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

[Namhyung Kim <namhyung@kernel.org>]

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@linux.intel.com>
> ---
>  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?

Thanks,
Namhyung

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