Re: [RFC][PATCH 12/21] tracing: Account for variables in named trigger compatibility

[Tom Zanussi]

On Mon, 2017-02-13 at 15:04 +0900, Namhyung Kim wrote:
> On Wed, Feb 08, 2017 at 11:25:08AM -0600, Tom Zanussi wrote:
> > Named triggers must also have the same set of variables in order to be
> > considered compatible - update the trigger match test to account for
> > that.
> > 
> > The reason for this requirement is that named triggers with variables
> > are meant to allow one or more events to set the same variable.
> > 
> > Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> > ---
> >  kernel/trace/trace_events_hist.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > index e707577..889455e 100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -1576,6 +1576,10 @@ static bool hist_trigger_match(struct event_trigger_data *data,
> >  			return false;
> >  		if (key_field->is_signed != key_field_test->is_signed)
> >  			return false;
> > +		if ((key_field->var_name && !key_field_test->var_name) ||
> > +		    (!key_field->var_name && key_field_test->var_name) ||
> > +		    strcmp(key_field->var_name, key_field_test->var_name) != 0)
> > +			return false;
> 
> What if key_field->var_name and key_field_test->var_name are both
> NULL?
> 

Yep, it's a problem, thanks for pointing it out.

Tom

> Thanks,
> Namhyung
> 
> >  	}
> >  
> >  	for (i = 0; i < hist_data->n_sort_keys; i++) {
> > -- 
> > 1.9.3
> >