[3/4] perf stat: Use evsel->core.cpus to iterate cpus in BPF cgroup counters

Commit Message

Namhyung Kim Sept. 16, 2022, 6:41 p.m. UTC

If it mixes core and uncore events, each evsel would have different cpu map.
But it assumed they are same with evlist's all_cpus and accessed by the same
index.  This resulted in a crash like below.

  $ perf stat -a --bpf-counters --for-each_cgroup ^. -e cycles,imc/cas_count_read/ sleep 1
  Segmentation fault

While it's not recommended to use uncore events for cgroup aggregation, it
should not crash.

Signed-off-by: Namhyung Kim <[e-mail]>
---
 tools/perf/util/bpf_counter_cgroup.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Patch

diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
index 97c69a249c6e..3c2df7522f6f 100644
--- a/tools/perf/util/bpf_counter_cgroup.c
+++ b/tools/perf/util/bpf_counter_cgroup.c
@@ -115,14 +115,14 @@  static int bperf_load_program(struct evlist *evlist)
 			evsel->cgrp = NULL;
 
 			/* open single copy of the events w/o cgroup */
-			err = evsel__open_per_cpu(evsel, evlist->core.all_cpus, -1);
+			err = evsel__open_per_cpu(evsel, evsel->core.cpus, -1);
 			if (err) {
 				pr_err("Failed to open first cgroup events\n");
 				goto out;
 			}
 
 			map_fd = bpf_map__fd(skel->maps.events);
-			perf_cpu_map__for_each_cpu(cpu, j, evlist->core.all_cpus) {
+			perf_cpu_map__for_each_cpu(cpu, j, evsel->core.cpus) {
 				int fd = FD(evsel, j);
 				__u32 idx = evsel->core.idx * total_cpus + cpu.cpu;
 
@@ -269,7 +269,7 @@  static int bperf_cgrp__read(struct evsel *evsel)
 			goto out;
 		}
 
-		perf_cpu_map__for_each_cpu(cpu, i, evlist->core.all_cpus) {
+		perf_cpu_map__for_each_cpu(cpu, i, evsel->core.cpus) {
 			counts = perf_counts(evsel->counts, i, 0);
 			counts->val = values[cpu.cpu].counter;
 			counts->ena = values[cpu.cpu].enabled;