From patchwork Fri Sep 18 20:14:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11786165 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 595EF92C for ; Fri, 18 Sep 2020 20:17:23 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 9792220684 for ; Fri, 18 Sep 2020 20:17:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mPsAHQEX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9792220684 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-19932-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 19951 invoked by uid 550); 18 Sep 2020 20:15:28 -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: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 19865 invoked from network); 18 Sep 2020 20:15:27 -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=H5U0Hz5E6z5ldjvQ4xJDZFkCK4qV/McKETGlhtu7sL8=; b=mPsAHQEXqvNlGarzu6iBRQPA6ECa8TLJT1//z5ygvSXXqueGgBTsUBMgdhH3MoF60t ZhVFIxUiDXEpZ89jhGqvkk+xwepAhB4h8zd+bjJyvbcb5izzUs/Tg/9RldZdUROXbjeI BxVX/BdnoiStlDzxH6+NO+6HwWWfNd4qZM0lZORWe65ACPTad8UErkxRWB5rEkhp08DZ 0KGl75iSGd/JKl1QjNefLbTEyfWqmsoCEu++j8qCHyYi8XPRYhVdpn0nAEZ8fdky4y7y S1k0KQu3X95IfiUivguLiKYbpdCh3C48qnuiieKQ7b0xjFzd4Be04GxhMxIhkfZAaqOO 4wGw== 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=H5U0Hz5E6z5ldjvQ4xJDZFkCK4qV/McKETGlhtu7sL8=; b=uNNqu+z16CWF3KO9JOPHTfDUR1gd2kt/MtkEiUiOGPiRRTBkOcrpewxt+dfAjffyPn ktO7rxiv6vb33E4nFMxs3uIQaMJTF3w0ZSmi2XhLMOZRSBerMVv6nf4qpqkRE8wxiRZc AHMTVmm7fjoNOisNXytHxBNKaKYWW4xvJuoKUnLVe6lhrWVoBS46zBUxqSRsCVgmG8Ww SwLJVuxWUhSl7BPHBd/IyolL6HoBluV1gyTIm2K+tLGonXkwIhsvtqpontLu5+Wz89E2 AODhGukfUd8HTyFLp0I3NJ2IM3GRAusUpCLq/wl+weLOoKjaye1JMNrOApQ2l9wh/yaw n1rg== X-Gm-Message-State: AOAM5315bES8UKZjtIZgO/7+RkJ0doKUvQcVC3sRKfWdYgiZCiVZ/REo nSWyb3QTYpRBNZBsXMBQvK/7okwyBfeCcMqWBP0= X-Google-Smtp-Source: ABdhPJw8z6vjGGaGGnrlRrziyohZvVfic1DZGt/qPzbkK2DflW6NVM+pA6gyTB+Ke9wzzcJbF1DtstV10V20omnh/NQ= 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:ad4:47cc:: with SMTP id p12mr34218336qvw.25.1600460116095; Fri, 18 Sep 2020 13:15:16 -0700 (PDT) Date: Fri, 18 Sep 2020 13:14:22 -0700 In-Reply-To: <20200918201436.2932360-1-samitolvanen@google.com> Message-Id: <20200918201436.2932360-17-samitolvanen@google.com> Mime-Version: 1.0 References: <20200918201436.2932360-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.681.g6f77f65b4e-goog Subject: [PATCH v3 16/30] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen To: Masahiro Yamada , Will Deacon Cc: Peter Zijlstra , Steven Rostedt , 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 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 541dbe791743..b417c697536e 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