On Wed, 3 Jan 2024 at 03:36, Jiri Slaby <jirislaby@xxxxxxxxxx> wrote: > > What are those "things" doing that "splice to tty", I don't recall and > the commit message above ^^^ does not spell that out. Linus? It's some annoying SSL VPN thing that splices to pppd: https://lore.kernel.org/all/C8KER7U60WXE.25UFD8RE6QZQK@oguc/ and I'd be happy to try to limit splice to tty's to maybe just the one case that pppd uses. So I don't think we should remove splice_write for tty's entirely, but maybe we can limit it to only the case that the VPN thing used. I never saw the original issue personally, and I think only Oliver reported it, so cc'ing Oliver. Maybe that VPN thing already has the pty in non-blocking mode, for example, and we could make the tty splicing fail for any blocking op? Linus