Re: [PATCH v2 08/11] tty: splice_read: disable

[Oliver Giles]

On Wed, Jan 3 2024 at 11:14:59 -08:00:00, Linus Torvalds 
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> It's some annoying SSL VPN thing that splices to pppd:
>
>    https://lore.kernel.org/all/C8KER7U60WXE.25UFD8RE6QZQK@oguc/

I'm happy to report that that particular SSL VPN tool is no longer 
around.
And it had anyway grown a fall-back-to-read/write in case splice() 
fails.
So at least from my perspective, no objections to splice-to-tty going 
away
altogether.

> and I'd be happy to try to limit splice to tty's to maybe just the one
> case that pppd uses.

To be exact, pppd is just providing a pty with which other (now all 
extinct?)
applications can do nefarious things.

> 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?

FWIW, the SSL VPN tool did indeed have the pty in non-blocking mode.

Oliver