From f231e43333124d92a82acd19431f8104b8e48a75 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 21 Sep 2017 00:17:50 +0900 Subject: [PATCH 01/30] hexagon: get rid of #include is created (or updated) when Kbuild descends into the init/ directory. In parallel building from a pristine source tree, there is no guarantee exists when arch/hexagon/kernel/ptrace.c is compiled. For hexagon architecture, we know UTS_MACHINE is a fixed string "hexagon", so let's hard-code it, like many architectures do. Signed-off-by: Masahiro Yamada Acked-by: Richard Kuo --- arch/hexagon/kernel/ptrace.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/hexagon/kernel/ptrace.c b/arch/hexagon/kernel/ptrace.c index ecd75e2e8eb391..fa76493c174596 100644 --- a/arch/hexagon/kernel/ptrace.c +++ b/arch/hexagon/kernel/ptrace.c @@ -18,8 +18,6 @@ * 02110-1301, USA. */ -#include - #include #include #include @@ -180,7 +178,7 @@ static const struct user_regset hexagon_regsets[] = { }; static const struct user_regset_view hexagon_user_view = { - .name = UTS_MACHINE, + .name = "hexagon", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI, .regsets = hexagon_regsets, From 278ae6040397f37fa6a96a6b86ed02d4762080a7 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 22 Sep 2017 14:31:13 +0900 Subject: [PATCH 02/30] kbuild: link-vmlinux.sh: simplify .version increment Since commit 1f2bfbd00e46 ("kbuild: link of vmlinux moved to a script"), it is easy to increment .version without using a temporary file .old_version. I do not see anybody who creates the .tmp_version. Probably it is a left-over of commit 4e25d8bb9550fb ("[PATCH] kbuild: adjust .version updating"). Just remove it. Signed-off-by: Masahiro Yamada --- Makefile | 2 +- scripts/link-vmlinux.sh | 15 +++++---------- 2 files changed, 6 insertions(+), 11 deletions(-) diff --git a/Makefile b/Makefile index cf007a31d575d6..9aa47218100e75 100644 --- a/Makefile +++ b/Makefile @@ -1278,7 +1278,7 @@ CLEAN_DIRS += $(MODVERDIR) # Directories & files removed with 'make mrproper' MRPROPER_DIRS += include/config usr/include include/generated \ arch/*/include/generated .tmp_objdiff -MRPROPER_FILES += .config .config.old .version .old_version \ +MRPROPER_FILES += .config .config.old .version \ Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \ signing_key.pem signing_key.priv signing_key.x509 \ x509.genkey extra_certificates signing_key.x509.keyid \ diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index e7b7eee31538e6..0cdb25b66e6f98 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -187,10 +187,8 @@ sortextable() # Delete output files in case of error cleanup() { - rm -f .old_version rm -f .tmp_System.map rm -f .tmp_kallsyms* - rm -f .tmp_version rm -f .tmp_vmlinux* rm -f built-in.o rm -f System.map @@ -238,12 +236,12 @@ esac # Update version info GEN .version -if [ ! -r .version ]; then - rm -f .version; - echo 1 >.version; +if [ -r .version ]; then + VERSION=$(expr 0$(cat .version) + 1) + echo $VERSION > .version else - mv .version .old_version; - expr 0$(cat .old_version) + 1 >.version; + rm -f .version + echo 1 > .version fi; # final build of init/ @@ -331,6 +329,3 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then exit 1 fi fi - -# We made a new kernel - delete old version file -rm -f .old_version From 37131ec4f9cb60750be6f75fca20ff6bbf1b8efd Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 22 Sep 2017 14:31:14 +0900 Subject: [PATCH 03/30] kbuild: mkcompile_h: do not create .version This script does not need to create .version; it will be created by scripts/link-vmlinux.sh later. Clean-up the code slightly. Signed-off-by: Masahiro Yamada --- scripts/mkcompile_h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h index fd8fdb91581dd4..f1ee4ebd6518be 100755 --- a/scripts/mkcompile_h +++ b/scripts/mkcompile_h @@ -27,12 +27,7 @@ LC_ALL=C export LC_ALL if [ -z "$KBUILD_BUILD_VERSION" ]; then - if [ -r .version ]; then - VERSION=`cat .version` - else - VERSION=0 - echo 0 > .version - fi + VERSION=$(cat .version 2>/dev/null || echo 1) else VERSION=$KBUILD_BUILD_VERSION fi From 9d022c540606a5a8ae5d1cc02fc12de362ba4585 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:04 +0900 Subject: [PATCH 04/30] kbuild: replace $(hdr-arch) with $(SRCARCH) Since commit 5e53879008b9 ("sparc,sparc64: unify Makefile"), hdr-arch and SRCARCH always match. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 21 +++++++++------------ scripts/Makefile.headersinst | 2 +- 2 files changed, 10 insertions(+), 13 deletions(-) diff --git a/Makefile b/Makefile index 9aa47218100e75..27fcdc1d4ec946 100644 --- a/Makefile +++ b/Makefile @@ -283,9 +283,6 @@ ifeq ($(ARCH),tilegx) SRCARCH := tile endif -# Where to locate arch specific headers -hdr-arch := $(SRCARCH) - KCONFIG_CONFIG ?