From patchwork Sat Jul 30 00:08:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 12932836 X-Patchwork-Delegate: bpf@iogearbox.net 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 87475C19F2B for ; Sat, 30 Jul 2022 00:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231613AbiG3AIQ (ORCPT ); Fri, 29 Jul 2022 20:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229686AbiG3AIP (ORCPT ); Fri, 29 Jul 2022 20:08:15 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 340012DD2 for ; Fri, 29 Jul 2022 17:08:14 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id s186-20020a255ec3000000b0067162ed1bd3so4905421ybb.8 for ; Fri, 29 Jul 2022 17:08:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=ygYl5hGZ24k4L+KNLWiCjZLerg9rcrzN2XqVmkrfAqI=; b=lRW6K6xsNU098e9/CzalGgViIHKpHRG5NVC2/eGInDRQas8UZK2jh3f+JXHi52zWRe qdkgWOPGNvv8kpY94i8PJ4dafwW9WGgpmS05HO7cwEJ9LJDZ+/i+019NwLq/CDi4b4bR 749VCJBE97ZCVkAKrqib9ZcBiXEMEBaecbohh26jaNnCiIHcr+Dt22HCE7YnJIvd5H+8 d9wTKuXRkEX2OjidVZnugsc7HjCLeVOcEvihIkRAT4NJlt43fwCWQ7QEdIUAfxLhnW/Z QbGTI0Z3Ta2dfieOig27J2SzXZ3T8JzhlrutqFLyR/KEf5Y14iBAhLRf1D6J59rzFN2R xAig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=ygYl5hGZ24k4L+KNLWiCjZLerg9rcrzN2XqVmkrfAqI=; b=OSfgNpbicBcb68P/sb7WJA5Du29zWrfkXgD9q9jprsHGOT57GxnBRSQ8L2i7JfATyR dEgwidCCe71Rc30LKhiOFyj5K3Jgbk+azGjPDbkw8wgvoBQokw1+trOeYx79DnS6a0Nv ztU6T+DzeSlv6AazFkymOxLEyBLJBYDRNYYND61sRyFx02nCyvJ49U2guqoMXB3uEEMv KAq44Yrg/x41s8BoAHsavwgnpb/afW1MW0AebZ5gab70V3pAKN5TUpWV1SBVH3bnKlS4 ldNdI7AzbjHela2EdnWYbGS7jdW19sH7niCQplVNKW1ZpFDLMxp6R7xyfK+BDAa0hWv0 dnAQ== X-Gm-Message-State: ACgBeo0+Z9DeGPGiCIsfoFI0WnO/5VKDync5k1ljbVKOKmd8vyhPqzqX 774v9DzdDyjM/Gy7qU8Mz1xMIQX4EvE+qpdaN1pYHnho3uoVJgUHFETDkJY2GegovE9tfzfmmUS yLNcQzRHu6PAuAWTqKJfvzpRPX27zbgu+8OpOU0LzQHxSgCDLTA== X-Google-Smtp-Source: AA6agR4MtEXVw6YNpH0DwpqrZTk1HTCqpD9WIXG4rRmYAG6eiNgxzdeHCLD6uXtgfPIWLlaqhwxgTFU= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a25:3841:0:b0:670:a1b9:f18e with SMTP id f62-20020a253841000000b00670a1b9f18emr4498939yba.480.1659139693332; Fri, 29 Jul 2022 17:08:13 -0700 (PDT) Date: Fri, 29 Jul 2022 17:08:09 -0700 In-Reply-To: <20220730000809.312891-1-sdf@google.com> Message-Id: <20220730000809.312891-2-sdf@google.com> Mime-Version: 1.0 References: <20220730000809.312891-1-sdf@google.com> X-Mailer: git-send-email 2.37.1.455.g008518b4e5-goog Subject: [PATCH bpf-next 2/2] selftests/bpf: Excercise bpf_obj_get_info_by_fd for bpf2bpf From: Stanislav Fomichev To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Apparently, no existing selftest covers it. Add a new one where we load cgroup/bind4 program and attach fentry to it. Calling bpf_obj_get_info_by_fd on the fentry program should return non-zero btf_id/btf_obj_id instead of crashing the kernel. Signed-off-by: Stanislav Fomichev --- .../selftests/bpf/prog_tests/attach_to_bpf.c | 109 ++++++++++++++++++ .../selftests/bpf/progs/attach_to_bpf.c | 12 ++ 2 files changed, 121 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/attach_to_bpf.c create mode 100644 tools/testing/selftests/bpf/progs/attach_to_bpf.c diff --git a/tools/testing/selftests/bpf/prog_tests/attach_to_bpf.c b/tools/testing/selftests/bpf/prog_tests/attach_to_bpf.c new file mode 100644 index 000000000000..fcf726c5ff0f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/attach_to_bpf.