From patchwork Fri Apr 28 07:17:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 677821 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 7C450C77B61 for ; Fri, 28 Apr 2023 07:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345480AbjD1HSD (ORCPT ); Fri, 28 Apr 2023 03:18:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345440AbjD1HR7 (ORCPT ); Fri, 28 Apr 2023 03:17:59 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52A38468E for ; Fri, 28 Apr 2023 00:17:58 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id 98e67ed59e1d1-247526f0eceso6799817a91.2 for ; Fri, 28 Apr 2023 00:17:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1682666278; x=1685258278; 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=4couG4BvY3JielUUZmpwOAXPZt7eiYYa/cnyqJtYMcY=; b=UNZiuLA31nfuIZXnpg1UDGAw70JBijGze3Ipp7cFW7Xes/GxV5/ep/9cZIhyX/f6LW 3WOJLCPMKF0SOuMFT8IKdFith2VP+RLp2ImQDFWvn00bNCZEObQ+48FpxaMljx0UgaxJ jZ2irFzHRE/SCeFgOgo3c6Gy9dTFXwssAkoteZ5L5jDkhCFboqWY1Q7Esia5Lcs3EHTn XNl49vIpjuCo5owRYU3+pgWJbl175FF/vNvIPOkgYB+nhXTj9ccpfFqeKvVBpuocHAp+ vmLQJtfw4EbJNWAdMuAmPDacE+8YkameJBei+xVuYm05JY2XlDmWHliAgUr0ZQnRtuiz b2Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682666278; x=1685258278; 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=4couG4BvY3JielUUZmpwOAXPZt7eiYYa/cnyqJtYMcY=; b=jV1rVmnRBfCBTP2/8trWFNmTBhqL3x+2nF00YZ9ipwqj07Sd0bhTW83sDbNxorVklg CINEPcoenHqKMg0QodA407Pv4eNBZTQd3WmD5Rp0MoNxsGHuT5Q4f4Rq9wbuqLI/5E1i P1EPrr8Jx6aQwr+GLs8YYDhPoazioZQswB7Usr2S0jDBo56GpOMPYTMCWGAhnYvTdUL+ oMEsb0J1vpDYLUMZqFneH+IrsT4N7uP6LB/BTR/Uh/GJ/J24zJoZsTBQkFdISWUBGhmW mxOgnU8Pi4geBFIa1aYdslZ2wO2UP1xvguXlD9ilGwSZ1fSRsHyPepbFelAqGQ+kW4DR zcpg== X-Gm-Message-State: AC+VfDxfzf8bM8KwoJ1V2NXPHM3vzAqxDJ/RqOwmmuVeIOx+KIv4Sov3 suQlX5b88jRPk1JtWKU3OeDa/w== X-Google-Smtp-Source: ACHHUZ5CWg/M4bQAH4GZcYwHsNyR5prU/jNcdmueDnZTm3k4N46PrmOMlEcbkil/EUWg6ndcG4AvLQ== X-Received: by 2002:a17:90a:d3d5:b0:24b:b22d:c78c with SMTP id d21-20020a17090ad3d500b0024bb22dc78cmr4412642pjw.9.1682666277813; Fri, 28 Apr 2023 00:17:57 -0700 (PDT) Received: from C02F52LSML85.bytedance.net ([139.177.225.254]) by smtp.gmail.com with ESMTPSA id j2-20020a17090a318200b0024739d29252sm14159939pjb.15.2023.04.28.00.17.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Apr 2023 00:17:57 -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 v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc Date: Fri, 28 Apr 2023 15:17:36 +0800 Message-Id: <20230428071737.43849-2-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230428071737.43849-1-zhoufeng.zf@bytedance.com> References: <20230428071737.43849-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Feng Zhou Add a kfunc that's similar to the bpf_current_task_under_cgroup. The difference is that it is a designated task. When hook sched related functions, sometimes it is necessary to specify a task instead of the current task. Signed-off-by: Feng Zhou Acked-by: Yonghong Song --- kernel/bpf/helpers.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index bb6b4637ebf2..453cbd312366 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2149,6 +2149,25 @@ __bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid) return NULL; return cgrp; } + +/** + * bpf_task_under_cgroup - wrap task_under_cgroup_hierarchy() as a kfunc, test + * task's membership of cgroup ancestry. + * @task: the task to be tested + * @ancestor: possible ancestor of @task's cgroup + * + * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. + * It follows all the same rules as cgroup_is_descendant, and only applies + * to the default hierarchy. + */ +__bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, + struct cgroup *ancestor) +{ + if (unlikely(!ancestor || !task)) + return -EINVAL; + + return task_under_cgroup_hierarchy(task, ancestor); +} #endif /* CONFIG_CGROUPS */ /** @@ -2400,6 +2419,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE) BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_SET8_END(generic_btf_ids) From patchwork Fri Apr 28 07:17:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 677820 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 AAFF3C77B60 for ; Fri, 28 Apr 2023 07:18:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345488AbjD1HSo (ORCPT ); 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Fri, 28 Apr 2023 00:18:05 -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 v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Date: Fri, 28 Apr 2023 15:17:37 +0800 Message-Id: <20230428071737.43849-3-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230428071737.43849-1-zhoufeng.zf@bytedance.com> References: <20230428071737.43849-1-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 --- tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../bpf/prog_tests/task_under_cgroup.c | 55 +++++++++++++++++++ .../bpf/progs/test_task_under_cgroup.c | 51 +++++++++++++++++ 3 files changed, 107 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..5e79dff86dec --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c @@ -0,0 +1,55 @@ +// 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 = -1; + 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); + else if (pid == -1) + printf("Couldn't fork process!\n"); + + wait(NULL); + + test_task_under_cgroup__detach(skel); + + ASSERT_NEQ(skel->bss->remote_pid, skel->rodata->local_pid, + "test task_under_cgroup"); + +cleanup: + if (foo >= 0) + close(foo); + + test_task_under_cgroup__destroy(skel); +} 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..5bcb726d6d0a --- /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 long 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 = NULL; + + 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 (acquired) + bpf_task_release(acquired); + if (cgrp) + bpf_cgroup_release(cgrp); + return 0; +} + +char _license[] SEC("license") = "GPL";