Re: [PATCH 6/6] perf parse events: demystify memory allocations

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Jul 02, 2013 at 01:27:25PM -0600, David Ahern wrote:
> List heads are currently allocated way down the function chain in __add_event
> and add_tracepoint and then freed when the scanner code calls
> parse_events_update_lists.
> 
> Be more explicit with where memory is allocated and who should free it. With
> this patch the list_head is allocated in the scanner code and freed when the
> scanner code calls parse_events_update_lists.
> 

SNIP

> @@ -266,9 +279,10 @@ event_legacy_mem:
>  PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
>  {
>  	struct parse_events_evlist *data = _data;
> -	struct list_head *list = NULL;
> +	struct list_head *list;
>  
> -	ABORT_ON(parse_events_add_breakpoint(&list, &data->idx,
> +	ALLOC_LIST(list);
> +	ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
>  					     (void *) $2, $4));
>  	$$ = list;
>  }
> @@ -276,9 +290,10 @@ PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
>  PE_PREFIX_MEM PE_VALUE sep_dc
>  {
>  	struct parse_events_evlist *data = _data;
> -	struct list_head *list = NULL;
> +	struct list_head *list;
>  
> -	ABORT_ON(parse_events_add_breakpoint(&list, &data->idx,
> +	ALLOC_LIST(list);
> +	ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
>  					     (void *) $2, NULL));

so who now frees the list if there's an error
in parse_events_add_breakpoint?

ditto for other ABORT_ON cases

jirka