openwrt/include/kernel-build.mk
Christian Marangi 53a08e3743
build: make find_md5 reproducible with AUTOREMOVE
While experimenting with the AUTOREMOVE option in search of a way to use
prebuilt host tools in different buildroot, it was discovered that the
md5 generated by find_md5 in depends.mk is not reproducible.

Currently the hash is generated by the path of the file in addition to
the file mod time. Out of confusion, probably, there was an idea that
such command was used on the package build_dir. Reality is that this
command is run on the package files. (Makefile, patches, src)

This is problematic because the package Makefile (for example) change at
each git clone and base the hash on the Makefile mtime doesn't really
reflect if the Makefile actually changes across a buildroot or not.

A better approach is to generate an hash of each file and then generate
an hash on the sort hash list. This way we remove the problem of git
clone setting a wrong mtime while keeping the integrity of checking if a
file changed for the package as any change will result in a different
hash.

Introduce a new kind of find_md5 function, find_md5_reproducible that
apply this new logic and limit it only with AUTOREMOVE option set to
prevent any kind of slowdown due to additional hash generation.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
2022-09-30 22:26:51 +02:00

184 lines
5.8 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2006-2020 OpenWrt.org
include $(INCLUDE_DIR)/prereq.mk
include $(INCLUDE_DIR)/depends.mk
ifneq ($(DUMP),1)
all: compile
endif
KERNEL_FILE_DEPENDS=$(GENERIC_BACKPORT_DIR) $(GENERIC_PATCH_DIR) $(GENERIC_HACK_DIR) $(PATCH_DIR) $(GENERIC_FILES_DIR) $(FILES_DIR)
STAMP_PREPARED=$(LINUX_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call $(if $(CONFIG_AUTOREMOVE),find_md5_reproducible,find_md5),$(KERNEL_FILE_DEPENDS),)))
STAMP_CONFIGURED:=$(LINUX_DIR)/.configured
include $(INCLUDE_DIR)/download.mk
include $(INCLUDE_DIR)/quilt.mk
include $(INCLUDE_DIR)/kernel-defaults.mk
define Kernel/Prepare
$(call Kernel/Prepare/Default)
endef
define Kernel/Configure
$(call Kernel/Configure/Default)
endef
define Kernel/CompileModules
$(call Kernel/CompileModules/Default)
endef
define Kernel/CompileImage
$(call Kernel/CompileImage/Default)
$(call Kernel/CompileImage/Initramfs)
endef
define Kernel/Clean
$(call Kernel/Clean/Default)
endef
define Download/kernel
URL:=$(LINUX_SITE)
FILE:=$(LINUX_SOURCE)
HASH:=$(LINUX_KERNEL_HASH)
endef
KERNEL_GIT_OPTS:=
ifneq ($(strip $(CONFIG_KERNEL_GIT_LOCAL_REPOSITORY)),"")
KERNEL_GIT_OPTS+=--reference $(CONFIG_KERNEL_GIT_LOCAL_REPOSITORY)
endif
define Download/git-kernel
URL:=$(call qstrip,$(CONFIG_KERNEL_GIT_CLONE_URI))
PROTO:=git
VERSION:=$(CONFIG_KERNEL_GIT_REF)
FILE:=$(LINUX_SOURCE)
SUBDIR:=linux-$(LINUX_VERSION)
OPTS:=$(KERNEL_GIT_OPTS)
endef
ifdef CONFIG_COLLECT_KERNEL_DEBUG
define Kernel/CollectDebug
rm -rf $(KERNEL_BUILD_DIR)/debug
mkdir -p $(KERNEL_BUILD_DIR)/debug/modules
$(CP) $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/debug/
-$(CP) \
$(STAGING_DIR_ROOT)/lib/modules/$(LINUX_VERSION)/* \
$(KERNEL_BUILD_DIR)/debug/modules/
$(FIND) $(KERNEL_BUILD_DIR)/debug -type f | $(XARGS) $(KERNEL_CROSS)strip --only-keep-debug
$(TAR) c -C $(KERNEL_BUILD_DIR) debug \
$(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)") \
| zstd -T0 -f -o $(BIN_DIR)/kernel-debug.tar.zst
endef
endif
ifeq ($(DUMP)$(filter prereq clean refresh update,$(MAKECMDGOALS)),)
ifneq ($(if $(QUILT),,$(CONFIG_AUTOREBUILD)),)
