KERNEL_STACK_SIZE  117 include/asm-xtensa/ptrace.h   (task_stack_page(tsk) + KERNEL_STACK_SIZE - (XCHAL_NUM_AREGS-16)*4) - 1)
KERNEL_STACK_SIZE  129 include/asm-xtensa/ptrace.h #define PT_REGS_OFFSET	  (KERNEL_STACK_SIZE - PT_USER_SIZE)