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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 849D0C432BE for ; Thu, 19 Aug 2021 00:02:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E85A61075 for ; Thu, 19 Aug 2021 00:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235474AbhHSAC4 (ORCPT ); Wed, 18 Aug 2021 20:02:56 -0400 Received: from conuserg-12.nifty.com ([210.131.2.79]:38683 "EHLO conuserg-12.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235452AbhHSACz (ORCPT ); Wed, 18 Aug 2021 20:02:55 -0400 Received: from localhost.localdomain (133-32-232-101.west.xps.vectant.ne.jp [133.32.232.101]) (authenticated) by conuserg-12.nifty.com with ESMTP id 17J01JAq002135; Thu, 19 Aug 2021 09:01:19 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-12.nifty.com 17J01JAq002135 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1629331280; bh=dDA48cE2QbNp7aCgzfGh6ePv10lHArBqOHlfXE7pros=; h=From:To:Cc:Subject:Date:From; b=ZauWzjVBRhoLV61SwZfpXF/25uYTu4P5h1GfwgTQD1ft9NCJpLRsY4Hhrg/AMLSeC pan2wOmX/npxC3AB2yUkKquLoeWOgaOyRzqse2JO4ywnRnXLccHLSLQ35vmYvj6Qxh 2IqCvuSjX1BtgBQTLS79Qqodx+hUvkrmk5U3QI+RcCyVXiUyzuZhTGyiUBaHxTejPx BdQGE2IqW0WeO088dUL1CqOH2rHyp3f92xVuC64J0B+EkTfvAkx+14CcuXWu56u/JJ k8nUIHzh4n+rX6aFFjVF2JJauVwBGIe2Cvy9VRp2s12skqFgYhSFPJXvkrU+Rnmjd9 3DD5f/aT7fqIA== X-Nifty-SrcIP: [133.32.232.101] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Masahiro Yamada , Nathan Chancellor , Nick Desaulniers , Nicolas Pitre , clang-built-linux@googlegroups.com Subject: [PATCH v2] kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y Date: Thu, 19 Aug 2021 09:01:14 +0900 Message-Id: <20210819000114.634042-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When CONFIG_TRIM_UNUSED_KSYMS is enabled, I see some warnings like this: nm: arch/x86/entry/vdso/vdso32/note.o: no symbols $NM (both GNU nm and llvm-nm) warns when no symbol is found in the object. Suppress the stderr. Fangrui Song mentioned binutils>=2.37 `nm -q` can be used to suppress "no symbols" [1], and llvm-nm>=13.0.0 supports -q as well. We cannot use it for now, but note it as a TODO. [1]: https://sourceware.org/bugzilla/show_bug.cgi?id=27408 Fixes: bbda5ec671d3 ("kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS") Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor --- Changes in v2: - Add TODO - Fix 'stdout' to 'stderr' in the comment scripts/gen_ksymdeps.sh | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh index 1324986e1362..725e8c9c1b53 100755 --- a/scripts/gen_ksymdeps.sh +++ b/scripts/gen_ksymdeps.sh @@ -4,7 +4,13 @@ set -e # List of exported symbols -ksyms=$($NM $1 | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z) +# +# If the object has no symbol, $NM warns 'no symbols'. +# Suppress the stderr. +# TODO: +# Use -q instead of 2>/dev/null when we upgrade the minimum version of +# binutils to 2.37, llvm to 13.0.0. +ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z) if [ -z "$ksyms" ]; then exit 0 -- 2.30.2