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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 F1E66C33CB3 for ; Wed, 15 Jan 2020 13:12:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B51B82084D for ; Wed, 15 Jan 2020 13:12:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TEQEIlL9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726559AbgAONM6 (ORCPT ); Wed, 15 Jan 2020 08:12:58 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:35689 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726088AbgAONM5 (ORCPT ); Wed, 15 Jan 2020 08:12:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579093975; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vkwac9ipxdwjGCmCWEvnGmzcnFiuL5QS83aF2p0l61Q=; b=TEQEIlL9CgBuOp71ae4LX8a0q5C/C2BRwBqbuaT5PwdIZx0UOhKo5HlhiCRkkOK20Y0eVg NJs8elP2fv9Aona6/MQBjhBme4Zlqam7FteCYzkzUMEiRHxKz8rt33TPYHiCiXm42rkeGB BUxHz4nvHV+klYwilVQEx1v2olz96Q8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-10-Zo8P_6BKNDOiDqkk_gRyXg-1; Wed, 15 Jan 2020 08:12:51 -0500 X-MC-Unique: Zo8P_6BKNDOiDqkk_gRyXg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2B3D5800D41; Wed, 15 Jan 2020 13:12:50 +0000 (UTC) Received: from [10.36.117.241] (ovpn-117-241.ams2.redhat.com [10.36.117.241]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C676484326; Wed, 15 Jan 2020 13:12:48 +0000 (UTC) From: "Eelco Chaudron" To: "Andrii Nakryiko" , maciej.fijalkowski@intel.com Cc: bpf , "David S. Miller" , "Alexei Starovoitov" , Networking Subject: Re: [PATCH bpf-next v2] selftests/bpf: Add a test for attaching a bpf fentry/fexit trace to an XDP program Date: Wed, 15 Jan 2020 14:12:46 +0100 Message-ID: <18AB9E9B-FB00-4BC6-BB6F-B7001340C064@redhat.com> In-Reply-To: References: <157901745600.30872.10096561620432101095.stgit@xdp-tutorial> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Andrii and Maciej thanks for your reviews, I=E2=80=99ve addressed all you= r=20 comments, and will send out a v3 soon=E2=80=A6 //Eelco On 14 Jan 2020, at 19:49, Andrii Nakryiko wrote: > On Tue, Jan 14, 2020 at 7:58 AM Eelco Chaudron =20 > wrote: >> >> Add a test that will attach a FENTRY and FEXIT program to the XDP=20 >> test >> program. It will also verify data from the XDP context on FENTRY and >> verifies the return code on exit. >> >> Signed-off-by: Eelco Chaudron >> >> --- >> v1 -> v2: >> - Changed code to use the BPF skeleton >> - Replace static volatile with global variable in eBPF code >> >> .../testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c | 69=20 >> ++++++++++++++++++++ >> .../testing/selftests/bpf/progs/test_xdp_bpf2bpf.c | 44=20 >> +++++++++++++ >> 2 files changed, 113 insertions(+) >> create mode 100644=20 >> tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c >> create mode 100644=20 >> tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c >> >> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c=20 >> b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c >> new file mode 100644 >> index 000000000000..e6e849df2632 >> --- /dev/null >> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c >> @@ -0,0 +1,69 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +#include >> +#include >> +#include "test_xdp.skel.h" >> +#include "test_xdp_bpf2bpf.skel.h" >> + >> +void test_xdp_bpf2bpf(void) >> +{ >> + > > extra line > >> + struct test_xdp *pkt_skel =3D NULL; >> + struct test_xdp_bpf2bpf *ftrace_skel =3D NULL; > > something with indentation? > >> + __u64 *ftrace_res; >> + > > variable declarations shouldn't be split, probably? > >> + struct vip key4 =3D {.protocol =3D 6, .family =3D AF_INET}; >> + struct iptnl_info value4 =3D {.family =3D AF_INET}; >> + char buf[128]; >> + struct iphdr *iph =3D (void *)buf + sizeof(struct ethhdr); >> + __u32 duration =3D 0, retval, size; >> + int err, pkt_fd, map_fd; >> + >> + /* Load XDP program to introspect */ >> + pkt_skel =3D test_xdp__open_and_load(); >> + if (CHECK(!pkt_skel, "pkt_skel_load", "test_xdp skeleton=20 >> failed\n")) >> + return; >> + >> + pkt_fd =3D