[PATCH v1 2/2] rust: task: add `Send` marker to `Task`

[Alice Ryhl <aliceryhl@google.com>]

When a type also implements `Sync`, the meaning of `Send` is just "this
type may be accessed mutably from threads other than the one it is
created on". That's ok for this type.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 rust/kernel/task.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 526d29a0ae27..4f1fe9aa9f6e 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -64,6 +64,11 @@ macro_rules! current {
 #[repr(transparent)]
 pub struct Task(pub(crate) Opaque<bindings::task_struct>);
 
+// SAFETY: The only situation in which this can be accessed mutably is when the refcount drops to
+// zero and the destructor runs. It is safe for that to happen on any thread, so it is ok for this
+// type to be `Send`.
+unsafe impl Send for Task {}
+
 // SAFETY: It's OK to access `Task` through references from other threads because we're either
 // accessing properties that don't change (e.g., `pid`, `group_leader`) or that are properly
 // synchronised by C code (e.g., `signal_pending`).
-- 
2.40.1.606.ga4b1b128d6-goog