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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C68CC19F2A for ; Wed, 3 Aug 2022 06:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237249AbiHCG3l (ORCPT ); Wed, 3 Aug 2022 02:29:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237191AbiHCG3f (ORCPT ); Wed, 3 Aug 2022 02:29:35 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9579957247; Tue, 2 Aug 2022 23:29:32 -0700 (PDT) From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1659508171; 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: in-reply-to:in-reply-to:references:references; bh=m1qsL55BteuTwDu3+h+SjLPzdZh13JHKIId3RPSdQyM=; b=nKAFnlD7yYR37GqZvxGdY5UrDZHVaUAEKnsresvrhaffvWTJ57auG6QfWFKfzbOc0/bgUQ r/J7Cu1MCcCiUyg182UIyYixLklp7bgka1WOqnaSqt7yeg7sJptVjWd6r1QeWl9cS7XWh+ AIqTfLg83+XhrOj3szZKIh5MVi2Z7crXBDMqyUts3O2yntblQ6yuAzQMKflDEXoRXJynJp BSq7rhpfIGe3oICsMu2nieEJ28MtcrQKS0hQrcSBz118t5l2YILoHenOEbh2avgDP5bzH/ o6B5BsqVIhNN+ZKcpdVTpJv59RWARWmXOsrGkUWF9uOFxGK9gj8Ck37vo/sLhw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1659508171; 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: in-reply-to:in-reply-to:references:references; bh=m1qsL55BteuTwDu3+h+SjLPzdZh13JHKIId3RPSdQyM=; b=fHfVZk7nC1DotnSE/H4xTQkCQNZC669A+3fIPopIrXOXDA2Wk0xVrrDPvkvnRidLMgG172 TdwTEpaTj+Q+7zDQ== To: Alexei Starovoitov Cc: Jesper Dangaard Brouer , Thomas Gleixner , Jesper Dangaard Brouer , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Joanne Koong , Jiri Olsa , Dave Marchevsky , Lorenzo Bianconi , Geliang Tang , Jakub Sitnicki , Network Development , bpf Subject: Re: [PATCH bpf-next] bpf: Add BPF-helper for accessing CLOCK_TAI In-Reply-To: References: <20220606103734.92423-1-kurt@linutronix.de> <875ylc6djv.ffs@tglx> <87pmhj15vf.fsf@kurt> Date: Wed, 03 Aug 2022 08:29:29 +0200 Message-ID: <87edxxg7qu.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --=-=-= Content-Type: text/plain On Tue Aug 02 2022, Alexei Starovoitov wrote: > On Tue, Aug 2, 2022 at 12:06 AM Kurt Kanzenbach wrote: >> >> Hi Alexei, >> >> On Tue Jun 07 2022, Alexei Starovoitov wrote: >> > Anyway I guess new helper bpf_ktime_get_tai_ns() is ok, since >> > it's so trivial, but selftest is necessary. >> >> So, I did write a selftest [1] for testing bpf_ktime_get_tai_ns() and >> verifying that the access to the clock works. It uses AF_XDP sockets and >> timestamps the incoming packets. The timestamps are then validated in >> user space. >> >> Since AF_XDP related code is migrating from libbpf to libxdp, I'm >> wondering if that sample fits into the kernel's selftests or not. What >> kind of selftest are you looking for? > > Please use selftests/bpf framework. > There are plenty of networking tests in there. > bpf_ktime_get_tai_ns() doesn't have to rely on af_xdp. OK. > It can be skb based. Something like this? +++ b/tools/testing/selftests/bpf/prog_tests/check_tai.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022 Linutronix GmbH */ + +#include +#include + +#include +#include + +#define TAI_THRESHOLD 1000000000ULL /* 1s */ +#define NSEC_PER_SEC 1000000000ULL + +static __u64 ts_to_ns(const struct timespec *ts) +{ + return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec; +} + +void test_tai(void) +{ + struct __sk_buff skb = { + .tstamp = 0, + .hwtstamp = 0, + }; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .ctx_in = &skb, + .ctx_size_in = sizeof(skb), + .ctx_out = &skb, + .ctx_size_out = sizeof(skb), + ); + struct timespec now_tai; + struct bpf_object *obj; + int ret, prog_fd; + + ret = bpf_prog_test_load("./test_tai.o", + BPF_PROG_TYPE_SCHED_CLS, &obj, &prog_fd); + if (!ASSERT_OK(ret, "load")) + return; + ret = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(ret, "test_run"); + + /* TAI != 0 */ + ASSERT_NEQ(skb.tstamp, 0, "tai_ts0_0"); + ASSERT_NEQ(skb.hwtstamp, 0, "tai_ts0_1"); + + /* TAI is moving forward only */ + ASSERT_GT(skb.hwtstamp, skb.tstamp, "tai_forward"); + + /* Check for reasoneable range */ + ret = clock_gettime(CLOCK_TAI, &now_tai); + ASSERT_EQ(ret, 0, "tai_gettime"); + ASSERT_TRUE((ts_to_ns(&now_tai) - skb.hwtstamp) < TAI_THRESHOLD, + "tai_range"); + + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/test_tai.c b/tools/testing/selftests/bpf/progs/test_tai.c new file mode 100644 index 000000000000..34ac4175e29d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tai.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022 Linutronix GmbH */ + +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("tc") +int save_tai(struct __sk_buff *skb) +{ + /* Save TAI timestamps */ + skb->tstamp = bpf_ktime_get_tai_ns(); + skb->hwtstamp = bpf_ktime_get_tai_ns(); + + return 0; +} --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJHBAEBCgAxFiEEvLm/ssjDfdPf21mSwZPR8qpGc4IFAmLqFckTHGt1cnRAbGlu dXRyb25peC5kZQAKCRDBk9HyqkZzgoZGEACo7ODXo1jnKwFPs8liSbG418EZwe/F oKWWzarRsYvdFtJZBQu/B19YqalwVDWcvhxjiSvs5jrfnuVMAUXzZe2I0okxYhzk glU/TvAMQJZuTtSswRreUI2vT4eTs0/DoCTQVTLBfTIHzube/AloFkOCP4wH6DwT q4oVlnZgejwgn/g4uYfKlHz8Dp+VfH7D2Q/lzxdCclyzMjvGcIRgaK6sgwe7JU9h 91E0o/D00AZt14M+qIvzYQftRYD2Qq7HYJNyZXxcYgylE7/yYb9qMyWbsl7OTlOw aE7ebxqT/5iMZh22qsRKEiOETBagC7mjFifNhcMm+K7loGS9EvqPjlc/LiBhvHlR 2JdCTEFMAecCwQOfxsFsAKMzJ5+C96nx/8joIrEwzEE4QSAdwA4lz+ZqI5Q86zuI lU9wts83ikr29InOKZc4jDR6FSc0GN63imiN728dtqjStgprU6Z4OElLCMoSJNAH 2EKleqMXSIbLknzVtEzSMDW1axiBu/Cxy7JxIv8ikasEtA0qUrTIOu84ZG3b3ZBy alhiXqkiMyJ8BeC7sYRG2YM+Wry9N/XW7c18sR2l0ac0m+J1d4dGzc26y8HstEEk ffmbsaBsQbvILdL8jJ+nTIyS5BJjdJ+1/isL1vEtJQTssDqo0Bf1J5ZfhgLHVs/Q Josc5wPsqsJAxQ== =7TkQ -----END PGP SIGNATURE----- --=-=-=--