kbuild: link of vmlinux moved to a script (1f2bfbd0) · Commits · 戴 / test

Makefile

+12 −203

Original line number	Diff line number	Diff line
		@@ -337,7 +337,6 @@ AWK = awk
		GENKSYMS = scripts/genksyms/genksyms
		INSTALLKERNEL := installkernel
		DEPMOD = /sbin/depmod
		KALLSYMS = scripts/kallsyms
		PERL = perl
		CHECK = sparse

		@@ -723,191 +722,21 @@ libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
		libs-y2 := $(patsubst %/, %/built-in.o, $(libs-y))
		libs-y := $(libs-y1) $(libs-y2)

		# externally visible symbols
		# Externally visible symbols (used by link-vmlinux.sh)
		export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
		export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y)
		export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
		export LDFLAGS_vmlinux

		# Build vmlinux
		# ---------------------------------------------------------------------------
		# vmlinux is built from the objects selected by $(vmlinux-init) and
		# $(vmlinux-main). Most are built-in.o files from top-level directories
		# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
		# Ordering when linking is important, and $(vmlinux-init) must be first.
		#
		# vmlinux
		# ^
		# \|
		# +-< $(vmlinux-init)
		# \| +--< init/version.o + more
		# \|
		# +--< $(vmlinux-main)
		# \| +--< driver/built-in.o mm/built-in.o + more
		# \|
		# +-< kallsyms.o (see description in CONFIG_KALLSYMS section)
		#
		# vmlinux version (uname -v) cannot be updated during normal
		# descending-into-subdirs phase since we do not yet know if we need to
		# update vmlinux.
		# Therefore this step is delayed until just before final link of vmlinux -
		# except in the kallsyms case where it is done just before adding the
		# symbols to the kernel.
		#
		# System.map is generated to document addresses of all kernel symbols

		vmlinux-init := $(head-y) $(init-y)
		vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y)
		vmlinux-all := $(vmlinux-init) $(vmlinux-main)
		vmlinux-lds := arch/$(SRCARCH)/kernel/vmlinux.lds

		# Rule to link vmlinux - also used during CONFIG_KALLSYMS
		# May be overridden by arch/$(ARCH)/Makefile
		quiet_cmd_vmlinux__ ?= LD $@
		cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ \
		-T $(vmlinux-lds) $(vmlinux-init) \
		--start-group $(vmlinux-main) --end-group \
		$(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^)

		# Generate new vmlinux version
		quiet_cmd_vmlinux_version = GEN .version
		cmd_vmlinux_version = set -e; \
		if [ ! -r .version ]; then \
		rm -f .version; \
		echo 1 >.version; \
		else \
		mv .version .old_version; \
		expr 0$$(cat .old_version) + 1 >.version; \
		fi; \
		$(MAKE) $(build)=init

		# Generate System.map
		quiet_cmd_sysmap = SYSMAP
		cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap

		# Link of vmlinux
		# If CONFIG_KALLSYMS is set .version is already updated
		# Generate System.map and verify that the content is consistent
		# Use + in front of the vmlinux_version rule to silent warning with make -j2
		# First command is ':' to allow us to use + in front of the rule
		define rule_vmlinux__
		:
		$(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))

		$(call cmd,vmlinux__)
		$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd

		$(Q)$(if $($(quiet)cmd_sysmap), \
		echo ' $($(quiet)cmd_sysmap) System.map' &&) \
		$(cmd_sysmap) $@ System.map; \
		if [ $$? -ne 0 ]; then \
		rm -f $@; \
		/bin/false; \
		fi;
		$(verify_kallsyms)
		endef


		ifdef CONFIG_KALLSYMS
		# Generate section listing all symbols and add it into vmlinux $(kallsyms.o)
		# It's a three stage process:
		# o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is
		# empty
		# Running kallsyms on that gives us .tmp_kallsyms1.o with
		# the right size - vmlinux version (uname -v) is updated during this step
		# o .tmp_vmlinux2 now has a __kallsyms section of the right size,
		# but due to the added section, some addresses have shifted.
		# From here, we generate a correct .tmp_kallsyms2.o
		# o The correct .tmp_kallsyms2.o is linked into the final vmlinux.
		# o Verify that the System.map from vmlinux matches the map from
		# .tmp_vmlinux2, just in case we did not generate kallsyms correctly.
		# o If 'make KALLSYMS_EXTRA_PASS=1" was used, do an extra pass using
		# .tmp_vmlinux3 and .tmp_kallsyms3.o. This is only meant as a
		# temporary bypass to allow the kernel to be built while the
		# maintainers work out what went wrong with kallsyms.

