From patchwork Mon Feb 10 12:31:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 231878 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9545BC352A5 for ; Mon, 10 Feb 2020 13:02:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DF8F20708 for ; Mon, 10 Feb 2020 13:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581339754; bh=860PfVHuVvVmnE/uxN+52Ty0cY9gG8ZaYg2GcEvQW/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H0Nqrxm/h2JceT2V8CUZL5U6slZKxu8KeXMIjXS4cYHIce5hOs1eEAM8N6rDjMw14 SGdRI1JJ7Kuuoyq+lJ3fZZvn1gT8tz+At2BGfFEfdjGDCCz6ndDI4GoyAt7T73ipwt y2fOglBVKiZSMHWaOpHx00bpTYFX9k5C7U3ieEfc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729905AbgBJNC0 (ORCPT ); Mon, 10 Feb 2020 08:02:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:40920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729763AbgBJMkf (ORCPT ); Mon, 10 Feb 2020 07:40:35 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 449D524676; Mon, 10 Feb 2020 12:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338435; bh=860PfVHuVvVmnE/uxN+52Ty0cY9gG8ZaYg2GcEvQW/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cC4TUljoqo618JXMLocmreau6U9asmSSMNIUiYETsUPVWzyF9fOl0npzTQPskPGm5 Zp/bBOrX5/dZPH8xzjNxkwgp+LNmbxVxRWWqd6oi/+7pENHXf0ScJAFxNOdEiRAS6x GCk8fQ5SalFF20FS+/V9NUxNtmL2a52pgIfzKU2U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jesper Dangaard Brouer , Alexei Starovoitov , Andrii Nakryiko Subject: [PATCH 5.5 168/367] samples/bpf: Xdp_redirect_cpu fix missing tracepoint attach Date: Mon, 10 Feb 2020 04:31:21 -0800 Message-Id: <20200210122440.403356701@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jesper Dangaard Brouer commit f9e6bfdbaf0cf304d72c70a05d81acac01a04f48 upstream. When sample xdp_redirect_cpu was converted to use libbpf, the tracepoints used by this sample were not getting attached automatically like with bpf_load.c. The BPF-maps was still getting loaded, thus nobody notice that the tracepoints were not updating these maps. This fix doesn't use the new skeleton code, as this bug was introduced in v5.1 and stable might want to backport this. E.g. Red Hat QA uses this sample as part of their testing. Fixes: bbaf6029c49c ("samples/bpf: Convert XDP samples to libbpf usage") Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/157685877642.26195.2798780195186786841.stgit@firesoul Signed-off-by: Greg Kroah-Hartman --- samples/bpf/xdp_redirect_cpu_user.c | 59 +++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 4 deletions(-) --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -16,6 +16,10 @@ static const char *__doc__ = #include #include #include +#include + +#define __must_check +#include #include #include @@ -46,6 +50,10 @@ static int cpus_count_map_fd; static int cpus_iterator_map_fd; static int exception_cnt_map_fd; +#define NUM_TP 5 +struct bpf_link *tp_links[NUM_TP] = { 0 }; +static int tp_cnt = 0; + /* Exit return codes */ #define EXIT_OK 0 #define EXIT_FAIL 1 @@ -88,6 +96,10 @@ static void int_exit(int sig) printf("program on interface changed, not removing\n"); } } + /* Detach tracepoints */ + while (tp_cnt) + bpf_link__destroy(tp_links[--tp_cnt]); + exit(EXIT_OK); } @@ -588,23 +600,61 @@ static void stats_poll(int interval, boo free_stats_record(prev); } +static struct bpf_link * attach_tp(struct bpf_object *obj, + const char *tp_category, + const char* tp_name) +{ + struct bpf_program *prog; + struct bpf_link *link; + char sec_name[PATH_MAX]; + int len; + + len = snprintf(sec_name, PATH_MAX, "tracepoint/%s/%s", + tp_category, tp_name); + if (len < 0) + exit(EXIT_FAIL); + + prog = bpf_object__find_program_by_title(obj, sec_name); + if (!prog) { + fprintf(stderr, "ERR: finding progsec: %s\n", sec_name); + exit(EXIT_FAIL_BPF); + } + + link = bpf_program__attach_tracepoint(prog, tp_category, tp_name); + if (IS_ERR(link)) + exit(EXIT_FAIL_BPF); + + return link; +} + +static void init_tracepoints(struct bpf_object *obj) { + tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_redirect_err"); + tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_redirect_map_err"); + tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_exception"); + tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_cpumap_enqueue"); + tp_links[tp_cnt++] = attach_tp(obj, "xdp", "xdp_cpumap_kthread"); +} + static int init_map_fds(struct bpf_object *obj) { - cpu_map_fd = bpf_object__find_map_fd_by_name(obj, "cpu_map"); - rx_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rx_cnt"); + /* Maps updated by tracepoints */ redirect_err_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "redirect_err_cnt"); + exception_cnt_map_fd = + bpf_object__find_map_fd_by_name(obj, "exception_cnt"); cpumap_enqueue_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "cpumap_enqueue_cnt"); cpumap_kthread_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "cpumap_kthread_cnt"); + + /* Maps used by XDP */ + rx_cnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rx_cnt"); + cpu_map_fd = bpf_object__find_map_fd_by_name(obj, "cpu_map"); cpus_available_map_fd = bpf_object__find_map_fd_by_name(obj, "cpus_available"); cpus_count_map_fd = bpf_object__find_map_fd_by_name(obj, "cpus_count"); cpus_iterator_map_fd = bpf_object__find_map_fd_by_name(obj, "cpus_iterator"); - exception_cnt_map_fd = - bpf_object__find_map_fd_by_name(obj, "exception_cnt"); if (cpu_map_fd < 0 || rx_cnt_map_fd < 0 || redirect_err_cnt_map_fd < 0 || cpumap_enqueue_cnt_map_fd < 0 || @@ -662,6 +712,7 @@ int main(int argc, char **argv) strerror(errno)); return EXIT_FAIL; } + init_tracepoints(obj); if (init_map_fds(obj) < 0) { fprintf(stderr, "bpf_object__find_map_fd_by_name failed\n"); return EXIT_FAIL;