From patchwork Fri May 5 06:08:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 13232170 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 E3BFAC77B7C for ; Fri, 5 May 2023 06:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229781AbjEEGJO (ORCPT ); Fri, 5 May 2023 02:09:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229713AbjEEGJO (ORCPT ); Fri, 5 May 2023 02:09:14 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 632DC15EE4 for ; Thu, 4 May 2023 23:08:46 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id d2e1a72fcca58-64115e652eeso17481548b3a.0 for ; Thu, 04 May 2023 23:08:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1683266926; x=1685858926; 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=to2GelvfQOYiPdEg5VbR1Ww7puasvELAAcMjuLN9bQo=; b=giSZniElR4IwMglaX8J4DvYJVEoN9PIDwI+g5ofE55e+BQbq+0IL+eL5pOqhO0ciCb eJNGrAiKfCddux7ahLTbRwM22glGy/6T95p55GKxSVI3oihQN7P5y5y/xb/2vbAgkuZn XYtRaOP5bocO/I0ZqTOK6We5w8c65E27MA9ZqSdH3x1I+fWh2kso0l+aTFFARHQT3KgD oYmXnp91OADgI8ooJ/SJz0MYyIh/ViFJ//WkzwqPD3cTbul+r6TpcWY7r46Rl7fJu5Ac CM1UGkDc+CqmkWafJYZw22L+tggPFMse3cMoobg85Opm4sT182vrPghkkei6nDwAGI0p i/Pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683266926; x=1685858926; 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=to2GelvfQOYiPdEg5VbR1Ww7puasvELAAcMjuLN9bQo=; b=ScF3MnFg9zRockcdrV4jvFPEEQEZzx1vFC2s3jiaISHZllZm7Dh90O3lP1oBMjr1r9 lHdiPuQwYq7zDQt+4KtV/3RCpRud7tx0yh4fAR+JkCFdAwML7mtMjsiV/gTvsXGMBWw/ FFRKZpmDo6NluOnzn1WHWndPrrfdSXWqJMVoY6HeQK/axjO4fUVG2mZE4xnJ2cnIghXn G5ipsuxhxU3BazDlJA0+sTOf/pE1MI5B4xlu1kpMYJa36KahoiMQQiCnF+Nt00iP3kkP yZBj2YOrzrybP6/YBhM4cqmyLq7Pa4APOs/coUtD/gIoNSTuWnYq/28/DKPEweOr8NWH 43pw== X-Gm-Message-State: AC+VfDzdB4xWGt8aynnMBQSmj8qLEfubjatY1FEG6MQneIEiABJTdgCW ZsLVVpL4hNFSN1b0nMiK1E8nNQ== X-Google-Smtp-Source: ACHHUZ6ivCxc1L9sOJcav8doABE8zYv32BcS+mhDa+KDZSJ0e905pj0HzXHx6WVlNQvHjJ4Rx53wmg== X-Received: by 2002:a05:6a00:13a8:b0:63d:6744:8cae with SMTP id t40-20020a056a0013a800b0063d67448caemr833671pfg.2.1683266925850; Thu, 04 May 2023 23:08:45 -0700 (PDT) Received: from C02F52LSML85.bytedance.net ([139.177.225.238]) by smtp.gmail.com with ESMTPSA id a15-20020aa780cf000000b0063799398eb9sm762160pfn.58.2023.05.04.23.08.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 May 2023 23:08:45 -0700 (PDT) From: Feng zhou To: martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mykolal@fb.com, shuah@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, yangzhenze@bytedance.com, wangdongdong.6@bytedance.com, zhoufeng.zf@bytedance.com Subject: [PATCH bpf-next v6 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Date: Fri, 5 May 2023 14:08:18 +0800 Message-Id: <20230505060818.60037-3-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230505060818.60037-1-zhoufeng.zf@bytedance.com> References: <20230505060818.60037-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Feng Zhou test_progs: Tests new kfunc bpf_task_under_cgroup(). The bpf program saves the new task's pid within a given cgroup to the remote_pid, which is convenient for the user-mode program to verify the test correctness. The user-mode program creates its own mount namespace, and mounts the cgroupsv2 hierarchy in there, call the fork syscall, then check if remote_pid and local_pid are unequal. Signed-off-by: Feng Zhou Acked-by: Yonghong Song --- tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../bpf/prog_tests/task_under_cgroup.c | 53 +++++++++++++++++++ .../bpf/progs/test_task_under_cgroup.c | 51 ++++++++++++++++++ 3 files changed, 105 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c create mode 100644 tools/testing/selftests/bpf/progs/test_task_under_cgroup.c diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x index c7463f3ec3c0..5061d9e24c16 100644 --- a/tools/testing/selftests/bpf/DENYLIST.s390x +++ b/tools/testing/selftests/bpf/DENYLIST.s390x @@ -26,3 +26,4 @@ user_ringbuf # failed to find kernel BTF type ID of verif_stats # trace_vprintk__open_and_load unexpected error: -9 (?) xdp_bonding # failed to auto-attach program 'trace_on_entry': -524 (trampoline) xdp_metadata # JIT does not support calling kernel function (kfunc) +test_task_under_cgroup # JIT does not support calling kernel function (kfunc) diff --git a/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c new file mode 100644 index 000000000000..4224727fb364 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Bytedance */ + +#include +#include +#include +#include "test_task_under_cgroup.skel.h" + +#define FOO "/foo" + +void test_task_under_cgroup(void) +{ + struct test_task_under_cgroup *skel; + int ret, foo; + pid_t pid; + + foo = test__join_cgroup(FOO); + if (!ASSERT_OK(foo < 0, "cgroup_join_foo")) + return; + + skel = test_task_under_cgroup__open(); + if (!ASSERT_OK_PTR(skel, "test_task_under_cgroup__open")) + goto cleanup; + + skel->rodata->local_pid = getpid(); + skel->bss->remote_pid = getpid(); + skel->rodata->cgid = get_cgroup_id(FOO); + + ret = test_task_under_cgroup__load(skel); + if (!ASSERT_OK(ret, "test_task_under_cgroup__load")) + goto cleanup; + + ret = test_task_under_cgroup__attach(skel); + if (!ASSERT_OK(ret, "test_task_under_cgroup__attach")) + goto cleanup; + + pid = fork(); + if (pid == 0) + exit(0); + + ret = (pid == -1); + if (ASSERT_OK(ret, "fork process")) + wait(NULL); + + test_task_under_cgroup__detach(skel); + + ASSERT_NEQ(skel->bss->remote_pid, skel->rodata->local_pid, + "test task_under_cgroup"); + +cleanup: + test_task_under_cgroup__destroy(skel); + close(foo); +} diff --git a/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c new file mode 100644 index 000000000000..56cdc0a553f0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Bytedance */ + +#include +#include +#include + +#include "bpf_misc.h" + +struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; +long bpf_task_under_cgroup(struct task_struct *task, struct cgroup *ancestor) __ksym; +void bpf_cgroup_release(struct cgroup *p) __ksym; +struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym; +void bpf_task_release(struct task_struct *p) __ksym; + +const volatile int local_pid; +const volatile __u64 cgid; +int remote_pid; + +SEC("tp_btf/task_newtask") +int BPF_PROG(handle__task_newtask, struct task_struct *task, u64 clone_flags) +{ + struct cgroup *cgrp = NULL; + struct task_struct *acquired; + + if (local_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + acquired = bpf_task_acquire(task); + if (!acquired) + return 0; + + if (local_pid == acquired->tgid) + goto out; + + cgrp = bpf_cgroup_from_id(cgid); + if (!cgrp) + goto out; + + if (bpf_task_under_cgroup(acquired, cgrp)) + remote_pid = acquired->tgid; + +out: + if (cgrp) + bpf_cgroup_release(cgrp); + bpf_task_release(acquired); + + return 0; +} + +char _license[] SEC("license") = "GPL";