Re: [PATCH 3/4] tracing: Add action comparisons when testing matching hist triggers
From: Masami Hiramatsu
Date: Mon Apr 02 2018 - 11:10:37 EST
On Wed, 28 Mar 2018 15:10:55 -0500
Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> wrote:
> Actions also need to be considered when checking for matching triggers
> - triggers differing only by action should be allowed, but currently
> aren't because the matching check ignores the action and erroneously
> returns -EEXIST.
Hi Tom,
Could you show us the bad/good examples (maybe different onmatch() actions)?
And if it is real bugfix, I would like to add a ftracetest testcase for this fix.
Thank you,
>
> Add and call an actions_match() function to address that.
>
> Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> ---
> kernel/trace/trace_events_hist.c | 50 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> index 468e43f..ae84470 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -4363,6 +4363,53 @@ static void print_onmatch_spec(struct seq_file *m,
> seq_puts(m, ")");
> }
>
> +static bool actions_match(struct hist_trigger_data *hist_data,
> + struct hist_trigger_data *hist_data_test)
> +{
> + unsigned int i, j;
> +
> + if (hist_data->n_actions != hist_data_test->n_actions)
> + return false;
> +
> + for (i = 0; i < hist_data->n_actions; i++) {
> + struct action_data *data = hist_data->actions[i];
> + struct action_data *data_test = hist_data_test->actions[i];
> +
> + if (data->fn != data_test->fn)
> + return false;
> +
> + if (data->n_params != data_test->n_params)
> + return false;
> +
> + for (j = 0; j < data->n_params; j++) {
> + if (strcmp(data->params[j], data_test->params[j]) != 0)
> + return false;
> + }
> +
> + if (data->fn == action_trace) {
> + if (strcmp(data->onmatch.synth_event_name,
> + data_test->onmatch.synth_event_name) != 0)
> + return false;
> + if (strcmp(data->onmatch.match_event_system,
> + data_test->onmatch.match_event_system) != 0)
> + return false;
> + if (strcmp(data->onmatch.match_event,
> + data_test->onmatch.match_event) != 0)
> + return false;
> + } else if (data->fn == onmax_save) {
> + if (strcmp(data->onmax.var_str,
> + data_test->onmax.var_str) != 0)
> + return false;
> + if (strcmp(data->onmax.fn_name,
> + data_test->onmax.fn_name) != 0)
> + return false;
> + }
> + }
> +
> + return true;
> +}
> +
> +
> static void print_actions_spec(struct seq_file *m,
> struct hist_trigger_data *hist_data)
> {
> @@ -5173,6 +5220,9 @@ static bool hist_trigger_match(struct event_trigger_data *data,
> (strcmp(data->filter_str, data_test->filter_str) != 0))
> return false;
>
> + if (!actions_match(hist_data, hist_data_test))
> + return false;
> +
> return true;
> }
>
> --
> 1.9.3
>
--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>