From patchwork Sun Aug 2 01:32:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 262846 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C574C433E0 for ; Sun, 2 Aug 2020 01:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35C9E2076A for ; Sun, 2 Aug 2020 01:32:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="BoKRvvOe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727972AbgHBBca (ORCPT ); Sat, 1 Aug 2020 21:32:30 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:64632 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727945AbgHBBca (ORCPT ); Sat, 1 Aug 2020 21:32:30 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 0721WQGF001863 for ; Sat, 1 Aug 2020 18:32:29 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=dIRQgYPm2Ig0B9ZcNS3cvoWgnUdf0N22Gx5j7REbWhE=; b=BoKRvvOeesLfJa4pnQPJkOfb2ZAfz8LfMy9v51/F59Id/LqywGqX1VBO4YlzN6t6Acvy QmPN3bRV56MViX2No9VPeeQWZyN25pQFRnE+51bd8ltD/fHqPr29H8nLXVPkU/wRaLxr hiCFm5NQsrYbcJzyM4WqpQdbgWb8wzU+gnM= Received: from mail.thefacebook.com ([163.114.132.120]) by m0001303.ppops.net with ESMTP id 32n80t1syc-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sat, 01 Aug 2020 18:32:29 -0700 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Sat, 1 Aug 2020 18:32:27 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id E7BF32EC50C3; Sat, 1 Aug 2020 18:32:22 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 1/3] libbpf: add btf__parse_raw() and generic btf__parse() APIs Date: Sat, 1 Aug 2020 18:32:17 -0700 Message-ID: <20200802013219.864880-2-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200802013219.864880-1-andriin@fb.com> References: <20200802013219.864880-1-andriin@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-08-02_01:2020-07-31,2020-08-02 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 suspectscore=25 spamscore=0 clxscore=1015 lowpriorityscore=0 priorityscore=1501 impostorscore=0 mlxscore=0 mlxlogscore=798 phishscore=0 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008020009 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add public APIs to parse BTF from raw data file (e.g., /sys/kernel/btf/vmlinux), as well as generic btf__parse(), which will try to determine correct format, currently either raw or ELF. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/btf.c | 114 ++++++++++++++++++++++++++------------- tools/lib/bpf/btf.h | 5 +- tools/lib/bpf/libbpf.map | 2 + 3 files changed, 83 insertions(+), 38 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index ded5b29965f9..856b09a04563 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -562,6 +562,83 @@ struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) return btf; } +struct btf *btf__parse_raw(const char *path) +{ + void *data = NULL; + struct btf *btf; + FILE *f = NULL; + __u16 magic; + int err = 0; + long sz; + + f = fopen(path, "rb"); + if (!f) { + err = -errno; + goto err_out; + } + + /* check BTF magic */ + if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) { + err = -EIO; + goto err_out; + } + if (magic != BTF_MAGIC) { + /* definitely not a raw BTF */ + err = -EPROTO; + goto err_out; + } + + /* get file size */ + if (fseek(f, 0, SEEK_END)) { + err = -errno; + goto err_out; + } + sz = ftell(f); + if (sz < 0) { + err = -errno; + goto err_out; + } + /* rewind to the start */ + if (fseek(f, 0, SEEK_SET)) { + err = -errno; + goto err_out; + } + + /* pre-alloc memory and read all of BTF data */ + data = malloc(sz); + if (!data) { + err = -ENOMEM; + goto err_out; + } + if (fread(data, 1, sz, f) < sz) { + err = -EIO; + goto err_out; + } + + /* finally parse BTF data */ + btf = btf__new(data, sz); + +err_out: + free(data); + if (f) + fclose(f); + return err ? ERR_PTR(err) : btf; +} + +struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) +{ + struct btf *btf; + + if (btf_ext) + *btf_ext = NULL; + + btf = btf__parse_raw(path); + if (!IS_ERR(btf) || PTR_ERR(btf) != -EPROTO) + return btf; + + return btf__parse_elf(path, btf_ext); +} + static int compare_vsi_off(const void *_a, const void *_b) { const struct btf_var_secinfo *a = _a; @@ -2951,41 +3028,6 @@ static int btf_dedup_remap_types(struct btf_dedup *d) return 0; } -static struct btf *btf_load_raw(const char *path) -{ - struct btf *btf; - size_t read_cnt; - struct stat st; - void *data; - FILE *f; - - if (stat(path, &st)) - return ERR_PTR(-errno); - - data = malloc(st.st_size); - if (!data) - return ERR_PTR(-ENOMEM); - - f = fopen(path, "rb"); - if (!f) { - btf = ERR_PTR(-errno); - goto cleanup; - } - - read_cnt = fread(data, 1, st.st_size, f); - fclose(f); - if (read_cnt < st.st_size) { - btf = ERR_PTR(-EBADF); - goto cleanup; - } - - btf = btf__new(data, read_cnt); - -cleanup: - free(data); - return btf; -} - /* * Probe few well-known locations for vmlinux kernel image and try to load BTF * data out of it to use for target BTF. @@ -3021,7 +3063,7 @@ struct btf *libbpf_find_kernel_btf(void) continue; if (locations[i].raw_btf) - btf = btf_load_raw(path); + btf = btf__parse_raw(path); else btf = btf__parse_elf(path, NULL); diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 491c7b41ffdc..f4a1a1d2b9a3 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -64,8 +64,9 @@ struct btf_ext_header { LIBBPF_API void btf__free(struct btf *btf); LIBBPF_API struct btf *btf__new(const void *data, __u32 size); -LIBBPF_API struct btf *btf__parse_elf(const char *path, - struct btf_ext **btf_ext); +LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext); +LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext); +LIBBPF_API struct btf *btf__parse_raw(const char *path); LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); LIBBPF_API int btf__load(struct btf *btf); LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index ca49a6a7e5b2..edf6a38807ea 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -291,5 +291,7 @@ LIBBPF_0.1.0 { bpf_program__is_sk_lookup; bpf_program__set_autoload; bpf_program__set_sk_lookup; + btf__parse; + btf__parse_raw; btf__set_fd; } LIBBPF_0.0.9;