From patchwork Wed May 23 00:19:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laura Abbott X-Patchwork-Id: 10419791 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B3B0B6016C for ; Wed, 23 May 2018 00:20:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A282F28E2A for ; Wed, 23 May 2018 00:20:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 954B628E55; Wed, 23 May 2018 00:20:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3938728E2A for ; Wed, 23 May 2018 00:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753626AbeEWATv (ORCPT ); Tue, 22 May 2018 20:19:51 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:36465 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751872AbeEWATs (ORCPT ); Tue, 22 May 2018 20:19:48 -0400 Received: by mail-pl0-f66.google.com with SMTP id v24-v6so11872130plo.3 for ; Tue, 22 May 2018 17:19:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=43bEIrr3LkVBCP3gecETmDysn4uZEmPZf86ewWH6S0g=; b=ER5x4N7O8LxdOYxdX/7VcnLGKnViwfC+drEebhGJozIBV4SsUx8jcpNIq7SOT39Yl2 gJ7R5N9wujBQE0zp1c9wNYBlMFSXqmqjL7v4M1D5j3ljfc2nyQuwTmrPMGoysUwBAuQF lDh0xBGKpWvgAIm2ws2H3e5NkX+0WBbdCNNyU7TTp45ZOzVpKXwgVQJMMvzIBeUTcVGO PHtMLHGKbIxN4tSr8f6HHNY7g6ssZscaMJ1vgtNcCLotSjuh0AuGD+/uonMY2ezkErq1 UqtIuMNnFWwC3fMZJI/NPGdnTnSsI3I3Ii73iwOMrrP3BZ1FTcZ+G7yUeu+u24Ex4lcJ wv1A== X-Gm-Message-State: ALKqPwcDQZA44n78flR5EClK1zOVsswdQ/4jWkEZUx294YoK9KipsYot lVoa4q+pr9M5kv7gO3VGwP0BXA== X-Google-Smtp-Source: AB8JxZoTA0L/UQYCWyDX7oQULe2Qozx9Honuo6wH7puNJOVHw8GdgEndna9p9Qgu16fuQ/kYqQ4LCQ== X-Received: by 2002:a17:902:aa98:: with SMTP id d24-v6mr601375plr.185.1527034788062; Tue, 22 May 2018 17:19:48 -0700 (PDT) Received: from localhost.net ([2601:602:9802:a8dc::4dc5]) by smtp.gmail.com with ESMTPSA id 206-v6sm29303145pfy.51.2018.05.22.17.19.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 22 May 2018 17:19:47 -0700 (PDT) From: Laura Abbott To: Andy Lutomirski , mjw@fedoraproject.org, "H . J . Lu" , Masahiro Yamada Cc: Laura Abbott , Linus Torvalds , X86 ML , linux-kernel@vger.kernel.org, Nick Clifton , Cary Coutant , linux-kbuild@vger.kernel.org Subject: [PATCHv3 1/2] kbuild: Introduce build-salt linker script Date: Tue, 22 May 2018 17:19:38 -0700 Message-Id: <20180523001939.9431-2-labbott@redhat.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180523001939.9431-1-labbott@redhat.com> References: <20180523001939.9431-1-labbott@redhat.com> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The build id generated from --build-id can be generated in several different ways, with the default being the sha1 on the output of the linked file. For distributions, it can be useful to make sure this ID is unique, even if the actual file contents don't change. The easiest way to do this is to insert a comment section with some data. Introduce a generated linker script to link against the kernel/modules. This puts the kernel version in a .comment section which will generate a unique build id if the kernel version changes. Signed-off-by: Laura Abbott --- v3: Generate the linker script directly instead of just a header. --- Makefile | 4 +++- scripts/.gitignore | 1 + scripts/Makefile | 9 ++++++++- scripts/gensalt | 22 ++++++++++++++++++++++ scripts/link-vmlinux.sh | 3 ++- 5 files changed, 36 insertions(+), 3 deletions(-) create mode 100755 scripts/gensalt diff --git a/Makefile b/Makefile index ec6f45928fd4..87fe8992afd8 100644 --- a/Makefile +++ b/Makefile @@ -428,7 +428,8 @@ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE -KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds +KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds \ + -T $(obj)/scripts/build-salt.lds LDFLAGS := GCC_PLUGINS_CFLAGS := @@ -997,6 +998,7 @@ export KBUILD_VMLINUX_INIT := $(head-y) $(init-y) export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y) export KBUILD_VMLINUX_LIBS := $(libs-y1) export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds +export EXTRA_LDS := scripts/build-salt.lds export LDFLAGS_vmlinux # used by scripts/package/Makefile export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools) diff --git a/scripts/.gitignore b/scripts/.gitignore index 0442c06eefcb..1c840ef4f0c8 100644 --- a/scripts/.gitignore +++ b/scripts/.gitignore @@ -13,3 +13,4 @@ asn1_compiler extract-cert sign-file insert-sys-cert +build-salt.lds diff --git a/scripts/Makefile b/scripts/Makefile index 25ab143cbe14..019b0749ff46 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -25,7 +25,14 @@ HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include HOSTLOADLIBES_sign-file = -lcrypto HOSTLOADLIBES_extract-cert = -lcrypto -always := $(hostprogs-y) $(hostprogs-m) +always := $(hostprogs-y) $(hostprogs-m) build-salt.lds + +define filechk_build-salt.lds + ($(CONFIG_SHELL) $(srctree)/scripts/gensalt $(KERNELRELEASE)) +endef + +$(obj)/build-salt.lds: $(src)/gensalt FORCE + $(call filechk,build-salt.lds) # The following hostprogs-y programs are only build on demand hostprogs-y += unifdef diff --git a/scripts/gensalt b/scripts/gensalt new file mode 100755 index 000000000000..846c0407cc43 --- /dev/null +++ b/scripts/gensalt @@ -0,0 +1,22 @@ +#!/bin/sh + +if [[ $1 = "" ]]; then + echo "#define BUILD_ID_SALT" + exit 0 +fi + +BUILD_ID_SALT=$1 + +echo "SECTIONS {" +echo ".comment (INFO) :" +echo " {" + +_TAG=`echo $BUILD_ID_SALT | sed -e 's/\(.\)/\1 /g'` +for c in $_TAG; do + _HEX=`echo -n $c | od -A n -t x1 | tr -d ' ' ` + echo "BYTE(0x$_HEX);" +done +echo "BYTE(0x00);" + +echo " } " +echo " } " diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 9045823c7be7..588946dde658 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -84,6 +84,7 @@ modpost_link() vmlinux_link() { local lds="${objtree}/${KBUILD_LDS}" + local extra_lds="${objtree}/${EXTRA_LDS}" local objects if [ "${SRCARCH}" != "um" ]; then @@ -96,7 +97,7 @@ vmlinux_link() ${1}" ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \ - -T ${lds} ${objects} + -T ${lds} -T ${extra_lds} ${objects} else objects="-Wl,--whole-archive \ built-in.a \