Merge branch 'master' into mm-hotfixes-stable

1 files changed, 8 insertions, 2 deletions

diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 526d29a0ae27..7eda15e5f1b3 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -64,8 +64,14 @@ macro_rules! current {
 #[repr(transparent)]
 pub struct Task(pub(crate) Opaque<bindings::task_struct>);
 
-// 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
+// SAFETY: By design, the only way to access a `Task` is via the `current` function or via an
+// `ARef<Task>` obtained through the `AlwaysRefCounted` impl. This means that the only situation in
+// which a `Task` 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 shared 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`).
 unsafe impl Sync for Task {}