From patchwork Wed Jul 22 21:12:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1334186 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BBp8y6tSNz9sRW for ; Thu, 23 Jul 2020 07:13:22 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733022AbgGVVNW convert rfc822-to-8bit (ORCPT ); Wed, 22 Jul 2020 17:13:22 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:44244 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1733020AbgGVVNV (ORCPT ); Wed, 22 Jul 2020 17:13:21 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-91-OUWEx-chNhe75FG3lkmE6w-1; Wed, 22 Jul 2020 17:13:14 -0400 X-MC-Unique: OUWEx-chNhe75FG3lkmE6w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8E994185BDF3; Wed, 22 Jul 2020 21:13:12 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.194.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8115219C4F; Wed, 22 Jul 2020 21:13:09 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Wenbo Zhang , netdev@vger.kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , Martin KaFai Lau , David Miller , John Fastabend , KP Singh , Brendan Gregg , Florent Revest , Al Viro Subject: [PATCH v8 bpf-next 12/13] selftests/bpf: Add test for d_path helper Date: Wed, 22 Jul 2020 23:12:22 +0200 Message-Id: <20200722211223.1055107-13-jolsa@kernel.org> In-Reply-To: <20200722211223.1055107-1-jolsa@kernel.org> References: <20200722211223.1055107-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Adding test for d_path helper which is pretty much copied from Wenbo Zhang's test for bpf_get_fd_path, which never made it in. The test is doing fstat/close on several fd types, and verifies we got the d_path helper working on kernel probes for vfs_getattr/filp_close functions. Original-patch-by: Wenbo Zhang Signed-off-by: Jiri Olsa --- .../testing/selftests/bpf/prog_tests/d_path.c | 162 ++++++++++++++++++ .../testing/selftests/bpf/progs/test_d_path.c | 64 +++++++ 2 files changed, 226 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/d_path.c create mode 100644 tools/testing/selftests/bpf/progs/test_d_path.c diff --git a/tools/testing/selftests/bpf/prog_tests/d_path.c b/tools/testing/selftests/bpf/prog_tests/d_path.c new file mode 100644 index 000000000000..3b8f87fb17d7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/d_path.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include +#include +#include +#include + +#define MAX_PATH_LEN 128 +#define MAX_FILES 7 +#define MAX_EVENT_NUM 16 + +#include "test_d_path.skel.h" + +static struct { + __u32 cnt; + char paths[MAX_EVENT_NUM][MAX_PATH_LEN]; +} src; + +static int set_pathname(int fd, pid_t pid) +{ + char buf[MAX_PATH_LEN]; + + snprintf(buf, MAX_PATH_LEN, "/proc/%d/fd/%d", pid, fd); + return readlink(buf, src.paths[src.cnt++], MAX_PATH_LEN); +} + +static int trigger_fstat_events(pid_t pid) +{ + int sockfd = -1, procfd = -1, devfd = -1; + int localfd = -1, indicatorfd = -1; + int pipefd[2] = { -1, -1 }; + struct stat fileStat; + int ret = -1; + + /* unmountable pseudo-filesystems */ + if (CHECK_FAIL(pipe(pipefd) < 0)) + return ret; + /* unmountable pseudo-filesystems */ + sockfd = socket(AF_INET, SOCK_STREAM, 0); + if (CHECK_FAIL(sockfd < 0)) + goto out_close; + /* mountable pseudo-filesystems */ + procfd = open("/proc/self/comm", O_RDONLY); + if (CHECK_FAIL(procfd < 0)) + goto out_close; + devfd = open("/dev/urandom", O_RDONLY); + if (CHECK_FAIL(devfd < 0)) + goto out_close; + localfd = open("/tmp/d_path_loadgen.txt", O_CREAT | O_RDONLY); + if (CHECK_FAIL(localfd < 0)) + goto out_close; + /* bpf_d_path will return path with (deleted) */ + remove("/tmp/d_path_loadgen.txt"); + indicatorfd = open("/tmp/", O_PATH); + if (CHECK_FAIL(indicatorfd < 0)) + goto out_close; + + ret = set_pathname(pipefd[0], pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(pipefd[1], pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(sockfd, pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(procfd, pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(devfd, pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(localfd, pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + