[PATCH] perf: separate bpf_counter_list and bpf_filters

From: Song Liu
Date: Fri May 19 2023 - 20:01:58 EST


evsel uses a union for the two lists. This turned out to be error prone.
For example:

[root@quaco ~]# perf stat --bpf-prog 5246
Error: cpu-clock event does not have sample flags 66c660
failed to set filter "(null)" on event cpu-clock with 2 (No such file or
directory)

Fix this issue by separating the two lists.

Fixes: 56ec9457a4a2 ("perf bpf filter: Implement event sample filtering")
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/evsel.c | 1 +
tools/perf/util/evsel.h | 6 ++----
2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2f5910b31fa9..c2dbb5647e75 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -282,6 +282,7 @@ void evsel__init(struct evsel *evsel,
evsel->bpf_fd = -1;
INIT_LIST_HEAD(&evsel->config_terms);
INIT_LIST_HEAD(&evsel->bpf_counter_list);
+ INIT_LIST_HEAD(&evsel->bpf_filters);
perf_evsel__object.init(evsel);
evsel->sample_size = __evsel__sample_size(attr->sample_type);
evsel__calc_id_pos(evsel);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index df8928745fc6..0f54f28a69c2 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -151,10 +151,8 @@ struct evsel {
*/
struct bpf_counter_ops *bpf_counter_ops;

- union {
- struct list_head bpf_counter_list; /* for perf-stat -b */
- struct list_head bpf_filters; /* for perf-record --filter */
- };
+ struct list_head bpf_counter_list; /* for perf-stat -b */
+ struct list_head bpf_filters; /* for perf-record --filter */

/* for perf-stat --use-bpf */
int bperf_leader_prog_fd;
--
2.34.1