Davide, > > I'm working on the signalfd(2) man page, and I've come > > acorss some puzzling behaviour... > > > > What are the intended semantics of a signalfd file descriptor > > after an execve()? > > > > As far as I can work out, after an execve() the file descriptor > > is still available, but reads from it always return 0, even if: > > > > a) there were signals pending before the execve(). > > However, sigpending() shows the signal as pending, > > and the signal can be accepted using sigwaitinfo(). > > > > b) we generate a signal after the execve(). > > > > Is this intended behavior (the "orphaned sighand" condition > > mentioned in the draft man page you sent me?)? Is it a bug? > > It is the intended behaviour. Just like reading from a socket where the > remote peer disconnected.
I don't think this analogy is good; what is the "peer" in this situation? IMO, A better analogy is: signalfd() should provide similar semantics to sigwaitinfo()/sigtimedwait() (and/or handling signals with a signal handler). > A return 0 from a read from a signalfd should be > interpreted as the "virtual connection" with the signal source has been > dropped. Yes, but in this case why has the '"virtual connection" with the signal source' been dropped? Why shouldn't one be allowed to continue reading signals from the signalfd file descriptor after the execve()? After all, I can still fetch those signals with sigwaitinfo() after the execve(). Not being able to also dothat with signalfd just isn't consistent. Cheers, Michael -- Michael Kerrisk maintainer of Linux man pages Sections 2, 3, 4, 5, and 7 Want to help with man page maintenance? Grab the latest tarball at http://www.kernel.org/pub/linux/docs/manpages , read the HOWTOHELP file and grep the source files for 'FIXME'. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
