Re: [PATCH] Using sock_orphan in ax25 and netrom

[Jeroen Vreeken]

On 2001.11.21 19:42:23 +0100 Jeroen Vreeken wrote:
> Appearantly my patch from yesterday was a bit premature...
> 
> It looks like the ax25 and netrom stack do some magic with the dead
> sockets
> that is not compatible with sock_orphan. I will try and see if I can
> track
> them down.

Found the cause in datagram_poll() in datagram.c:

        if (sock_writeable(sk))
                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
        else
                set_bit(SOCK_ASYNC_NOSPACE, &sk->socket->flags);

Since our socket is dead its not writeable and the code tries to set
sk->socket->flags
However sk->socket has been set to NULL by sock_orphan()
Adding a check for this solves the problem:

        if (sock_writeable(sk))
                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
        else
                if (sk->socket)
                        set_bit(SOCK_ASYNC_NOSPACE, &sk->socket->flags);

Is there a reason datagram_poll() should not check this? (Or another place
to do it)
If not I will make a new patch including this change.

Jeroen