From 86df8ddc64fb12e03a6ed1ff48acabfa382e586c Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Sun, 11 Jun 2023 14:47:49 +0200
Subject: [PATCH] uhh oohh i guess it works

---
 hbvm/src/vm/mem/mod.rs | 41 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/hbvm/src/vm/mem/mod.rs b/hbvm/src/vm/mem/mod.rs
index a10490d..bad822e 100644
--- a/hbvm/src/vm/mem/mod.rs
+++ b/hbvm/src/vm/mem/mod.rs
@@ -64,8 +64,25 @@ impl Memory {
         }
 
         let mut value = MaybeUninit::<Value>::zeroed();
+        let overflow = (lookup.offset + S::BYTES).saturating_sub(lookup.size - 1);
+        let normal = S::BYTES - overflow;
+
         unsafe {
-            core::ptr::copy_nonoverlapping::<u8>(lookup.ptr, value.as_mut_ptr().cast(), 1);
+            core::ptr::copy_nonoverlapping::<u8>(lookup.ptr, value.as_mut_ptr().cast(), normal);
+            if overflow != 0 {
+                let lookup = self.page_lookup(lookup.ptr as u64 + lookup.size as u64)?;
+                match lookup.perm {
+                    Permission::Empty | Permission::Node => return None,
+                    Permission::Readonly | Permission::Write | Permission::Exec => (),
+                }
+
+                core::ptr::copy_nonoverlapping::<u8>(
+                    lookup.ptr,
+                    value.as_mut_ptr().cast::<u8>().add(normal),
+                    overflow,
+                );
+            }
+
             Some(value.assume_init())
         }
     }
@@ -76,9 +93,27 @@ impl Memory {
         if lookup.perm != Permission::Write {
             return Err(());
         }
-        
+
+        let overflow = (lookup.offset + S::BYTES).saturating_sub(lookup.size - 1);
+        let normal = S::BYTES - overflow;
         unsafe {
-            core::ptr::copy_nonoverlapping::<u8>((&value as *const Value).cast(), lookup.ptr, 1)
+            core::ptr::copy_nonoverlapping::<u8>(
+                (&value as *const Value).cast(),
+                lookup.ptr,
+                normal,
+            );
+
+            if overflow != 0 {
+                let lookup = self
+                    .page_lookup(lookup.ptr as u64 + lookup.size as u64)
+                    .ok_or(())?;
+
+                core::ptr::copy_nonoverlapping::<u8>(
+                    (&value as *const Value).cast::<u8>().add(normal),
+                    lookup.ptr,
+                    overflow,
+                );
+            }
         };
 
         Ok(())