From patchwork Fri Apr 23 18:53:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 426651 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 70FCDC433B4 for ; Fri, 23 Apr 2021 18:54:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EA9461463 for ; Fri, 23 Apr 2021 18:54:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243768AbhDWSyy convert rfc822-to-8bit (ORCPT ); Fri, 23 Apr 2021 14:54:54 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:56922 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243750AbhDWSyw (ORCPT ); Fri, 23 Apr 2021 14:54:52 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13NIsF8j005629 for ; Fri, 23 Apr 2021 11:54:15 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 383kvnmtqk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 23 Apr 2021 11:54:15 -0700 Received: from intmgw001.06.ash9.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 23 Apr 2021 11:54:06 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 5E3342ED5CA8; Fri, 23 Apr 2021 11:54:05 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH v2 bpf-next 3/6] libbpf: support static map definitions Date: Fri, 23 Apr 2021 11:53:54 -0700 Message-ID: <20210423185357.1992756-4-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210423185357.1992756-1-andrii@kernel.org> References: <20210423185357.1992756-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: ZDx9zkKvqw9XbJ1tL7BTUXKU0cKltTKB X-Proofpoint-ORIG-GUID: ZDx9zkKvqw9XbJ1tL7BTUXKU0cKltTKB X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.761 definitions=2021-04-23_07:2021-04-23,2021-04-23 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 bulkscore=0 malwarescore=0 clxscore=1015 suspectscore=0 spamscore=0 priorityscore=1501 impostorscore=0 mlxlogscore=994 mlxscore=0 lowpriorityscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104230122 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Change libbpf relocation logic to support references to static map definitions. This allows to use static maps and, combined with static linking, hide internal maps from other files, just like static variables. User-space will still be able to look up and modify static maps. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a1cddd17af7d..6c755c5f037d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3633,6 +3633,8 @@ static int bpf_program__record_reloc(struct bpf_program *prog, /* generic map reference relocation */ if (type == LIBBPF_MAP_UNSPEC) { + size_t map_offset = sym->st_value + insn->imm; + if (!bpf_object__shndx_is_maps(obj, shdr_idx)) { pr_warn("prog '%s': bad map relo against '%s' in section '%s'\n", prog->name, sym_name, sym_sec_name); @@ -3642,7 +3644,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog, map = &obj->maps[map_idx]; if (map->libbpf_type != type || map->sec_idx != sym->st_shndx || - map->sec_offset != sym->st_value) + map->sec_offset != map_offset) continue; pr_debug("prog '%s': found map %zd (%s, sec %d, off %zu) for insn #%u\n", prog->name, map_idx, map->name, map->sec_idx, @@ -3657,7 +3659,8 @@ static int bpf_program__record_reloc(struct bpf_program *prog, reloc_desc->type = RELO_LD64; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = map_idx; - reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */ + /* sym->st_value + insn->imm determines map_idx */ + reloc_desc->sym_off = 0; return 0; }