From patchwork Mon Aug 29 02:37:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12957404 X-Patchwork-Delegate: bpf@iogearbox.net 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 CE907C3DA6B for ; Mon, 29 Aug 2022 02:19:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229504AbiH2CTK (ORCPT ); Sun, 28 Aug 2022 22:19:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229487AbiH2CTJ (ORCPT ); Sun, 28 Aug 2022 22:19:09 -0400 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF9FA3C17A for ; Sun, 28 Aug 2022 19:19:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4MGDbr5zVVz6S3Gg for ; Mon, 29 Aug 2022 10:17:28 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgAnenMTIgxjzJZKAA--.51878S7; Mon, 29 Aug 2022 10:19:06 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org Cc: Song Liu , Sebastian Andrzej Siewior , Thomas Gleixner , Hao Sun , Hao Luo , Andrii Nakryiko , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , KP Singh , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Jiri Olsa , John Fastabend , Lorenz Bauer , houtao1@huawei.com Subject: [PATCH bpf-next v3 3/3] selftests/bpf: add test cases for htab update Date: Mon, 29 Aug 2022 10:37:09 +0800 Message-Id: <20220829023709.1958204-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220829023709.1958204-1-houtao@huaweicloud.com> References: <20220829023709.1958204-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgAnenMTIgxjzJZKAA--.51878S7 X-Coremail-Antispam: 1UD129KBjvJXoWxAry8Gr1DJr18tF1UCFyrXrb_yoWrKFykpa 48Ca4xtr4ftw1DXw1rta17KFWYkF4rXr4YyrZ5WF15ArWjvrnaqr1xKFyrtF4fJrZ5Zr1r Z3sxtF4UWayxZF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBFb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x07UAkuxUUUUU= X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao One test demonstrates the reentrancy of hash map update on the same bucket should fail, and another one shows concureently updates of the same hash map bucket should succeed and not fail due to the reentrancy checking for bucket lock. Signed-off-by: Hou Tao --- .../selftests/bpf/prog_tests/htab_update.c | 126 ++++++++++++++++++ .../testing/selftests/bpf/progs/htab_update.c | 29 ++++ 2 files changed, 155 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/htab_update.c create mode 100644 tools/testing/selftests/bpf/progs/htab_update.c diff --git a/tools/testing/selftests/bpf/prog_tests/htab_update.c b/tools/testing/selftests/bpf/prog_tests/htab_update.c new file mode 100644 index 000000000000..2bc85f4814f4 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/htab_update.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022. Huawei Technologies Co., Ltd */ +#define _GNU_SOURCE +#include +#include +#include +#include "htab_update.skel.h" + +struct htab_update_ctx { + int fd; + int loop; + bool stop; +}; + +static void test_reenter_update(void) +{ + struct htab_update *skel; + unsigned int key, value; + int err; + + skel = htab_update__open(); + if (!ASSERT_OK_PTR(skel, "htab_update__open")) + return; + + /* lookup_elem_raw() may be inlined and find_kernel_btf_id() will return -ESRCH */ + bpf_program__set_autoload(skel->progs.lookup_elem_raw, true); + err = htab_update__load(skel); + if (!ASSERT_TRUE(!err || err == -ESRCH, "htab_update__load") || err) + goto out; + + skel->bss->pid = getpid(); + err = htab_update__attach(skel); + if (!ASSERT_OK(err, "htab_update__attach")) + goto out; + + /* Will trigger the reentrancy of bpf_map_update_elem() */ + key = 0; + value = 0; + err = bpf_map_update_elem(bpf_map__fd(skel->maps.htab), &key, &value, 0); + if (!ASSERT_OK(err, "add element")) + goto out; + + ASSERT_EQ(skel->bss->update_err, -EBUSY, "no reentrancy"); +out: + htab_update__destroy(skel); +} + +static void *htab_update_thread(void *arg) +{ + struct htab_update_ctx *ctx = arg; + cpu_set_t cpus; + int i; + + /* Pinned on CPU 0 */ + CPU_ZERO(&cpus); + CPU_SET(0, &cpus); + pthread_setaffinity_np(pthread_self(), sizeof(cpus), &cpus); + + i = 0; + while (i++ < ctx->loop && !ctx->stop) { + unsigned int key = 0, value = 0; + int err; + + err = bpf_map_update_elem(ctx->fd, &key, &value, 0); + if (err) { + ctx->stop = true; + return (void *)(long)err; + } + } + + return NULL; +} + +static void test_concurrent_update(void) +{ + struct htab_update_ctx ctx; + struct htab_update *skel; + unsigned int i, nr; + pthread_t *tids; + int err; + + skel = htab_update__open_and_load(); + if (!ASSERT_OK_PTR(skel, "htab_update__open_and_load")) + return; + + ctx.fd = bpf_map__fd(skel->maps.htab); + ctx.loop = 1000; + ctx.stop = false; + + nr = 4; + tids = calloc(nr, sizeof(*tids)); + if (!ASSERT_NEQ(tids, NULL, "no mem")) + goto out; + + for (i = 0; i < nr; i++) { + err = pthread_create(&tids[i], NULL, htab_update_thread, &ctx); + if (!ASSERT_OK(err, "pthread_create")) { + unsigned int j; + + ctx.stop = true; + for (j = 0; j < i; j++) + pthread_join(tids[j], NULL); + goto out; + } + } + + for (i = 0; i < nr; i++) { + void *thread_err = NULL; + + pthread_join(tids[i], &thread_err); + ASSERT_EQ(thread_err, NULL, "update error"); + } + +out: + if (tids) + free(tids); + htab_update__destroy(skel); +} + +void test_htab_update(void) +{ + if (test__start_subtest("reenter_update")) + test_reenter_update(); + if (test__start_subtest("concurrent_update")) + test_concurrent_update(); +} diff --git a/tools/testing/selftests/bpf/progs/htab_update.c b/tools/testing/selftests/bpf/progs/htab_update.c new file mode 100644 index 000000000000..7481bb30b29b --- /dev/null +++ b/tools/testing/selftests/bpf/progs/htab_update.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022. Huawei Technologies Co., Ltd */ +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); +} htab SEC(".maps"); + +int pid = 0; +int update_err = 0; + +SEC("?fentry/lookup_elem_raw") +int lookup_elem_raw(void *ctx) +{ + __u32 key = 0, value = 1; + + if ((bpf_get_current_pid_tgid() >> 32) != pid) + return 0; + + update_err = bpf_map_update_elem(&htab, &key, &value, 0); + return 0; +}