From 591b214b234b509ebddde5c2b2f871d43fc1e248 Mon Sep 17 00:00:00 2001
From: Kunal Sareen <kunal.sareen@anu.edu.au>
Date: Sat, 10 May 2025 12:54:25 +1000
Subject: [PATCH] Fix `CopySpace::is_live`

This commit fixes the `CopySpace::is_live` function to check if a to-space object's address is actually below the current page resource cursor. By definition, a to-space object cannot be live if it is beyond the cursor.
---
 src/policy/copyspace.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/policy/copyspace.rs b/src/policy/copyspace.rs
index bbc66ccd4d..5e69e5729c 100644
--- a/src/policy/copyspace.rs
+++ b/src/policy/copyspace.rs
@@ -30,7 +30,11 @@ impl<VM: VMBinding> SFT for CopySpace<VM> {
     }
 
     fn is_live(&self, object: ObjectReference) -> bool {
-        !self.is_from_space() || object_forwarding::is_forwarded::<VM>(object)
+        if !self.is_from_space() {
+            object.to_raw_address() < self.pr.cursor()
+        } else {
+            object_forwarding::is_forwarded::<VM>(object)
+        }
     }
 
     #[cfg(feature = "object_pinning")]