		last_kallsyms := 2

		ifdef KALLSYMS_EXTRA_PASS
		ifneq ($(KALLSYMS_EXTRA_PASS),0)
		last_kallsyms := 3
		endif
		endif

		kallsyms.o := .tmp_kallsyms$(last_kallsyms).o

		define verify_kallsyms
		$(Q)$(if $($(quiet)cmd_sysmap), \
		echo ' $($(quiet)cmd_sysmap) .tmp_System.map' &&) \
		$(cmd_sysmap) .tmp_vmlinux$(last_kallsyms) .tmp_System.map
		$(Q)cmp -s System.map .tmp_System.map \|\| \
		(echo Inconsistent kallsyms data; \
		echo This is a bug - please report about it; \
		echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround; \
		rm .tmp_kallsyms* ; /bin/false )
		endef

		# Update vmlinux version before link
		# Use + in front of this rule to silent warning about make -j1
		# First command is ':' to allow us to use + in front of this rule
		cmd_ksym_ld = $(cmd_vmlinux__)
		define rule_ksym_ld
		:
		+$(call cmd,vmlinux_version)
		$(call cmd,vmlinux__)
		$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
		endef

		# Generate .S file with all kernel symbols
		quiet_cmd_kallsyms = KSYM $@
		cmd_kallsyms = $(NM) -n $< \| $(KALLSYMS) \
		$(if $(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
		vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN)

		.tmp_kallsyms1.o .tmp_kallsyms2.o .tmp_kallsyms3.o: %.o: %.S scripts FORCE
		$(call if_changed_dep,as_o_S)
		# Final link of vmlinux
		cmd_link-vmlinux = $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux)
		quiet_cmd_link-vmlinux = LINK $@

		.tmp_kallsyms%.S: .tmp_vmlinux% $(KALLSYMS)
		$(call cmd,kallsyms)

		# .tmp_vmlinux1 must be complete except kallsyms, so update vmlinux version
		.tmp_vmlinux1: $(vmlinux-lds) $(vmlinux-all) FORCE
		$(call if_changed_rule,ksym_ld)

		.tmp_vmlinux2: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms1.o FORCE
		$(call if_changed,vmlinux__)

		.tmp_vmlinux3: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms2.o FORCE
		$(call if_changed,vmlinux__)

		# Needs to visit scripts/ before $(KALLSYMS) can be used.
		$(KALLSYMS): scripts ;

		# Generate some data for debugging strange kallsyms problems
		debug_kallsyms: .tmp_map$(last_kallsyms)

		.tmp_map%: .tmp_vmlinux% FORCE
		($(OBJDUMP) -h $< \| $(AWK) '/^ +[0-9]/{print $$4 " 0 " $$2}'; $(NM) $<) \| sort > $@

		.tmp_map3: .tmp_map2

		.tmp_map2: .tmp_map1

		endif # ifdef CONFIG_KALLSYMS

		# Do modpost on a prelinked vmlinux. The finally linked vmlinux has
		# relevant sections renamed as per the linker script.
		quiet_cmd_vmlinux-modpost = LD $@
		cmd_vmlinux-modpost = $(LD) $(LDFLAGS) -r -o $@ \
		$(vmlinux-init) --start-group $(vmlinux-main) --end-group \
		$(filter-out $(vmlinux-init) $(vmlinux-main) FORCE ,$^)
		define rule_vmlinux-modpost
		:
		+$(call cmd,vmlinux-modpost)
		$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@
		$(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmd
		endef

