cpu_current_top_of_stack  384 arch/x86/include/asm/processor.h #define cpu_current_top_of_stack cpu_tss_rw.x86_tss.sp1
cpu_current_top_of_stack  219 arch/x86/include/asm/thread_info.h # define cpu_current_top_of_stack (cpu_tss_rw + TSS_sp1)