From: Baptiste Lepers <baptiste.lepers@gmail.com>
Date: Tue, 12 Aug 2025 14:42:11 +0000 (+0200)
Subject: rust: cpumask: Mark CpumaskVar as transparent
X-Git-Tag: v6.18-rc1~49^2^2~2^2~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=23fca458f6ab18927e50c2134fb7b60297f18b4e;p=thirdparty%2Fkernel%2Flinux.git

rust: cpumask: Mark CpumaskVar as transparent

Unsafe code in CpumaskVar's methods assumes that the type has the same
layout as `bindings::cpumask_var_t`. This is not guaranteed by
the default struct representation in Rust, but requires specifying the
`transparent` representation.

Fixes: 8961b8cb3099a ("rust: cpumask: Add initial abstractions")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---

diff --git a/rust/kernel/cpumask.rs b/rust/kernel/cpumask.rs
index e311ab9038dfd..c1d17826ae7bb 100644
--- a/rust/kernel/cpumask.rs
+++ b/rust/kernel/cpumask.rs
@@ -212,6 +212,7 @@ impl Cpumask {
 /// }
 /// assert_eq!(mask2.weight(), count);
 /// ```
+#[repr(transparent)]
 pub struct CpumaskVar {
     #[cfg(CONFIG_CPUMASK_OFFSTACK)]
     ptr: NonNull<Cpumask>,