Re: [RFC PATCH v2 01/13] perf parse-events: Fix comparison of evsel and leader pmu name

[John Garry]

On 27/04/2020 09:16, Jiri Olsa wrote:
> On Fri, Apr 17, 2020 at 06:41:12PM +0800, John Garry wrote:
> > Since we now strdup() the pmu name for the event selector, use strcmp()
> > instead of pointer equality for comparison.
> >
> > Fixes: d4953f7ef1a2 ("perf parse-events: Fix 3 use after frees found with clang ASANutil/parse-events.c")
> > Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
>
> I don't ee this change in your branch:
>    private-topic-perf-5.6-sys-pmu-events-v2-upstream
>
> do you have some updated tree?

I have started rebase work here:

https://github.com/hisilicon/kernel-dev/commits/private-topic-perf-5.7-sys-pmu-events-v2

Without this patch, I get this spewed for metric events:

	assertion failed at util/parse-events.c:1637

However, if there was a problem on mainline, I would expect some other 
reports now.

Thanks,
John



> > ---
> >
> > I am not 100% sure that this is the right fix....
> >
> >   tools/perf/util/parse-events.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 10107747b361..90ddade1ba23 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -1629,7 +1629,7 @@ parse_events__set_leader_for_uncore_aliase(char *name, struct list_head *list,
> >   		 * event. That can be used to distinguish the leader from
> >   		 * other members, even they have the same event name.
> >   		 */
> > -		if ((leader != evsel) && (leader->pmu_name == evsel->pmu_name)) {
> > +		if ((leader != evsel) && !strcmp(leader->pmu_name, evsel->pmu_name)) {
> >   			is_leader = false;
> >   			continue;
> >   		}
> > --
> > 2.16.4
>
> .