[PATCH] rust: workqueue: fix SAFETY comment Arc refs in Pin>

Sagar Taunk
2026-04-25T13:57:36Z

The `WorkItemPointer` implementation for `Pin<KBox<T>>` contained SAFETY
comments that incorrectly referenced `Arc::into_raw` instead of
`KBox::into_raw`. This implementation uses `KBox`, not `Arc`, so update
the comments to accurately reflect the actual ownership transfer.

Suggested-by: Onur Özkan <contact@onurozkan.dev>
Link: https://github.com/Rust-for-Linux/linux/issues/1233
Signed-off-by: Sagar Taunk <sagartaunk2@gmail.com>
---
rust/kernel/workqueue.rs | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 7e253b6f299c..74c59f2b1c09 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -890,9 +890,10 @@ unsafe impl<T, const ID: u64> WorkItemPointer<ID> for Pin<KBox<T>>
unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
// The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
let ptr = ptr.cast::<Work<T, ID>>();
- // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
+ // SAFETY: This computes the pointer that `__enqueue` got from `KBox::into_raw`.
let ptr = unsafe { T::work_container_of(ptr) };
- // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
+ // SAFETY: This pointer comes from `KBox::into_raw` and we have been given back ownership,
+ // as the workqueue guarantees `run` is called exactly once.
let boxed = unsafe { KBox::from_raw(ptr) };
// SAFETY: The box was already pinned when it was enqueued.
let pinned = unsafe { Pin::new_unchecked(boxed) };
--
2.54.0