Re: [PATCH 1/2] Does raw_field_ptr() supports __data_loc?

[Steven Rostedt <srostedt@redhat.com>]

On Mon, 2009-12-07 at 12:34 +0900, Hitoshi Mitake wrote:
> VERY very sorry for my long silence...
> 
> Please don't commit this patch, Ingo.
> This patch is required to test the next patch for perf lock.
> 
> I have a question for Steven Rostedt and Tom Zanussi.
> Does current raw_field_ptr() support __data_loc?
> 
> At 064739bc4b3d7f424b2f25547e6611bcf0132415 ,
> support for the modifier "__data_loc" of format is added.
> 
> But, when I wanted to parse format of lock_acquired (or some event else),
> raw_field_ptr() did not returned correct pointer.
> 
> So I modified raw_field_ptr() like this patch. Then raw_field_ptr() works well.
> Parser was large so I'd like to ask you about this.
> 
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Tom Zanussi <tzanussi@gmail.com>
> Cc: Steven Rostedt <srostedt@redhat.com>
> 
> I have a question
> ---
>  tools/perf/util/trace-event-parse.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
> index 0302405..494a470 100644
> --- a/tools/perf/util/trace-event-parse.c
> +++ b/tools/perf/util/trace-event-parse.c
> @@ -1925,6 +1925,13 @@ void *raw_field_ptr(struct event *event, const char *name, void *data)
>  	if (!field)
>  		return NULL;
>  
> +	if (field->flags & FIELD_IS_STRING) {
> +		int offset;
> +		offset = *(int *)(data + field->offset);
> +		offset &= 0xffff;
> +		return data + offset;
> +	}
> +

Hmm, I guess I need to update the code in perf again. The way I did this
was to have FIELD_IS_STRING evaluated in the eval_num_arg.


-- Steve

>  	return data + field->offset;
>  }
>