On Thu, Apr 10, 2025, Kevin Tian wrote:
> > From: Sean Christopherson <sea...@google.com>
> > +int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer,
> > + struct eventfd_ctx *eventfd)
> > {
> > struct irq_bypass_consumer *tmp;
> > struct irq_bypass_producer *producer;
> > int ret;
> >
> > - if (!consumer->token ||
> > - !consumer->add_producer || !consumer->del_producer)
> > + if (WARN_ON_ONCE(consumer->token))
> > + return -EINVAL;
> > +
> > + if (!consumer->add_producer || !consumer->del_producer)
> > return -EINVAL;
> >
> > mutex_lock(&lock);
> >
> > list_for_each_entry(tmp, &consumers, node) {
> > - if (tmp->token == consumer->token || tmp == consumer) {
> > + if (tmp->token == eventfd || tmp == consumer) {
> > ret = -EBUSY;
> > goto out_err;
> > }
> > }
>
> the 2nd check 'tmp == consumer' is redundant. If they are equal
> consumer->token is not NULL then the earlier WARN_ON will be
> triggered already.
Oh, nice. Good catch! That check subtly gets dropped on the conversion to
xarray, so it definitely makes sense to remove it in this patch.
