From patchwork Wed Feb 1 13:57:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13124362 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 0639BC636D3 for ; Wed, 1 Feb 2023 13:59:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232323AbjBAN7O (ORCPT ); Wed, 1 Feb 2023 08:59:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231904AbjBAN64 (ORCPT ); Wed, 1 Feb 2023 08:58:56 -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 6EFCB9743; Wed, 1 Feb 2023 05:58:35 -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 0BB38617BA; Wed, 1 Feb 2023 13:58:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABA6EC433EF; Wed, 1 Feb 2023 13:58:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675259914; bh=9vGidv5KK+VK6x+sZbtxgG6kbbBhATOZQnveCyOWlzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XJ3SKUrQ3KRicKqjZGSlmATsqBY/2uxl+ittryw9F94qxr3IHhp8yiAmNVgZV4F28 BvIzPZXif+N2jAVTa87Q4OyhJ+2kVDPKOU/IfJHNjiICJ3BTzDoCKr81v0+8jZF2/3 tyG7KooQLVd33ycGsDNsM+PVm4rVb8RcSASZfDR52CRsHXcm23iTtf32iutEA3ibfw mw2MTKI3hM/tHgLmqSy652HghxvCdCrkKNsbVbt5x3rkV5FjD4Jg+YJvC+SdbAj0nR i3tcDShTPNAaM96Nt1HVkQOA9p15tNuJ5D77H274EWMbGtBD12KW7WqTpQGtJ9TkDo L9AEDZVsw0XpA== From: Jiri Olsa To: Alexei Starovoitov , Andrii Nakryiko , Hao Luo , Andrew Morton , Alexander Viro , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo 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 Subject: [PATCH RFC 4/5] selftests/bpf: Add file_build_id test Date: Wed, 1 Feb 2023 14:57:36 +0100 Message-Id: <20230201135737.800527-5-jolsa@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230201135737.800527-1-jolsa@kernel.org> References: <20230201135737.800527-1-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 object. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/file_build_id.c | 70 +++++++++++++++++++ .../selftests/bpf/progs/file_build_id.c | 34 +++++++++ tools/testing/selftests/bpf/trace_helpers.c | 35 ++++++++++ tools/testing/selftests/bpf/trace_helpers.h | 1 + 4 files changed, 140 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/file_build_id.c create mode 100644 tools/testing/selftests/bpf/progs/file_build_id.c diff --git a/tools/testing/selftests/bpf/prog_tests/file_build_id.c b/tools/testing/selftests/bpf/prog_tests/file_build_id.c new file mode 100644 index 000000000000..a7b6307cc0f7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/file_build_id.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "file_build_id.skel.h" +#include "trace_helpers.h" + +#define BUILDID_STR_SIZE (BPF_BUILD_ID_SIZE*2 + 1) + +void test_file_build_id(void) +{ + int go[2], err, child_pid, child_status, c = 1, i; + char bpf_build_id[BUILDID_STR_SIZE] = {}; + struct file_build_id *skel; + char *bid = NULL; + + skel = file_build_id__open_and_load(); + if (!ASSERT_OK_PTR(skel, "file_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("/bin/bash", "bash", "-c", "exit 0", NULL, NULL); + exit(errno); + } + + /* parent, update child's pid and kick it */ + skel->bss->pid = child_pid; + + err = file_build_id__attach(skel); + if (!ASSERT_OK(err, "file_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; + + if (!ASSERT_OK(read_buildid("/bin/bash", &bid), "read_buildid")) + goto out; + + ASSERT_EQ(skel->bss->build_id_size, strlen(bid)/2, "build_id_size"); + + /* Convert bpf build id to string, so we can compare it later. */ + for (i = 0; i < skel->bss->build_id_size; i++) { + sprintf(bpf_build_id + i*2, "%02x", + (unsigned char) skel->bss->build_id[i]); + } + ASSERT_STREQ(bpf_build_id, bid, "build_id_data"); + +out: + file_build_id__destroy(skel); + free(bid); +} diff --git a/tools/testing/selftests/bpf/progs/file_build_id.c b/tools/testing/selftests/bpf/progs/file_build_id.c new file mode 100644 index 000000000000..639a7217a927 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/file_build_id.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +int pid; +u32 build_id_size; +char build_id[20]; + +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; + struct build_id *bid; + + if (pid != cur_pid) + return 0; + + if (!bprm->file || !bprm->file->f_bid) + return 0; + + bid = bprm->file->f_bid; + build_id_size = bid->sz; + + if (build_id_size > 20) + return 0; + + memcpy(build_id, bid->data, 20); + return 0; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 09a16a77bae4..f5557890e383 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include "trace_helpers.h" @@ -230,3 +231,37 @@ ssize_t get_rel_offset(uintptr_t addr) fclose(f); return -EINVAL; } + +int read_buildid(const char *path, char **build_id) +{ + char tmp[] = "/tmp/dataXXXXXX"; + char buf[PATH_MAX + 200]; + int err, fd; + FILE *f; + + fd = mkstemp(tmp); + if (fd == -1) + return -1; + close(fd); + + snprintf(buf, sizeof(buf), + "readelf -n %s 2>/dev/null | grep 'Build ID' | awk '{print $3}' > %s", + path, tmp); + + err = system(buf); + if (err) + goto out; + + f = fopen(tmp, "r"); + if (f) { + if (fscanf(f, "%ms$*\n", build_id) != 1) { + *build_id = NULL; + err = -1; + } + fclose(f); + } + +out: + unlink(tmp); + return err; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 53efde0e2998..1a38c808b6c2 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -23,4 +23,5 @@ void read_trace_pipe(void); ssize_t get_uprobe_offset(const void *addr); ssize_t get_rel_offset(uintptr_t addr); +int read_buildid(const char *path, char **build_id); #endif