ret = set_pathname(indicatorfd, pid); + if (CHECK_FAIL(ret < 0)) + goto out_close; + + /* triggers vfs_getattr */ + fstat(pipefd[0], &fileStat); + fstat(pipefd[1], &fileStat); + fstat(sockfd, &fileStat); + fstat(procfd, &fileStat); + fstat(devfd, &fileStat); + fstat(localfd, &fileStat); + fstat(indicatorfd, &fileStat); + +out_close: + /* triggers filp_close */ + close(pipefd[0]); + close(pipefd[1]); + close(sockfd); + close(procfd); + close(devfd); + close(localfd); + close(indicatorfd); + return ret; +} + +void test_d_path(void) +{ + struct test_d_path__bss *bss; + struct test_d_path *skel; + __u32 duration = 0; + int err; + + skel = test_d_path__open_and_load(); + if (CHECK(!skel, "test_d_path_load", "d_path skeleton failed\n")) + goto cleanup; + + err = test_d_path__attach(skel); + if (CHECK(err, "modify_return", "attach failed: %d\n", err)) + goto cleanup; + + bss = skel->bss; + bss->my_pid = getpid(); + + err = trigger_fstat_events(bss->my_pid); + if (CHECK_FAIL(err < 0)) + goto cleanup; + + for (int i = 0; i < MAX_FILES; i++) { + if (i < 3) { + CHECK((bss->paths_stat[i][0] == 0), "d_path", + "failed to filter fs [%d]: %s vs %s\n", + i, src.paths[i], bss->paths_stat[i]); + CHECK((bss->paths_close[i][0] == 0), "d_path", + "failed to filter fs [%d]: %s vs %s\n", + i, src.paths[i], bss->paths_close[i]); + CHECK((bss->rets_stat[i] < 0), "d_path", + "failed to filter fs [%d]: %s vs %s\n", + i, src.paths[i], bss->paths_close[i]); + CHECK((bss->rets_close[i] < 0), "d_path", + "failed to filter fs [%d]: %s vs %s\n", + i, src.paths[i], bss->paths_close[i]); + } else { + CHECK(strncmp(src.paths[i], bss->paths_stat[i], MAX_PATH_LEN), + "d_path", + "failed to get stat path[%d]: %s vs %s\n", + i, src.paths[i], bss->paths_stat[i]); + CHECK(strncmp(src.paths[i], bss->paths_close[i], MAX_PATH_LEN), + "d_path", + "failed to get close path[%d]: %s vs %s\n", + i, src.paths[i], bss->paths_close[i]); + /* The d_path helper returns size plus NUL char, hence + 1 */ + CHECK(bss->rets_stat[i] != strlen(bss->paths_stat[i]) + 1, + "d_path", + "failed to match stat return [%d]: %d vs %zd [%s]\n", + i, bss->rets_stat[i], strlen(bss->paths_stat[i]) + 1, + bss->paths_stat[i]); + CHECK(bss->rets_close[i] != strlen(bss->paths_stat[i]) + 1, + "d_path", + "failed to match stat return [%d]: %d vs %zd [%s]\n", + i, bss->rets_close[i], strlen(bss->paths_close[i]) + 1, + bss->paths_stat[i]); + } + } + +cleanup: + test_d_path__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_d_path.c b/tools/testing/selftests/bpf/progs/test_d_path.c new file mode 100644 index 000000000000..e02dce614256 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_d_path.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include +#include + +#define MAX_PATH_LEN 128 +#define MAX_EVENT_NUM 16 + +pid_t my_pid; +__u32 cnt_stat; +__u32 cnt_close; +char paths_stat[MAX_EVENT_NUM][MAX_PATH_LEN]; +char paths_close[MAX_EVENT_NUM][MAX_PATH_LEN]; +int rets_stat[MAX_EVENT_NUM]; +int rets_close[MAX_EVENT_NUM]; + +SEC("fentry/vfs_getattr") +int BPF_PROG(prog_stat, struct path *path, struct kstat *stat, + __u32 request_mask, unsigned int query_flags) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + int ret; + + if (pid != my_pid) + return 0; + + if (cnt_stat >= MAX_EVENT_NUM) + return 0; + ret = bpf_d_path(path, paths_stat[cnt_stat], MAX_PATH_LEN); + + /* We need to recheck cnt_stat for verifier. */ + if (cnt_stat >= MAX_EVENT_NUM) + return 0; + rets_stat[cnt_stat] = ret; + + cnt_stat++; + return 0; +} + +SEC("fentry/filp_close") +int BPF_PROG(prog_close, struct file *file, void *id) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + int ret; + + if (pid != my_pid) + return 0; + + if (cnt_close >= MAX_EVENT_NUM) + return 0; + ret = bpf_d_path(&file->f_path, + paths_close[cnt_close], MAX_PATH_LEN); + + /* We need to recheck cnt_stat for verifier. */ + if (cnt_close >= MAX_EVENT_NUM) + return 0; + rets_close[cnt_close] = ret; + + cnt_close++; + return 0; +} + +char _license[] SEC("license") = "GPL";