Index: kernel/arch/amd64/include/types.h
===================================================================
--- kernel/arch/amd64/include/types.h	(revision d21e72db3a6a377042525aa30bac82d8a2a48853)
+++ kernel/arch/amd64/include/types.h	(revision 8b6930d5d4a9a2fdd17c45b45770dd51a1d956a6)
@@ -37,4 +37,5 @@
 
 typedef uint64_t size_t;
+typedef int64_t ssize_t;
 
 typedef uint64_t uintptr_t;