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include +#include +#include +#include +#include "attach_to_bpf.skel.h" + +char bpf_log_buf[BPF_LOG_BUF_SIZE]; + +static int find_prog_btf_id(const char *name, __u32 attach_prog_fd) +{ + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + struct btf *btf; + int err; + + err = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len); + if (err) + return err; + + if (!info.btf_id) + return -EINVAL; + + btf = btf__load_from_kernel_by_id(info.btf_id); + err = libbpf_get_error(btf); + if (err) + return err; + + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); + btf__free(btf); + if (err <= 0) + return err; + + return err; +} + +int load_fentry(int attach_prog_fd, int attach_btf_id) +{ + LIBBPF_OPTS(bpf_prog_load_opts, opts, + .expected_attach_type = BPF_TRACE_FENTRY, + .attach_prog_fd = attach_prog_fd, + .attach_btf_id = attach_btf_id, + .log_buf = bpf_log_buf, + .log_size = sizeof(bpf_log_buf), + ); + struct bpf_insn insns[] = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }; + int ret; + + ret = bpf_prog_load(BPF_PROG_TYPE_TRACING, + "bind4_fentry", + "GPL", + insns, + ARRAY_SIZE(insns), + &opts); + if (ret) + printf("verifier log: %s\n", bpf_log_buf); + return ret; +} + +void test_attach_to_bpf(void) +{ + struct attach_to_bpf *skel = NULL; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + int cgroup_fd = -1; + int fentry_fd = -1; + int btf_id; + + cgroup_fd = test__join_cgroup("/attach_to_bpf"); + if (!ASSERT_GE(cgroup_fd, 0, "cgroup_fd")) + return; + + skel = attach_to_bpf__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel")) + goto cleanup; + + skel->links.bind4 = bpf_program__attach_cgroup(skel->progs.bind4, cgroup_fd); + if (!ASSERT_OK_PTR(skel, "bpf_program__attach_cgroup")) + goto cleanup; + + btf_id = find_prog_btf_id("bind4", bpf_program__fd(skel->progs.bind4)); + if (!ASSERT_GE(btf_id, 0, "find_prog_btf_id")) + goto cleanup; + + fentry_fd = load_fentry(bpf_program__fd(skel->progs.bind4), btf_id); + if (!ASSERT_GE(fentry_fd, 0, "load_fentry")) + goto cleanup; + + /* Make sure bpf_obj_get_info_by_fd works correctly when attaching + * to another BPF program. + */ + + if (!ASSERT_OK(bpf_obj_get_info_by_fd(fentry_fd, &info, &info_len), + "bpf_obj_get_info_by_fd")) + goto cleanup; + + ASSERT_EQ(info.btf_id, 0, "info.btf_id"); + ASSERT_GT(info.attach_btf_id, 0, "info.attach_btf_id"); + ASSERT_GT(info.attach_btf_obj_id, 0, "info.attach_btf_obj_id"); + +cleanup: + close(cgroup_fd); + close(fentry_fd); + attach_to_bpf__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/attach_to_bpf.c b/tools/testing/selftests/bpf/progs/attach_to_bpf.c new file mode 100644 index 000000000000..3f111fe96f8f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/attach_to_bpf.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +SEC("cgroup/bind4") +int bind4(struct bpf_sock_addr *ctx) +{ + return 1; +} + +char _license[] SEC("license") = "GPL";