= .config export KCONFIG_CONFIG @@ -378,8 +375,8 @@ CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ - -I$(srctree)/arch/$(hdr-arch)/include/uapi \ - -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \ + -I$(srctree)/arch/$(SRCARCH)/include/uapi \ + -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \ -I$(srctree)/include/uapi \ -I$(objtree)/include/generated/uapi \ -include $(srctree)/include/linux/kconfig.h @@ -387,8 +384,8 @@ USERINCLUDE := \ # Use LINUXINCLUDE when you must reference the include/ directory. # Needed to be compatible with the O= option LINUXINCLUDE := \ - -I$(srctree)/arch/$(hdr-arch)/include \ - -I$(objtree)/arch/$(hdr-arch)/include/generated \ + -I$(srctree)/arch/$(SRCARCH)/include \ + -I$(objtree)/arch/$(SRCARCH)/include/generated \ $(if $(KBUILD_SRC), -I$(srctree)/include) \ -I$(objtree)/include \ $(USERINCLUDE) @@ -1134,8 +1131,8 @@ headerdep: #Default location for installed headers export INSTALL_HDR_PATH = $(objtree)/usr -# If we do an all arch process set dst to include/arch-$(hdr-arch) -hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include) +# If we do an all arch process set dst to include/arch-$(SRCARCH) +hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include) PHONY += archheaders archheaders: @@ -1153,10 +1150,10 @@ headers_install_all: PHONY += headers_install headers_install: __headers - $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \ + $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \ $(error Headers not exportable for the $(SRCARCH) architecture)) $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include - $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) + $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) PHONY += headers_check_all headers_check_all: headers_install_all @@ -1165,7 +1162,7 @@ headers_check_all: headers_install_all PHONY += headers_check headers_check: headers_install $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1 - $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1 + $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1 # --------------------------------------------------------------------------- # Kernel selftest diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst index 343d586e566e56..5692d7a6616325 100644 --- a/scripts/Makefile.headersinst +++ b/scripts/Makefile.headersinst @@ -30,7 +30,7 @@ __headers: $(subdirs) $(subdirs): $(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(dst)/$@ -# Skip header install/check for include/uapi and arch/$(hdr-arch)/include/uapi. +# Skip header install/check for include/uapi and arch/$(SRCARCH)/include/uapi. # We have only sub-directories there. skip-inst := $(if $(filter %/uapi,$(obj)),1) From ba634eceb535d95e87ef09caae7814b3687c6036 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:05 +0900 Subject: [PATCH 05/30] kbuild: move "_all" target out of $(KBUILD_SRC) conditional The first "_all" occurrence around line 120 is only visible when KBUILD_SRC is unset. If O=... is specified, the working directory is relocated, then the only second occurrence around line 193 is visible, that is not set to PHONY. Move the first one to an always visible place. This clarifies "_all" is our default target and it is always set to PHONY. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/Makefile b/Makefile index 27fcdc1d4ec946..a793ed153f7ab2 100644 --- a/Makefile +++ b/Makefile @@ -10,6 +10,10 @@ NAME = Fearless Coyote # Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. +# That's our default target when none is given on the command line +PHONY := _all +_all: + # o Do not use make's built-in rules and variables # (this increases performance and avoids hard-to-debug behaviour); # o Look for make include files relative to root of kernel src @@ -116,10 +120,6 @@ ifeq ("$(origin O)", "command line") KBUILD_OUTPUT := $(O) endif -# That's our default target when none is given on the command line -PHONY := _all -_all: - # Cancel implicit rules on top Makefile $(CURDIR)/Makefile Makefile: ; From 2c1f4f125159f10521944cea23e33a00fcf85ede Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:06 +0900 Subject: [PATCH 06/30] kbuild: re-order the code to not parse unnecessary variables The top Makefile is divided into some sections such as mixed targets, config targets, build targets, etc. When we build mixed targets, Kbuild just invokes submake to process them one by one. In this case, compiler-related variables like CC, KBUILD_CFLAGS, etc. are unneeded. Check what kind of targets we are building first, and parse variables for building only when necessary. Signed-off-by: Masahiro Yamada --- Makefile | 233 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 118 insertions(+), 115 deletions(-) diff --git a/Makefile b/Makefile index a793ed153f7ab2..1ec97b902e5262 100644 --- a/Makefile +++ b/Makefile @@ -186,15 +186,6 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif -# If building an external module we do not care about the all: rule -# but instead _all depend on modules -PHONY += all -ifeq ($(KBUILD_EXTMOD),) -_all: all -else -_all: modules -endif - ifeq ($(KBUILD_SRC),) # building in the source tree srctree := . @@ -206,6 +197,9 @@ else srctree := $(KBUILD_SRC) endif endif + +export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC + objtree := . src := $(srctree) obj := $(objtree) @@ -214,6 +208,74 @@ VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD)) export srctree objtree VPATH +# To make sure we do not include .config for any of the *config targets +# catch them early, and hand them over to scripts/kconfig/Makefile +# It is allowed to specify more targets when calling make, including +# mixing *config targets and build targets. +# For example 'make oldconfig all'. +# Detect when mixed targets is specified, and make a second invocation +# of make so .config is not included in this case either (for *config). + +version_h := include/generated/uapi/linux/version.h +old_version_h := include/linux/version.h + +no-dot-config-targets := clean mrproper distclean \ + cscope gtags TAGS tags help% %docs check% coccicheck \ + $(version_h) headers_% archheaders archscripts \ + kernelversion %src-pkg + +config-targets := 0 +mixed-targets := 0 +dot-config := 1 + +ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) + ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) + dot-config := 0 + endif +endif + +ifeq ($(KBUILD_EXTMOD),) + ifneq ($(filter config %config,$(MAKECMDGOALS)),) + config-targets := 1 + ifneq ($(words $(MAKECMDGOALS)),1) + mixed-targets := 1 + endif + endif +endif +# install and modules_install need also be processed one by one +ifneq ($(filter install,$(MAKECMDGOALS)),) + ifneq ($(filter modules_install,$(MAKECMDGOALS)),) + mixed-targets := 1 + endif +endif + +ifeq ($(mixed-targets),1) +# =========================================================================== +# We're called with mixed targets (*config and build targets). +# Handle them one by one. + +PHONY += $(MAKECMDGOALS) __build_one_by_one + +$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one + @: + +__build_one_by_one: + $(Q)set -e; \ + for i in $(MAKECMDGOALS); do \ + $(MAKE) -f $(srctree)/Makefile $$i; \ + done + +else + +# We need some generic definitions (do not try to remake the file). +scripts/Kbuild.include: ; +include scripts/Kbuild.include + +# Read KERNELRELEASE from include/config/kernel.release (if it exists) +KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null) +KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION) +export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION + # SUBARCH tells the usermode build what the underlying arch is. That is set # first, and if a usermode build is happening, the "ARCH=um" on the command # line overrides the setting of ARCH below. If a native build is happening, @@ -308,40 +370,6 @@ HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \ -Wno-missing-field-initializers -fno-delete-null-pointer-checks endif -# Decide whether to build built-in, modular, or both. -# Normally, just do built-in. - -KBUILD_MODULES := -KBUILD_BUILTIN := 1 - -# If we have only "make modules", don't compile built-in objects. -# When we're building modules with modversions, we need to consider -# the built-in objects during the descend as well, in order to -# make sure the checksums are up to date before we record them. - -ifeq ($(MAKECMDGOALS),modules) - KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) -endif - -# If we have "make modules", compile modules -# in addition to whatever we do anyway. -# Just "make" or "make all" shall build modules as well - -ifneq ($(filter all _all modules,$(MAKECMDGOALS)),) - KBUILD_MODULES := 1 -endif - -ifeq ($(MAKECMDGOALS),) - KBUILD_MODULES := 1 -endif - -export KBUILD_MODULES KBUILD_BUILTIN -export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD - -# We need some generic definitions (do not try to remake the file). -scripts/Kbuild.include: ; -include scripts/Kbuild.include - # Make variables (CC, etc...) AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld @@ -406,11 +434,6 @@ KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds -# Read KERNELRELEASE from include/config/kernel.release (if it exists) -KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null) -KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION) - -export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE @@ -459,73 +482,6 @@ ifneq ($(KBUILD_SRC),) $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL) endif -# Support for using generic headers in asm-generic -PHONY += asm-generic uapi-asm-generic -asm-generic: uapi-asm-generic - $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ - src=asm obj=arch/$(SRCARCH)/include/generated/asm -uapi-asm-generic: - $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ - src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm - -# To make sure we do not include .config for any of the *config targets -# catch them early, and hand them over to scripts/kconfig/Makefile -# It is allowed to specify more targets when calling make, including -# mixing *config targets and build targets. -# For example 'make oldconfig all'. -# Detect when mixed targets is specified, and make a second invocation -# of make so .config is not included in this case either (for *config). - -version_h := include/generated/uapi/linux/version.h -old_version_h := include/linux/version.h - -no-dot-config-targets := clean mrproper distclean \ - cscope gtags TAGS tags help% %docs check% coccicheck \ - $(version_h) headers_% archheaders archscripts \ - kernelversion %src-pkg - -config-targets := 0 -mixed-targets := 0 -dot-config := 1 - -ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) - ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) - dot-config := 0 - endif -endif - -ifeq ($(KBUILD_EXTMOD),) - ifneq ($(filter config %config,$(MAKECMDGOALS)),) - config-targets := 1 - ifneq ($(words $(MAKECMDGOALS)),1) - mixed-targets := 1 - endif - endif -endif -# install and modules_install need also be processed one by one -ifneq ($(filter install,$(MAKECMDGOALS)),) - ifneq ($(filter modules_install,$(MAKECMDGOALS)),) - mixed-targets := 1 - endif -endif - -ifeq ($(mixed-targets),1) -# =========================================================================== -# We're called with mixed targets (*config and build targets). -# Handle them one by one. - -PHONY += $(MAKECMDGOALS) __build_one_by_one - -$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one - @: - -__build_one_by_one: - $(Q)set -e; \ - for i in $(MAKECMDGOALS); do \ - $(MAKE) -f $(srctree)/Makefile $$i; \ - done - -else ifeq ($(config-targets),1) # =========================================================================== # *config targets only - make sure prerequisites are updated, and descend @@ -548,6 +504,44 @@ else # Build targets only - this includes vmlinux, arch specific targets, clean # targets and others. In general all targets except *config targets. +# If building an external module we do not care about the all: rule +# but instead _all depend on modules +PHONY += all +ifeq ($(KBUILD_EXTMOD),) +_all: all +else +_all: modules +endif + +# Decide whether to build built-in, modular, or both. +# Normally, just do built-in. + +KBUILD_MODULES := +KBUILD_BUILTIN := 1 + +# If we have only "make modules", don't compile built-in objects. +# When we're building modules with modversions, we need to consider +# the built-in objects during the descend as well, in order to +# make sure the checksums are up to date before we record them. + +ifeq ($(MAKECMDGOALS),modules) + KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) +endif + +# If we have "make modules", compile modules +# in addition to whatever we do anyway. +# Just "make" or "make all" shall build modules as well + +ifneq ($(filter all _all modules,$(MAKECMDGOALS)),) + KBUILD_MODULES := 1 +endif + +ifeq ($(MAKECMDGOALS),) + KBUILD_MODULES := 1 +endif + +export KBUILD_MODULES KBUILD_BUILTIN + ifeq ($(KBUILD_EXTMOD),) # Additional helpers built in scripts/ # Carefully list dependencies so we do not try to build scripts twice @@ -1063,6 +1057,15 @@ prepare0: archprepare gcc-plugins # All the preparing.. prepare: prepare0 prepare-objtool +# Support for using generic headers in asm-generic +PHONY += asm-generic uapi-asm-generic +asm-generic: uapi-asm-generic + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ + src=asm obj=arch/$(SRCARCH)/include/generated/asm +uapi-asm-generic: + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ + src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm + PHONY += prepare-objtool prepare-objtool: $(objtool_target) From df16aaac26e92e97ab7234d3f93c953466adc4b5 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Sat, 7 Oct 2017 13:23:23 -0700 Subject: [PATCH 07/30] kbuild: clang: remove crufty HOSTCFLAGS When compiling with `make CC=clang HOSTCC=clang`, I was seeing warnings that clang did not recognize -fno-delete-null-pointer-checks for HOSTCC targets. These were added in commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang"). Clang does not support -fno-delete-null-pointer-checks, so adding it to HOSTCFLAGS if HOSTCC is clang does not make sense. It's not clear why the other warnings were disabled, and just for HOSTCFLAGS, but I can remove them, add -Werror to HOSTCFLAGS and compile with clang just fine. Suggested-by: Masahiro Yamada Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- Makefile | 5 ----- 1 file changed, 5 deletions(-) diff --git a/Makefile b/Makefile index 1ec97b902e5262..1254719958ca70 100644 --- a/Makefile +++ b/Makefile @@ -365,11 +365,6 @@ HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) HOST_LOADLIBES := $(HOST_LFS_LIBS) -ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1) -HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \ - -Wno-missing-field-initializers -fno-delete-null-pointer-checks -endif - # Make variables (CC, etc...) AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld From 8fdc3fbbd5b646650efa66d577b88807a948a1d1 Mon Sep 17 00:00:00 2001 From: Cao jin Date: Mon, 9 Oct 2017 11:49:11 +0800 Subject: [PATCH 08/30] kbuild: comments cleanup in Makefile.lib It has: 1. Move comments close to what it want to comment. 