Re: [PATCH 2/8] perf: Sanitize get_callchain_buffer()

[Frederic Weisbecker <fweisbec@gmail.com>]

On Thu, Aug 01, 2013 at 03:29:34PM +0200, Jiri Olsa wrote:
> On Tue, Jul 23, 2013 at 02:31:00AM +0200, Frederic Weisbecker wrote:
> SNIP
> 
> >  		if (event->attach_state & PERF_ATTACH_TASK)
> >  			static_key_slow_inc(&perf_sched_events.key);
> >  		if (event->attr.mmap || event->attr.mmap_data)
> > @@ -6572,16 +6570,19 @@ done:
> >  				atomic_inc(&per_cpu(perf_branch_stack_events,
> >  						    event->cpu));
> >  		}
> > -		if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
> > -			err = get_callchain_buffers();
> > -			if (err) {
> > -				free_event(event);
> > -				return ERR_PTR(err);
> > -			}
> > -		}
> >  	}
> >  
> >  	return event;
> > +
> > +err_pmu:
> > +	if (event->destroy)
> > +		event->destroy(event);
> > +err_ns:
> > +	if (event->ns)
> > +		put_pid_ns(event->ns);
> > +	kfree(event);
> > +
> > +	return ERR_PTR(err);
> 
> could we call __free_filter(event) here?

Hmm, the filters are installed from ioctl time so there shouldn't be any yet. But there should be
an exception with inherited events. I fail to find where the filter is inherited though. Do
we actually inherit those?

thanks.