		# vmlinux image - including updated kernel symbols
		vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCE
		# 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_HEADERS_CHECK
		$(Q)$(MAKE) -f $(srctree)/Makefile headers_check
		endif
		@@ -917,22 +746,11 @@ endif
		ifdef CONFIG_BUILD_DOCSRC
		$(Q)$(MAKE) $(build)=Documentation
		endif
		$(call vmlinux-modpost)
		$(call if_changed_rule,vmlinux__)
		$(Q)rm -f .old_version

		# build vmlinux.o first to catch section mismatch errors early
		ifdef CONFIG_KALLSYMS
		.tmp_vmlinux1: vmlinux.o
		endif

		modpost-init := $(filter-out init/built-in.o, $(vmlinux-init))
		vmlinux.o: $(modpost-init) $(vmlinux-main) FORCE
		$(call if_changed_rule,vmlinux-modpost)
		+$(call if_changed,link-vmlinux)

		# The actual objects are generated when descending,
		# make sure no implicit rule kicks in
		$(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ;
		$(sort $(vmlinux-deps)): $(vmlinux-dirs) ;

		# Handle descending into subdirectories listed in $(vmlinux-dirs)
		# Preset locale variables to speed up the build process. Limit locale
		@@ -1156,8 +974,6 @@ endif # CONFIG_MODULES

		# Directories & files removed with 'make clean'
		CLEAN_DIRS += $(MODVERDIR)
		CLEAN_FILES += vmlinux System.map \
		.tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map

		# Directories & files removed with 'make mrproper'
		MRPROPER_DIRS += include/config usr/include include/generated \
		@@ -1403,6 +1219,7 @@ scripts: ;
		endif # KBUILD_EXTMOD

		clean: $(clean-dirs)
		$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
		$(call cmd,rmdirs)
		$(call cmd,rmfiles)
		@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
		@@ -1536,14 +1353,6 @@ quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
		cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
		$(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)

		a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \
		$(KBUILD_AFLAGS_KERNEL) \
		$(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(KBUILD_CPPFLAGS) \
		$(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)

		quiet_cmd_as_o_S = AS $@
		cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<

		# read all saved command lines

		targets := $(wildcard $(sort $(targets)))

arch/um/Makefile

+2 −9

Original line number	Diff line number	Diff line
		@@ -121,15 +121,8 @@ LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc

		LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt))

		CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)
		define cmd_vmlinux__
		$(CC) $(CFLAGS_vmlinux) -o $@ \
		-Wl,-T,$(vmlinux-lds) $(vmlinux-init) \
		-Wl,--start-group $(vmlinux-main) -Wl,--end-group \
		-lutil \
		$(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o \
		FORCE ,$^) ; rm -f linux
		endef
		# Used by link-vmlinux.sh which has special support for um link
		export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)

		# When cleaning we don't include .config, so we don't include
		# TT or skas makefiles and don't clean skas_ptregs.h.

scripts/link-vmlinux.sh

0 → 100644

+211 −0

Original line number	Diff line number	Diff line
		#!/bin/sh
		#
		# link vmlinux
		#
		# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
		# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories
		# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
		# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first.
		#
		# vmlinux
		# ^
		# \|
		# +-< $(KBUILD_VMLINUX_INIT)
		# \| +--< init/version.o + more
		# \|
		# +--< $(KBUILD_VMLINUX_MAIN)
		# \| +--< drivers/built-in.o mm/built-in.o + more
		# \|
		# +-< ${kallsymso} (see description in KALLSYMS section)
		#
		# vmlinux version (uname -v) cannot be updated during normal
		# descending-into-subdirs phase since we do not yet know if we need to
		# update vmlinux.
		# Therefore this step is delayed until just before final link of vmlinux.
		#
		# System.map is generated to document addresses of all kernel symbols

		# Error out on error
		set -e

		# Nice output in kbuild format
		# Will be supressed by "make -s"
		info()
		{
		if [ "${quiet}" != "silent_" ]; then
		printf " %-7s %s\n" ${1} ${2}
		fi
		}

		# Link of vmlinux.o used for section mismatch analysis
		# ${1} output file
		modpost_link()
		{
		${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT} \
		--start-group ${KBUILD_VMLINUX_MAIN} --end-group
		}

