From patchwork Fri Dec 18 23:56:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 346183 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27B54C3526E for ; Fri, 18 Dec 2020 23:57:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBFF623BAD for ; Fri, 18 Dec 2020 23:57:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726068AbgLRX5H convert rfc822-to-8bit (ORCPT ); Fri, 18 Dec 2020 18:57:07 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:48834 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725885AbgLRX5G (ORCPT ); Fri, 18 Dec 2020 18:57:06 -0500 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BINsC2n013124 for ; Fri, 18 Dec 2020 15:56:26 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 35gxe5jqc9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 18 Dec 2020 15:56:26 -0800 Received: from intmgw002.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 18 Dec 2020 15:56:25 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 0F2E52ECB8FE; Fri, 18 Dec 2020 15:56:23 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 3/3] selftests/bpf: add tests for user- and non-CO-RE BPF_CORE_READ() variants Date: Fri, 18 Dec 2020 15:56:14 -0800 Message-ID: <20201218235614.2284956-4-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201218235614.2284956-1-andrii@kernel.org> References: <20201218235614.2284956-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-18_14:2020-12-18,2020-12-18 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 mlxscore=0 spamscore=0 clxscore=1034 priorityscore=1501 lowpriorityscore=0 mlxlogscore=999 adultscore=0 phishscore=0 bulkscore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012180163 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add selftests validating that newly added variations of BPF_CORE_READ(), for use with user-space addresses and for non-CO-RE reads, work as expected. Signed-off-by: Andrii Nakryiko --- .../bpf/prog_tests/core_read_macros.c | 64 +++++++++++++++++++ .../bpf/progs/test_core_read_macros.c | 51 +++++++++++++++ 2 files changed, 115 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/core_read_macros.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_read_macros.c diff --git a/tools/testing/selftests/bpf/prog_tests/core_read_macros.c b/tools/testing/selftests/bpf/prog_tests/core_read_macros.c new file mode 100644 index 000000000000..96f5cf3c6fa2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/core_read_macros.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include + +struct callback_head { + struct callback_head *next; + void (*func)(struct callback_head *head); +}; + +/* ___shuffled flavor is just an illusion for BPF code, it doesn't really + * exist and user-space needs to provide data in the memory layout that + * matches callback_head. We just defined ___shuffled flavor to make it easier + * to work with the skeleton + */ +struct callback_head___shuffled { + struct callback_head___shuffled *next; + void (*func)(struct callback_head *head); +}; + +#include "test_core_read_macros.skel.h" + +void test_core_read_macros(void) +{ + int duration = 0, err; + struct test_core_read_macros* skel; + struct test_core_read_macros__bss *bss; + struct callback_head u_probe_in; + struct callback_head___shuffled u_core_in; + + skel = test_core_read_macros__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + bss = skel->bss; + bss->my_pid = getpid(); + + /* next pointers have to be set from the kernel side */ + bss->k_probe_in.func = (void *)(long)0x1234; + bss->k_core_in.func = (void *)(long)0xabcd; + + u_probe_in.next = &u_probe_in; + u_probe_in.func = (void *)(long)0x5678; + bss->u_probe_in = &u_probe_in; + + u_core_in.next = &u_core_in; + u_core_in.func = (void *)(long)0xdbca; + bss->u_core_in = &u_core_in; + + err = test_core_read_macros__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* trigger tracepoint */ + usleep(1); + + ASSERT_EQ(bss->k_probe_out, 0x1234, "k_probe_out"); + ASSERT_EQ(bss->k_core_out, 0xabcd, "k_core_out"); + + ASSERT_EQ(bss->u_probe_out, 0x5678, "u_probe_out"); + ASSERT_EQ(bss->u_core_out, 0xdbca, "u_core_out"); + +cleanup: + test_core_read_macros__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_core_read_macros.c b/tools/testing/selftests/bpf/progs/test_core_read_macros.c new file mode 100644 index 000000000000..50054af0a928 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_core_read_macros.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +/* shuffled layout for relocatable (CO-RE) reads */ +struct callback_head___shuffled { + void (*func)(struct callback_head___shuffled *head); + struct callback_head___shuffled *next; +}; + +struct callback_head k_probe_in = {}; +struct callback_head___shuffled k_core_in = {}; + +struct callback_head *u_probe_in = 0; +struct callback_head___shuffled *u_core_in = 0; + +long k_probe_out = 0; +long u_probe_out = 0; + +long k_core_out = 0; +long u_core_out = 0; + +int my_pid = 0; + +SEC("raw_tracepoint/sys_enter") +int handler(void *ctx) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + + if (my_pid != pid) + return 0; + + /* next pointers for kernel address space have to be initialized from + * BPF side, user-space mmaped addresses are stil user-space addresses + */ + k_probe_in.next = &k_probe_in; + __builtin_preserve_access_index(({k_core_in.next = &k_core_in;})); + + k_probe_out = (long)BPF_PROBE_READ(&k_probe_in, next, next, func); + k_core_out = (long)BPF_CORE_READ(&k_core_in, next, next, func); + u_probe_out = (long)BPF_PROBE_READ_USER(u_probe_in, next, next, func); + u_core_out = (long)BPF_CORE_READ_USER(u_core_in, next, next, func); + + return 0; +} +