[PATCH] perf: separate bpf_counter_list and bpf_filters

[PATCH] perf: separate bpf_counter_list and bpf_filters

[Song Liu]

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@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
---
 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

Re: [PATCH] perf: separate bpf_counter_list and bpf_filters

[Arnaldo Carvalho de Melo]

Em Fri, May 19, 2023 at 04:57:57PM -0700, Song Liu escreveu:
> 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.


Thanks, applied.

- Arnaldo

 
> Fixes: 56ec9457a4a2 ("perf bpf filter: Implement event sample filtering")
> Signed-off-by: Song Liu <song@kernel.org>
> Acked-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  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
> 

-- 

- Arnaldo