On Monday 16 March 2015 14:44:20 Kees Cook wrote: > > O_CLOEXEC > > Set the close-on-exec flag on the new file > >descriptor. See the description of the O_CLOEXEC flag in open(2) for > >reasons why this may be useful. > > This begs the question: what happens when all CLONE_FD fds for a > process are closed? Will the parent get SIGCHLD instead, will it > auto-reap, or will it be un-wait-able (I assume not this...)
Depends on CLONE_AUTOREAP. If it's on, then no one gets SIGCHLD, no one can wait() on it and the process autoreaps itself. If it's no active, then the old rules apply: parent gets SIGCHILD and can wait(). If the parent exited first, then the child gets reparented to init, which can do the wait(). A child without CLONE_AUTOREAP should be wait()able. If it gets wait()ed before the clonefd is read, the clonefd() will return a 0 read. If it gets read before wait, then wait() reaps another child or returns -ECHILD. That's no different than two threads doing simultaneous wait() on the same child. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
