no_sigio 76 arch/um/drivers/chan_user.c sigset_t old, no_sigio; no_sigio 81 arch/um/drivers/chan_user.c sigemptyset(&no_sigio); no_sigio 82 arch/um/drivers/chan_user.c sigaddset(&no_sigio, SIGIO); no_sigio 83 arch/um/drivers/chan_user.c if (sigprocmask(SIG_BLOCK, &no_sigio, &old))