From patchwork Tue Feb 28 09:32:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13154612 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 0567AC7EE31 for ; Tue, 28 Feb 2023 09:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231373AbjB1JeR (ORCPT ); Tue, 28 Feb 2023 04:34:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231375AbjB1JeJ (ORCPT ); Tue, 28 Feb 2023 04:34:09 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 934772069E; Tue, 28 Feb 2023 01:33:57 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 1DFDD61027; Tue, 28 Feb 2023 09:33:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4462DC433D2; Tue, 28 Feb 2023 09:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677576836; bh=v7m3NBy45N+El792surZKP+8N2u7TLJVtr7h9aVoZ3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CyNEGeiJh2hA0zwJNzVbvcRv6+QHDsr6iTjXBPAfvWILgkkPZYkyJWjabJgFTcgOz +tEugTlLcvM2FjUSspt2SZrIkU9+pvmpiBl5uTt7FuqPEN7vfyub3oHWfvuaqO9aSs Jmi26GTZAFipKJDW8bpPIsCZ4s20pU2eQaaPd6muUmEwKDazp16sZJLHI7p0M85fXk lS1p/MSgROM6HKQrNDqGsyhrIABsgqU4QshrTJNIVI519Tor+O7fWvS/tQkZoVR4wQ 74c9LC0+Og9JHKP8WxKXm91ifBrX/0gdPSBVu9EEp1wdP2NDpBoUNtRyK17iMJLJ3c EeioIfex1Td4g== 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 Subject: [PATCH RFC v2 bpf-next 8/9] selftests/bpf: Add inode_build_id test Date: Tue, 28 Feb 2023 10:32:05 +0100 Message-Id: <20230228093206.821563-9-jolsa@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230228093206.821563-1-jolsa@kernel.org> References: <20230228093206.821563-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The test attaches bpf program to sched_process_exec tracepoint and gets build of executed file from bprm->file->f_inode object. We use urandom_read as the test program and in addition we also attach uprobe to liburandom_read.so:urandlib_read_without_sema and retrieve and check build id of that shared library. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/inode_build_id.c | 68 +++++++++++++++++++ .../selftests/bpf/progs/inode_build_id.c | 62 +++++++++++++++++ tools/testing/selftests/bpf/test_progs.h | 10 +++ 3 files changed, 140 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/inode_build_id.c create mode 100644 tools/testing/selftests/bpf/progs/inode_build_id.c diff --git a/tools/testing/selftests/bpf/prog_tests/inode_build_id.c b/tools/testing/selftests/bpf/prog_tests/inode_build_id.c new file mode 100644 index 000000000000..d0add90f187d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/inode_build_id.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "inode_build_id.skel.h" +#include "trace_helpers.h" + +void test_inode_build_id(void) +{ + int go[2], err, child_pid, child_status, c = 1, sz; + char build_id[BPF_BUILD_ID_SIZE]; + struct inode_build_id *skel; + + skel = inode_build_id__open_and_load(); + if (!ASSERT_OK_PTR(skel, "inode_build_id__open_and_load")) + return; + + if (!ASSERT_OK(pipe(go), "pipe")) + goto out; + + child_pid = fork(); + if (child_pid < 0) + goto out; + + /* child */ + if (child_pid == 0) { + /* wait for parent's pid update */ + err = read(go[0], &c, 1); + if (!ASSERT_EQ(err, 1, "child_read_pipe")) + exit(err); + + execle("./urandom_read", "urandom_read", NULL, NULL); + exit(errno); + } + + /* parent, update child's pid and kick it */ + skel->bss->pid = child_pid; + + err = inode_build_id__attach(skel); + if (!ASSERT_OK(err, "inode_build_id__attach")) + goto out; + + err = write(go[1], &c, 1); + if (!ASSERT_EQ(err, 1, "child_write_pipe")) + goto out; + + /* wait for child to exit */ + waitpid(child_pid, &child_status, 0); + if (!ASSERT_EQ(WEXITSTATUS(child_status), 0, "child_exit_value")) + goto out; + + sz = read_build_id("./urandom_read", build_id); + if (!ASSERT_GT(sz, 0, "read_build_id")) + goto out; + + ASSERT_EQ(skel->bss->build_id_bin_size, sz, "build_id_bin_size"); + ASSERT_MEMEQ(skel->bss->build_id_bin, build_id, sz, "build_id_bin"); + + sz = read_build_id("./liburandom_read.so", build_id); + if (!ASSERT_GT(sz, 0, "read_build_id")) + goto out; + + ASSERT_EQ(skel->bss->build_id_lib_size, sz, "build_id_lib_size"); + ASSERT_MEMEQ(skel->bss->build_id_lib, build_id, sz, "build_id_lib"); + +out: + inode_build_id__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/inode_build_id.c b/tools/testing/selftests/bpf/progs/inode_build_id.c new file mode 100644 index 000000000000..eceb215b56b8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/inode_build_id.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include "err.h" +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +int pid; + +u32 build_id_bin_size; +u32 build_id_lib_size; + +char build_id_bin[20]; +char build_id_lib[20]; + +static int store_build_id(struct inode *inode, char *build_id, u32 *sz) +{ + struct build_id *bid; + + bid = inode->i_build_id; + if (IS_ERR_OR_NULL(bid)) + return 0; + *sz = bid->sz; + if (bid->sz > sizeof(bid->data)) + return 0; + __builtin_memcpy(build_id, bid->data, sizeof(bid->data)); + return 0; +} + +SEC("tp_btf/sched_process_exec") +int BPF_PROG(prog, struct task_struct *p, pid_t old_pid, struct linux_binprm *bprm) +{ + int cur_pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != cur_pid) + return 0; + if (!bprm->file || !bprm->file->f_inode) + return 0; + return store_build_id(bprm->file->f_inode, build_id_bin, &build_id_bin_size); +} + +static long check_vma(struct task_struct *task, struct vm_area_struct *vma, + void *data) +{ + if (!vma || !vma->vm_file || !vma->vm_file->f_inode) + return 0; + return store_build_id(vma->vm_file->f_inode, build_id_lib, &build_id_lib_size); +} + +SEC("uprobe/liburandom_read.so:urandlib_read_without_sema") +int BPF_UPROBE(urandlib_read_without_sema) +{ + struct task_struct *task = bpf_get_current_task_btf(); + int cur_pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != cur_pid) + return 0; + return bpf_find_vma(task, ctx->ip, check_vma, NULL, 0); +} diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index 3825c2797a4b..8156d6d4cb3b 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -310,6 +310,16 @@ int test__join_cgroup(const char *path); ___ok; \ }) +#define ASSERT_MEMEQ(actual, expected, sz, name) ({ \ + static int duration = 0; \ + const char *___act = actual; \ + const char *___exp = expected; \ + bool ___ok = memcmp(___act, ___exp, sz) == 0; \ + CHECK(!___ok, (name), \ + "unexpected %s does not match\n", (name)); \ + ___ok; \ +}) + #define ASSERT_STRNEQ(actual, expected, len, name) ({ \ static int duration = 0; \ const char *___act = actual; \