6.16-stable review patch. If anyone has any objections, please let me know.
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From: Miguel Ojeda ojeda@kernel.org
[ Upstream commit 0f580d5d3d9d9cd0953695cd32e43aac3a946338 ]
Commit fde578c86281 ("rust: alloc: replace aligned_size() with Kmalloc::aligned_layout()") provides a public `aligned_layout` function in `Kamlloc`, but not in `Cmalloc`, and thus uses of it will trigger an error in `rusttest`.
Such a user appeared in the following commit 22ab0641b939 ("rust: drm: ensure kmalloc() compatible Layout"):
error[E0599]: no function or associated item named `aligned_layout` found for struct `alloc::allocator_test::Cmalloc` in the current scope --> rust/kernel/drm/device.rs:100:31 | 100 | let layout = Kmalloc::aligned_layout(Layout::new::<Self>()); | ^^^^^^^^^^^^^^ function or associated item not found in `Cmalloc` | ::: rust/kernel/alloc/allocator_test.rs:19:1 | 19 | pub struct Cmalloc; | ------------------ function or associated item `aligned_layout` not found for this struct
Thus add an equivalent one for `Cmalloc`.
Fixes: fde578c86281 ("rust: alloc: replace aligned_size() with Kmalloc::aligned_layout()") Signed-off-by: Miguel Ojeda ojeda@kernel.org Link: https://lore.kernel.org/r/20250816204215.2719559-1-ojeda@kernel.org Signed-off-by: Danilo Krummrich dakr@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- rust/kernel/alloc/allocator_test.rs | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs index d19c06ef0498..981e002ae3fc 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;