diff options
| author | Gary Guo <gary@garyguo.net> | 2026-03-02 16:42:34 +0000 |
|---|---|---|
| committer | Danilo Krummrich <dakr@kernel.org> | 2026-03-07 23:02:45 +0100 |
| commit | 08da98f18f4f99aa16838397b76086d2d1d364b3 (patch) | |
| tree | 5300a4e3cf293bab3d1336c6f9046e2bb9296fe4 /rust/kernel | |
| parent | 11439c4635edd669ae435eec308f4ab8a0804808 (diff) | |
rust: ptr: add `KnownSize` trait to support DST size info extraction
Add a `KnownSize` trait which is used obtain a size from a raw pointer's
metadata. This makes it possible to obtain size information on a raw slice
pointer. This is similar to Rust `core::mem::size_of_val_raw` which is not
yet stable.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260302164239.284084-2-gary@kernel.org
[ Fix wording in doc-comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/lib.rs | 1 | ||||
| -rw-r--r-- | rust/kernel/ptr.rs | 27 |
2 files changed, 27 insertions, 1 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 3da92f18f4ee..510cc7fe4961 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -20,6 +20,7 @@ #![feature(generic_nonzero)] #![feature(inline_const)] #![feature(pointer_is_aligned)] +#![feature(slice_ptr_len)] // // Stable since Rust 1.80.0. #![feature(slice_flatten)] diff --git a/rust/kernel/ptr.rs b/rust/kernel/ptr.rs index 5b6a382637fe..e91de5f0d78f 100644 --- a/rust/kernel/ptr.rs +++ b/rust/kernel/ptr.rs @@ -2,7 +2,10 @@ //! Types and functions to work with pointers and addresses. -use core::mem::align_of; +use core::mem::{ + align_of, + size_of, // +}; use core::num::NonZero; /// Type representing an alignment, which is always a power of two. @@ -225,3 +228,25 @@ macro_rules! impl_alignable_uint { } impl_alignable_uint!(u8, u16, u32, u64, usize); + +/// Trait to represent compile-time known size information. +/// +/// This is a generalization of [`size_of`] that works for dynamically sized types. +pub trait KnownSize { + /// Get the size of an object of this type in bytes, with the metadata of the given pointer. + fn size(p: *const Self) -> usize; +} + +impl<T> KnownSize for T { + #[inline(always)] + fn size(_: *const Self) -> usize { + size_of::<T>() + } +} + +impl<T> KnownSize for [T] { + #[inline(always)] + fn size(p: *const Self) -> usize { + p.len() * size_of::<T>() + } +} |