Re: [PATCH 2/3] perf script: Fix crash because of missing evsel->priv

[Arnaldo Carvalho de Melo]

Em Wed, Jun 20, 2018 at 07:00:29PM +0530, Ravi Bangoria escreveu:
> perf script in pipped mode is crashing because evsel->priv is not
> set properly. Fix it.
> 
> Before:
>   # ./perf record -o - -- ls | ./perf script
>     Segmentation fault (core dumped)
> 
> After:
>   # ./perf record -o - -- ls | ./perf script
>   ls 2282 1031.731974:  250000 cpu-clock:uhH:  7effe4b3d29e
>   ls 2282 1031.732222:  250000 cpu-clock:uhH:  7effe4b3a650
> 
> Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
> Fixes: a14390fde64e ("perf script: Allow creating per-event dump files")

Humm, this cset doesn't set evsel->priv to a 'struct perf_evsel_script'
object, will check which one does to continue review.

- Arnaldo

> ---
>  tools/perf/builtin-script.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 4d1cee68cfd2..acee05562f5e 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -1822,6 +1822,7 @@ static int process_attr(struct perf_tool *tool, union perf_event *event,
>  	struct perf_evlist *evlist;
>  	struct perf_evsel *evsel, *pos;
>  	int err;
> +	static struct perf_evsel_script *es;
>  
>  	err = perf_event__process_attr(tool, event, pevlist);
>  	if (err)
> @@ -1830,6 +1831,19 @@ static int process_attr(struct perf_tool *tool, union perf_event *event,
>  	evlist = *pevlist;
>  	evsel = perf_evlist__last(*pevlist);
>  
> +	if (!evsel->priv) {
> +		if (scr->per_event_dump) {
> +			evsel->priv = perf_evsel_script__new(evsel,
> +						scr->session->data);
> +		} else {
> +			es = zalloc(sizeof(*es));
> +			if (!es)
> +				return -ENOMEM;
> +			es->fp = stdout;
> +			evsel->priv = es;
> +		}
> +	}
> +
>  	if (evsel->attr.type >= PERF_TYPE_MAX &&
>  	    evsel->attr.type != PERF_TYPE_SYNTH)
>  		return 0;
> -- 
> 2.14.4