SIG_DFL 66 include/linux/init_task.h .action = { { { .sa_handler = SIG_DFL, } }, }, \ SIG_DFL 420 include/linux/signal.h (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \ SIG_DFL 425 include/linux/signal.h (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)