Merge tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild (58f051fc) · Commits · e / devices / android_kernel_xiaomi_sm6125

Documentation/kbuild/makefiles.txt

+6 −35

Original line number	Original line	Diff line number	Diff line
	@@ -45,10 +45,9 @@ This document describes the Linux kernel Makefiles.

	=== 7 Kbuild syntax for exported headers		=== 7 Kbuild syntax for exported headers
	--- 7.1 no-export-headers		--- 7.1 no-export-headers
	--- 7.2 genhdr-y		--- 7.2 generic-y
	--- 7.3 generic-y		--- 7.3 generated-y
	--- 7.4 generated-y		--- 7.4 mandatory-y
	--- 7.5 mandatory-y

	=== 8 Kbuild Variables		=== 8 Kbuild Variables
	=== 9 Makefile language		=== 9 Makefile language
	@@ -487,22 +486,6 @@ more details, with real examples.
	respectively.		respectively.
	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options		Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options

	cc-option-align
	gcc versions >= 3.0 changed the type of options used to specify
	alignment of functions, loops etc. $(cc-option-align), when used
	as prefix to the align options, will select the right prefix:
	gcc < 3.00
	cc-option-align = -malign
	gcc >= 3.00
	cc-option-align = -falign

	Example:
	KBUILD_CFLAGS += $(cc-option-align)-functions=4

	In the above example, the option -falign-functions=4 is used for
	gcc >= 3.00. For gcc < 3.00, -malign-functions=4 is used.
	Note: cc-option-align uses KBUILD_CFLAGS for $(CC) options

	cc-disable-warning		cc-disable-warning
	cc-disable-warning checks if gcc supports a given warning and returns		cc-disable-warning checks if gcc supports a given warning and returns
	the commandline switch to disable it. This special function is needed,		the commandline switch to disable it. This special function is needed,
	@@ -1277,18 +1260,7 @@ See subsequent chapter for the syntax of the Kbuild file.
	avoid exporting specific headers (e.g. kvm.h) on architectures that do		avoid exporting specific headers (e.g. kvm.h) on architectures that do
	not support it. It should be avoided as much as possible.		not support it. It should be avoided as much as possible.

	--- 7.2 genhdr-y		--- 7.2 generic-y

	genhdr-y specifies asm files to be generated.

	Example:
	#arch/x86/include/uapi/asm/Kbuild
	genhdr-y += unistd_32.h
	genhdr-y += unistd_64.h
	genhdr-y += unistd_x32.h


	--- 7.3 generic-y

	If an architecture uses a verbatim copy of a header from		If an architecture uses a verbatim copy of a header from
	include/asm-generic then this is listed in the file		include/asm-generic then this is listed in the file
	@@ -1315,11 +1287,10 @@ See subsequent chapter for the syntax of the Kbuild file.
	Example: termios.h		Example: termios.h
	#include <asm-generic/termios.h>		#include <asm-generic/termios.h>

	--- 7.4 generated-y		--- 7.3 generated-y

	If an architecture generates other header files alongside generic-y		If an architecture generates other header files alongside generic-y
	wrappers, and not included in genhdr-y, then generated-y specifies		wrappers, generated-y specifies them.
	them.

	This prevents them being treated as stale asm-generic wrappers and		This prevents them being treated as stale asm-generic wrappers and
	removed.		removed.

Makefile

+8 −16

Original line number	Original line	Diff line number	Diff line
	@@ -84,17 +84,10 @@ endif
	# If the user is running make -s (silent mode), suppress echoing of		# If the user is running make -s (silent mode), suppress echoing of
	# commands		# commands

	ifneq ($(filter 4.%,$(MAKE_VERSION)),) # make-4		ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
	ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),)
	quiet=silent_		quiet=silent_
	tools_silent=s		tools_silent=s
	endif		endif
	else # make-3.8x
	ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
	quiet=silent_
	tools_silent=-s
	endif
	endif

	export quiet Q KBUILD_VERBOSE		export quiet Q KBUILD_VERBOSE

	@@ -113,8 +106,8 @@ export quiet Q KBUILD_VERBOSE
	# The O= assignment takes precedence over the KBUILD_OUTPUT environment		# The O= assignment takes precedence over the KBUILD_OUTPUT environment
	# variable.		# variable.

