Re: [PATCH net] bpf: don't zero out the info struct in bpf_obj_get_info_by_fd()

On 07/26/2017 01:15 AM, Jakub Kicinski wrote:

On Wed, 26 Jul 2017 00:59:49 +0200, Daniel Borkmann wrote:

quoted

quoted

@@ -418,6 +420,8 @@ static void test_bpf_obj_id(void)
   		nr_id_found++;

   		err = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &info_len);
+		prog_infos[i].jited_prog_insns = 0;
+		prog_infos[i].xlated_prog_insns = 0;

Can you elaborate why this one above is needed?

Ah, I removed the comment about it at the last minute.  The check below
compares the info we get here with info we got reading the programs in
the earlier loop - using memcmp().

Yep, makes sense. I mistook it for 'length' given it is not NULL but 0,
but that is due to __aligned_u64. ;) Anyway, thanks for clarifying.

Acked-by: Daniel Borkmann <daniel@iogearbox.net>