[gentoo-user] Re: openpty() failing with UNIX98 ptys

[walt]

On 01/26/2013 08:46 PM, Mike Edenfield wrote:
> At some point recently, one of my systems has begun having problems
> allocating pseudo-terminals via the UNIX98 pty scheme. I am using the same
> kernel configuration I've had for years, and running the latest ~amd64
> version of all the relevant packages. The problem manifests itself on any
> program that attempts to allocate a pseudo-terminal, including portage and
> openssh. I first noticed the problem when I could no longer ssh into the
> server because it would not allocate a pty.
>
> I have the latest udev installed, and udev-mount is running on boot. Both
> /dev and /dev/pts are mounted, and /dev/ptmx exists and is world-readable:
>
> basement package.use # mount | grep /dev
> /dev/root on / type ext3
> (rw,seclabel,noatime,errors=continue,barrier=1,data=writeback)
> devpts on /dev/pts type devpts
> (rw,seclabel,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
> shm on /dev/shm type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime)
> udev on /dev type devtmpfs
> (rw,seclabel,nosuid,relatime,size=10240k,nr_inodes=248584,mode=755)
>
> basement package.use # ls -alF /dev/ptmx /dev/pts
> crw-rw-rw-. 1 root tty  5, 2 Jan 26 13:18 /dev/ptmx
>
> /dev/pts:
> total 0
> drwxr-xr-x.  2 root root    40 Jan 26 13:18 ./
> drwxr-xr-x. 10 root root 13300 Jan 26 13:18 ../
>
> When I trace sshd's attempt to open a new pty, I see it doing this:
>
> * open /dev/ptmx
> * stat /dev/pts
> * stat /dev
> * try (and fail) to open /dev/ptyp0
>
> Since I know that last bit is openssh trying to open an old-style BSD pty, I
> can only assume that something is going wrong trying to allocate the pty the
> correct way.
>
> For the time being I've added BSD pty support into my kernel and everything
> seems to be working now, but I'm at a loss as to what I did to break things
> in the first place.

Do you have any files left in /usr/lib/udev ?  If so, try re-emerging the
package that owns those files.