feat: utils: linked_list: do not require clone trait

kernel/src/objects/cap.rs

@@ -35,7 +35,6 @@ impl RawCap {
     }
 }
 
-#[derive(Clone)]
 pub struct CapEntry {
     pub cap:  Cell<RawCap>,
     pub link: Link<Self>,
@@ -59,6 +58,14 @@ impl CapEntry {
     }
 }
 
+impl Clone for CapEntry {
+    fn clone(&self) -> Self {
+        let mut cte = Self::new(self.cap.get());
+        cte.link = self.link.clone();
+        cte
+    }
+}
+
 impl From<RawCap> for CapEntry {
     fn from(value: RawCap) -> Self {
         Self::new(value)

lib/utils/src/linked_list.rs

@@ -10,7 +10,7 @@ macro_rules! LinkHelperImpl {
     };
 }
 
-pub trait LinkHelper: Clone {
+pub trait LinkHelper: Sized {
     const LINK_OFFSET: usize;
 
     /// # Safety
@@ -20,7 +20,6 @@ pub trait LinkHelper: Clone {
     }
 }
 
-#[derive(Clone)]
 pub struct Link<T: LinkHelper> {
     pub prev: Cell<Option<NonNull<T>>>,
     pub next: Cell<Option<NonNull<T>>>,
@@ -35,6 +34,15 @@ impl<T: LinkHelper> Default for Link<T> {
     }
 }
 
+impl<T: LinkHelper> Clone for Link<T> {
+    fn clone(&self) -> Self {
+        Self {
+            prev: Cell::new(self.prev.get()),
+            next: Cell::new(self.next.get()),
+        }
+    }
+}
+
 impl<T: LinkHelper> Link<T> {
     /// # Safety
     /// LINK_OFFSET must be a valid field offset of T
@@ -113,7 +121,6 @@ impl<T: LinkHelper> Link<T> {
 mod tests {
     use super::*;
 
-    #[derive(Clone)]
     struct Node {
         link:  Link<Node>,
         value: i32,