Re: [PATCH 01/10] tracing: Update cond flag when enabling or disabling a trigger

[Masami Hiramatsu]

On 2015/05/21 6:19, Tom Zanussi wrote:
> When a trigger is enabled, the cond flag should be set beforehand,
> otherwise a trigger that's expecting to process a trace record
> (e.g. one with post_trigger set) could be invoked without one.
> 
> Likewise a trigger's cond flag should be reset after it's disabled,
> not before.
> 
> Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> Signed-off-by: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

Thank you!

> ---
>  kernel/trace/trace_events_trigger.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index 8712df9..51e2664 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -543,11 +543,12 @@ static int register_trigger(char *glob, struct event_trigger_ops *ops,
>  	list_add_rcu(&data->list, &file->triggers);
>  	ret++;
>  
> +	update_cond_flag(file);
>  	if (trace_event_trigger_enable_disable(file, 1) < 0) {
>  		list_del_rcu(&data->list);
> +		update_cond_flag(file);
>  		ret--;
>  	}
> -	update_cond_flag(file);
>  out:
>  	return ret;
>  }
> @@ -575,8 +576,8 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
>  		if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
>  			unregistered = true;
>  			list_del_rcu(&data->list);
> -			update_cond_flag(file);
>  			trace_event_trigger_enable_disable(file, 0);
> +			update_cond_flag(file);
>  			break;
>  		}
>  	}
> @@ -1319,11 +1320,12 @@ static int event_enable_register_trigger(char *glob,
>  	list_add_rcu(&data->list, &file->triggers);
>  	ret++;
>  
> +	update_cond_flag(file);
>  	if (trace_event_trigger_enable_disable(file, 1) < 0) {
>  		list_del_rcu(&data->list);
> +		update_cond_flag(file);
>  		ret--;
>  	}
> -	update_cond_flag(file);
>  out:
>  	return ret;
>  }
> @@ -1344,8 +1346,8 @@ static void event_enable_unregister_trigger(char *glob,
>  		    (enable_data->file == test_enable_data->file)) {
>  			unregistered = true;
>  			list_del_rcu(&data->list);
> -			update_cond_flag(file);
>  			trace_event_trigger_enable_disable(file, 0);
> +			update_cond_flag(file);
>  			break;
>  		}
>  	}
> 


-- 
Masami HIRAMATSU
Linux Technology Research Center, System Productivity Research Dept.
Center for Technology Innovation - Systems Engineering
Hitachi, Ltd., Research & Development Group
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
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