	# KBUILD_SRC is set on invocation of make in OBJ directory		# KBUILD_SRC is not intended to be used by the regular user (for now),
	# KBUILD_SRC is not intended to be used by the regular user (for now)		# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
	ifeq ($(KBUILD_SRC),)		ifeq ($(KBUILD_SRC),)

	# OK, Make called in directory where kernel src resides		# OK, Make called in directory where kernel src resides
	@@ -135,7 +128,6 @@ ifneq ($(words $(subst :, ,$(CURDIR))), 1)
	endif		endif

	ifneq ($(KBUILD_OUTPUT),)		ifneq ($(KBUILD_OUTPUT),)
	# Invoke a second make in the output directory, passing relevant variables
	# check that the output directory actually exists		# check that the output directory actually exists
	saved-output := $(KBUILD_OUTPUT)		saved-output := $(KBUILD_OUTPUT)
	KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \		KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
	@@ -148,6 +140,7 @@ PHONY += $(MAKECMDGOALS) sub-make
	$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make		$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
	@:		@:

			# Invoke a second make in the output directory, passing relevant variables
	sub-make:		sub-make:
	$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \		$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))		-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
	@@ -303,7 +296,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \

	HOSTCC = gcc		HOSTCC = gcc
	HOSTCXX = g++		HOSTCXX = g++
	HOSTCFLAGS = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89		HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
	HOSTCXXFLAGS = -O2		HOSTCXXFLAGS = -O2

	ifeq ($(shell $(HOSTCC) -v 2>&1 \| grep -c "clang version"), 1)		ifeq ($(shell $(HOSTCC) -v 2>&1 \| grep -c "clang version"), 1)
	@@ -388,12 +381,10 @@ USERINCLUDE := \
	# Needed to be compatible with the O= option		# Needed to be compatible with the O= option
	LINUXINCLUDE := \		LINUXINCLUDE := \
	-I$(srctree)/arch/$(hdr-arch)/include \		-I$(srctree)/arch/$(hdr-arch)/include \
	-I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
	-I$(objtree)/arch/$(hdr-arch)/include/generated \		-I$(objtree)/arch/$(hdr-arch)/include/generated \
	$(if $(KBUILD_SRC), -I$(srctree)/include) \		$(if $(KBUILD_SRC), -I$(srctree)/include) \
	-I$(objtree)/include		-I$(objtree)/include \
			$(USERINCLUDE)
	LINUXINCLUDE += $(filter-out $(LINUXINCLUDE),$(USERINCLUDE))

	KBUILD_CPPFLAGS := -D__KERNEL__		KBUILD_CPPFLAGS := -D__KERNEL__

	@@ -707,6 +698,7 @@ KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
	KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)		KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
	KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)		KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
	KBUILD_CFLAGS += $(call cc-disable-warning, gnu)		KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
			KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
	# Quiet clang warning: comparison of unsigned expression < 0 is always false		# Quiet clang warning: comparison of unsigned expression < 0 is always false
	KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)		KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
	# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the		# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the

arch/arm/include/uapi/asm/Kbuild

+3 −3

Original line number	Original line	Diff line number	Diff line
	# UAPI Header export list		# UAPI Header export list
	include include/uapi/asm-generic/Kbuild.asm		include include/uapi/asm-generic/Kbuild.asm

	genhdr-y += unistd-common.h		generated-y += unistd-common.h
	genhdr-y += unistd-oabi.h		generated-y += unistd-oabi.h
	genhdr-y += unistd-eabi.h		generated-y += unistd-eabi.h

	generic-y += siginfo.h		generic-y += siginfo.h

arch/x86/Makefile

+25 −8

Original line number	Original line	Diff line number	Diff line
	@@ -11,6 +11,14 @@ else
	KBUILD_DEFCONFIG := $(ARCH)_defconfig		KBUILD_DEFCONFIG := $(ARCH)_defconfig
	endif		endif

			# For gcc stack alignment is specified with -mpreferred-stack-boundary,
			# clang has the option -mstack-alignment for that purpose.
			ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
			cc_stack_align_opt := -mpreferred-stack-boundary
			else ifneq ($(call cc-option, -mstack-alignment=4),)
			cc_stack_align_opt := -mstack-alignment
			endif

