From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (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 15C5D291C34; Fri, 27 Jun 2025 23:40:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751067606; cv=none; b=ZygzlH0OFCuqvpx4ugpBpKeqqxUb3nuPPjJWgN4xq/E7zqzLJOSw1BZx5q1P76qQAbdJ7QeMdmDUW8/SLQHjUzasBlcHn6UDmmJH9qfc6XpdiCEqyUnyjH2EEEJmAIEW/EwBBK+n8UetePl5S96lsda/RmmCl9M94mar3Wqn4gU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751067606; c=relaxed/simple; bh=xUGX55h8nFeANftT7sLX3g8kJGakPkOONRo0TbD4WFo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VUL9FkMfBGqeXNNvrYIN6vS0eA5Nqfb4H6lWFoiJ1n75Ct70mze5N5BQ0wij4snSsl+C/OD1q86/WK9rvtMw7MmkY0+FYdfimxbVn4nKmkGcMKFQsQ2QlzFIBLUxDbkbGXstJ652Qwc4HfR9jCVrrrUrAM80dLGnAUpiYomW0r0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Ir3i0yOg; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ir3i0yOg" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-237e6963f63so550195ad.2; Fri, 27 Jun 2025 16:40:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1751067604; x=1751672404; 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=iObp/3c6/tNbk6nfNMkT56WdCpWJQbF1znOFK9fVavA=; b=Ir3i0yOg5e1gcDRdCl7h1v5j0LWsMMkxcy5XMcalHv4I4v9g09kSawDopmnoM84wYQ fxpI9sNgEzCdXqfvn5AURf2qgv4utjJnBS7tC0f7MW/beqyPK0EVzfqN7vCaYqDbpG0X Mn4ccPAveqFpcqOWj0JW9PMRnYfWItGZJ1UZaS6RByRoGJRGVkA/HPHrp8XmGY6dS6kF 3R2d7AHL932TgcR/IyxoZcv9HlzJbYNp41wZjyCa0OTHZ3GXdZH+1a1rAvTbJQIRn9S1 qzU6ECoaVSleRqjkkKDfdIcl3DnmQfon0+H8ZyVp6Y/W50gUVi0XvKDNzJD6Vgj2S30J 6x0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751067604; x=1751672404; 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=iObp/3c6/tNbk6nfNMkT56WdCpWJQbF1znOFK9fVavA=; b=hhT5PYI1Tit0zddU0yIRXIRHqlUi/ttPAwO185jIYN8x1KPTMGDnZHGMLWnRdcbVg1 avYjKyrEoBncTo2lfThdtmNHarHb9RJ3mfV3btN2b50UZ+0tYexEDZOUEz3W2JCeDU6Z 9tMUAdLup8GJO+Oy50/TCm8b8L+kOl1wwk9oiWVPQiJTCoSpbJUNttlddgjAeeyW3eeG PK4QM8C0IKfivw48AikHijI70236zcr25kxdjezcAyCdNnT/xKw2dLFQmQmakea8ABa9 jxHn61EZ/5JzZHTkj/+uo5yVffDXtsw+UkBy5RkXiLMugXfjzEUAWipQD26cUd8lCi/5 ns/A== X-Gm-Message-State: AOJu0Yw8yqAB9Rawnnrb42I6N1XyA7pzEak0gXq/Gi1h78D/+f8Lt1XE 5nlnkjXAJ/yXS04r/r3HV/ZJxuH7KNh+qT6YdQF61eI8hzv9h3TiMEvFLA8IGQ== X-Gm-Gg: ASbGncupDYgWp6QdGuJS1XBR+AVEA8mCVCxoP1JAurdf+3i11HUX/ryD0I92bEjCpLu stNojlbIgJ2aia+fQi91sdC+aFZlJA1oZJb/PKlqWofOwZ1/rjTqhvdPhwDWxFFDln5P/e6jWcA YEAsqIu4B4MH4v3kMw/cZvb4D43PnBgxwyGdL5zTjqfJQ/LwPm5PDhtbzNqUisw0cPuR+EYoC0l f9/etrjfa/MfQQJy70TLOO2uMYc+ldYV+aiyHxdvL57rVjkHas4EbcMPq3KXWNAunMcwn1bI0+0 Ex8GWFwt56H2jUknxtrt34VY8UqrpULhVvZDqYnq9tb0duVUaeEc X-Google-Smtp-Source: AGHT+IGJ837FxfipMc5AaN6FNNOihgI5Bcq+9yqrLL1XpaK4HTlYPmLP88ITsxEPdUX5eX5ujyF0pQ== X-Received: by 2002:a17:903:2983:b0:234:aa98:7d41 with SMTP id d9443c01a7336-23ac4685adbmr82539415ad.42.1751067604171; Fri, 27 Jun 2025 16:40:04 -0700 (PDT) Received: from localhost ([2a03:2880:ff:3::]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-23acb2f1d0csm24588255ad.56.2025.06.27.16.40.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Jun 2025 16:40:03 -0700 (PDT) From: Amery Hung To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, alexei.starovoitov@gmail.com, andrii@kernel.org, daniel@iogearbox.net, tj@kernel.org, memxor@gmail.com, martin.lau@kernel.org, ameryhung@gmail.com, kernel-team@meta.com Subject: [PATCH bpf-next v5 3/3] selftests/bpf: Test concurrent task local data key creation Date: Fri, 27 Jun 2025 16:39:57 -0700 Message-ID: <20250627233958.2602271-4-ameryhung@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250627233958.2602271-1-ameryhung@gmail.com> References: <20250627233958.2602271-1-ameryhung@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Test thread-safety of