From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406462AbgFXUdN (ORCPT ); Wed, 24 Jun 2020 16:33:13 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A846C061795 for ; Wed, 24 Jun 2020 13:33:13 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id n11so3511192ybg.15 for ; Wed, 24 Jun 2020 13:33:13 -0700 (PDT) Date: Wed, 24 Jun 2020 13:31:46 -0700 In-Reply-To: <20200624203200.78870-1-samitolvanen@google.com> Message-Id: <20200624203200.78870-9-samitolvanen@google.com> Mime-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> Subject: [PATCH 08/22] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Masahiro Yamada , Will Deacon Cc: Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org, Sami Tolvanen With LTO, llvm-nm prints out symbols for each archive member separately, which results in a lot of duplicate dependencies in the .mod file when CONFIG_TRIM_UNUSED_SYMS is enabled. When a module consists of several compilation units, the output can exceed the default xargs command size limit and split the dependency list to multiple lines, which results in used symbols getting trimmed. This change removes duplicate dependencies, which will reduce the probability of this happening and makes .mod files smaller and easier to read. Signed-off-by: Sami Tolvanen --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 82977350f5a6..82b465ce3ca0 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -291,7 +291,7 @@ endef # List module undefined symbols (or empty line if not enabled) ifdef CONFIG_TRIM_UNUSED_KSYMS -cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo +cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | sort -u | xargs echo else cmd_undef_syms = echo endif -- 2.27.0.212.ge8ba1cc988-goog