From patchwork Wed Oct 27 22:00:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 12588849 X-Patchwork-Delegate: bpf@iogearbox.net 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9636C433EF for ; Wed, 27 Oct 2021 22:00:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA4A3610CA for ; Wed, 27 Oct 2021 22:00:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229946AbhJ0WDS (ORCPT ); Wed, 27 Oct 2021 18:03:18 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:13434 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbhJ0WDS (ORCPT ); Wed, 27 Oct 2021 18:03:18 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19RLfRuQ031166 for ; Wed, 27 Oct 2021 15:00:52 -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=oYyKoBU/ysy/RT9UZVgiFUATRbAvLEUIdecO1J+uyZQ=; b=gSLfinbFX8z0aWQG1R3xnpvyx3JfC/MQaM/nC/1D0IgXV+e4Gw+QA3QHcvCcbVX462N1 idFFb/UPeI8jvHVMWIgE0mSOyVhDCAPXvKHZ07ztdRIPZs4nfKFnBPFQ+UArC6+AqydA 5RtQSm/QI2FuLtMoMoHvsfdgM+jfINcmLpI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3by6x1p0ev-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 27 Oct 2021 15:00:52 -0700 Received: from intmgw002.06.ash9.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Wed, 27 Oct 2021 15:00:51 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 6BC7B1B7DA3EF; Wed, 27 Oct 2021 15:00:50 -0700 (PDT) From: Song Liu To: , CC: , , , , , Song Liu Subject: [PATCH bpf-next 2/2] selftests/bpf: add tests for bpf_find_vma Date: Wed, 27 Oct 2021 15:00:43 -0700 Message-ID: <20211027220043.1937648-3-songliubraving@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211027220043.1937648-1-songliubraving@fb.com> References: <20211027220043.1937648-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-ORIG-GUID: 1Q7A7sa9DIlURqofvejm1hUI-5mZqX_- X-Proofpoint-GUID: 1Q7A7sa9DIlURqofvejm1hUI-5mZqX_- X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-10-27_06,2021-10-26_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 suspectscore=0 lowpriorityscore=0 clxscore=1015 bulkscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 impostorscore=0 mlxscore=0 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2110270121 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add tests for bpf_find_vma in perf_event program and kprobe program. The perf_event program is triggered from NMI context, so the second call of bpf_find_vma() will return -EBUSY (irq_work busy). The kprobe program, on the other hand, does not have this constraint. Signed-off-by: Song Liu --- .../selftests/bpf/prog_tests/find_vma.c | 95 +++++++++++++++++++ tools/testing/selftests/bpf/progs/find_vma.c | 70 ++++++++++++++ 2 files changed, 165 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/find_vma.c create mode 100644 tools/testing/selftests/bpf/progs/find_vma.c diff --git a/tools/testing/selftests/bpf/prog_tests/find_vma.c b/tools/testing/selftests/bpf/prog_tests/find_vma.c new file mode 100644 index 0000000000000..34d4d02c60153 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/find_vma.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#include +#include +#include +#include "find_vma.skel.h" + +static void test_and_reset_skel(struct find_vma *skel, int expected_find_zero_ret) +{ + ASSERT_EQ(skel->bss->found_vm_exec, 1, "found_vm_exec"); + ASSERT_EQ(skel->data->find_addr_ret, 0, "find_addr_ret"); + ASSERT_EQ(skel->data->find_zero_ret, expected_find_zero_ret, "find_zero_ret"); + ASSERT_OK_PTR(strstr(skel->bss->d_iname, "test_progs"), "find_test_progs"); + + skel->bss->found_vm_exec = 0; + skel->data->find_addr_ret = -1; + skel->data->find_zero_ret = -1; + skel->bss->d_iname[0] = 0; +} + +static int open_pe(void) +{ + struct perf_event_attr attr = {0}; + int pfd; + + /* create perf event */ + attr.size = sizeof(attr); + attr.type = PERF_TYPE_HARDWARE; + attr.config = PERF_COUNT_HW_CPU_CYCLES; + attr.freq = 1; + attr.sample_freq = 4000; + pfd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, PERF_FLAG_FD_CLOEXEC); + + return pfd >= 0 ? pfd : -errno; +} + +static void test_find_vma_pe(struct find_vma *skel) +{ + struct bpf_link *link = NULL; + volatile int j = 0; + int pfd = -1, i; + + pfd = open_pe(); + if (pfd < 0) { + if (pfd == -ENOENT || pfd == -EOPNOTSUPP) { + printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__); + test__skip(); + } + if (!ASSERT_GE(pfd, 0, "perf_event_open")) + goto cleanup; + } + + link = bpf_program__attach_perf_event(skel->progs.handle_pe, pfd); + if (!ASSERT_OK_PTR(link, "attach_perf_event")) + goto cleanup; + + for (i = 0; i < 1000000; ++i) + ++j; + + test_and_reset_skel(skel, -EBUSY /* in nmi, irq_work is busy */); +cleanup: + bpf_link__destroy(link); + close(pfd); + /* caller will clean up skel */ +} + +static void test_find_vma_kprobe(struct find_vma *skel) +{ + int err; + + err = find_vma__attach(skel); + if (!ASSERT_OK(err, "get_branch_snapshot__attach")) + return; /* caller will cleanup skel */ + + getpgid(skel->bss->target_pid); + test_and_reset_skel(skel, -ENOENT /* could not find vma for ptr 0 */); +} + +void serial_test_find_vma(void) +{ + struct find_vma *skel; + + skel = find_vma__open_and_load(); + if (!ASSERT_OK_PTR(skel, "find_vma__open_and_load")) + return; + + skel->bss->target_pid = getpid(); + skel->bss->addr = (__u64)test_find_vma_pe; + + test_find_vma_pe(skel); + usleep(100000); /* allow the irq_work to finish */ + test_find_vma_kprobe(skel); + + find_vma__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/find_vma.c b/tools/testing/selftests/bpf/progs/find_vma.c new file mode 100644 index 0000000000000..2776718a54e29 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/find_vma.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct callback_ctx { + int dummy; +}; + +#define VM_EXEC 0x00000004 +#define DNAME_INLINE_LEN 32 + +pid_t target_pid = 0; +char d_iname[DNAME_INLINE_LEN] = {0}; +__u32 found_vm_exec = 0; +__u64 addr = 0; +int find_zero_ret = -1; +int find_addr_ret = -1; + +static __u64 +check_vma(struct task_struct *task, struct vm_area_struct *vma, + struct callback_ctx *data) +{ + if (vma->vm_file) + bpf_probe_read_kernel_str(d_iname, DNAME_INLINE_LEN - 1, + vma->vm_file->f_path.dentry->d_iname); + + /* check for VM_EXEC */ + if (vma->vm_flags & VM_EXEC) + found_vm_exec = 1; + + return 0; +} + +SEC("kprobe/__x64_sys_getpgid") +int handle_getpid(void) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct callback_ctx data = {0}; + + if (task->pid != target_pid) + return 0; + + find_addr_ret = bpf_find_vma(task, addr, check_vma, &data, 0); + + /* this should return -ENOENT */ + find_zero_ret = bpf_find_vma(task, 0, check_vma, &data, 0); + return 0; +} + +SEC("perf_event") +int handle_pe(void) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct callback_ctx data = {0}; + + if (task->pid != target_pid) + return 0; + + find_addr_ret = bpf_find_vma(task, addr, check_vma, &data, 0); + + /* In NMI, this should return -EBUSY, as the previous call is using + * the irq_work. + */ + find_zero_ret = bpf_find_vma(task, 0, check_vma, &data, 0); + return 0; +}