Return error when dup buf is not empty

ahcid/src/scheme.rs

@@ -70,7 +70,11 @@ impl Scheme for DiskScheme {
         }
     }
 
-    fn dup(&self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         let mut handles = self.handles.lock();
         let new_handle = {
             let handle = handles.get(&id).ok_or(Error::new(EBADF))?;

alxd/src/device/mod.rs

@@ -1797,7 +1797,11 @@ impl scheme::SchemeMut for Alx {
         }
     }
 
-    fn dup(&mut self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&mut self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         Ok(id)
     }
 

e1000d/src/device.rs

@@ -110,7 +110,11 @@ impl Scheme for Intel8254x {
         }
     }
 
-    fn dup(&self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         Ok(id)
     }
 

rtl8168d/src/device.rs

@@ -83,7 +83,11 @@ impl SchemeMut for Rtl8168 {
         }
     }
 
-    fn dup(&mut self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&mut self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         Ok(id)
     }
 

vesad/src/scheme.rs

@@ -114,7 +114,11 @@ impl SchemeMut for DisplayScheme {
         }
     }
 
-    fn dup(&mut self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&mut self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         let handle = self.handles.get(&id).map(|handle| handle.clone()).ok_or(Error::new(EBADF))?;
 
         let new_id = self.next_id;