From mboxrd@z Thu Jan 1 00:00:00 1970 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=-14.1 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, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5D553C4727C for ; Sat, 26 Sep 2020 01:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23A9C20936 for ; Sat, 26 Sep 2020 01:14:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="fp38aUXb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729909AbgIZBO5 (ORCPT ); Fri, 25 Sep 2020 21:14:57 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:44728 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729822AbgIZBO4 (ORCPT ); Fri, 25 Sep 2020 21:14:56 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08Q1EEV3024127 for ; Fri, 25 Sep 2020 18:14:56 -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=4XxEFqSWZ2fU0OtZqRN5wmUcc2YG7N8MWGdSie2XoBs=; b=fp38aUXbGHeNR+MuIiFqgFOpbniJ2FaEzfAw66IdIp5wZk8OH1oYZrQak9OtPCm+k4sF jLdtRFP6wepKininJwYXPQvpdMST6SXUf1tZxD/RPhHOjlBwVgxviKFdU+NdL7zggJWu /ra/T/y9UQCTUEMgx8SCq3xVZJ5+4+eMBlA= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 33qsp6ats9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 25 Sep 2020 18:14:56 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 25 Sep 2020 18:14:42 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id B9BF82EC75B0; Fri, 25 Sep 2020 18:14:36 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , , Andrii Nakryiko , Arnaldo Carvalho de Melo , John Fastabend Subject: [PATCH v2 bpf-next 6/9] libbpf: add btf__new_empty() to create an empty BTF object Date: Fri, 25 Sep 2020 18:13:54 -0700 Message-ID: <20200926011357.2366158-7-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200926011357.2366158-1-andriin@fb.com> References: <20200926011357.2366158-1-andriin@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-25_19:2020-09-24,2020-09-25 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 mlxlogscore=910 clxscore=1015 suspectscore=25 impostorscore=0 adultscore=0 lowpriorityscore=0 bulkscore=0 phishscore=0 spamscore=0 priorityscore=1501 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009260006 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add an ability to create an empty BTF object from scratch. This is going = to be used by pahole for BTF encoding. And also by selftest for convenient crea= tion of BTF objects. Acked-by: John Fastabend Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/btf.c | 30 ++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 1 + tools/lib/bpf/libbpf.map | 1 + 3 files changed, 32 insertions(+) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 040f3b8ee39f..54861a5ba9d9 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -565,6 +565,36 @@ void btf__free(struct btf *btf) free(btf); } =20 +struct btf *btf__new_empty(void) +{ + struct btf *btf; + + btf =3D calloc(1, sizeof(*btf)); + if (!btf) + return ERR_PTR(-ENOMEM); + btf->fd =3D -1; + btf->ptr_sz =3D sizeof(void *); + + /* +1 for empty string at offset 0 */ + btf->raw_size =3D sizeof(struct btf_header) + 1; + btf->raw_data =3D calloc(1, btf->raw_size); + if (!btf->raw_data) { + free(btf); + return ERR_PTR(-ENOMEM); + } + + btf->hdr =3D btf->raw_data; + btf->hdr->hdr_len =3D sizeof(struct btf_header); + btf->hdr->magic =3D BTF_MAGIC; + btf->hdr->version =3D BTF_VERSION; + + btf->types_data =3D btf->raw_data + btf->hdr->hdr_len; + btf->strs_data =3D btf->raw_data + btf->hdr->hdr_len; + btf->hdr->str_len =3D 1; /* empty string at offset 0 */ + + return btf; +} + struct btf *btf__new(const void *data, __u32 size) { struct btf *btf; diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index d88b6447c222..b387d0b61f1c 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -27,6 +27,7 @@ struct bpf_object; =20 LIBBPF_API void btf__free(struct btf *btf); LIBBPF_API struct btf *btf__new(const void *data, __u32 size); +LIBBPF_API struct btf *btf__new_empty(void); 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); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index c38aca688a39..6e75cb0e1b17 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -306,6 +306,7 @@ LIBBPF_0.2.0 { bpf_program__section_name; btf__add_str; btf__find_str; + btf__new_empty; perf_buffer__buffer_cnt; perf_buffer__buffer_fd; perf_buffer__epoll_fd; --=20 2.24.1