define Kernel/Autoclean
$(PKG_BUILD_DIR)/.dep_files: $(STAMP_PREPARED)
$(call rdep,$(KERNEL_FILE_DEPENDS),$(STAMP_PREPARED),$(PKG_BUILD_DIR)/.dep_files,-x "*/.dep_*")
endef
endif
endif
define BuildKernel
$(if $(QUILT),$(Build/Quilt))
$(if $(LINUX_SITE),$(call Download,kernel))
$(if $(call qstrip,$(CONFIG_KERNEL_GIT_CLONE_URI)),$(call Download,git-kernel))
.NOTPARALLEL:
$(Kernel/Autoclean)
$(STAMP_PREPARED): $(if $(LINUX_SITE),$(DL_DIR)/$(LINUX_SOURCE))
-rm -rf $(KERNEL_BUILD_DIR)
-mkdir -p $(KERNEL_BUILD_DIR)
$(Kernel/Prepare)
touch $$@
$(KERNEL_BUILD_DIR)/symtab.h: FORCE
rm -f $(KERNEL_BUILD_DIR)/symtab.h
touch $(KERNEL_BUILD_DIR)/symtab.h
+$(KERNEL_MAKE) vmlinux
find $(LINUX_DIR) $(STAGING_DIR_ROOT)/lib/modules -name \*.ko | \
xargs $(TARGET_CROSS)nm | \
awk '$$$$1 == "U" { print $$$$2 } ' | \
sort -u > $(KERNEL_BUILD_DIR)/mod_symtab.txt
$(TARGET_CROSS)nm -n $(LINUX_DIR)/vmlinux.o | awk '/^[0-9a-f]+ [rR] __ksymtab_/ {print substr($$$$3,11)}' > $(KERNEL_BUILD_DIR)/kernel_symtab.txt
grep -Ff $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_include.txt
grep -Fvf $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_exclude.txt
( \
echo '#define SYMTAB_KEEP \'; \
cat $(KERNEL_BUILD_DIR)/sym_include.txt | \
awk '{print "KEEP(*(___ksymtab+" $$$$1 ")) \\" }'; \
echo; \
echo '#define SYMTAB_KEEP_GPL \'; \
cat $(KERNEL_BUILD_DIR)/sym_include.txt | \
awk '{print "KEEP(*(___ksymtab_gpl+" $$$$1 ")) \\" }'; \
echo; \
echo '#define SYMTAB_DISCARD \'; \
cat $(KERNEL_BUILD_DIR)/sym_exclude.txt | \
awk '{print "*(___ksymtab+" $$$$1 ") \\" }'; \
echo; \
echo '#define SYMTAB_DISCARD_GPL \'; \
cat $(KERNEL_BUILD_DIR)/sym_exclude.txt | \
awk '{print "*(___ksymtab_gpl+" $$$$1 ") \\" }'; \
echo; \
) > $$@
$(STAMP_CONFIGURED): $(STAMP_PREPARED) $(LINUX_KCONFIG_LIST) $(TOPDIR)/.config FORCE
$(Kernel/Configure)
touch $$@
$(LINUX_DIR)/.modules: export STAGING_PREFIX=$$(STAGING_DIR_HOST)
$(LINUX_DIR)/.modules: export PKG_CONFIG_PATH=$$(STAGING_DIR_HOST)/lib/pkgconfig
$(LINUX_DIR)/.modules: export PKG_CONFIG_LIBDIR=$$(STAGING_DIR_HOST)/lib/pkgconfig
$(LINUX_DIR)/.modules: export FAIL_ON_UNCONFIGURED=1
$(LINUX_DIR)/.modules: $(STAMP_CONFIGURED) $(LINUX_DIR)/.config FORCE
$(Kernel/CompileModules)
touch $$@
$(LINUX_DIR)/.image: export STAGING_PREFIX=$$(STAGING_DIR_HOST)
$(LINUX_DIR)/.image: export PKG_CONFIG_PATH=$$(STAGING_DIR_HOST)/lib/pkgconfig
$(LINUX_DIR)/.image: export PKG_CONFIG_LIBDIR=$$(STAGING_DIR_HOST)/lib/pkgconfig
$(LINUX_DIR)/.image: $(STAMP_CONFIGURED) $(if $(CONFIG_STRIP_KERNEL_EXPORTS),$(KERNEL_BUILD_DIR)/symtab.h) FORCE
$(Kernel/CompileImage)
$(Kernel/CollectDebug)
touch $$@
mostlyclean: FORCE
$(Kernel/Clean)
define BuildKernel
endef
download: $(if $(LINUX_SITE),$(DL_DIR)/$(LINUX_SOURCE))
prepare: $(STAMP_PREPARED)
compile: $(LINUX_DIR)/.modules
$(MAKE) -C image compile TARGET_BUILD=
oldconfig menuconfig nconfig xconfig: $(STAMP_PREPARED) $(STAMP_CHECKED) FORCE
rm -f $(LINUX_DIR)/.config.prev
rm -f $(STAMP_CONFIGURED)
$(LINUX_RECONF_CMD) > $(LINUX_DIR)/.config
$(_SINGLE)$(KERNEL_MAKE) \
$(if $(findstring Darwin,$(HOST_OS)), \
HOSTLDLIBS_mconf="-L$(STAGING_DIR_HOST)/lib -lncurses" \
filechk_conf_cfg=" :" \
) \
YACC=$(STAGING_DIR_HOST)/bin/bison \
$$@
$(call LINUX_RECONF_DIFF,$(LINUX_DIR)/.config) > $(LINUX_RECONFIG_TARGET)
install: $(LINUX_DIR)/.image
+$(MAKE) -C image compile install TARGET_BUILD=
clean: FORCE
rm -rf $(KERNEL_BUILD_DIR)
image-prereq:
@+$(NO_TRACE_MAKE) -s -C image prereq TARGET_BUILD=
prereq: image-prereq
endef