TIF_BLOCK_STEP
#define _TIF_BLOCK_STEP BIT(TIF_BLOCK_STEP)
clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
set_tsk_thread_flag(task, TIF_BLOCK_STEP);
if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))