Index: arch/amd64/src/smp/ap.S
===================================================================
--- arch/amd64/src/smp/ap.S	(revision 42edee68a13aac5a6de6c8e953f681abf64096ff)
+++ arch/amd64/src/smp/ap.S	(revision 5e3757dcfae6da1c144148796d220e496a470e3f)
@@ -69,4 +69,6 @@
 	movw %ax, %es
 	movw %ax, %ss
+	movw $gdtselector(UDATA_DES), %ax
+	movw %ax, %gs
 	
 	# Enable 64-bit page transaltion entries - CR4.PAE = 1.