From patchwork Thu Mar 16 17:01:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13178107 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8214FC6FD1F for ; Thu, 16 Mar 2023 17:04:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231438AbjCPRE2 (ORCPT ); Thu, 16 Mar 2023 13:04:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231248AbjCPREL (ORCPT ); Thu, 16 Mar 2023 13:04:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D2CC2007C; Thu, 16 Mar 2023 10:03:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C4E28B8227C; Thu, 16 Mar 2023 17:03:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 333CFC433EF; Thu, 16 Mar 2023 17:03:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678986219; bh=BTNFjFR6qedMLNKodJS0I96kmDjan/r2p24kIgmK3/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d8LC/I53yNMvhKiJ3Oq2YxbSToYguXOf9YL7kJ0By7G0BvjLuZlszeTUgYFPhKnB6 KllaisUOamvTTtPjic6nqgztIrsZwVGjjWK7vG8ozFTcCgp2HkZJ6X4LbSKvyuVkjT qcXbW0Ckyvbgso20/1phg1107C1gTiClR3Hj+lRcjG0M0Ki2RtZMhnjx3Mmkobv12K Xx2SF6Fu+XDxUx7rHArRgUS80ARKH6R5eLB3AJkRH4Tn9g3ZGexQwoFvU3DWzsHOsF 9xxpJNXwqQRN1HimKUC14dXXfdR2JKVwCqre7Kw9d/jzAuYtlvOVeUrVxp6AMWSvzO Dkxo8jLgLZv+w== From: Jiri Olsa To: Alexei Starovoitov , Andrii Nakryiko , Hao Luo , Andrew Morton , Alexander Viro , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Matthew Wilcox Cc: bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-perf-users@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Daniel Borkmann , Namhyung Kim , Dave Chinner Subject: [PATCHv3 bpf-next 8/9] selftests/bpf: Add iter_task_vma_buildid test Date: Thu, 16 Mar 2023 18:01:48 +0100 Message-Id: <20230316170149.4106586-9-jolsa@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230316170149.4106586-1-jolsa@kernel.org> References: <20230316170149.4106586-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Testing iterator access to build id in vma->vm_file object by storing each binary with build id into map and checking it against build id retrieved in user space. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/bpf_iter.c | 78 +++++++++++++++++++ .../bpf/progs/bpf_iter_task_vma_buildid.c | 56 +++++++++++++ 2 files changed, 134 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 1f02168103dd..c7dd89e7cad0 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -33,6 +33,7 @@ #include "bpf_iter_bpf_link.skel.h" #include "bpf_iter_ksym.skel.h" #include "bpf_iter_sockmap.skel.h" +#include "bpf_iter_task_vma_buildid.skel.h" static int duration; @@ -1536,6 +1537,81 @@ static void test_task_vma_dead_task(void) bpf_iter_task_vma__destroy(skel); } +#define D_PATH_BUF_SIZE 1024 + +struct build_id { + u32 sz; + char data[BPF_BUILD_ID_SIZE]; +}; + +static void test_task_vma_buildid(void) +{ + int err, iter_fd = -1, proc_maps_fd = -1, sz; + struct bpf_iter_task_vma_buildid *skel; + char key[D_PATH_BUF_SIZE], *prev_key; + char build_id[BPF_BUILD_ID_SIZE]; + int len, files_fd, cnt = 0; + struct build_id val; + char c; + + skel = bpf_iter_task_vma_buildid__open_and_load(); + if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma_buildid__open_and_load")) + return; + + skel->links.proc_maps = bpf_program__attach_iter( + skel->progs.proc_maps, NULL); + + if (!ASSERT_OK_PTR(skel->links.proc_maps, "bpf_program__attach_iter")) { + skel->links.proc_maps = NULL; + goto out; + } + + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.proc_maps)); + if (!ASSERT_GE(iter_fd, 0, "create_iter")) + goto out; + + /* trigger the iterator, there's no output, just map */ + len = read(iter_fd, &c, 1); + ASSERT_EQ(len, 0, "len_check"); + + files_fd = bpf_map__fd(skel->maps.files); + + prev_key = NULL; + + while (true) { + err = bpf_map_get_next_key(files_fd, prev_key, &key); + if (err) { + if (errno == ENOENT) + err = 0; + break; + } + if (bpf_map_lookup_elem(files_fd, key, &val)) + break; + if (!ASSERT_LE(val.sz, BPF_BUILD_ID_SIZE, "buildid_size")) + break; + + sz = read_build_id(key, build_id); + /* If there's an error, the build id is not present or malformed, kernel + * should see the same result and bpf program pushed zero build id. + */ + if (sz < 0) { + memset(build_id, 0x0, BPF_BUILD_ID_SIZE); + sz = BPF_BUILD_ID_SIZE; + } + ASSERT_EQ(val.sz, sz, "build_id_size"); + ASSERT_MEMEQ(val.data, build_id, sz, "build_id_data"); + + prev_key = key; + cnt++; + } + + printf("checked %d files\n", cnt); +out: + close(proc_maps_fd); + close(iter_fd); + bpf_iter_task_vma_buildid__destroy(skel); +} + void test_bpf_sockmap_map_iter_fd(void) { struct bpf_iter_sockmap *skel; @@ -1659,6 +1735,8 @@ void test_bpf_iter(void) test_task_vma(); if (test__start_subtest("task_vma_dead_task")) test_task_vma_dead_task(); + if (test__start_subtest("task_vma_buildid")) + test_task_vma_buildid(); if (test__start_subtest("task_btf")) test_task_btf(); if (test__start_subtest("tcp4")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c new file mode 100644 index 000000000000..11a59c0f1aba --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bpf_iter.h" +#include "err.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +#define VM_EXEC 0x00000004 +#define D_PATH_BUF_SIZE 1024 + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 10000); + __type(key, char[D_PATH_BUF_SIZE]); + __type(value, struct build_id); +} files SEC(".maps"); + +static char path[D_PATH_BUF_SIZE]; +static struct build_id build_id; + +SEC("iter/task_vma") +int proc_maps(struct bpf_iter__task_vma *ctx) +{ + struct vm_area_struct *vma = ctx->vma; + struct task_struct *task = ctx->task; + struct file *file; + + if (task == (void *)0 || vma == (void *)0) + return 0; + + if (!(vma->vm_flags & VM_EXEC)) + return 0; + + file = vma->vm_file; + if (!file) + return 0; + + __builtin_memset(path, 0x0, D_PATH_BUF_SIZE); + bpf_d_path(&file->f_path, (char *) &path, D_PATH_BUF_SIZE); + + if (bpf_map_lookup_elem(&files, &path)) + return 0; + + if (IS_ERR_OR_NULL(file->f_build_id)) { + /* On error return empty build id. */ + __builtin_memset(&build_id.data, 0x0, sizeof(build_id.data)); + build_id.sz = BUILD_ID_SIZE_MAX; + } else { + __builtin_memcpy(&build_id, file->f_build_id, sizeof(*file->f_build_id)); + } + + bpf_map_update_elem(&files, &path, &build_id, 0); + return 0; +}