x86_hw_tss
unsigned long stack[(PAGE_SIZE - sizeof(struct x86_hw_tss)) / sizeof(unsigned long)];
struct x86_hw_tss tss;
static inline void __set_tss_desc(unsigned cpu, unsigned int entry, struct x86_hw_tss *addr)
(offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1)
struct x86_hw_tss x86_tss;
BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);