tools: bpftool: preserve JSON for batch mode when dumping insns to file

Print a "null" JSON object to standard output when bpftool is used to
print program instructions to a file, so as to avoid breaking JSON
output on batch mode.

This null object was added for most commands in a previous commit, but
this specific case had been omitted.

Fixes: 004b45c0e51a ("tools: bpftool: provide JSON output for all possible commands")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index e8e2baaf93c2665c4a7cf998a85e35eda76b009d..e549e329be8216646dbab3c11a6485d85d02f1c6 100644 (file)
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -774,6 +774,9 @@ static int do_dump(int argc, char **argv)
                              n < 0 ? strerror(errno) : "short write");
                        goto err_free;
                }
+
+               if (json_output)
+                       jsonw_null(json_wtr);
        } else {
                if (member_len == &info.jited_prog_len) {
                        const char *name = NULL;