From patchwork Mon Aug 21 17:34:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Marchevsky X-Patchwork-Id: 13359697 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D5BB8C16 for ; Mon, 21 Aug 2023 17:35:02 +0000 (UTC) Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82D84114 for ; Mon, 21 Aug 2023 10:34:57 -0700 (PDT) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 37LGS8si002201 for ; Mon, 21 Aug 2023 10:34:57 -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=bCen6zmSioX3EuaMKsc3zqIezrOBODd4ABsAZsebbOE=; b=Hgvok7g3jGH1uc4cst1M5exNgCuS1VCj5aaQHUvY6krrCF45vtfkPfXFKZUuQvJojzrT IPY6qqiJJDz5eVtu0ES5fn2/1OticOm1vq2DIKdvBHADHd9QqhLnzcnjbUw+7SS8wqYw B+S0lJLoA5OHji2KlLOPzi2GoXmsE6gV8LI= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3smbfc0mm9-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 21 Aug 2023 10:34:57 -0700 Received: from twshared34392.14.frc2.facebook.com (2620:10d:c0a8:1b::30) by mail.thefacebook.com (2620:10d:c0a8:83::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 21 Aug 2023 10:34:28 -0700 Received: by devbig077.ldc1.facebook.com (Postfix, from userid 158236) id DDCE82300E6EA; Mon, 21 Aug 2023 10:34:17 -0700 (PDT) From: Dave Marchevsky To: CC: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Kernel Team , , , Dave Marchevsky Subject: [PATCH v2 bpf-next 3/3] selftests/bpf: Add tests for open-coded task_vma iter Date: Mon, 21 Aug 2023 10:34:15 -0700 Message-ID: <20230821173415.1970776-4-davemarchevsky@fb.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230821173415.1970776-1-davemarchevsky@fb.com> References: <20230821173415.1970776-1-davemarchevsky@fb.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: UifQGwhAfAwGYaZQuBzyKkSfnG5Vc_Fc X-Proofpoint-ORIG-GUID: UifQGwhAfAwGYaZQuBzyKkSfnG5Vc_Fc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-08-21_06,2023-08-18_01,2023-05-22_02 X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_NONE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The open-coded task_vma iter added earlier in this series allows for natural iteration over a task's vmas using existing open-coded iter infrastructure, specifically bpf_for_each. This patch adds a test demonstrating this pattern and validating correctness. The vma->vm_start and vma->vm_end addresses of the first 1000 vmas are recorded and compared to /proc/PID/maps output. As expected, both see the same vmas and addresses - with the exception of the [vsyscall] vma - which is explained in a comment in the prog_tests program. Signed-off-by: Dave Marchevsky --- .../testing/selftests/bpf/prog_tests/iters.c | 71 +++++++++++++++++++ .../selftests/bpf/progs/iters_task_vma.c | 56 +++++++++++++++ 2 files changed, 127 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/iters_task_vma.c diff --git a/tools/testing/selftests/bpf/prog_tests/iters.c b/tools/testing/selftests/bpf/prog_tests/iters.c index 10804ae5ae97..f91f4a49066a 100644 --- a/tools/testing/selftests/bpf/prog_tests/iters.c +++ b/tools/testing/selftests/bpf/prog_tests/iters.c @@ -8,6 +8,7 @@ #include "iters_looping.skel.h" #include "iters_num.skel.h" #include "iters_testmod_seq.skel.h" +#include "iters_task_vma.skel.h" static void subtest_num_iters(void) { @@ -90,6 +91,74 @@ static void subtest_testmod_seq_iters(void) iters_testmod_seq__destroy(skel); } +static void subtest_task_vma_iters(void) +{ + unsigned long start, end, bpf_iter_start, bpf_iter_end; + struct iters_task_vma *skel; + char rest_of_line[1000]; + unsigned int seen; + int err; + FILE *f; + + skel = iters_task_vma__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + bpf_program__set_autoload(skel->progs.iter_task_vma_for_each, true); + + err = iters_task_vma__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + skel->bss->target_pid = getpid(); + + err = iters_task_vma__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + iters_task_vma__detach(skel); + getpgid(skel->bss->target_pid); + + if (!ASSERT_GT(skel->bss->vmas_seen, 0, "vmas_seen_gt_zero")) + goto cleanup; + + f = fopen("/proc/self/maps", "r"); + if (!ASSERT_OK_PTR(f, "proc_maps_fopen")) + goto cleanup; + + seen = 0; + while (fscanf(f, "%lx-%lx %[^\n]\n", &start, &end, rest_of_line) == 3) { + /* [vsyscall] vma isn't _really_ part of task->mm vmas. + * /proc/PID/maps returns it when out of vmas - see get_gate_vma + * calls in fs/proc/task_mmu.c + */ + if (strstr(rest_of_line, "[vsyscall]")) + continue; + + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.vm_start), + &seen, &bpf_iter_start); + if (!ASSERT_OK(err, "vm_start map_lookup_elem")) + goto cleanup; + + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.vm_end), + &seen, &bpf_iter_end); + if (!ASSERT_OK(err, "vm_end map_lookup_elem")) + goto cleanup; + + ASSERT_EQ(bpf_iter_start, start, "vma->vm_start match"); + ASSERT_EQ(bpf_iter_end, end, "vma->vm_end match"); + seen++; + } + + fclose(f); + + if (!ASSERT_EQ(skel->bss->vmas_seen, seen, "vmas_seen_eq")) + goto cleanup; + +cleanup: + iters_task_vma__destroy(skel); +} + void test_iters(void) { RUN_TESTS(iters_state_safety); @@ -103,4 +172,6 @@ void test_iters(void) subtest_num_iters(); if (test__start_subtest("testmod_seq")) subtest_testmod_seq_iters(); + if (test__start_subtest("task_vma")) + subtest_task_vma_iters(); } diff --git a/tools/testing/selftests/bpf/progs/iters_task_vma.c b/tools/testing/selftests/bpf/progs/iters_task_vma.c new file mode 100644 index 000000000000..b961d0a12223 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/iters_task_vma.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "vmlinux.h" +#include +#include "bpf_misc.h" + +pid_t target_pid = 0; +unsigned int vmas_seen = 0; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1000); + __type(key, int); + __type(value, unsigned long); +} vm_start SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1000); + __type(key, int); + __type(value, unsigned long); +} vm_end SEC(".maps"); + +SEC("?raw_tp/sys_enter") +int iter_task_vma_for_each(const void *ctx) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct vm_area_struct *vma; + unsigned long *start, *end; + + if (task->pid != target_pid) + return 0; + + bpf_for_each(task_vma, vma, task, 0) { + if (vmas_seen >= 1000) + break; + + start = bpf_map_lookup_elem(&vm_start, &vmas_seen); + if (!start) + break; + *start = vma->vm_start; + + end = bpf_map_lookup_elem(&vm_end, &vmas_seen); + if (!end) + break; + *end = vma->vm_end; + + vmas_seen++; + } + return 0; +} + +char _license[] SEC("license") = "GPL";