Re: [PATCH 3/4] perf tools: Copy metric events properly when expand cgroups

[Namhyung Kim]

On Fri, Sep 18, 2020 at 10:45 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Wed, Sep 16, 2020 at 03:31:28PM +0900, Namhyung Kim wrote:
>
> SNIP
>
> > +                                     free(new_expr);
> > +                                     return -ENOMEM;
> > +                             }
> > +
> > +                             memcpy(new_expr->metric_refs, old_expr->metric_refs,
> > +                                    nr * alloc_size);
> > +                     } else {
> > +                             new_expr->metric_refs = NULL;
> > +                     }
> > +
> > +                     /* calculate number of metric_events */
> > +                     for (nr = 0; old_expr->metric_events[nr]; nr++)
> > +                             continue;
> > +                     alloc_size = sizeof(*new_expr->metric_events);
> > +                     new_expr->metric_events = calloc(nr + 1, alloc_size);
> > +                     if (!new_expr->metric_events) {
> > +                             free(new_expr->metric_refs);
> > +                             free(new_expr);
> > +                             return -ENOMEM;
> > +                     }
> > +
> > +                     /* copy evsel in the same position */
> > +                     for (idx = 0; idx < nr; idx++) {
> > +                             evsel = old_expr->metric_events[idx];
> > +                             evsel = evlist__get_evsel(evlist, evsel->idx);
>
> this probably won't happen, but evlist__get_evsel can return NULL

Hmm.. yeah, it should not happen.  Anyway I'll check the result.

Thanks
Namhyung

>
> > +                             new_expr->metric_events[idx] = evsel;
> > +                     }
> > +
> > +                     list_add(&new_expr->nd, &new_me->head);
> > +             }
> > +     }
> > +     return 0;
> > +}
>
> SNIP
>