tld_create_key(). Since tld_create_key() does not rely on locks but memory barriers and atomic operations to protect the shared metadata, the thread-safety of the function is non-trivial. Make sure concurrent tld_key_create(), both valid and invalid, can not race and corrupt metatada, which may leads to TLDs not being thread- specific or duplicate TLDs with the same name. Signed-off-by: Amery Hung --- .../bpf/prog_tests/test_task_local_data.c | 103 ++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c index 53cdb8466f8e..99a1ddaf3e67 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c +++ b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c @@ -184,8 +184,111 @@ static void test_task_local_data_basic(void) test_task_local_data__destroy(skel); } +#define TEST_RACE_THREAD_NUM (TLD_MAX_DATA_CNT - 3) + +void *test_task_local_data_race_thread(void *arg) +{ + int err = 0, id = (intptr_t)arg; + char key_name[32]; + tld_key_t key; + + key = tld_create_key("value_not_exist", TLD_PAGE_SIZE + 1); + if (tld_key_err_or_zero(key) != -E2BIG) { + err = 1; + goto out; + } + + /* + * If more than one thread succeed in creating value1 or value2, + * some threads will fail to create thread_ later. + */ + key = tld_create_key("value1", sizeof(int)); + if (!tld_key_is_err(key)) + tld_keys[TEST_RACE_THREAD_NUM] = key; + key = tld_create_key("value2", sizeof(struct test_struct)); + if (!tld_key_is_err(key)) + tld_keys[TEST_RACE_THREAD_NUM + 1] = key; + + snprintf(key_name, 32, "thread_%d", id); + tld_keys[id] = tld_create_key(key_name, sizeof(int)); + if (tld_key_is_err(tld_keys[id])) + err = 2; +out: + return (void *)(intptr_t)err; +} + +static void test_task_local_data_race(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + pthread_t thread[TEST_RACE_THREAD_NUM]; + struct test_task_local_data *skel; + int fd, i, j, err, *data; + void *ret = NULL; + + skel = test_task_local_data__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) + return; + + tld_keys = calloc(TEST_RACE_THREAD_NUM + 2, sizeof(tld_key_t)); + if (!ASSERT_OK_PTR(tld_keys, "calloc tld_keys")) + goto out; + + fd = bpf_map__fd(skel->maps.tld_data_map); + + for (j = 0; j < 100; j++) { + reset_tld(); + + for (i = 0; i < TEST_RACE_THREAD_NUM; i++) { + /* + * Try to make tld_create_key() race with each other. Call + * tld_create_key(), both valid and invalid, from different threads. + */ + err = pthread_create(&thread[i], NULL, test_task_local_data_race_thread, + (void *)(intptr_t)i); + if (CHECK_FAIL(err)) + break; + } + + /* Wait for all tld_create_key() to return */ + for (i = 0; i < TEST_RACE_THREAD_NUM; i++) { + pthread_join(thread[i], &ret); + if (CHECK_FAIL(ret)) + break; + } + + /* Write a unique number in the range of [0, TEST_RACE_THREAD_NUM) to each TLD */ + for (i = 0; i < TEST_RACE_THREAD_NUM; i++) { + data = tld_get_data(fd, tld_keys[i]); + if (CHECK_FAIL(!data)) + break; + *data = i; + } + + /* Read TLDs and check the value to see if any address collides with another */ + for (i = 0; i < TEST_RACE_THREAD_NUM; i++) { + data = tld_get_data(fd, tld_keys[i]); + if (CHECK_FAIL(*data != i)) + break; + } + + /* Run task_main to make sure no invalid TLDs are added */ + err = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.task_main), &opts); + ASSERT_OK(err, "run task_main"); + ASSERT_OK(opts.retval, "task_main retval"); + } +out: + if (tld_keys) { + free(tld_keys); + tld_keys = NULL; + } + tld_free(); + test_task_local_data__destroy(skel); +} + void test_task_local_data(void) { if (test__start_subtest("task_local_data_basic")) test_task_local_data_basic(); + if (test__start_subtest("task_local_data_race")) + test_task_local_data_race(); } -- 2.47.1