From patchwork Sun Aug 27 07:20:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuyi Zhou X-Patchwork-Id: 13366854 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63BAE20EC for ; Sun, 27 Aug 2023 07:21:19 +0000 (UTC) Received: from mail-pf1-x433.google.com (mail-pf1-x433.google.com [IPv6:2607:f8b0:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA0B212A for ; Sun, 27 Aug 2023 00:21:17 -0700 (PDT) Received: by mail-pf1-x433.google.com with SMTP id d2e1a72fcca58-68c0d262933so1108534b3a.0 for ; Sun, 27 Aug 2023 00:21:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1693120877; x=1693725677; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VuhzP1mvDliga8ZbFq7tNuDQGJoX13wAFAeRiusEr7I=; b=SOl9rzX3hguTSxfuEkxfuXzVtNZ5qfD4ojQw7O7tIc1ndHCwJzXzN1T2XQ+ytML/0b MEZIW+DY7E8Y7hyI21eH9SNzkdIssGL6M12YDMq2Sh38jPO5YBh40rU9DzZbH0ZxJeEm zPJAbJ7xblpXB3fgSUZ61l49B6+dr43mnNzZRa0C+YaCTYzEr11HnaS8qitqPWj/rRgX WqE2+CB/EbpZyZl9A/DIIpd7WkclPFyYjRWuTTSWXX+YEmSsiHT2P1vmpXj0PmgYqtbJ dxkIELZunwXiauQyfEuraD/tE5y3JExEZ556CWusZ+bKpVsOppUSI55WEN7mJLkyE9yf 2kaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693120877; x=1693725677; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VuhzP1mvDliga8ZbFq7tNuDQGJoX13wAFAeRiusEr7I=; b=LZ1A97apyivveU+TV4k+jWgPP109Ko9KXpv61IR0isVJibyf96SdKVYnDD0udFEi9X v7b8D6d8ZYPAsehelAlhZQgoDAje3FPMo0wMOSVQUk+gECRP6oZyIGVJ0ZUq9bFZdx+6 v9+AdPwYEiG6Z3i+uuuQzVTGEDggFPt18K/U/j2LXPCU3IqrpgKXNHlHQOZTUx9xyGEA aQXgKvWhFsR/0B4aACi2BvYbmFQUJuvXbYIfzPWljROA7TcRX2zE4SPP8l/QwJi5WnKd /pM2bJUhcZJc3Srl5U9e6OdlpIBpAigA/IUYCYpPmhtwt0reUA0xCvOCnuvppn4TL19c icow== X-Gm-Message-State: AOJu0YwJrS1rZ6YHlG/nyCKfbDbhfEYKaB7xrLzhG9X/GO8y5F4Rql/n BRvaBr0yUej/Rg70x2HI6CgX2PHQBXcF2weSq4E= X-Google-Smtp-Source: AGHT+IGWV2gD2RUmv9++GcZpjEOn0s1qVF1eTnrQZ8zvHW1Ywv6QKs+mggUI3tHsWbQu7TX5S5PCDg== X-Received: by 2002:a17:903:1212:b0:1b0:3df7:5992 with SMTP id l18-20020a170903121200b001b03df75992mr21746419plh.32.1693120877251; Sun, 27 Aug 2023 00:21:17 -0700 (PDT) Received: from n37-019-243.byted.org ([180.184.51.134]) by smtp.gmail.com with ESMTPSA id m3-20020a1709026bc300b001befac3b3cbsm4769723plt.290.2023.08.27.00.21.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Aug 2023 00:21:17 -0700 (PDT) From: Chuyi Zhou To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, linux-kernel@vger.kernel.org, Chuyi Zhou Subject: [RFC PATCH bpf-next 4/4] selftests/bpf: Add tests for open-coded task and css iter Date: Sun, 27 Aug 2023 15:20:57 +0800 Message-Id: <20230827072057.1591929-5-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230827072057.1591929-1-zhouchuyi@bytedance.com> References: <20230827072057.1591929-1-zhouchuyi@bytedance.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC This patch adds three tests to demonstrate these patterns and validating correctness. test1: We use bpf_for_each(process, task) to iterate all processed in the system and search for the current process with a given pid. test2: We create a cgroup and add the current process to the cgroup. In the BPF program, we would use bpf_for_each(css_task, task, css) to iterate all tasks under the cgroup. As expected, we would find the current process. test3: We create a cgroup tree. In the BPF program, we use bpf_for_each(css, pos, root) to iterate all descendant under the root with post order. As expected, we would find all descendant and the last iterating cgroup is root cgroup. Signed-off-by: Chuyi Zhou --- .../testing/selftests/bpf/prog_tests/iters.c | 123 ++++++++++++++++++ .../testing/selftests/bpf/progs/iters_task.c | 83 ++++++++++++ 2 files changed, 206 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/iters_task.c diff --git a/tools/testing/selftests/bpf/prog_tests/iters.c b/tools/testing/selftests/bpf/prog_tests/iters.c index 10804ae5ae97..88fb565a3e97 100644 --- a/tools/testing/selftests/bpf/prog_tests/iters.c +++ b/tools/testing/selftests/bpf/prog_tests/iters.c @@ -2,12 +2,14 @@ /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ #include +#include "cgroup_helpers.h" #include "iters.skel.h" #include "iters_state_safety.skel.h" #include "iters_looping.skel.h" #include "iters_num.skel.h" #include "iters_testmod_seq.skel.h" +#include "iters_task.skel.h" static void subtest_num_iters(void) { @@ -90,6 +92,121 @@ static void subtest_testmod_seq_iters(void) iters_testmod_seq__destroy(skel); } +static void subtest_process_iters(void) +{ + struct iters_task *skel; + int err; + + skel = iters_task__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + bpf_program__set_autoload(skel->progs.iter_task_for_each, true); + err = iters_task__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + skel->bss->target_pid = getpid(); + err = iters_task__attach(skel); + if (!ASSERT_OK(err, "iters_task__attach")) + goto cleanup; + + iters_task__detach(skel); + ASSERT_EQ(skel->bss->process_cnt, 1, "process_cnt"); + +cleanup: + iters_task__destroy(skel); +} + +static void subtest_css_task_iters(void) +{ + struct iters_task *skel; + int err, cg_fd, cg_id; + const char *cgrp_path = "/cg1"; + + err = setup_cgroup_environment(); + if (!ASSERT_OK(err, "setup_cgroup_environment")) + goto cleanup; + cg_fd = create_and_get_cgroup(cgrp_path); + if (!ASSERT_GE(cg_fd, 0, "cg_create")) + goto cleanup; + cg_id = get_cgroup_id(cgrp_path); + err = join_cgroup(cgrp_path); + if (!ASSERT_OK(err, "setup_cgroup_environment")) + goto cleanup; + + skel = iters_task__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + + bpf_program__set_autoload(skel->progs.iter_css_task_for_each, true); + err = iters_task__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + skel->bss->target_pid = getpid(); + skel->bss->cg_id = cg_id; + err = iters_task__attach(skel); + + if (!ASSERT_OK(err, "iters_task__attach")) + goto cleanup; + + iters_task__detach(skel); + ASSERT_EQ(skel->bss->css_task_cnt, 1, "css_task_cnt"); + +cleanup: + cleanup_cgroup_environment(); + iters_task__destroy(skel); +} + +static void subtest_css_dec_iters(void) +{ + struct iters_task *skel; + struct { + const char *path; + int fd; + } cgs[] = { + { "/cg1" }, + { "/cg1/cg2" }, + { "/cg1/cg2/cg3" }, + { "/cg1/cg2/cg3/cg4" }, + }; + int err, cg_nr = ARRAY_SIZE(cgs); + int i; + + err = setup_cgroup_environment(); + if (!ASSERT_OK(err, "setup_cgroup_environment")) + goto cleanup; + for (i = 0; i < cg_nr; i++) { + cgs[i].fd = create_and_get_cgroup(cgs[i].path); + if (!ASSERT_GE(cgs[i].fd, 0, "cg_create")) + goto cleanup; + } + + skel = iters_task__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + bpf_program__set_autoload(skel->progs.iter_css_dec_for_each, true); + err = iters_task__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + skel->bss->target_pid = getpid(); + skel->bss->cg_id = get_cgroup_id(cgs[0].path); + + err = iters_task__attach(skel); + + if (!ASSERT_OK(err, "iters_task__attach")) + goto cleanup; + + iters_task__detach(skel); + ASSERT_EQ(skel->bss->css_dec_cnt, cg_nr, "post order search dec count"); + ASSERT_EQ(skel->bss->last_cg_id, get_cgroup_id(cgs[0].path), + "post order search last cgroup id"); + +cleanup: + cleanup_cgroup_environment(); + iters_task__destroy(skel); +} + void test_iters(void) { RUN_TESTS(iters_state_safety); @@ -103,4 +220,10 @@ void test_iters(void) subtest_num_iters(); if (test__start_subtest("testmod_seq")) subtest_testmod_seq_iters(); + if (test__start_subtest("process")) + subtest_process_iters(); + if (test__start_subtest("css_task")) + subtest_css_task_iters(); + if (test__start_subtest("css_dec")) + subtest_css_dec_iters(); } diff --git a/tools/testing/selftests/bpf/progs/iters_task.c b/tools/testing/selftests/bpf/progs/iters_task.c new file mode 100644 index 000000000000..524926b505b0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/iters_task.c @@ -0,0 +1,83 @@ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +pid_t target_pid = 0; +int process_cnt = 0; +int css_task_cnt = 0; +int css_dec_cnt = 0; + +u64 cg_id; +u64 last_cg_id; + +struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; +struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp) __ksym; +void bpf_cgroup_release(struct cgroup *p) __ksym; + +SEC("?tp_btf/sys_enter") +int BPF_PROG(iter_task_for_each) +{ + struct task_struct *task; + struct task_struct *cur_task = bpf_get_current_task_btf(); + + if (cur_task->pid != target_pid) + return 0; + + bpf_for_each(process, task) + if (task->pid == target_pid) + process_cnt += 1; + + return 0; +} + +SEC("?tp_btf/sys_enter") +int iter_css_task_for_each(const void *ctx) +{ + struct task_struct *task; + struct task_struct *cur_task = bpf_get_current_task_btf(); + + if (cur_task->pid != target_pid) + return 0; + + struct cgroup *cgrp = bpf_cgroup_from_id(cg_id); + + if (cgrp == NULL) + return 0; + struct cgroup_subsys_state *css = &cgrp->self; + + bpf_for_each(css_task, task, css, 0) + if (task->pid == target_pid) + css_task_cnt += 1; + + bpf_cgroup_release(cgrp); + return 0; +} + +SEC("?tp_btf/sys_enter") +int iter_css_dec_for_each(const void *ctx) +{ + struct task_struct *cur_task = bpf_get_current_task_btf(); + bool is_post_order = true; + + if (cur_task->pid != target_pid) + return 0; + + struct cgroup *cgrp = bpf_cgroup_from_id(cg_id); + + if (cgrp == NULL) + return 0; + struct cgroup_subsys_state *root = &cgrp->self; + struct cgroup_subsys_state *pos = NULL; + + bpf_for_each(css, pos, root, is_post_order) { + struct cgroup *cur_cgrp = pos->cgroup; + + css_dec_cnt += 1; + if (cur_cgrp) + last_cg_id = cur_cgrp->kn->id; + } + bpf_cgroup_release(cgrp); + return 0; +}