bpf_program__fd(pkt_skel->progs._xdp_tx_iptunnel); >> + >> + map_fd =3D bpf_map__fd(pkt_skel->maps.vip2tnl); >> + bpf_map_update_elem(map_fd, &key4, &value4, 0); >> + >> + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, >> + .attach_prog_fd =3D pkt_fd, >> + ); > > DECLARE_LIBBPF_OPTS is a variable declaration, so should go together > with all other declarations. Compiler should complain about this, but > I guess selftests/bpf Makefile doesn't have necessary flags, that > other kernel code has. You can declare opts first and then initialize > some extra fields later: > > DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); > > ... later in code ... > > opts.attach_prog_fd =3D pkt_fd; > > >> + >> + ftrace_skel =3D test_xdp_bpf2bpf__open_opts(&opts); >> + if (CHECK(!ftrace_skel, "__open", "ftrace skeleton=20 >> failed\n")) >> + goto out; >> + >> + if (CHECK(test_xdp_bpf2bpf__load(ftrace_skel), "__load",=20 >> "ftrace skeleton failed\n")) >> + goto out; > > for consistency with attach check below and for readability, move out > load call into separate statement, it's easy to miss when it is inside > CHECK() > >> + >> + err =3D test_xdp_bpf2bpf__attach(ftrace_skel); >> + if (CHECK(err, "ftrace_attach", "ftrace attach failed: %d\n",=20 >> err)) >> + goto out; >> + >> + /* Run test program */ >> + err =3D bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4), >> + buf, &size, &retval, &duration); >> + >> + CHECK(err || retval !=3D XDP_TX || size !=3D 74 || >> + iph->protocol !=3D IPPROTO_IPIP, "ipv4", >> + "err %d errno %d retval %d size %d\n", >> + err, errno, retval, size); > > should it goto out here as well? > >> + >> + /* Verify test results */ >> + ftrace_res =3D (__u64 *)ftrace_skel->bss; >> + >> + if (CHECK(ftrace_res[0] !=3D if_nametoindex("lo"), "result", >> + "fentry failed err %llu\n", ftrace_res[0])) >> + goto out; >> + >> + if (CHECK(ftrace_res[1] !=3D XDP_TX, "result", >> + "fexit failed err %llu\n", ftrace_res[1])) >> + goto out; > > why this casting? You can do access those variables much more > naturally with ftrace_skel->bss->test_result_fentry and > ftrace_skel->bss->test_result_fexit without making dangerous > assumptions about their offsets within data section. > > >> + >> +out: >> + test_xdp__destroy(pkt_skel); >> + test_xdp_bpf2bpf__destroy(ftrace_skel); >> +} >> diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c=20 >> b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c >> new file mode 100644 >> index 000000000000..74c78b30ae07 >> --- /dev/null >> +++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c >> @@ -0,0 +1,44 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +#include >> +#include "bpf_helpers.h" >> +#include "bpf_trace_helpers.h" >> + >> +struct net_device { >> + /* Structure does not need to contain all entries, >> + * as "preserve_access_index" will use BTF to fix this... >> + */ >> + int ifindex; >> +} __attribute__((preserve_access_index)); >> + >> +struct xdp_rxq_info { >> + /* Structure does not need to contain all entries, >> + * as "preserve_access_index" will use BTF to fix this... >> + */ >> + struct net_device *dev; >> + __u32 queue_index; >> +} __attribute__((preserve_access_index)); >> + >> +struct xdp_buff { >> + void *data; >> + void *data_end; >> + void *data_meta; >> + void *data_hard_start; >> + unsigned long handle; >> + struct xdp_rxq_info *rxq; >> +} __attribute__((preserve_access_index)); >> + >> +__u64 test_result_fentry =3D 0; >> +BPF_TRACE_1("fentry/_xdp_tx_iptunnel", trace_on_entry, >> + struct xdp_buff *, xdp) > > BPF_TRACE_x is no more, see BPF_PROG and how it's used for=20 > fentry/fexit tests: > > SEC("fentry/_xdp_tx_iptunnel") > int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) > >> +{ >> + test_result_fentry =3D xdp->rxq->dev->ifindex; >> + return 0; >> +} >> + >> +__u64 test_result_fexit =3D 0; >> +BPF_TRACE_2("fexit/_xdp_tx_iptunnel", trace_on_exit, >> + struct xdp_buff*, xdp, int, ret) >> +{ >> + test_result_fexit =3D ret; >> + return 0; >> +} >>