From patchwork Tue Dec 1 21:36:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943971 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=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 9B15AC64E7A for ; Tue, 1 Dec 2020 21:38:21 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 9C7982086A for ; Tue, 1 Dec 2020 21:38:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cTOyof8D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C7982086A 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-20494-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16028 invoked by uid 550); 1 Dec 2020 21:37:37 -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 15953 invoked from network); 1 Dec 2020 21:37:36 -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=Ioq5snZDZDriQbZnteUYOvtfB50kdQ3NzmE0Bt/uZj4=; b=cTOyof8D27Eb15ctHFkguMw8fQJTDxevhAv86xzy/JyHIKohwC9kcPozSDGX4ZvhjH hv1rR4G53Z3ln+Cmqb9RjUK77Rma8WI1knxtAcMzXLo7jpqZX03s3IjAuAKcPGe698IA tqCRwqNReUE6+2DHbVXsqGEAH3DKihfcNiemIM2g7zH4vjz4yRgdtjEGOxPucEoKGI7o TP0NKml15Zj0kVGxkNppCMBBYfw5RCgEPqWu/IFdSOVZwRHRqv5Cob9LcnhewWjKXfLJ uxIRAby/D2ArEQUd3zLg1F9Be0crsc+S/9EwAcR/g6vVudxNV4zhBdGhHukse6etLm6r ljAg== 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=Ioq5snZDZDriQbZnteUYOvtfB50kdQ3NzmE0Bt/uZj4=; b=Dg8zcllXc2K4dVxJqSFXZkTf15YoOqr76SnzB9ZTwkKjHAViIwHvtWtVwAJeExPBL1 M46jU77f0na7q2voFE+BCQK2CfKU5+sZM0WyseaeB8+CWXL1MLZ49DYuySPwelqwY+Z5 3EMgIPlqHIVkbj2ifjPeN5ljUSgFIXNWp1iXQv5l0iHWmb7DjMCYQmFdwABvteT5g7CH F7edkzUDtlLHAdpoE873JZORIL8XkZ5h9j1gNtUq597AxGftD16oFZgccctzD9XGI2BU tY22IchECbKay3gIym4y5PwX0m0DWO1Onilzc+AwNCdQ2rev3tNDgmWmX+z2NhcTJpwI qgLg== X-Gm-Message-State: AOAM5313LfrQfZnVQA7A2qZs68FbGjYm+DUJIz65X1ESE9eXRH7UbqDi XvLoCgJUHNAevBcSbhKIIBy0TVxCyORbiBKRfEo= X-Google-Smtp-Source: ABdhPJys1KC5O8D1Yq/SB6UjKKBqwmwFlcdQVBXthpLtwbdm6607CxLE6p9eN4XkDXwUu6B0iPn5A0SVU7zu7mNfSPU= 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:ad4:4051:: with SMTP id r17mr5301753qvp.39.1606858644813; Tue, 01 Dec 2020 13:37:24 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:57 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 06/16] 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