From patchwork Tue Oct 13 00:31:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11834791 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 60B0D14D5 for ; Tue, 13 Oct 2020 02:45:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A58320678 for ; Tue, 13 Oct 2020 02:45:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CfMw3Lf2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727531AbgJMAdX (ORCPT ); Mon, 12 Oct 2020 20:33:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727215AbgJMAdB (ORCPT ); Mon, 12 Oct 2020 20:33:01 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B908C0613DF for ; Mon, 12 Oct 2020 17:32:36 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id z9so10745644pfk.2 for ; Mon, 12 Oct 2020 17:32:36 -0700 (PDT) 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=DpuJXx1WliobL9HRAJvDB4EueX/nkwee4R6OYiJCbJpoLMKrhnia+8rQ7o7jzRPgKJ I4/bfVL5k09DEVTGY8F9wOVEhJvTVXXfySydIykHI58HhulruyZ3nB9Lvm95byE+i/Ec ycd226oY4oRFeDdkZiByxUKFKmX+sJs44wXAc5R15k/cshRK3SMshaYFpR05a//yptak OfV8BXGbjTUwVVmELflmKFbOI5vLSMGuAMGnBUWTN3oG/yFxPJrUTWluL1wdk7BEUg6I A//JZQRMRwC8LtsmZWtboo8XzxgSupvR61UvV0csHmX2zpbH3rRKYv6E8+apmMZBtHsi kEoQ== X-Gm-Message-State: AOAM5327FVI5vowb1kEQ1M90Clnz4J3J57AuxKHyPBEWHm5huVYmhgiG D0Sliqp6YpSRur5CG9ufYmEum3wi8JlLofipheU= 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 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org 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