TFD_CLOEXEC 393 fs/timerfd.c BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC); TFD_CLOEXEC 14 include/linux/timerfd.h #define TFD_SHARED_FCNTL_FLAGS (TFD_CLOEXEC | TFD_NONBLOCK)