From patchwork Sat Mar 16 16:22:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jose Fernandez X-Patchwork-Id: 780789 Received: from mail-il1-f175.google.com (mail-il1-f175.google.com [209.85.166.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B12D41BC37 for ; Sat, 16 Mar 2024 16:23:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710606186; cv=none; b=BGNwiepawS4KmqE6LFROq453MnwOIMQHvkXCB7UokweOTWoi/LuKB6vVy3X/x2Sq8QZulWw6bxb6jhTQLfXwiPiZwkBcEX2KcO6UTjaoez3AN43VwgTZyBOC0p9TqeQsfwLZ5abaol7MkOmFtKL+1aD/Hn8zYV8lcOlZvgNof7o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710606186; c=relaxed/simple; bh=3T/N87s1TiFY5CTbl7PLYpRpVqYPbSLIXW4VbrW9Qr4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=BIrS3ucVVdQ36RtvElQrjVoB32DaR5wnlmnOavMLE/RzcSae7QJweMj5m7eysPW1iDHnIiJyg1/0VEIsK208baVDUguc6M+3z1KHOAjrg9jQ8LJNXAgvZPMA10lyxYbFn8S8gKT8PxHHhCkkfFWQvhX4KBkJDNb2muGBKE6mM1g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=netflix.com; spf=pass smtp.mailfrom=netflix.com; dkim=pass (1024-bit key) header.d=netflix.com header.i=@netflix.com header.b=IeQ/wunu; arc=none smtp.client-ip=209.85.166.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=netflix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netflix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=netflix.com header.i=@netflix.com header.b="IeQ/wunu" Received: by mail-il1-f175.google.com with SMTP id e9e14a558f8ab-36695f8029aso6940625ab.3 for ; Sat, 16 Mar 2024 09:23:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netflix.com; s=google; t=1710606184; x=1711210984; darn=vger.kernel.org; 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=FR+HdfxLkkzGogNavG10On9pl0CTmo3qowHlz+D4lik=; b=IeQ/wunulIJh644LmVGaP4TsG2ufkdFJbSA92QJ9l3FCE3lD+75fMotwzn9EGVQa72 caqIWJ7qwAphbbJzwB/QdCv6kDiOOeQhbt8apQ0tsPK7vG5WZLg8soqVkd2DyKYVL0bZ Z1z7sAXNdbIAaD4e/x8rriB6Ht4cMRBq5nocU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710606184; x=1711210984; 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=FR+HdfxLkkzGogNavG10On9pl0CTmo3qowHlz+D4lik=; b=hwPNm7fZ66/qI+Wz7TCybqsdq4aNucb/aPLXcBw/COnMBHCwnruvCJuWSscPtfU0SJ +lP9QDK8Jsdrt4e02Kg/F5/5oQU73qF5ghPQ76pDz4WmuO0gI0Bn6tXZYtiGrSeikUQD f6TS4bihYLk56W3m7uA99smuqRKuTT0KaACFubXzq9l+kpAqPUwCAjh9FnRMCym4wq0F D9UgZ3YxCJfTqCMZcH9iVOVibKo7Q3MCdzQRm1OfB3bZozmmUzURMA7VFueZz/oqjcFK vap3ND54TWNQKL1vzIzt0+azfPGbF6z+2dk0TfLy5vLWjM3vLnEfNqMQ9UZPXhv9DnPu bHGg== X-Forwarded-Encrypted: i=1; AJvYcCW6sUfukPue9pUq+CmIGuFJDT/a/r8nMsbiPMWzWFUl5hX7gXi/Tkz2k/i0iObDdmE3Dj7rzFAJ55r3iwhrPWOtTBks6fZfv4PWi1CM8gFe X-Gm-Message-State: AOJu0YxpkfhQ3BEsUAAKfholkrtoOtiI1UQXjqgOSzKny8Su/xJCqrsr I+i7NVprCrIh8ZFovAXATbUkwI66QkMgN4g9f/lPqwL2P9/dxl9CXgmE0XQ2tgU= X-Google-Smtp-Source: AGHT+IGcQ3XP+3qarC5wBmrvkYQ3EjpLmKBi8RlI1pDwXP/BaiR7qNci2pcjPRzQ5wA6UbIVH8QunQ== X-Received: by 2002:a6b:7315:0:b0:7cb:f297:a94b with SMTP id e21-20020a6b7315000000b007cbf297a94bmr5599660ioh.15.1710606183865; Sat, 16 Mar 2024 09:23:03 -0700 (PDT) Received: from localhost ([2601:285:8700:8f20:db82:ef0d:e122:37fc]) by smtp.gmail.com with UTF8SMTPSA id o27-20020a02cc3b000000b00474f364aac9sm1362211jap.71.2024.03.16.09.23.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 16 Mar 2024 09:23:03 -0700 (PDT) From: Jose Fernandez To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Jose Fernandez , Tycho Andersen Subject: [PATCH V2 bpf-next 2/2] selftests/bpf: add selftest for bpf_task_get_cgroup Date: Sat, 16 Mar 2024 10:22:41 -0600 Message-Id: <20240316162241.628855-2-josef@netflix.