Commit 25fe63db authored Mar 25, 2026 by Danilo Krummrich

rust: uaccess: generalize write_dma() to accept any Coherent<T>



Generalize write_dma() from &Coherent<[u8]> to &Coherent<T> where
T: KnownSize + AsBytes + ?Sized. The function body only uses as_ptr()
and size(), which work for any such T, so there is no reason to
restrict it to byte slices.

Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260325003921.3420-1-dakr@kernel.org


Signed-off-by: Danilo Krummrich <dakr@kernel.org>

parent 80df573a

rust/kernel/uaccess.rs

+7 −1

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@
		ffi::{c_char, c_void},
		fs::file,
		prelude::*,
		ptr::KnownSize,
		transmute::{AsBytes, FromBytes},
		};
		use core::mem::{size_of, MaybeUninit};
		@@ -524,7 +525,12 @@ pub fn write_slice(&mut self, data: &[u8]) -> Result {
		/// writer.write_dma(alloc, 0, 256)
		/// }
		/// ```
		pub fn write_dma(&mut self, alloc: &Coherent<[u8]>, offset: usize, count: usize) -> Result {
		pub fn write_dma<T: KnownSize + AsBytes + ?Sized>(
		&mut self,
		alloc: &Coherent<T>,
		offset: usize,
		count: usize,
		) -> Result {
		let len = alloc.size();
		if offset.checked_add(count).ok_or(EOVERFLOW)? > len {
		return Err(ERANGE);