From patchwork Tue Sep 29 21:46:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11807173 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 0FE3D618 for ; Tue, 29 Sep 2020 21:49:21 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 4EC872076D for ; Tue, 29 Sep 2020 21:49:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="J0iZkzh/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4EC872076D 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-20046-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 31982 invoked by uid 550); 29 Sep 2020 21:47:22 -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 31792 invoked from network); 29 Sep 2020 21:47:20 -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=SD1yF5YD1LCllhQ+wHxnWDGScJRWPVuGZBuH/1UV7E0=; b=J0iZkzh/GjzAvSvvMSQSffvTtscp77TuS/rOOUU4WJ9pgFewxPSYIc3SuYF5TYZa3f nnJs5NE+Z7HnfV7im6jer/93vPDjH2tAsMsDCCOkNJH1RmXE5K6MIkNKUWtTL0TsRGwX qAdqdJq3CyXfTerbts+lbY6m8AMjwxizFh09pkc2952byTSLnpnpLEsH+VeTxDQPhQlK KJc/bEwAWARFDxCjnLIpypY36iZV6YBpeoMe0S3Fhkxk2EnpJ3bKxAnnRVKOCtJywZ8S cn4idbWnDoWjvaMpJXjclpVdG1XxH/TZB3j/SaC5oSMROSGKYvddyUIYzmMFA/b7OTLC QNvA== 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=SD1yF5YD1LCllhQ+wHxnWDGScJRWPVuGZBuH/1UV7E0=; b=laUh/Q0/h08//RiL6lI6PJGCxrJw4cBXhlCEegYK7fEvCZgG2T3iqLUuKNwEAQ025L mMgnpgngHU2hk5DqAKG7hXUrlp9lYI8Je5jdGjdeSxky8Q0EWFXsWrNWTXBgIa+c/8nH YJxi1JLqIF4SeonDd25it8bxSi9VEyo6Nezy+fVBf7029B5l1uwpmofSOldk5Oe+cfV1 N8iQkUsaz9Il4exnzGhIk4BSLaO/NGRVVOaeJhIVFHiG+NtqBOrGQRzzDAyudp/vc6K9 IKbiUZf1/v5fkZKUXxulNK0yG/8gCFwImPlFBedlJVPmoHh7y1zngaAa7cRj0a/ZwMKm 0HNw== X-Gm-Message-State: AOAM533hPpOKAa4JKcCgt7+dVPBmTc9tyPMiy5XD5SPVsWefO6ZG/6d4 5QtutAJTM6ESbko/zgmz/ey0i1b/ZnxHgN3LTtI= X-Google-Smtp-Source: ABdhPJy7ECnfWEGwUFe6hxmbM3YxQNxU/8qssaAcXSiWxNNwaQyUUyZL5rJnjOfK3ZrxDFzMzY/3wIlsYUo/Me039B4= 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:ad4:55ce:: with SMTP id bt14mr6729584qvb.2.1601416029039; Tue, 29 Sep 2020 14:47:09 -0700 (PDT) Date: Tue, 29 Sep 2020 14:46:18 -0700 In-Reply-To: <20200929214631.3516445-1-samitolvanen@google.com> Message-Id: <20200929214631.3516445-17-samitolvanen@google.com> Mime-Version: 1.0 References: <20200929214631.3516445-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog Subject: [PATCH v4 16/29] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen To: Masahiro Yamada , Will Deacon , Steven Rostedt Cc: 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 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