diff --git a/linker/linker_block_allocator.cpp b/linker/linker_block_allocator.cpp
index d72cad3..fdb4c85 100644
--- a/linker/linker_block_allocator.cpp
+++ b/linker/linker_block_allocator.cpp
@@ -55,7 +55,8 @@
   : block_size_(
       round_up(block_size < sizeof(FreeBlockInfo) ? sizeof(FreeBlockInfo) : block_size, 16)),
     page_list_(nullptr),
-    free_block_list_(nullptr)
+    free_block_list_(nullptr),
+    allocated_(0)
 {}
 
 void* LinkerBlockAllocator::alloc() {
@@ -76,6 +77,8 @@
 
   memset(block_info, 0, block_size_);
 
+  ++allocated_;
+
   return block_info;
 }
 
@@ -104,6 +107,8 @@
   block_info->num_free_blocks = 1;
 
   free_block_list_ = block_info;
+
+  --allocated_;
 }
 
 void LinkerBlockAllocator::protect_all(int prot) {
@@ -154,3 +159,18 @@
 
   abort();
 }
+
+void LinkerBlockAllocator::purge() {
+  if (allocated_) {
+    return;
+  }
+
+  LinkerBlockAllocatorPage* page = page_list_;
+  while (page) {
+    LinkerBlockAllocatorPage* next = page->next;
+    munmap(page, kAllocateSize);
+    page = next;
+  }
+  page_list_ = nullptr;
+  free_block_list_ = nullptr;
+}