		# Link of vmlinux
		# ${1} - optional extra .o files
		# ${2} - output file
		vmlinux_link()
		{
		local lds="${objtree}/${KBUILD_LDS}"

		if [ "${SRCARCH}" != "um" ]; then
		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
		-T ${lds} ${KBUILD_VMLINUX_INIT} \
		--start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
		else
		${CC} ${CFLAGS_vmlinux} -o ${2} \
		-Wl,-T,${lds} ${KBUILD_VMLINUX_INIT} \
		-Wl,--start-group \
		${KBUILD_VMLINUX_MAIN} \
		-Wl,--end-group \
		-lutil ${1}
		rm -f linux
		fi
		}


		# Create ${2} .o file with all symbols from the ${1} object file
		kallsyms()
		{
		info KSYM ${2}
		local kallsymopt;

		if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
		kallsymopt=--all-symbols
		fi

		local aflags="${KBUILD_AFLAGS} ${NOSTDINC_FLAGS} \
		${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"

		${NM} -n ${1} \| \
		scripts/kallsyms ${kallsymopt} \| \
		${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
		}

		# Create map file with all symbols from ${1}
		# See mksymap for additional details
		mksysmap()
		{
		${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
		}

		# Delete output files in case of error
		trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
		cleanup()
		{
		rm -f .old_version
		rm -f .tmp_System.map
		rm -f .tmp_kallsyms*
		rm -f .tmp_version
		rm -f .tmp_vmlinux*
		rm -f System.map
		rm -f vmlinux
		rm -f vmlinux.o
		}

		#
		#
		# Use "make V=1" to debug this script
		case "${KBUILD_VERBOSE}" in
		1)
		set -x
		;;
		esac

		if [ "$1" = "clean" ]; then
		cleanup
		exit 0
		fi

		# We need access to CONFIG_ symbols
		. ./.config

		#link vmlinux.o
		info LD vmlinux.o
		modpost_link vmlinux.o

		# modpost vmlinux.o to check for section mismatches
		${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o

		# Update version
		info GEN .version
		if [ ! -r .version ]; then
		rm -f .version;
		echo 1 >.version;
		else
		mv .version .old_version;
		expr 0$(cat .old_version) + 1 >.version;
		fi;

		# final build of init/
		${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init

		kallsymso=""
		kallsyms_vmlinux=""
		if [ -n "${CONFIG_KALLSYMS}" ]; then

		# kallsyms support
		# Generate section listing all symbols and add it into vmlinux
		# It's a three step process:
		# 1) Link .tmp_vmlinux1 so it has all symbols and sections,
		# but __kallsyms is empty.
		# Running kallsyms on that gives us .tmp_kallsyms1.o with
		# the right size
		# 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
		# the right size, but due to the added section, some
		# addresses have shifted.
		# From here, we generate a correct .tmp_kallsyms2.o
		# 2a) We may use an extra pass as this has been necessary to
		# woraround some alignment related bugs.
		# KALLSYMS_EXTRA_PASS=1 is used to trigger this.
		# 3) The correct ${kallsymso} is linked into the final vmlinux.
		#
		# a) Verify that the System.map from vmlinux matches the map from
		# ${kallsymso}.

		kallsymso=.tmp_kallsyms2.o
		kallsyms_vmlinux=.tmp_vmlinux2

		# step 1
		vmlinux_link "" .tmp_vmlinux1
		kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o

		# step 2
		vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
		kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o

		# step 2a
		if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
		kallsymso=.tmp_kallsyms3.o
		kallsyms_vmlinux=.tmp_vmlinux3

		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3

		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
		fi
		fi

		info LD vmlinux
		vmlinux_link "${kallsymso}" vmlinux

		info SYSMAP System.map
		mksysmap vmlinux System.map

		# step a (see comment above)
		if [ -n "${CONFIG_KALLSYMS}" ]; then
		mksysmap ${kallsyms_vmlinux} .tmp_System.map

		if ! cmp -s System.map .tmp_System.map; then
		echo Inconsistent kallsyms data
		echo echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
		cleanup
		exit 1
		fi
		fi

		# We made a new kernel - delete old version file
		rm -f .old_version

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