From patchwork Sat Mar 13 19:35:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 12136981 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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 BC531C43619 for ; Sat, 13 Mar 2021 19:36:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A797064DD8 for ; Sat, 13 Mar 2021 19:36:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234653AbhCMTgR convert rfc822-to-8bit (ORCPT ); Sat, 13 Mar 2021 14:36:17 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:57118 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234490AbhCMTf6 (ORCPT ); Sat, 13 Mar 2021 14:35:58 -0500 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12DJVBmG002077 for ; Sat, 13 Mar 2021 11:35:57 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 378uyfsc86-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sat, 13 Mar 2021 11:35:57 -0800 Received: from intmgw001.37.frc1.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sat, 13 Mar 2021 11:35:56 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 42AB92ED20BF; Sat, 13 Mar 2021 11:35:50 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH v2 bpf-next 05/11] libbpf: add generic BTF type shallow copy API Date: Sat, 13 Mar 2021 11:35:31 -0800 Message-ID: <20210313193537.1548766-6-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210313193537.1548766-1-andrii@kernel.org> References: <20210313193537.1548766-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-13_07:2021-03-12,2021-03-13 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 clxscore=1015 priorityscore=1501 mlxscore=0 suspectscore=0 spamscore=0 bulkscore=0 malwarescore=0 impostorscore=0 lowpriorityscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103130151 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add btf__add_type() API that performs shallow copy of a given BTF type from the source BTF into the destination BTF. All the information and type IDs are preserved, but all the strings encountered are added into the destination BTF and corresponding offsets are rewritten. BTF type IDs are assumed to be correct or such that will be (somehow) modified afterwards. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/btf.c | 48 ++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 2 ++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 51 insertions(+) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index fe087592ad35..d30e67e7e1e5 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1629,6 +1629,54 @@ static int btf_commit_type(struct btf *btf, int data_sz) return btf->start_id + btf->nr_types - 1; } +struct btf_pipe { + const struct btf *src; + struct btf *dst; +}; + +static int btf_rewrite_str(__u32 *str_off, void *ctx) +{ + struct btf_pipe *p = ctx; + int off; + + if (!*str_off) /* nothing to do for empty strings */ + return 0; + + off = btf__add_str(p->dst, btf__str_by_offset(p->src, *str_off)); + if (off < 0) + return off; + + *str_off = off; + return 0; +} + +int btf__add_type(struct btf *btf, const struct btf *src_btf, const struct btf_type *src_type) +{ + struct btf_pipe p = { .src = src_btf, .dst = btf }; + struct btf_type *t; + int sz, err; + + sz = btf_type_size(src_type); + if (sz < 0) + return sz; + + /* deconstruct BTF, if necessary, and invalidate raw_data */ + if (btf_ensure_modifiable(btf)) + return -ENOMEM; + + t = btf_add_type_mem(btf, sz); + if (!t) + return -ENOMEM; + + memcpy(t, src_type, sz); + + err = btf_type_visit_str_offs(t, btf_rewrite_str, &p); + if (err) + return err; + + return btf_commit_type(btf, sz); +} + /* * Append new BTF_KIND_INT type with: * - *name* - non-empty, non-NULL type name; diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 029a9cfc8c2d..3b0b17ba94a1 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -93,6 +93,8 @@ LIBBPF_API struct btf *libbpf_find_kernel_btf(void); LIBBPF_API int btf__find_str(struct btf *btf, const char *s); LIBBPF_API int btf__add_str(struct btf *btf, const char *s); +LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf, + const struct btf_type *src_type); LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding); LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index ec898f464ab9..d31d8c968097 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -354,4 +354,5 @@ LIBBPF_0.3.0 { LIBBPF_0.4.0 { global: btf__add_float; + btf__add_type; } LIBBPF_0.3.0;