[PATCH 1/2] perf bpf-filter: Fix sample flag check with ||

From: Namhyung Kim
Date: Thu Aug 10 2023 - 22:58:33 EST


For logical OR operator, the actual sample_flags are in the 'groups'
list so it needs to check entries in the list instead. Otherwise it
would show the following error message.

$ sudo perf record -a -e cycles:p --filter 'period > 100 || weight > 0' sleep 1
Error: cycles:p event does not have sample flags 0
failed to set filter "BPF" on event cycles:p with 2 (No such file or directory)

Actually it should warn on 'weight' is used without WEIGHT flag.

Error: cycles:p event does not have PERF_SAMPLE_WEIGHT
Hint: please add -W option to perf record
failed to set filter "BPF" on event cycles:p with 2 (No such file or directory)

Fixes: 4310551b76e0 ("perf bpf filter: Show warning for missing sample flags")
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/bpf-filter.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c
index 47f01df658d9..b51544996046 100644
--- a/tools/perf/util/bpf-filter.c
+++ b/tools/perf/util/bpf-filter.c
@@ -62,6 +62,16 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *
if (evsel->core.attr.sample_type & expr->sample_flags)
return 0;

+ if (expr->op == PBF_OP_GROUP_BEGIN) {
+ struct perf_bpf_filter_expr *group;
+
+ list_for_each_entry(group, &expr->groups, list) {
+ if (check_sample_flags(evsel, group) < 0)
+ return -1;
+ }
+ return 0;
+ }
+
info = get_sample_info(expr->sample_flags);
if (info == NULL) {
pr_err("Error: %s event does not have sample flags %lx\n",
--
2.41.0.640.ga95def55d0-goog