Re: [PATCH] tty: cleanup prohibition of direct opening for unix98 pty master

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

Greg KH wrote:
> On Tue, Jan 03, 2012 at 12:51:11PM +0400, Konstantin Khlebnikov wrote:
>> cleanup hack added in v2.6.27-3203-g15582d3
>>
>> comment from that patch:
>>
>> : pty: If the administrator creates a device for a ptmx slave we should not error
>> :
>> : The open path for ptmx slaves is via the ptmx device. Opening them any
>> : other way is not allowed. Vegard Nossum found that previously this was not
>> : the case and mknod foo c 128 42; cat foo would produce nasty diagnostics
>> :
>> : Signed-off-by: Alan Cox<alan@redhat.com>
>> : Signed-off-by: Linus Torvalds<torvalds@linux-foundation.org>
>>
>> devpts_get_tty() returns non-null only for inodes on devpts, but there is no
>> inodes for master-devices, /dev/ptmx (/dev/pts/ptmx) is the only way to open them.
>> Thus we can completely forbid lookup for master-devices and eliminate that hack in
>> tty_init_dev() because tty_open() will get EIO from tty_driver_lookup_tty().
>>
>> Signed-off-by: Konstantin Khlebnikov<khlebnikov@openvz.org>
>
> What tree did you make this patch against?  I get fuzz warnings when
> applying it to the tty-next branch (it's in the linux-next releases).
>
> Please rediff it and resend it.

Sorry for that, I did not expect such activity in tty-layer =)

>
> thanks,
>
> greg k-h