Re: [PATCH 2/2] perf annotate-data: Ensure the number of type histograms

[Arnaldo Carvalho de Melo]

On Fri, May 10, 2024 at 02:27:36PM -0700, Ian Rogers wrote:
> On Fri, May 10, 2024 at 2:04 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >
> > Arnaldo reported that there is a case where nr_histograms and histograms
> > don't agree each other.  It ended up in a segfault trying to access NULL
> > histograms array.  Let's make sure to update the nr_histograms when the
> > histograms array is changed.
> >
> > Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> 
> Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks, applied to perf-tools-next,

- Arnaldo
 
> Thanks,
> Ian
> 
> > ---
> >  tools/perf/util/annotate-data.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> > index 57e7d4b3550b..965da6c0b542 100644
> > --- a/tools/perf/util/annotate-data.c
> > +++ b/tools/perf/util/annotate-data.c
> > @@ -1800,7 +1800,6 @@ static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_en
> >         sz += sizeof(struct type_hist_entry) * adt->self.size;
> >
> >         /* Allocate a table of pointers for each event */
> > -       adt->nr_histograms = nr_entries;
> >         adt->histograms = calloc(nr_entries, sizeof(*adt->histograms));
> >         if (adt->histograms == NULL)
> >                 return -ENOMEM;
> > @@ -1814,6 +1813,8 @@ static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_en
> >                 if (adt->histograms[i] == NULL)
> >                         goto err;
> >         }
> > +
> > +       adt->nr_histograms = nr_entries;
> >         return 0;
> >
> >  err:
> > @@ -1827,7 +1828,9 @@ static void delete_data_type_histograms(struct annotated_data_type *adt)
> >  {
> >         for (int i = 0; i < adt->nr_histograms; i++)
> >                 zfree(&(adt->histograms[i]));
> > +
> >         zfree(&adt->histograms);
> > +       adt->nr_histograms = 0;
> >  }
> >
> >  void annotated_data_type__tree_delete(struct rb_root *root)
> > --
> > 2.45.0.118.g7fe29c98d7-goog
> >