Re: [PATCH 60/80] tty: extract the pty init time special cases

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

> So you are saying that if I merge my ptyx module into the kernel tree THEN 
> these
> exports would be added?  They would have to be, since I would still want 

It would then seem reasonable to do so

> my 
> driver to be a module instead of statically linked with the kernel like 
> pty is.

Sure - although it might make more sense to add any neede features to the
generic pty driver - hard to tell when you don't seem interested in
discussing that.

> I think the fact that you had to "ask at the time what other PTY drivers 
> there 
> were" indicates that these symbols should have been simply exported to 
> avoid 
> any problems with out of tree PTY drivers.

The linux kernel doesn't carry extra symbols for out of tree drivers. Why
should it - even keeping an index of them would be hard and it would be
impossible to know which ones are in use. Plus they change regularly -
the tty layer will change further soon for example, it's just having a
settling in period before the next big changes.

> By not exporting these symbols it means that the Linux kernel is now 
> forcing 
> anyone who wants to develop a PTY type TTY driver to be merged into the 
> kernel 
> tree by not exporting these TTY functions. This doesn't seem very "open 
> and 
> flexible".

No you can provide the GPL symbol exports with the same patch as your pty
driver. There are millions of Linux users and each unused EXPORT_SYMBOL
costs memory to all those people - why should they carry that burden ?

Alan