Index: kernel/arch/amd64/include/mm/as.h
===================================================================
--- kernel/arch/amd64/include/mm/as.h	(revision dc0b96419120ee5e704d73292cca782d65f45781)
+++ kernel/arch/amd64/include/mm/as.h	(revision c263c77c4712f982349c184bbee4df2163f68baa)
@@ -43,9 +43,6 @@
 #define KERNEL_ADDRESS_SPACE_START_ARCH  UINT64_C(0xffff800000000000)
 #define KERNEL_ADDRESS_SPACE_END_ARCH    UINT64_C(0xffffffffffffffff)
-
-#define USER_ADDRESS_SPACE_START_ARCH  UINT64_C(0x0000000000000000)
-#define USER_ADDRESS_SPACE_END_ARCH    UINT64_C(0x00007fffffffffff)
-
-#define USTACK_ADDRESS_ARCH  (USER_ADDRESS_SPACE_END_ARCH - (PAGE_SIZE - 1))
+#define USER_ADDRESS_SPACE_START_ARCH    UINT64_C(0x0000000000000000)
+#define USER_ADDRESS_SPACE_END_ARCH      UINT64_C(0x00007fffffffffff)
 
 #define as_constructor_arch(as, flags)  (as != as)