From mboxrd@z Thu Jan 1 00:00:00 1970 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 E09DCC4707A for ; Tue, 12 Apr 2022 08:40:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383225AbiDLIgW (ORCPT ); Tue, 12 Apr 2022 04:36:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356455AbiDLHfz (ORCPT ); Tue, 12 Apr 2022 03:35:55 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2240E5158B; Tue, 12 Apr 2022 00:09:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B6BADB81B4E; Tue, 12 Apr 2022 07:09:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CFDAC385A1; Tue, 12 Apr 2022 07:09:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649747366; bh=wDcLxwej26NS4LB06tWq4HGyqInkKqDEgOV0hiCt7+4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tJI7SrZaf3JY9oRraKiogqmVBPD2mGnJfLGxc1d54VqHWzDnwE5j+3wK91g3yOU+o ANMnShUhH4WvyIBMKMoy2W7E2lrt+jADVQuOB/w4RnI2taqn8dKPzakc8TiymURKy9 vL0T6R5O/a9aVQse9G5eWu7TfMflejSrIWUuWnqY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Delyan Kratunov , Yonghong Song , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.17 052/343] libbpf: Fix build issue with llvm-readelf Date: Tue, 12 Apr 2022 08:27:50 +0200 Message-Id: <20220412062952.607814356@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062951.095765152@linuxfoundation.org> References: <20220412062951.095765152@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yonghong Song [ Upstream commit 0908a66ad1124c1634c33847ac662106f7f2c198 ] 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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220204214355.502108-1-yhs@fb.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- tools/lib/bpf/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -131,7 +131,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s -- 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_ 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 \