From patchwork Wed Nov 18 22:07:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11916029 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 1FADEC83019 for ; Wed, 18 Nov 2020 22:08:50 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 2FC23246EE for ; Wed, 18 Nov 2020 22:08:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tgB3HeaM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2FC23246EE 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-20412-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 3330 invoked by uid 550); 18 Nov 2020 22:07:58 -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 3226 invoked from network); 18 Nov 2020 22:07:57 -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=tITgh0Ssflf3KIdl9iLTasR/nuysgEKXGj2aGzu0djg=; b=tgB3HeaMLte4FwdwEskpNo3M1G5NMSWdaU3NGnSytOclNILrFVdkD4YBIH/89JtDHP XW414KEtYQqChtXVzZCo6FESh8Tttug6ipG4Xwymb06bhNxw7eh44JTB82tQMjdgKeKe mvE5QooVVjUOl15f8Ufkoo4CuDQMkoEAowvId9Xo6ILJqfJzsuuAiniFNxOTXgItR15s eH6Dk79v+bV/G/7k27PzU2M0pCmQclWaJYIJjA3ojY/R+Z8tO+3QxQrtlIwXnz5RyeCM j8ggYjzxLirUlC9AaKsU1v+JkHXIBzxtLSTtx1qvPQUhEgNQSe/pESJS3QjFV5EMv/+O IZUA== 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=tITgh0Ssflf3KIdl9iLTasR/nuysgEKXGj2aGzu0djg=; b=XzfZs0U3lAcponWdSSDuKB6mpVrf9ndRJzSDnmgqJxEBOE/PkhuWfQ2SGafGYzCCXw DsdwUFLk8j5/9WrF4tP8UB2GflTaBtmv2W5FJaDazg37ocCTQbU/YuM2ZDdnsKcAr+uD 8ACtXsiMeC9NDXbac3/uQlQ0WYX3KzmIgL7HH8BiYpD9u/NgWkFRA60P0nM6jrEbqhhL fXhXVwS6tqlNz4WaDCMtcFXMcLkaOQ7cNOnAo6rjslJavLSFzLG2Ox2vfeqHfu6B4a5V +EA3zRHSQMgjfMHK7JywtsGhPLMSh7w0xCw/T85QW7qfd2d4LOCfFmoUt2dagnH+cVQZ wRPw== X-Gm-Message-State: AOAM533W29xE2Elv5dwjvo6Pvv7a4QobHmlwMr2N+BLdu0iDol5PcKF3 MVbzVsUg6J2830Ua4vWByMDeifsZjNzJ9Vp98Zo= X-Google-Smtp-Source: ABdhPJyru6u4Sy3c6z545hXKz2Lse9yOurfwR7Sqj4soym8ldc5jriOTeAoDW2j8p87AYgdDtayu2H1jxl4fDBYzugo= 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:a5b:c0e:: with SMTP id f14mr12957716ybq.83.1605737265629; Wed, 18 Nov 2020 14:07:45 -0800 (PST) Date: Wed, 18 Nov 2020 14:07:20 -0800 In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com> Message-Id: <20201118220731.925424-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20201118220731.925424-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH v7 06/17] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , 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, 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 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 eae2f5386a03..f80ada58271d 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -281,7 +281,7 @@ 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