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240316162241.628855-1-josef@netflix.com> References: <20240316162241.628855-1-josef@netflix.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This patch adds a selftest for the `bpf_task_get_cgroup` kfunc. The test focuses on the use case of obtaining the cgroup ID of the previous task in a `sched_switch` tracepoint. The selftest involves creating a test cgroup, attaching a BPF program that utilizes the `bpf_task_get_cgroup` during a `sched_switch` tracepoint, and validating that the obtained cgroup ID for the previous task matches the expected cgroup ID. Signed-off-by: Jose Fernandez Reviewed-by: Tycho Andersen --- V1 -> V2: Refactor test to work with a cgroup pointer instead of the ID .../bpf/prog_tests/task_get_cgroup.c | 58 +++++++++++++++++++ .../bpf/progs/test_task_get_cgroup.c | 37 ++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c create mode 100644 tools/testing/selftests/bpf/progs/test_task_get_cgroup.c diff --git a/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c new file mode 100644 index 000000000000..67ed65d0c461 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2024 Netflix, Inc. + +#include +#include +#include "test_task_get_cgroup.skel.h" +#include + +#define TEST_CGROUP "/test-task-get-cgroup/" + +void test_task_get_cgroup(void) +{ + struct test_task_get_cgroup *skel; + int err, fd; + pid_t pid; + __u64 cgroup_id, expected_cgroup_id; + const struct timespec req = { + .tv_sec = 1, + .tv_nsec = 0, + }; + + fd = test__join_cgroup(TEST_CGROUP); + if (!ASSERT_OK(fd < 0, "test_join_cgroup_TEST_CGROUP")) + return; + + skel = test_task_get_cgroup__open(); + if (!ASSERT_OK_PTR(skel, "test_task_get_cgroup__open")) + goto cleanup; + + err = test_task_get_cgroup__load(skel); + if (!ASSERT_OK(err, "test_task_get_cgroup__load")) + goto cleanup; + + err = test_task_get_cgroup__attach(skel); + if (!ASSERT_OK(err, "test_task_get_cgroup__attach")) + goto cleanup; + + pid = getpid(); + expected_cgroup_id = get_cgroup_id(TEST_CGROUP); + if (!ASSERT_GT(expected_cgroup_id, 0, "get_cgroup_id")) + goto cleanup; + + /* Trigger nanosleep to enter the sched_switch tracepoint */ + /* The previous task should be this process */ + syscall(__NR_nanosleep, &req, NULL); + + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.pid_to_cgid_map), &pid, + &cgroup_id); + + if (!ASSERT_OK(err, "bpf_map_lookup_elem")) + goto cleanup; + + ASSERT_EQ(cgroup_id, expected_cgroup_id, "cgroup_id"); + +cleanup: + test_task_get_cgroup__destroy(skel); + close(fd); +} diff --git a/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c new file mode 100644 index 000000000000..580f8f0657d5 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2024 Netflix, Inc. + +#include "vmlinux.h" +#include +#include + +struct cgroup *bpf_task_get_cgroup(struct task_struct *task) __ksym; +void bpf_cgroup_release(struct cgroup *cgrp) __ksym; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 4096); + __type(key, __u32); + __type(value, __u64); +} pid_to_cgid_map SEC(".maps"); + +SEC("tp_btf/sched_switch") +int BPF_PROG(sched_switch, bool preempt, struct task_struct *prev, + struct task_struct *next) +{ + struct cgroup *cgrp; + u64 cgroup_id; + u32 pid; + + cgrp = bpf_task_get_cgroup(prev); + if (cgrp == NULL) + return 0; + cgroup_id = cgrp->kn->id; + pid = prev->pid; + bpf_map_update_elem(&pid_to_cgid_map, &pid, &cgroup_id, BPF_ANY); + + bpf_cgroup_release(cgrp); + return 0; +} + +char _license[] SEC("license") = "GPL";