[PATCH 6.18 092/122] rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts

Greg Kroah-Hartman
2026-02-04T15:33:08Z

From: Miguel Ojeda <ojeda@kernel.org>

commit bd36f6e2abf7f85644f7ea8deb1de4040b03bbc1 upstream.

For arm32, on a x86_64 builder, running the `rusttest` target yields:

error[E0080]: evaluation of constant value failed
--> rust/kernel/static_assert.rs:37:23
|
37 | const _: () = ::core::assert!($condition $(,$arg)?);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: size_of::<isize>() == size_of::<isize_atomic_repr>()', rust/kernel/sync/atomic/predefine.rs:68:1
|
::: rust/kernel/sync/atomic/predefine.rs:68:1
|
68 | static_assert!(size_of::<isize>() == size_of::<isize_atomic_repr>());
| -------------------------------------------------------------------- in this macro invocation
|
= note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)

The reason is that `rusttest` runs on the host, so for e.g. a x86_64
builder `isize` is 64 bits but it is not a `CONFIG_64BIT` build.

Fix it by providing a stub for `rusttest` as usual.

Fixes: 84c6d36bcaf9 ("rust: sync: atomic: Add Atomic<{usize,isize}>")
Cc: stable@vger.kernel.org
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260123233432.22703-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
rust/kernel/sync/atomic/predefine.rs | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/rust/kernel/sync/atomic/predefine.rs b/rust/kernel/sync/atomic/predefine.rs
index 45a17985cda4..0fca1ba3c2db 100644
--- a/rust/kernel/sync/atomic/predefine.rs
+++ b/rust/kernel/sync/atomic/predefine.rs
@@ -35,12 +35,23 @@ fn rhs_into_delta(rhs: i64) -> i64 {
// as `isize` and `usize`, and `isize` and `usize` are always bi-directional transmutable to
// `isize_atomic_repr`, which also always implements `AtomicImpl`.
#[allow(non_camel_case_types)]
+#[cfg(not(testlib))]
#[cfg(not(CONFIG_64BIT))]
type isize_atomic_repr = i32;
#[allow(non_camel_case_types)]
+#[cfg(not(testlib))]
#[cfg(CONFIG_64BIT)]
type isize_atomic_repr = i64;

+#[allow(non_camel_case_types)]
+#[cfg(testlib)]
+#[cfg(target_pointer_width = "32")]
+type isize_atomic_repr = i32;
+#[allow(non_camel_case_types)]
+#[cfg(testlib)]
+#[cfg(target_pointer_width = "64")]
+type isize_atomic_repr = i64;
+
// Ensure size and alignment requirements are checked.
static_assert!(size_of::<isize>() == size_of::<isize_atomic_repr>());
static_assert!(align_of::<isize>() == align_of::<isize_atomic_repr>());
--
2.53.0