Index: arch/amd64/src/smp/ap.S
===================================================================
--- arch/amd64/src/smp/ap.S	(revision fa2d38295826e03b7d6e05160b05886ceb03f652)
+++ arch/amd64/src/smp/ap.S	(revision 4fdf3cc59b40f9758bf5a619c64a5a4718be1fee)
@@ -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.