graphics: Fix memory leak when resizing the display

graphics/driver-graphics/src/lib.rs

@@ -496,6 +496,23 @@ impl<T: GraphicsAdapter> SchemeSync for GraphicsScheme<T> {
 
                     Ok(size_of::<ipc::DumbFramebufferMapOffset>())
                 }
+                ipc::DESTROY_DUMB_FRAMEBUFFER => {
+                    if payload.len() < size_of::<ipc::DestroyDumbFramebuffer>() {
+                        return Err(Error::new(EINVAL));
+                    }
+                    let payload = unsafe {
+                        transmute::<
+                            &mut [u8; size_of::<ipc::DestroyDumbFramebuffer>()],
+                            &mut ipc::DestroyDumbFramebuffer,
+                        >(payload.as_mut_array().unwrap())
+                    };
+
+                    if fbs.remove(&{ payload.fb_id }).is_none() {
+                        return Err(Error::new(ENOENT));
+                    }
+
+                    Ok(size_of::<ipc::DestroyDumbFramebuffer>())
+                }
                 ipc::UPDATE_PLANE => {
                     if payload.len() < size_of::<ipc::UpdatePlane>() {
                         return Err(Error::new(EINVAL));

graphics/fbbootlogd/src/scheme.rs

@@ -95,6 +95,8 @@ impl FbbootlogScheme {
                             },
                         );
 
+                        let _ = map.display_handle.destroy_dumb_framebuffer(map.fb);
+
                         map.fb = fb;
                         map.inner = new_map;
 

graphics/graphics-ipc/src/v2.rs

@@ -124,6 +124,19 @@ impl V2GraphicsHandle {
         Ok(unsafe { DisplayMap::new(offscreen, width as usize, height as usize) })
     }
 
+    pub fn destroy_dumb_framebuffer(&self, id: usize) -> io::Result<usize> {
+        let mut cmd = ipc::DestroyDumbFramebuffer { fb_id: id };
+        unsafe {
+            sys_call(
+                &self.file,
+                &mut cmd,
+                0,
+                &[ipc::DESTROY_DUMB_FRAMEBUFFER, 0, 0],
+            )?;
+        }
+        Ok(cmd.fb_id)
+    }
+
     pub fn update_plane(&self, display_id: usize, fb_id: usize, damage: Damage) -> io::Result<()> {
         let mut cmd = ipc::UpdatePlane {
             display_id,
@@ -172,7 +185,13 @@ pub mod ipc {
         pub offset: usize,
     }
 
-    pub const UPDATE_PLANE: u64 = 5;
+    pub const DESTROY_DUMB_FRAMEBUFFER: u64 = 5;
+    #[repr(C, packed)]
+    pub struct DestroyDumbFramebuffer {
+        pub fb_id: usize,
+    }
+
+    pub const UPDATE_PLANE: u64 = 6;
     #[repr(C, packed)]
     pub struct UpdatePlane {
         pub display_id: usize,