FLAT_RING3_SS32    26 arch/x86/include/asm/xen/interface_64.h #define FLAT_KERNEL_SS32 FLAT_RING3_SS32
FLAT_RING3_SS32    36 arch/x86/include/asm/xen/interface_64.h #define FLAT_USER_SS32 FLAT_RING3_SS32