[PATCH v1 4/4] perf header: Don't write empty BPF/BTF info

[Ian Rogers <irogers@google.com>]

If there are no values in bpf_prog_info or bpf_btf feature don't write
the data into the header.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/header.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 69e4f6aae293..6657b02d4a81 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1016,10 +1016,13 @@ static int write_bpf_prog_info(struct feat_fd *ff,
 	struct perf_env *env = &ff->ph->env;
 	struct rb_root *root;
 	struct rb_node *next;
-	int ret;
+	int ret = 0;
 
 	down_read(&env->bpf_progs.lock);
 
+	if (env->bpf_progs.infos_cnt == 0)
+		goto out;
+
 	ret = do_write(ff, &env->bpf_progs.infos_cnt,
 		       sizeof(env->bpf_progs.infos_cnt));
 	if (ret < 0)
@@ -1058,10 +1061,13 @@ static int write_bpf_btf(struct feat_fd *ff,
 	struct perf_env *env = &ff->ph->env;
 	struct rb_root *root;
 	struct rb_node *next;
-	int ret;
+	int ret = 0;
 
 	down_read(&env->bpf_progs.lock);
 
+	if (env->bpf_progs.btfs_cnt == 0)
+		goto out;
+
 	ret = do_write(ff, &env->bpf_progs.btfs_cnt,
 		       sizeof(env->bpf_progs.btfs_cnt));
 
-- 
2.50.0.rc0.604.gd4ff7b7c86-goog