[Linuxarm] Re: [PATCH] perf metricgroup: Fix for metrics containing duration_time

On Thu, Jan 21, 2021 at 12:18:38AM +0800, John Garry wrote:

Metrics containing duration_time cause a segfault:

$./perf stat -v -M L1D_Cache_Fill_BW sleep 1 Using CPUID GenuineIntel-6-3D-4 metric expr 64 * l1d.replacement / 1000000000 / duration_time for L1D_Cache_Fill_BW found event duration_time found event l1d.replacement adding {l1d.replacement}:W,duration_time l1d.replacement -> cpu/umask=0x1,(null)=0x1e8483,event=0x51/ Segmentation fault

In commit c2337d67199a ("perf metricgroup: Fix metrics using aliases covering multiple PMUs"), the logic in find_evsel_group() when iter'ing events was changed to not only select events in same group, but also for aliased PMUs.

Checking whether events were for aliased PMUs was done by comparing the event PMU name. This was not safe for duration_time event, which has no associated PMU (and no PMU name), so fix by checking if the event PMU name is set also.

Fixes: c2337d67199a ("perf metricgroup: Fix metrics using aliases covering multiple PMUs") Reported-by: Joakim Zhang qiangqing.zhang@nxp.com Signed-off-by: John Garry john.garry@huawei.com

Tested/Acked-by: Jiri Olsa jolsa@redhat.com

thanks, jirka

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 2e60ee170abc..e6d3452031e5 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -162,6 +162,14 @@ static bool contains_event(struct evsel **metric_events, int num_events, return false; }

+static bool evsel_same_pmu(struct evsel *ev1, struct evsel *ev2) +{

• if (!ev1->pmu_name || !ev2->pmu_name)

• return false;
  

• return !strcmp(ev1->pmu_name, ev2->pmu_name);

+}

/**

• Find a group of events in perf_evlist that correspond to those from a parsed
• metric expression. Note, as find_evsel_group is called in the same order as

@@ -280,8 +288,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist, */ if (!has_constraint && ev->leader != metric_events[i]->leader &&

• 	    !strcmp(ev->leader->pmu_name,
  

• 		    metric_events[i]->leader->pmu_name))
  

• 	    evsel_same_pmu(ev->leader, metric_events[i]->leader))
  	break;
  if (!strcmp(metric_events[i]->name, ev->name)) {
  	set_bit(ev->idx, evlist_used);
  

-- 2.26.2