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author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-30 19:12:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-30 19:12:49 -0700 |
commit | f4e0ff7e45c30f4665cfbbe2f0538e9c5789bebc (patch) | |
tree | 6703541ef1fec9d20dafc751d2e971879c429884 /rust/kernel/alloc/allocator_test.rs | |
parent | ae28ed4578e6d5a481e39c5a9827f27048661fdd (diff) | |
parent | f3f6b3664302e16ef1c6b91034a72df5564d6b8a (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.rs | 124 |
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())) - } -} |