From patchwork Sat Sep 26 01:13:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 11801053 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3AF1C92C 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 206C920878 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 X-FB-Internal: Safe 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 creation 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); } +struct btf *btf__new_empty(void) +{ + struct btf *btf; + + btf = calloc(1, sizeof(*btf)); + if (!btf) + return ERR_PTR(-ENOMEM); + btf->fd = -1; + btf->ptr_sz = sizeof(void *); + + /* +1 for empty string at offset 0 */ + btf->raw_size = sizeof(struct btf_header) + 1; + btf->raw_data = calloc(1, btf->raw_size); + if (!btf->raw_data) { + free(btf); + return ERR_PTR(-ENOMEM); + } + + btf->hdr = btf->raw_data; + btf->hdr->hdr_len = sizeof(struct btf_header); + btf->hdr->magic = BTF_MAGIC; + btf->hdr->version = BTF_VERSION; + + btf->types_data = btf->raw_data + btf->hdr->hdr_len; + btf->strs_data = btf->raw_data + btf->hdr->hdr_len; + btf->hdr->str_len = 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; 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;