[PATCH v1 1/2] perf metrics: Avoid segv if default metricgroup isn't set

[Arnaldo Carvalho de Melo]

Em Tue, Dec 05, 2023 at 09:24:42AM -0800, Namhyung Kim escreveu:
> Hi Arnaldo,
> 
> On Tue, Dec 5, 2023 at 7:51 AM Arnaldo Carvalho de Melo <acme at kernel.org> wrote:
> >
> > Em Mon, Dec 04, 2023 at 07:33:18PM -0800, Namhyung Kim escreveu:
> > > On Mon, Dec 4, 2023 at 2:45 PM Ilkka Koskinen <ilkka at os.amperecomputing.com> wrote:
> > > > On Mon, 4 Dec 2023, Ian Rogers wrote:
> > > > > A metric is default by having "Default" within its groups. The default
> > > > > metricgroup name needn't be set and this can result in segv in
> > > > > default_metricgroup_cmp and perf_stat__print_shadow_stats_metricgroup
> > > > > that assume it has a value when there is a Default metric group. To
> > > > > avoid the segv initialize the value to "".
> >
> > > > > Fixes: 1c0e47956a8e ("perf metrics: Sort the Default metricgroup")
> > > > > Signed-off-by: Ian Rogers <irogers at google.com>
> >
> > > > Thanks! I was going to look for the bug but got pulled to other
> > > > tasks. The patch looks good to me and I tested it successfully on
> > > > AmpereOne.
> >
> > > >    Reviewed-and-tested-by: Ilkka Koskinen <ilkka at os.amperecomputing.com>
> >
> > > Looks like it needs to go through perf-tools for v6.7.
> > > Ian, do you think this one is enough?
> >
> > So I had this on my local perf-tools-next, removed now, I also have some
> > other fixes by Ian on the tmp.perf-tools-next, please let me know what
> > you guys decide to have in perf-tools for v6.7 so that I can remove it
> > from there.
> 
> I think we need this one and the Ampere default-metric-group fix.
> 
> https://lore.kernel.org/r/20231201021550.1109196-2-ilkka@os.amperecomputing.com/
> 
> Also perf list JSON fix can go to v6.7.
> 
> https://lore.kernel.org/r/20231129213428.2227448-2-irogers@google.com/

Ok, removed both, please augment the later description to:

"perf list: Fix JSON segfault by setting the used skip_fuplicate_pmus callback"

The original description was vague, improving it a bit like that helps
when just looking at the output of "git log --oneline".

Thanks,

- Arnaldo