From patchwork Tue Jun 16 05:04:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 217728 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 0D37FC433E0 for ; Tue, 16 Jun 2020 05:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E146C207E8 for ; Tue, 16 Jun 2020 05:04:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="aFz9X8Pq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726552AbgFPFEw (ORCPT ); Tue, 16 Jun 2020 01:04:52 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:3050 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726052AbgFPFEs (ORCPT ); Tue, 16 Jun 2020 01:04:48 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05G4xf7O026086 for ; Mon, 15 Jun 2020 22:04:46 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=PVwmhV2PrDu3ZbF6r4dNJymVeVSH6LlWOQKH14ICpPI=; b=aFz9X8PqpJwkVRSu3Te0/wCJu1d2y7fAt4v7VygxCWl6H2BidS6XGw6be4ZzVeGLsagY QXjN3Y8t3Zzt1O67kWUPp2WELSi6csVKstz+UTizlEExGwI6cYd43z0iEZizBGZ+6rfj NSNQ9VAROcC/vCHgdOZMuP6ybTurEbpUxBs= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 31pnd9ge3r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 15 Jun 2020 22:04:46 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 15 Jun 2020 22:04:45 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id CF7782EC2F00; Mon, 15 Jun 2020 22:04:36 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko , Christoph Hellwig Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf 2/2] selftests/bpf: add variable-length data concatenation pattern test Date: Mon, 15 Jun 2020 22:04:31 -0700 Message-ID: <20200616050432.1902042-2-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200616050432.1902042-1-andriin@fb.com> References: <20200616050432.1902042-1-andriin@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-15_11:2020-06-15,2020-06-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 clxscore=1015 mlxscore=0 spamscore=0 suspectscore=8 impostorscore=0 phishscore=0 mlxlogscore=941 malwarescore=0 bulkscore=0 priorityscore=1501 cotscore=-2147483648 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006160035 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add selftest that validates variable-length data reading and concatentation with one big shared data array. This is a common pattern in production use for monitoring and tracing applications, that potentially can read a lot of data, but usually reads much less. Such pattern allows to determine precisely what amount of data needs to be sent over perfbuf/ringbuf and maximize efficiency. This is the first BPF selftest that at all looks at and tests bpf_probe_read_str()-like helper's return value, closing a major gap in BPF testing. It surfaced the problem with bpf_probe_read_kernel_str() returning 0 on success, instead of amount of bytes successfully read. Signed-off-by: Andrii Nakryiko --- .../testing/selftests/bpf/prog_tests/varlen.c | 56 +++++++++++ .../testing/selftests/bpf/progs/test_varlen.c | 96 +++++++++++++++++++ 2 files changed, 152 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/varlen.c create mode 100644 tools/testing/selftests/bpf/progs/test_varlen.c diff --git a/tools/testing/selftests/bpf/prog_tests/varlen.c b/tools/testing/selftests/bpf/prog_tests/varlen.c new file mode 100644 index 000000000000..e498e2b90da1 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/varlen.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include "test_varlen.skel.h" + +#define CHECK_VAL(got, exp) \ + CHECK((got) != (exp), "check", "got %ld != exp %ld\n", \ + (long)(got), (long)(exp)) + +void test_varlen(void) +{ + int duration = 0, err; + struct test_varlen* skel; + struct test_varlen__bss *bss; + struct test_varlen__data *data; + const char str1[] = "Hello, "; + const char str2[] = "World!"; + const char exp_str[] = "Hello, \0World!\0"; + const int size1 = sizeof(str1); + const int size2 = sizeof(str2); + + skel = test_varlen__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + bss = skel->bss; + data = skel->data; + + err = test_varlen__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + bss->test_pid = getpid(); + + /* trigger everything */ + memcpy(bss->buf_in1, str1, size1); + memcpy(bss->buf_in2, str2, size2); + bss->capture = true; + usleep(1); + bss->capture = false; + + CHECK_VAL(bss->payload1_len1, size1); + CHECK_VAL(bss->payload1_len2, size2); + CHECK_VAL(bss->total1, size1 + size2); + CHECK(memcmp(bss->payload1, exp_str, size1 + size2), "content_check", + "doesn't match!"); + + CHECK_VAL(data->payload2_len1, size1); + CHECK_VAL(data->payload2_len2, size2); + CHECK_VAL(data->total2, size1 + size2); + CHECK(memcmp(data->payload2, exp_str, size1 + size2), "content_check", + "doesn't match!"); +cleanup: + test_varlen__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_varlen.c b/tools/testing/selftests/bpf/progs/test_varlen.c new file mode 100644 index 000000000000..09691852debf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_varlen.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include "vmlinux.h" +#include +#include +#include + +#define MAX_LEN 256 + +char buf_in1[MAX_LEN] = {}; +char buf_in2[MAX_LEN] = {}; + +int test_pid = 0; +bool capture = false; + +/* .bss */ +long payload1_len1 = 0; +long payload1_len2 = 0; +long total1 = 0; +char payload1[MAX_LEN + MAX_LEN] = {}; + +/* .data */ +int payload2_len1 = -1; +int payload2_len2 = -1; +int total2 = -1; +char payload2[MAX_LEN + MAX_LEN] = { 1 }; + +SEC("raw_tp/sys_enter") +int handler64(void *regs) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + void *payload = payload1; + u64 len; + + /* ignore irrelevant invocations */ + if (test_pid != pid || !capture) + return 0; + + len = bpf_probe_read_kernel_str(payload, MAX_LEN, &buf_in1[0]); + if (len <= MAX_LEN) { + payload += len; + payload1_len1 = len; + } + + len = bpf_probe_read_kernel_str(payload, MAX_LEN, &buf_in2[0]); + if (len <= MAX_LEN) { + payload += len; + payload1_len2 = len; + } + + total1 = payload - (void *)payload1; + + return 0; +} + +SEC("tp_btf/sys_enter") +int handler32(void *regs) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + void *payload = payload2; + u32 len; + + /* ignore irrelevant invocations */ + if (test_pid != pid || !capture) + return 0; + + len = bpf_probe_read_kernel_str(payload, MAX_LEN, &buf_in1[0]); + if (len <= MAX_LEN) { + payload += len; + payload2_len1 = len; + } + + len = bpf_probe_read_kernel_str(payload, MAX_LEN, &buf_in2[0]); + if (len <= MAX_LEN) { + payload += len; + payload2_len2 = len; + } + + total2 = payload - (void *)payload2; + + return 0; +} + +SEC("tp_btf/sys_exit") +int handler_exit(void *regs) +{ + long bla; + + if (bpf_probe_read_kernel(&bla, sizeof(bla), 0)) + return 1; + else + return 0; +} + +char LICENSE[] SEC("license") = "GPL";