From patchwork Thu Feb 18 20:07:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 62247 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp784972lbl; Thu, 18 Feb 2016 12:10:10 -0800 (PST) X-Received: by 10.98.16.69 with SMTP id y66mr12866239pfi.86.1455826210312; Thu, 18 Feb 2016 12:10:10 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 17si11230149pfr.69.2016.02.18.12.10.10; Thu, 18 Feb 2016 12:10:10 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965387AbcBRUKH (ORCPT + 30 others); Thu, 18 Feb 2016 15:10:07 -0500 Received: from relais.videotron.ca ([24.201.245.36]:50003 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1427000AbcBRUHJ (ORCPT ); Thu, 18 Feb 2016 15:07:09 -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 <0O2R0001OEJUIBM0@VL-VM-MR003.ip.videotron.ca>; Thu, 18 Feb 2016 15:07:07 -0500 (EST) Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id C05B22DA0541; Thu, 18 Feb 2016 15:07:06 -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 v3 6/7] create/adjust generated/autoksyms.h Date: Thu, 18 Feb 2016 15:07:02 -0500 Message-id: <1455826023-2134-7-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.5.0 In-reply-to: <1455826023-2134-1-git-send-email-nicolas.pitre@linaro.org> References: <1455826023-2134-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 2.5.0 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)): $(vmlinux-dirs) ; diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh new file mode 100755 index 0000000000..898a3ca1b2 --- /dev/null +++ b/scripts/adjust_autoksyms.sh @@ -0,0 +1,97 @@ +#!/bin/sh + +# Script to create/update include/generated/autoksyms.h and dependency files +# +# Copyright: (C) 2016 Linaro Limited +# Created by: Nicolas Pitre, January 2016 +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 as +# published by the Free Software Foundation. + +# Create/update the include/generated/autoksyms.h file from the list +# of all module's needed symbols as recorded on the third line of +# .tmp_versions/*.mod files. +# +# For each symbol being added or removed, the corresponding dependency +# file's timestamp is updated to force a rebuild of the affected source +# file. All arguments passed to this script are assumed to be a command +# to be exec'd to trigger a rebuild of those files. + +set -e + +cur_ksyms_file="include/generated/autoksyms.h" +new_ksyms_file="include/generated/autoksyms.h.tmpnew" + +info() { [ "$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_" "$new_ksyms_file" || true) + info "KSYMS" "symbols: before=$old, after=$new, changed=$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