perf header: Don't write empty BPF/BTF info

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>
Link: https://lore.kernel.org/r/20250617223356.2752099-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a9538bb1004db1a68678e236629fca0af02722cc..487f663ed2de058aa20eb8b2c47544c1f53b9c45 100644 (file)
--- 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));