked at runtime. assert_eq!(Alignment::new_checked(15), None); assert_eq!(Alignment::of::<u8>().log2(), 0); assert_eq!(0x25u8.align_down(Alignment::new::<0x10>()), 0x20); assert_eq!(0x5u8.align_up(Alignment::new::<0x10>()), Some(0x10)); assert_eq!(u8::MAX.align_up(Alignment::new::<0x10>()), None); It also includes its first use in Nova. - Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching Rust 1.80.0. - Keep going with the steps on our migration to the standard library 'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use upstream method names). - 'error' module: improve 'Error::from_errno' and 'to_result' documentation, including examples/tests. - 'sync' module: extend 'aref' submodule documentation now that it exists, and more updates to complete the ongoing move of 'ARef' and 'AlwaysRefCounted' to 'sync::aref'. - 'list' module: add an example/test for 'ListLinksSelfPtr' usage. - 'alloc' module: - Implement 'Box::pin_slice()', which constructs a pinned slice of elements. - Provide information about the minimum alignment guarantees of 'Kmalloc', 'Vmalloc' and 'KVmalloc'. - Take minimum alignment guarantees of allocators for 'ForeignOwnable' into account. - Remove the 'allocator_test' (including 'Cmalloc'). - Add doctest for 'Vec::as_slice()'. - Constify various methods. - 'time' module: - Add methods on 'HrTimer' that can only be called with exclusive access to an unarmed timer, or from timer callback context. - Add arithmetic operations to 'Instant' and 'Delta'. - Add a few convenience and access methods to 'HrTimer' and 'Instant'. 'macros' crate: - Reduce collections in 'quote!' macro. And a few other cleanups and improvements" * tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits) gpu: nova-core: use Alignment for alignment-related operations rust: add `Alignment` type rust: macros: reduce collections in `quote!` macro rust: acpi: use `core::ffi::CStr` method names rust: of: use `core::ffi::CStr` method names rust: net: use `core::ffi::CStr` method names rust: miscdevice: use `core::ffi::CStr` method names rust: kunit: use `core::ffi::CStr` method names rust: firmware: use `core::ffi::CStr` method names rust: drm: use `core::ffi::CStr` method names rust: cpufreq: use `core::ffi::CStr` method names rust: configfs: use `core::ffi::CStr` method names rust: auxiliary: use `core::ffi::CStr` method names drm/panic: use `core::ffi::CStr` method names rust: device: use `kernel::{fmt,prelude::fmt!}` rust: sync: use `kernel::{fmt,prelude::fmt!}` rust: seq_file: use `kernel::{fmt,prelude::fmt!}` rust: kunit: use `kernel::{fmt,prelude::fmt!}` rust: file: use `kernel::{fmt,prelude::fmt!}` rust: device: use `kernel::{fmt,prelude::fmt!}` ...
Diffstat (limited to 'rust/kernel/alloc/allocator_test.rs')
-rw-r--r--rust/kernel/alloc/allocator_test.rs124
1 files changed, 0 insertions, 124 deletions
diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs
deleted file mode 100644
index 90dd987d40e4..000000000000
--- a/rust/kernel/alloc/allocator_test.rs
+++ /dev/null
@@ -1,124 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-//! So far the kernel's `Box` and `Vec` types can't be used by userspace test cases, since all users
-//! of those types (e.g. `CString`) use kernel allocators for instantiation.
-//!
-//! In order to allow userspace test cases to make use of such types as well, implement the
-//! `Cmalloc` allocator within the `allocator_test` module and type alias all kernel allocators to
-//! `Cmalloc`. The `Cmalloc` allocator uses libc's `realloc()` function as allocator backend.
-
-#![allow(missing_docs)]
-
-use super::{flags::*, AllocError, Allocator, Flags};
-use core::alloc::Layout;
-use core::cmp;
-use core::ptr;
-use core::ptr::NonNull;
-
-/// The userspace allocator based on libc.
-pub struct Cmalloc;
-
-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;
-
- #[link_name = "free"]
- fn libc_free(ptr: *mut crate::ffi::c_void);
-}
-
-// SAFETY:
-// - memory remains valid until it is explicitly freed,
-// - passing a pointer to a valid memory allocation created by this `Allocator` is always OK,
-// - `realloc` provides the guarantees as provided in the `# Guarantees` section.
-unsafe impl Allocator for Cmalloc {
- unsafe fn realloc(
- ptr: Option<NonNull<u8>>,
- layout: Layout,
- old_layout: Layout,
- flags: Flags,
- ) -> Result<NonNull<[u8]>, AllocError> {
- let src = match ptr {
- Some(src) => {
- if old_layout.size() == 0 {
- ptr::null_mut()
- } else {
- src.as_ptr()
- }
- }
- None => ptr::null_mut(),
- };
-
- if layout.size() == 0 {
- // SAFETY: `src` is either NULL or was previously allocated with this `Allocator`
- unsafe { libc_free(src.cast()) };
-
- return Ok(NonNull::slice_from_raw_parts(
- crate::alloc::dangling_from_layout(layout),
- 0,
- ));
- }
-
- // ISO C (ISO/IEC 9899:2011) defines `aligned_alloc`:
- //
- // > The value of alignment shall be a valid alignment supported by the implementation
- // [...].
- //
- // As an example of the "supported by the implementation" requirement, POSIX.1-2001 (IEEE
- // 1003.1-2001) defines `posix_memalign`:
- //
- // > The value of alignment shall be a power of two multiple of sizeof (void *).
- //
- // and POSIX-based implementations of `aligned_alloc` inherit this requirement. At the time
- // of writing, this is known to be the case on macOS (but not in glibc).
- //
- // Satisfy the stricter requirement to avoid spurious test failures on some platforms.
- let min_align = core::mem::size_of::<*const crate::ffi::c_void>();
- let layout = layout.align_to(min_align).map_err(|_| AllocError)?;
- let layout = layout.pad_to_align();
-
- // 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()) }.cast::<u8>();
- let dst = NonNull::new(dst).ok_or(AllocError)?;
-
- if flags.contains(__GFP_ZERO) {
- // SAFETY: The preceding calls to `libc_aligned_alloc` and `NonNull::new`
- // guarantee that `dst` points to memory of at least `layout.size()` bytes.
- unsafe { dst.as_ptr().write_bytes(0, layout.size()) };
- }
-
- if !src.is_null() {
- // SAFETY:
- // - `src` has previously been allocated with this `Allocator`; `dst` has just been
- // newly allocated, hence the memory regions do not overlap.
- // - both` src` and `dst` are properly aligned and valid for reads and writes
- unsafe {
- ptr::copy_nonoverlapping(
- src,
- dst.as_ptr(),
- cmp::min(layout.size(), old_layout.size()),
- )
- };
- }
-
- // SAFETY: `src` is either NULL or was previously allocated with this `Allocator`
- unsafe { libc_free(src.cast()) };
-
- Ok(NonNull::slice_from_raw_parts(dst, layout.size()))
- }
-}