PID of the given task.
     pub fn pid(&self) -> Pid {
         // SAFETY: The pid of a task never changes after initialization, so reading this field is
@@ -345,6 +333,18 @@ pub fn active_pid_ns(&self) -> Option<&PidNamespace> {
         // `release_task()` call.
         Some(unsafe { PidNamespace::from_ptr(active_ns) })
     }
+
+    /// Returns the group leader of the current task.
+    pub fn group_leader(&self) -> &Task {
+        // SAFETY: The group leader of a task never changes while the task is running, and `self`
+        // is the current task, which is guaranteed running.
+        let ptr = unsafe { (*self.as_ptr()).group_leader };
+
+        // SAFETY: `current->group_leader` stays valid for at least the duration in which `current`
+        // is running, and the signature of this function ensures that the returned `&Task` can
+        // only be used while `current` is still valid, thus still running.
+        unsafe { &*ptr.cast() }
+    }
 }
 
 // SAFETY: The type invariants guarantee that `Task` is always refcounted.
-- 
2.51.0[PATCH 6.19 366/781] rust: task: restrict Task::group_leader() to currentGreg Kroah-Hartman <gregkh@linuxfoundation.org> undefinedstable@vger.kernel.org undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined³