Move linear memory faulted guard page tracking into Memory.

This commit moves the tracking for faulted guard pages in a linear memory into
`Memory`.

crates/runtime/src/instance/allocator.rs

@@ -602,8 +602,6 @@ unsafe impl InstanceAllocator for OnDemandInstanceAllocator {
                 )),
                 dropped_data: RefCell::new(EntitySet::with_capacity(req.module.passive_data.len())),
                 host_state,
-                #[cfg(all(feature = "uffd", target_os = "linux"))]
-                guard_page_faults: RefCell::new(Vec::new()),
                 vmctx: VMContext {},
             };
             let layout = instance.alloc_layout();

crates/runtime/src/instance/allocator/pooling.rs

@@ -367,8 +367,6 @@ impl InstancePool {
                     dropped_elements: RefCell::new(EntitySet::new()),
                     dropped_data: RefCell::new(EntitySet::new()),
                     host_state: Box::new(()),
-                    #[cfg(all(feature = "uffd", target_os = "linux"))]
-                    guard_page_faults: RefCell::new(Vec::new()),
                     vmctx: VMContext {},
                 },
             );
@@ -431,9 +429,15 @@ impl InstancePool {
             let memory = mem::take(memory);
             debug_assert!(memory.is_static());
 
+            // Reset any faulted guard pages as the physical memory may be reused for another instance in the future
+            #[cfg(all(feature = "uffd", target_os = "linux"))]
+            memory
+                .reset_guard_pages()
+                .expect("failed to reset guard pages");
+
             let size = (memory.size() * WASM_PAGE_SIZE) as usize;
             drop(memory);
-            decommit_memory_pages(base, size).unwrap();
+            decommit_memory_pages(base, size).expect("failed to decommit linear memory pages");
         }
 
         instance.memories.clear();
@@ -450,7 +454,7 @@ impl InstancePool {
             );
 
             drop(table);
-            decommit_table_pages(base, size).unwrap();
+            decommit_table_pages(base, size).expect("failed to decommit table pages");
         }
 
         instance.tables.clear();
@@ -469,12 +473,6 @@ impl InstancePool {
     ) -> Result<(), InstantiationError> {
         let module = instance.module.as_ref();
 
-        // Reset all guard pages before reusing the instance
-        #[cfg(all(feature = "uffd", target_os = "linux"))]
-        instance
-            .reset_guard_pages()
-            .map_err(|e| InstantiationError::Resource(e.to_string()))?;
-
         debug_assert!(instance.memories.is_empty());
 
         for plan in

crates/runtime/src/instance/allocator/pooling/uffd.rs

@@ -313,8 +313,12 @@ unsafe fn handle_page_fault(
                 None => {
                     log::trace!("out of bounds memory access at {:p}", addr);
 
-                    // Record the guard page fault with the instance so it can be reset later.
-                    instance.record_guard_page_fault(page_addr, len, reset_guard_page);
+                    // Record the guard page fault so the page protection level can be reset later
+                    instance.memories[memory_index].record_guard_page_fault(
+                        page_addr,
+                        len,
+                        reset_guard_page,
+                    );
                     wake_guard_page_access(&uffd, page_addr, len)?;
                 }
             }