linux-kernel - [PATCH] rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20260123233432.22703-1-ojeda@kernel.org>
Date: Sat, 24 Jan 2026 00:34:32 +0100
From: Miguel Ojeda <ojeda@...nel.org>
To: Will Deacon <will@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Boqun Feng <boqun.feng@...il.com>,
	Miguel Ojeda <ojeda@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>,
	Gary Guo <gary@...yguo.net>,
	linux-kernel@...r.kernel.org,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>,
	Benno Lossin <lossin@...nel.org>,
	Andreas Hindborg <a.hindborg@...nel.org>,
	Alice Ryhl <aliceryhl@...gle.com>,
	Trevor Gross <tmgross@...ch.edu>,
	Danilo Krummrich <dakr@...nel.org>,
	rust-for-linux@...r.kernel.org,
	stable@...r.kernel.org
Subject: [PATCH] rust: sync: atomic: Provide stub for `rusttest` 32-bit hosts

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@...r.kernel.org
Signed-off-by: Miguel Ojeda <ojeda@...nel.org>
---
I kept the `cfg`s separated instead of using `all` so that, when we get
to remove this (since these tests will eventually be moved to KUnit), it
will just be line deletions (and I find it easier to read, too).

 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>());

base-commit: a44bfed9df8a514962e2cb076d9c0b594caeff36
--
2.52.0