diff --git a/mm/nommu.c b/mm/nommu.c
index 6341933..11a69b2 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1709,16 +1709,21 @@
 }
 EXPORT_SYMBOL(do_munmap);
 
-SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+int vm_munmap(struct mm_struct *mm, unsigned long addr, size_t len)
 {
 	int ret;
-	struct mm_struct *mm = current->mm;
 
 	down_write(&mm->mmap_sem);
 	ret = do_munmap(mm, addr, len);
 	up_write(&mm->mmap_sem);
 	return ret;
 }
+EXPORT_SYMBOL(vm_munmap);
+
+SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+{
+	return vm_munmap(current->mm, addr, len);
+}
 
 /*
  * release all the mappings made in a process's VM space