Cong Wang wrote:
> On Mon, May 10, 2021 at 10:34 PM John Fastabend
> <john.fastabend@xxxxxxxxx> wrote:
> > > +static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
> > > + sk_read_actor_t recv_actor)
> > > +{
> > > + int copied = 0;
> > > +
> > > + while (1) {
> > > + struct unix_sock *u = unix_sk(sk);
> > > + struct sk_buff *skb;
> > > + int used, err;
> > > +
> > > + mutex_lock(&u->iolock);
> > > + skb = skb_recv_datagram(sk, 0, 1, &err);
> > > + if (!skb) {
> > > + mutex_unlock(&u->iolock);
> > > + return err;
> >
> > Here we should check copied and break if copied is >0. Sure the caller here
> > has desc.count = 1 but its still fairly fragile.
>
> Technically, sockmap does not even care about what we return
> here, so I am sure what you suggest here even makes a difference.
> Also, desc->count is always 1 and never changes here.
Right, so either don't wrap it in a while() loop so its obviously
not workable or fix it so that it returns the correct copied value if
we ever did pass it count > 1..
>
> Thanks.
