From patchwork Wed Feb 10 05:08:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 8268511 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 62017BEEED for ; Wed, 10 Feb 2016 05:10:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5145B201BC for ; Wed, 10 Feb 2016 05:10:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32B0020270 for ; Wed, 10 Feb 2016 05:10:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751374AbcBJFKU (ORCPT ); Wed, 10 Feb 2016 00:10:20 -0500 Received: from relais.videotron.ca ([24.201.245.36]:25651 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbcBJFIg (ORCPT ); Wed, 10 Feb 2016 00:08:36 -0500 Content-transfer-encoding: 7BIT Received: from yoda.home ([96.23.157.65]) by VL-VM-MR003.ip.videotron.ca (Oracle Communications Messaging Exchange Server 7u4-22.01 64bit (built Apr 21 2011)) with ESMTP id <0O2B004SJFMBWV00@VL-VM-MR003.ip.videotron.ca>; Wed, 10 Feb 2016 00:08:36 -0500 (EST) Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id D04AC2DA053E; Wed, 10 Feb 2016 00:08:35 -0500 (EST) From: Nicolas Pitre To: Michal Marek , linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Al Viro , Rusty Russell Subject: [PATCH v2 5/6] create/adjust generated/autoksyms.h Date: Wed, 10 Feb 2016 00:08:27 -0500 Message-id: <1455080908-22272-6-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.5.0 In-reply-to: <1455080908-22272-1-git-send-email-nicolas.pitre@linaro.org> References: <1455080908-22272-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Given the list of exported symbols needed by all modules, we can create a header file containing preprocessor defines for each of those symbols. Also, when some symbols are added and/or removed from the list, we can update the time on the corresponding files used as build dependencies for those symbols. And finally, if any symbol did change state, the corresponding source files must be rebuilt. The insertion or removal of an EXPORT_SYMBOL() entry within a module may create or remove the need for another exported symbol. This is why this operation has to be repeated until the list of needed exported symbols becomes stable. Only then the final kernel and modules link take place. Signed-off-by: Nicolas Pitre Acked-by: Rusty Russell --- Makefile | 13 ++++++ scripts/adjust_autoksyms.sh | 97 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 110 insertions(+) create mode 100755 scripts/adjust_autoksyms.sh diff --git a/Makefile b/Makefile index e916428cf7..bb865095ca 100644 --- a/Makefile +++ b/Makefile @@ -921,6 +921,10 @@ quiet_cmd_link-vmlinux = LINK $@ # Include targets which we want to # execute if the rest of the kernel build went well. vmlinux: scripts/link-vmlinux.sh $(vmlinux-deps) FORCE +ifdef CONFIG_TRIM_UNUSED_KSYMS + $(Q)$(CONFIG_SHELL) scripts/adjust_autoksyms.sh \ + "$(MAKE) KBUILD_MODULES=1 -f $(srctree)/Makefile autoksyms_recursive" +endif ifdef CONFIG_HEADERS_CHECK $(Q)$(MAKE) -f $(srctree)/Makefile headers_check endif @@ -935,6 +939,15 @@ ifdef CONFIG_GDB_SCRIPTS endif +$(call if_changed,link-vmlinux) +autoksyms_recursive: $(vmlinux-deps) + $(Q)$(CONFIG_SHELL) scripts/adjust_autoksyms.sh \ + "$(MAKE) KBUILD_MODULES=1 -f $(srctree)/Makefile autoksyms_recursive" +PHONY += autoksyms_recursive + +# standalone target for easier testing +include/generated/autoksyms.h: FORCE + $(Q)$(CONFIG_SHELL) scripts/adjust_autoksyms.sh true + # The actual objects are generated when descending, # make sure no implicit rule kicks in $(sort $(vmlinux-deps)): $(vmlinux-dirs) ; diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh new file mode 100755 index 0000000000..0cc8ac3349 --- /dev/null +++ b/scripts/adjust_autoksyms.sh @@ -0,0 +1,97 @@ +#!/bin/sh + +# Script to create/update include/generated/autoksyms.h and dependency files +# +# Copyright: (C) 2016 Linaro Limited +# Created by: Nicolas Pitre, January 2016 +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 as +# published by the Free Software Foundation. + +# Create/update the include/generated/autoksyms.h file from the list +# of all module's needed symbols as recorded on the third line of +# .tmp_versions/*.mod files. +# +# For each symbol being added or removed, the corresponding dependency +# file's timestamp is updated to force a rebuild of the affected source +# file. All arguments passed to this script are assumed to be a command +# to be exec'd to trigger a rebuild of those files. + +set -e + +cur_ksyms_file="include/generated/autoksyms.h" +new_ksyms_file="include/generated/autoksyms.h.tmpnew" + +info() { [ "$quiet" != "silent_" ] && printf " %-7s %s\n" "$1" "$2"; } + +info "CHK" "$cur_ksyms_file" + +# Use "make V=1" to debug this script. +case "$KBUILD_VERBOSE" in +*1*) + set -x + ;; +esac + +# We need access to CONFIG_ symbols +case "${KCONFIG_CONFIG}" in +*/*) + . "${KCONFIG_CONFIG}" + ;; +*) + # Force using a file from the current directory + . "./${KCONFIG_CONFIG}" +esac + +# In case it doesn't exist yet... +[ -e "$cur_ksyms_file" ] || touch "$cur_ksyms_file" + +# Generate a new ksym list file with symbols needed by the current +# set of modules. +cat > "$new_ksyms_file" << EOT +/* + * Automatically generated file; DO NOT EDIT. + */ + +EOT +sed -ns -e '3s/ /\n/gp' "$MODVERDIR"/*.mod | sort -u | +while read sym; do + if [ -n "$CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX" ]; then + sym=$(sed 's/^_//' <<< "$sym") + fi + echo "#define __KSYM_${sym} 1" +done >> "$new_ksyms_file" + +# Special case for modversions (see modpost.c) +if [ -n "$CONFIG_MODVERSIONS" ]; then + echo "#define __KSYM_module_layout 1" >> "$new_ksyms_file" +fi + +# Extract changes between old and new list and touch corresponding +# dependency files. +# Note: sort -m doesn't work well with underscore prefixed symbols so we +# use 'cat ... | sort' instead. +changed=0 +while read sympath; do + [ -z "$sympath" ] && continue + depfile="include/config/ksym/${sympath}.h" + mkdir -p "$(dirname "$depfile")" + touch "$depfile" + changed=$((changed + 1)) +done <<< "$( + cat "$cur_ksyms_file" "$new_ksyms_file" | sort | uniq -u | + sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" )" + +if [ $changed -gt 0 ]; then + # Replace the old list with tne new one + old=$(grep -c "^#define __KSYM_" "$cur_ksyms_file" || true) + new=$(grep -c "^#define __KSYM_" "$new_ksyms_file" || true) + info "KSYMS" "symbols: $old old, $new new, $changed changed" + info "UPD" "$cur_ksyms_file" + mv -f "$new_ksyms_file" "$cur_ksyms_file" + # Then trigger a rebuild of affected source files + exec $@ +else + rm -f "$new_ksyms_file" +fi