From patchwork Fri Feb 4 21:43:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12735749 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 4D8CFC433EF for ; Fri, 4 Feb 2022 21:44:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237538AbiBDVoI (ORCPT ); Fri, 4 Feb 2022 16:44:08 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:43568 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236194AbiBDVoH (ORCPT ); Fri, 4 Feb 2022 16:44:07 -0500 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 214JliCu026316 for ; Fri, 4 Feb 2022 13:44:07 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=mIZyl4F0hjIrFz9KJ2kE3xhOpLeDt+Twz17ojYoeNMg=; b=Wg6GVqqb++hCqNECMCbD+D58MywW+wpSdTFG0Btk9Ygij5FvY5jV0BSTaiof8aGOpCM3 erc3EDbvxFjzoW1SW2sXqEXdrtTeiWZJD/nLOBu87j8vpV1M2JlAe+jEf2RTRon4CCcS L+m26+HJsqIPSramcctw6ViHo+b9a6JLkm4= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3e0puaf6jg-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 04 Feb 2022 13:44:07 -0800 Received: from twshared18912.14.frc2.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 4 Feb 2022 13:44:06 -0800 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 1BAEC5FA84E4; Fri, 4 Feb 2022 13:43:55 -0800 (PST) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , Delyan Kratunov Subject: [PATCH bpf-next v2] libbpf: fix build issue with llvm-readelf Date: Fri, 4 Feb 2022 13:43:55 -0800 Message-ID: <20220204214355.502108-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: ceZrmSzrDoEyVOms4i7ZVsydwOlC6ReL X-Proofpoint-GUID: ceZrmSzrDoEyVOms4i7ZVsydwOlC6ReL X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-04_07,2022-02-03_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=fb_outbound_notspam policy=fb_outbound score=0 priorityscore=1501 bulkscore=0 clxscore=1015 adultscore=0 suspectscore=0 mlxlogscore=952 lowpriorityscore=0 malwarescore=0 spamscore=0 impostorscore=0 phishscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202040120 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net There are cases where clang compiler is packaged in a way readelf is a symbolic link to llvm-readelf. In such cases, llvm-readelf will be used instead of default binutils readelf, and the following error will appear during libbpf build: Warning: Num of global symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367) does NOT match with num of versioned symbols in /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ... +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ... @@ -324,6 +324,22 @@ btf__str_by_offset btf__type_by_id btf__type_cnt +LIBBPF_0.0.1 +LIBBPF_0.0.2 +LIBBPF_0.0.3 +LIBBPF_0.0.4 +LIBBPF_0.0.5 +LIBBPF_0.0.6 +LIBBPF_0.0.7 +LIBBPF_0.0.8 +LIBBPF_0.0.9 +LIBBPF_0.1.0 +LIBBPF_0.2.0 +LIBBPF_0.3.0 +LIBBPF_0.4.0 +LIBBPF_0.5.0 +LIBBPF_0.6.0 +LIBBPF_0.7.0 libbpf_attach_type_by_name libbpf_find_kernel_btf libbpf_find_vmlinux_btf_id make[2]: *** [Makefile:184: check_abi] Error 1 make[1]: *** [Makefile:140: all] Error 2 The above failure is due to different printouts for some ABS versioned symbols. For example, with the same libbpf.so, $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0 ... $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS 134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0 202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0 ... The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does. Such a difference caused libbpf build failure with llvm-readelf. The proposed fix filters out all ABS symbols as they are not part of the comparison. This works for both binutils readelf and llvm-readelf. Reported-by: Delyan Kratunov Signed-off-by: Yonghong Song --- tools/lib/bpf/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index f947b61b2107..b8b37fe76006 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -131,7 +131,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \ sort -u | wc -l) VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ - awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \ + awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}' | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) @@ -194,7 +194,7 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) sort -u > $(OUTPUT)libbpf_global_syms.tmp; \ readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \ sed 's/\[.*\]//' | \ - awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \ + awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}'| \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \ sort -u > $(OUTPUT)libbpf_versioned_syms.tmp; \ diff -u $(OUTPUT)libbpf_global_syms.tmp \