	# How to compile the 16-bit code. Note we always compile for -march=i386;		# How to compile the 16-bit code. Note we always compile for -march=i386;
	# that way we can complain to the user if the CPU is insufficient.		# that way we can complain to the user if the CPU is insufficient.
	#		#
	@@ -24,10 +32,11 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \
	-DDISABLE_BRANCH_PROFILING \		-DDISABLE_BRANCH_PROFILING \
	-Wall -Wstrict-prototypes -march=i386 -mregparm=3 \		-Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
	-fno-strict-aliasing -fomit-frame-pointer -fno-pic \		-fno-strict-aliasing -fomit-frame-pointer -fno-pic \
	-mno-mmx -mno-sse \		-mno-mmx -mno-sse
	$(call cc-option, -ffreestanding) \
	$(call cc-option, -fno-stack-protector) \		REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
	$(call cc-option, -mpreferred-stack-boundary=2)		REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
			REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align_opt)=2)
	export REALMODE_CFLAGS		export REALMODE_CFLAGS

	# BITS is used as extension for files which are available in a 32 bit		# BITS is used as extension for files which are available in a 32 bit
	@@ -64,8 +73,10 @@ ifeq ($(CONFIG_X86_32),y)
	# with nonstandard options		# with nonstandard options
	KBUILD_CFLAGS += -fno-pic		KBUILD_CFLAGS += -fno-pic

	# prevent gcc from keeping the stack 16 byte aligned		# Align the stack to the register width instead of using the default
	KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)		# alignment of 16 bytes. This reduces stack usage and the number of
			# alignment instructions.
			KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=2)

	# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use		# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
	# a lot more stack due to the lack of sharing of stacklots:		# a lot more stack due to the lack of sharing of stacklots:
	@@ -97,8 +108,14 @@ else
	KBUILD_CFLAGS += $(call cc-option,-mno-80387)		KBUILD_CFLAGS += $(call cc-option,-mno-80387)
	KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)		KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)

	# Use -mpreferred-stack-boundary=3 if supported.		# By default gcc and clang use a stack alignment of 16 bytes for x86.
	KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)		# However the standard kernel entry on x86-64 leaves the stack on an
			# 8-byte boundary. If the compiler isn't informed about the actual
			# alignment it will generate extra alignment instructions for the
			# default alignment which keep the stack misaligned.
			# Furthermore an alignment to the register width reduces stack usage
			# and the number of alignment instructions.
			KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=3)

	# Use -mskip-rax-setup if supported.		# Use -mskip-rax-setup if supported.
	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)		KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)

arch/x86/Makefile_32.cpu

+3 −4

Original line number	Original line	Diff line number	Diff line
	@@ -9,7 +9,6 @@ else
	tune = $(call cc-option,-mcpu=$(1),$(2))		tune = $(call cc-option,-mcpu=$(1),$(2))
	endif		endif

	align := $(cc-option-align)
	cflags-$(CONFIG_M486) += -march=i486		cflags-$(CONFIG_M486) += -march=i486
	cflags-$(CONFIG_M586) += -march=i586		cflags-$(CONFIG_M586) += -march=i586
	cflags-$(CONFIG_M586TSC) += -march=i586		cflags-$(CONFIG_M586TSC) += -march=i586
	@@ -24,11 +23,11 @@ cflags-$(CONFIG_MK6) += -march=k6
	# They make zero difference whatsosever to performance at this time.		# They make zero difference whatsosever to performance at this time.
	cflags-$(CONFIG_MK7) += -march=athlon		cflags-$(CONFIG_MK7) += -march=athlon
	cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon)		cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon)
	cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0		cflags-$(CONFIG_MCRUSOE) += -march=i686 -falign-functions=0 -falign-jumps=0 -falign-loops=0
	cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0		cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) -falign-functions=0 -falign-jumps=0 -falign-loops=0
	cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586)		cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586)
	cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586)		cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586)
	cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0		cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) -falign-functions=0 -falign-jumps=0 -falign-loops=0
	cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686)		cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686)
	cflags-$(CONFIG_MVIAC7) += -march=i686		cflags-$(CONFIG_MVIAC7) += -march=i686
	cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2)		cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2)