From patchwork Thu Feb 24 10:14:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 12758281 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41D76C433F5 for ; Thu, 24 Feb 2022 10:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232231AbiBXKEm (ORCPT ); Thu, 24 Feb 2022 05:04:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232026AbiBXKEl (ORCPT ); Thu, 24 Feb 2022 05:04:41 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D4FA285ABA for ; Thu, 24 Feb 2022 02:04:12 -0800 (PST) Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4K47kn4KvZzdfYB; Thu, 24 Feb 2022 18:02:57 +0800 (CST) Received: from huawei.com (10.67.174.197) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Thu, 24 Feb 2022 18:04:09 +0800 From: Xu Kuohai To: CC: Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Yonghong Song , Shuah Khan , Martin KaFai Lau , Song Liu Subject: [PATCH bpf-next v2 1/2] libbpf: Skip forward declaration when Date: Thu, 24 Feb 2022 05:14:43 -0500 Message-ID: <20220224101444.1169015-2-xukuohai@huawei.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220224101444.1169015-1-xukuohai@huawei.com> References: <20220224101444.1169015-1-xukuohai@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.197] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Currently if a forward declaration appears in the BTF before the definition, the definition is dumped as a conflicting name, eg: $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'" [81287] FWD 'unix_sock' fwd_kind=struct [89336] STRUCT 'unix_sock' size=1024 vlen=14 $ bpftool btf dump file vmlinux format c | grep "struct unix_sock" struct unix_sock; struct unix_sock___2 { <--- conflict, the "___2" is unexpected struct unix_sock___2 *unix_sk; This causes a "definition not found" compilation error if the dump output is used as a header file. Fix it by skipping forward declaration when counting duplicated type names. Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Signed-off-by: Xu Kuohai Acked-by: Song Liu --- tools/lib/bpf/btf_dump.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 07ebe70d3a30..6b1bc1f43728 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1505,6 +1505,11 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id, if (s->name_resolved) return *cached_name ? *cached_name : orig_name; + if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) { + s->name_resolved = 1; + return orig_name; + } + dup_cnt = btf_dump_name_dups(d, name_map, orig_name); if (dup_cnt > 1) { const size_t max_len = 256;