* Peter Zijlstra <peterz@xxxxxxxxxxxxx> [2011-11-24 10:49:59]:
> On Thu, 2011-11-24 at 12:33 +0530, Srikar Dronamraju wrote:
> > > On Fri, 2011-11-18 at 16:37 +0530, Srikar Dronamraju wrote:
> > > > +int register_uprobe(struct inode *inode, loff_t offset,
> > > > + struct uprobe_consumer *consumer)
> > > > +{
> > > > + struct uprobe *uprobe;
> > > > + int ret = -EINVAL;
> > > > +
> > > > + if (!consumer || consumer->next)
> > > > + return ret;
> > > > +
> > > > + inode = igrab(inode);
> > >
> > > So why are you dealing with !consumer but not with !inode? and why
> > > does
> > > it make sense to allow !consumer at all?
> > >
> >
> >
> > I am not sure if I got your comment correctly.
> >
> > I do check for inode just after the igrab.
>
> No you don't, you check the return value of igrab(), but you crash hard
> when someone calls register_uprobe(.inode=NULL).
>
Okay. will add a check for inode before we do the igrab.
> > I am actually not dealing with !consumer.
> > If the consumer is NULL, then we dont have any handler to run so why
> > would we want to register such a probe?
>
> Why allow someone calling register_uprobe(.consumer=NULL) to begin with?
> That doesn't make any sense.
>
> > Also if consumer->next is Non-NULL, that means that this consumer was
> > already used. Reusing the consumer, can result in consumers list getting
> > broken into two.
>
> Yeah, although at that point why be nice about it? Just but a WARN_ON()
> in or so.
>
I thought you werent happy with prints and WARN_ON/BUG_ON unless it was
really really necessary. If we were to have a WARN_ON for a wrong
consumer passed, then we would need a warn_On for NULL inode too.
So I think we should leave this as is.
Unless I have commented, I agree to your comments sent in other threads
and will resolve them accordingly.
--
Thanks and Regards
Srikar
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