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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 09484C433DF for ; Tue, 13 Oct 2020 00:34:34 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 3561B21655 for ; Tue, 13 Oct 2020 00:34:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CfMw3Lf2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3561B21655 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20187-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16070 invoked by uid 550); 13 Oct 2020 00:32:48 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 15963 invoked from network); 13 Oct 2020 00:32:47 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=s6lKkOY6jDvHdKU5rddxnOybuTgb4UG6S62YgATiqsw=; b=CfMw3Lf2RqxuH1gK/LplrUVdrli+0+CHSSkm8IVXoxiERluD9UBxqoVgGLYbB0zcGH fcd+f/qjElRp1j6Jdey9Bh7NDBDe4hB9i6yurpQFinDV80y/ezy2gjJtTugW6x9+TxXB lOD7ufXL8OAxIH+6uzRqxS9SQox8gQ5U7CudTH1hC4sfe/ktNYfAhjsreZIIFTMjFG1C RQt8+AhPqYKsAgf3F+x4HsSqm87l4hiDBx+TxXtL+Ap2+aCO42F+hEV40MZGJK2CkBo8 P4FhwGbSHoh+MmiJ53pkyum1T4qHIVaGpa4LSlzx+7mtM5okXCbjhUku3Y3pd0VFE6Pn ksJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=s6lKkOY6jDvHdKU5rddxnOybuTgb4UG6S62YgATiqsw=; b=nb7iYcSB3s20sJFSsH82nxWiq8Q5EmlJs+m7zPhdYjbv31ckVQorOYCxYeC843KDXR kNnXtfUY1IkA++lBr2gDI1Ag1PGk8tCLFDeSYAYhpug30misS0QGEidcYkye9lmPfdfZ vlAm2pZJO+qJ6oRTWG1rpr3LiiIIQK9GO6NZQLXPw5wRIGKc43TaYBsl6tUZGLUDaZBb +Tq5pwwuxyXkgO38YOuABuvOeNCmzu9pcNmRjrNjvV3GH1jXWOdJ6wIVXBVzLJsXKHxl vfYwqVc9r6nH3Lz1sw+yzrlI/vfC/ZquKlBFLDRgJzYXIgPhlwcIHOCZWPeHIum3Jqa1 DesA== X-Gm-Message-State: AOAM531xmHpOr1gKVwCpRRAE7YOkR6QCkcO9UlLs5iTB2DBQCJGxR5+u SSL00f7FOa0riEvQJ4Fu/RwymRX/selAUfuHO+o= X-Google-Smtp-Source: ABdhPJyFxyU35wX46NP9k8EgBAnMCUQ4LjUrf9Ha6HBecKs6BME4DjIGIM9k+HTmfXPW/UAyVK3X9uWCjK1Lv7DEg7U= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:aa7:8492:0:b029:155:79b1:437a with SMTP id u18-20020aa784920000b029015579b1437amr18970192pfn.26.1602549155518; Mon, 12 Oct 2020 17:32:35 -0700 (PDT) Date: Mon, 12 Oct 2020 17:31:52 -0700 In-Reply-To: <20201013003203.4168817-1-samitolvanen@google.com> Message-Id: <20201013003203.4168817-15-samitolvanen@google.com> Mime-Version: 1.0 References: <20201013003203.4168817-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.1011.ga647a8990f-goog Subject: [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt Cc: Will Deacon , Peter Zijlstra , 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 Content-Type: text/plain; charset="UTF-8" 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 Reviewed-by: Kees Cook --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ab0ddf4884fd..96d6c9e18901 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -266,7 +266,7 @@ 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 -- 2.28.0.1011.ga647a8990f-goog