[PATCH perf,bpf 2/2] perf, bpf: show BPF program name in print_bpf_prog_info()

[Song Liu <songliubraving@xxxxxx>]

This patch enables showing bpf program name in the header.

Before the patch:

  perf report --header-only
  ...
  # bpf_prog_info of id 9
  # bpf_prog_info of id 10
  # bpf_prog_info of id 13

After the patch:

  # bpf_prog_info 9: bpf_prog_7be49e3934a125ba
  # bpf_prog_info 10: bpf_prog_2a142ef67aaad174
  # bpf_prog_info 13: bpf_prog_47368425825d7384_task__task_newt

Signed-off-by: Song Liu <songliubraving@xxxxxx>
---
 tools/perf/util/bpf-event.c | 36 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/bpf-event.h | 10 +++++++++-
 tools/perf/util/header.c    |  5 +++--
 3 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 6e035e08aa2d..dde35a36e2de 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -433,3 +433,39 @@ int bpf_event__add_sb_event(struct perf_evlist **evlist,
 
 	return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
 }
+
+void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
+				    struct perf_env *env,
+				    FILE *fp)
+{
+	char name[KSYM_NAME_LEN];
+	struct btf *btf = NULL;
+	u32 sub_prog_cnt, i;
+
+	sub_prog_cnt = info->nr_jited_ksyms;
+	if (sub_prog_cnt != info->nr_prog_tags ||
+	    sub_prog_cnt != info->nr_jited_func_lens)
+		return;
+
+	if (info->btf_id) {
+		struct btf_node *node;
+
+		node = perf_env__find_btf(env, info->btf_id);
+		if (node)
+			btf = btf__new((__u8 *)(node->data),
+				       node->data_size);
+	}
+
+	if (sub_prog_cnt == 1) {
+		synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
+		fprintf(fp, "# bpf_prog_info %u: %s\n", info->id, name);
+		return;
+	}
+
+	fprintf(fp, "# bpf_prog_info %u:\n", info->id);
+	for (i = 0; i < sub_prog_cnt; i++) {
+		synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
+
+		fprintf(fp, "# \tsub_prog %u: %s\n", i, name);
+	}
+}
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 249909c826e7..4270dfd9cde9 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -38,7 +38,9 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
 				      struct record_opts *opts);
 int bpf_event__add_sb_event(struct perf_evlist **evlist,
 				 struct perf_env *env);
-
+void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
+				    struct perf_env *env,
+				    FILE *fp);
 #else
 static inline int machine__process_bpf_event(struct machine *machine __maybe_unused,
 					     union perf_event *event __maybe_unused,
@@ -61,5 +63,11 @@ static int bpf_event__add_sb_event(struct perf_evlist **evlist __maybe_unused,
 	return 0;
 }
 
+void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
+				    struct perf_env *env,
+				    FILE *fp)
+{
+
+}
 #endif // HAVE_LIBBPF_SUPPORT
 #endif
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7decd2d1dbda..588a80bdd500 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1434,8 +1434,9 @@ static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
 
 		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
 		next = rb_next(&node->rb_node);
-		fprintf(fp, "# bpf_prog_info of id %u\n",
-			node->info_linear->info.id);
+
+		bpf_event__print_bpf_prog_info(&node->info_linear->info,
+					       env, fp);
 	}
 
 	up_read(&env->bpf_progs.lock);
-- 
2.17.1