From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 427D2C48BCD for ; Wed, 9 Jun 2021 16:33:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2222F61376 for ; Wed, 9 Jun 2021 16:33:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235211AbhFIQfi (ORCPT ); Wed, 9 Jun 2021 12:35:38 -0400 Received: from mga05.intel.com ([192.55.52.43]:21173 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234055AbhFIQfh (ORCPT ); Wed, 9 Jun 2021 12:35:37 -0400 IronPort-SDR: KodCqx9GWWi+nVnJkDfqrVdpqOcJ6cR/lZ3vFOBseRh6Oqy/Dha5/z0QqlcHWeAcSC1VUsIql7 2kunFW6zX/yA== X-IronPort-AV: E=McAfee;i="6200,9189,10010"; a="290739938" X-IronPort-AV: E=Sophos;i="5.83,261,1616482800"; d="scan'208";a="290739938" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2021 09:33:40 -0700 IronPort-SDR: hPuEAVrs68tdOfGu7fByPS1wrajql9AVvmjTaGdCNlf69gS5i3JsLAkIaqZE5D2bSeFxhHeOPn cxxKyAPpNCgg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,261,1616482800"; d="scan'208";a="448343988" Received: from ranger.igk.intel.com ([10.102.21.164]) by orsmga008.jf.intel.com with ESMTP; 09 Jun 2021 09:33:37 -0700 Date: Wed, 9 Jun 2021 18:21:08 +0200 From: Maciej Fijalkowski To: John Fastabend Cc: ast@kernel.org, daniel@iogearbox.net, andriin@fb.com, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH bpf 2/2] bpf: selftest to verify mixing bpf2bpf calls and tailcalls with insn patch Message-ID: <20210609162108.GA12650@ranger.igk.intel.com> References: <162318053542.323820.3719766457956848570.stgit@john-XPS-13-9370> <162318063321.323820.18256758193426055338.stgit@john-XPS-13-9370> <20210609155704.GB12061@ranger.igk.intel.com> <60c0eb99aa8c2_98621208ad@john-XPS-13-9370.notmuch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <60c0eb99aa8c2_98621208ad@john-XPS-13-9370.notmuch> User-Agent: Mutt/1.12.1 (2019-06-15) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, Jun 09, 2021 at 09:26:01AM -0700, John Fastabend wrote: > Maciej Fijalkowski wrote: > > On Tue, Jun 08, 2021 at 12:30:33PM -0700, John Fastabend wrote: > > > This adds some extra noise to the tailcall_bpf2bpf4 tests that will cause > > > verifier to patch insns. This then moves around subprog start/end insn > > > index and poke descriptor insn index to ensure that verify and JIT will > > > continue to track these correctly. > > > > This test is the most complicated one where I tried to document the scope > > of it on the side of prog_tests/tailcalls.c. I feel that it would make it > > more difficult to debug it if under any circumstances something would have > > been broken with that logic. > > > > Maybe a separate test scenario? Or is this an overkill? If so, I would > > vote for moving it to tailcall_bpf2bpf1.c and have a little comment that > > testing other bpf helpers mixed in is in scope of that test. > > I like pushing it into the complex test to get the most instruction > patching combinations possible. Makes sense after a second thought, that was the intention of that test case, to squeeze out the feature out here. I still would ask to have it commented on the prog_tests/tailcalls.c side, WDYT? > > > > > > > > > Reviewed-by: Daniel Borkmann > > > Signed-off-by: John Fastabend > > > --- > > > .../selftests/bpf/progs/tailcall_bpf2bpf4.c | 17 +++++++++++++++++ > > > 1 file changed, 17 insertions(+) > > > > > > diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c > > > index 9a1b166b7fbe..0d70de5f97e2 100644 > > > --- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c > > > +++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c > > > @@ -2,6 +2,13 @@ > > > #include > > > #include > > > > > > +struct { > > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > > + __uint(max_entries, 1); > > > + __uint(key_size, sizeof(__u32)); > > > + __uint(value_size, sizeof(__u32)); > > > +} nop_table SEC(".maps"); > > > + > > > struct { > > > __uint(type, BPF_MAP_TYPE_PROG_ARRAY); > > > __uint(max_entries, 3); > > > @@ -11,9 +18,19 @@ struct { > > > > > > static volatile int count; > > > > > > +__noinline > > > +int subprog_noise(struct __sk_buff *skb) > > > +{ > > > + __u32 key = 0; > > > + > > > + bpf_map_lookup_elem(&nop_table, &key); > > > + return 0; > > > +} > > > + > > > __noinline > > > int subprog_tail_2(struct __sk_buff *skb) > > > { > > > + subprog_noise(skb); > > > bpf_tail_call_static(skb, &jmp_table, 2); > > > return skb->len * 3; > > > } > > > > > > > >