From patchwork Mon Mar 14 02:42:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 63785 Delivered-To: patch@linaro.org Received: by 10.112.199.169 with SMTP id jl9csp2245592lbc; Sun, 13 Mar 2016 19:44:34 -0700 (PDT) X-Received: by 10.98.80.10 with SMTP id e10mr26647580pfb.141.1457923474241; Sun, 13 Mar 2016 19:44:34 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 79si22455520pfm.61.2016.03.13.19.44.33; Sun, 13 Mar 2016 19:44:34 -0700 (PDT) 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 S1754673AbcCNCoN (ORCPT + 30 others); Sun, 13 Mar 2016 22:44:13 -0400 Received: from alt32.smtp-out.videotron.ca ([24.53.0.21]:4181 "EHLO alt32.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754523AbcCNCnE (ORCPT ); Sun, 13 Mar 2016 22:43:04 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id fITGaMLuEomgUfITHanY4d; Sun, 13 Mar 2016 22:43:03 -0400 X-Authority-Analysis: v=2.1 cv=T+wsN6+Q c=1 sm=1 tr=0 a=keA3yYpnlypCNW5BNWqu+w==:117 a=keA3yYpnlypCNW5BNWqu+w==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=7OsogOcEt9IA:10 a=KKAkSRfTAAAA:8 a=Tty9oNO6AAAA:8 a=Emx3EsyQ1RuaEW2k4w4A:9 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id 6E3C92DA0649; Sun, 13 Mar 2016 22:43:01 -0400 (EDT) From: Nicolas Pitre To: Michal Marek Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 6/8] create/adjust generated/autoksyms.h Date: Sun, 13 Mar 2016 22:42:14 -0400 Message-Id: <1457923336-2732-7-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1457923336-2732-1-git-send-email-nicolas.pitre@linaro.org> References: <1457923336-2732-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfIx4rCWf8+F27ThqiJMl+7tBmhhTnNchXgqkeoAsfRyTT6nUggNXv0Vs8HuYKmSHdh6lObyx4tQZFKkz2xTIL/n0CyGCGutWBO7H5TIF8F07CLLsZVms 5uKPaiopHFkQrQecjWy9Rx5VZ/Chu4/jFtzuBsToVIupIBpRy/hskoYydg6kqrSJeegO+EeMoFjnPlX6bT0sbLxY27F7MMDyK9sU+dStGywHM9JM0xcY0cps ISl7aGdCozw0b9bA/LydtA== 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 | 101 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 114 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)): $(vmlinux-dirs) ; diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh new file mode 100755 index 0000000000..5bf538f1ed --- /dev/null +++ b/scripts/adjust_autoksyms.sh @@ -0,0 +1,101 @@ +#!/bin/sh + +# Script to create/update include/generated/autoksyms.h and dependency files +# +# Copyright: (C) 2016 Linaro Limited +# Created by: Nicolas Pitre, January 2016 +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 as +# published by the Free Software Foundation. + +# Create/update the include/generated/autoksyms.h file from the list +# of all module's needed symbols as recorded on the third line of +# .tmp_versions/*.mod files. +# +# For each symbol being added or removed, the corresponding dependency +# file's timestamp is updated to force a rebuild of the affected source +# file. All arguments passed to this script are assumed to be a command +# to be exec'd to trigger a rebuild of those files. + +set -e + +cur_ksyms_file="include/generated/autoksyms.h" +new_ksyms_file="include/generated/autoksyms.h.tmpnew" + +info() { + if [ "$quiet" != "silent_" ]; then + printf " %-7s %s\n" "$1" "$2" + fi +} + +info "CHK" "$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... +if [ -e "$cur_ksyms_file" ]; then touch "$cur_ksyms_file"; fi + +# 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 "$CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX" ]; then + sym="${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. +changed=$( +count=0 +sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u | +sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" | +while read sympath; do + if [ -z "$sympath" ]; then continue; fi + depfile="include/config/ksym/${sympath}.h" + mkdir -p "$(dirname "$depfile")" + touch "$depfile" + echo $((count += 1)) +done | tail -1 ) +changed=${changed:-0} + +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