Re: [PATCH 19/24] ftrace: Fix trace_add_event_call() to initialize list

[Masami Hiramatsu <mhiramat@redhat.com>]

Li Zefan wrote:
>> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
>> index ba34920..83cc2c0 100644
>> --- a/kernel/trace/trace_events.c
>> +++ b/kernel/trace/trace_events.c
>> @@ -1010,9 +1010,12 @@ static int __trace_add_event_call(struct ftrace_event_call *call)
>>  		return -ENOENT;
>>  
>>  	list_add(&call->list, &ftrace_events);
>> -	return event_create_dir(call, d_events, &ftrace_event_id_fops,
>> +	ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
>>  				&ftrace_enable_fops, &ftrace_event_filter_fops,
>>  				&ftrace_event_format_fops);
>> +	if (ret < 0)
>> +		list_del(&call->list);
>> +	return ret;
> 
> seems it's a bit better to call list_add() after event_create_dir()
> returns 0.

Sure, that's another way to do. But I'm afraid that will make a difference
from trace_module_add_events() path.

---
                call->mod = mod;
                list_add(&call->list, &ftrace_events);
                event_create_dir(call, d_events,
                                 &file_ops->id, &file_ops->enable,
                                 &file_ops->filter, &file_ops->format);
---
Anyway, this also needs to check the result of event_create_dir().

Thank you,

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com