Re: [PATCH] perf jevents: Fix event code for events referencing std arch events

[John Garry <john.garry@huawei.com>]

On 12/10/2020 12:24, Jiri Olsa wrote:
> On Mon, Oct 12, 2020 at 12:15:04PM +0100, John Garry wrote:
>> On 12/10/2020 11:54, Jiri Olsa wrote:
>>>> ff --git a/tools/perf/pmu-events/jevents.c b/tools/perf/pmu-events/jevents.c
>>>> index 99df41a9543d..e47644cab3fa 100644
>>>> --- a/tools/perf/pmu-events/jevents.c
>>>> +++ b/tools/perf/pmu-events/jevents.c
>>>> @@ -505,20 +505,15 @@ static char *real_event(const char *name, char *event)
>>>>    }
>>>>    static int
>>>> -try_fixup(const char *fn, char *arch_std, unsigned long long eventcode,
>>>> -	  struct json_event *je)
>>>> +try_fixup(const char *fn, char *arch_std, struct json_event *je, char **event)
>>>>    {
>>>>    	/* try to find matching event from arch standard values */
>>>>    	struct event_struct *es;
>>>>    	list_for_each_entry(es, &arch_std_events, list) {
>>>>    		if (!strcmp(arch_std, es->name)) {
>>>> -			if (!eventcode && es->event) {
>>>> -				/* allow EventCode to be overridden */
>>>> -				free(je->event);
>>>> -				je->event = NULL;
>>>> -			}
>>>>    			FOR_ALL_EVENT_STRUCT_FIELDS(TRY_FIXUP_FIELD);
>>>> +			*event = je->event;
>>> I'm bit rusty on this code, but isn't je->event NULL at this point?
>>
>> je->event should be now assigned from es->event because of
>> FOR_ALL_EVENT_STRUCT_FIELDS(TRY_FIXUP_FIELD):
>>
>> #define TRY_FIXUP_FIELD(field) do { if (es->field && !*field) {\
>> 	*field = strdup(es->field);				\
>> 	if (!*field)						\
>> 		return -ENOMEM;					\
>> } } while (0)
>>
>> And es->event should be set.
> 
> right, thanks
> 
> Acked-by: Jiri Olsa <jolsa@redhat.com>
> 
> jirka
> 
> .
> 

"PMU events" testcase was still passing as it does not cover this 
scenario, so I'll look to expand the test to catch such problems.

Thanks,
John