2. Comments cleanup & improvement. Signed-off-by: Cao jin Signed-off-by: Masahiro Yamada --- scripts/Makefile.lib | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 5e975fee0f5b44..580e605118e493 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -4,8 +4,7 @@ ccflags-y += $(EXTRA_CFLAGS) cppflags-y += $(EXTRA_CPPFLAGS) ldflags-y += $(EXTRA_LDFLAGS) -# -# flags that take effect in sub directories +# flags that take effect in current and sub directories export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y) export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y) @@ -14,14 +13,16 @@ export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y) # When an object is listed to be built compiled-in and modular, # only build the compiled-in version - obj-m := $(filter-out $(obj-y),$(obj-m)) # Libraries are always collected in one lib file. # Filter out objects already built-in - lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) +# Determine modorder. +# Unfortunately, we don't have information about ordering between -y +# and -m subdirs. Just put -y's first. +modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko)) # Handle objects in subdirs # --------------------------------------------------------------------------- @@ -29,12 +30,6 @@ lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) # and add the directory to the list of dirs to descend into: $(subdir-y) # o if we encounter foo/ in $(obj-m), remove it from $(obj-m) # and add the directory to the list of dirs to descend into: $(subdir-m) - -# Determine modorder. -# Unfortunately, we don't have information about ordering between -y -# and -m subdirs. Just put -y's first. -modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko)) - __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) subdir-y += $(__subdir-y) __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m))) @@ -43,10 +38,9 @@ obj-y := $(patsubst %/, %/built-in.o, $(obj-y)) obj-m := $(filter-out %/, $(obj-m)) # Subdirectories we need to descend into - subdir-ym := $(sort $(subdir-y) $(subdir-m)) -# if $(foo-objs) exists, foo.o is a composite object +# if $(foo-objs), $(foo-y), or $(foo-m) exists, foo.o is a composite object multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m)))) multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m)))) multi-used := $(multi-used-y) $(multi-used-m) @@ -90,8 +84,7 @@ subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) obj-dirs := $(addprefix $(obj)/,$(obj-dirs)) # These flags are needed for modversions and compiling, so we define them here -# already -# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will +# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will # end up in (or would, if it gets compiled in) # Note: Files that end up in two or more modules are compiled without the # KBUILD_MODNAME definition. The reason is that any made-up name would From 336303ae7fad4a491290a800547b3fde80ac8865 Mon Sep 17 00:00:00 2001 From: Cao jin Date: Mon, 9 Oct 2017 15:11:45 +0800 Subject: [PATCH 09/30] arm/kbuild: replace {C, LD}FLAGS_MODULE with KBUILD_{C, LD}FLAGS_MODULE As kbuild document & commit 6588169d51 says: KBUILD_{C,LD}FLAGS_MODULE are used to add arch-specific options for $(CC) and $(LD). From commandline, {C,LD}FLAGS_MODULE shall be used. Doesn't have any functional change, but just follow kbuild rules. Signed-off-by: Cao jin CC: Russell King CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Masahiro Yamada --- arch/arm/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 47d3a1ab08d249..a945b1fad0d184 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -16,11 +16,11 @@ LDFLAGS := LDFLAGS_vmlinux :=-p --no-undefined -X --pic-veneer ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) LDFLAGS_vmlinux += --be8 -LDFLAGS_MODULE += --be8 +KBUILD_LDFLAGS_MODULE += --be8 endif ifeq ($(CONFIG_ARM_MODULE_PLTS),y) -LDFLAGS_MODULE += -T $(srctree)/arch/arm/kernel/module.lds +KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm/kernel/module.lds endif GZFLAGS :=-9 @@ -120,7 +120,7 @@ CFLAGS_ISA :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN) AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb # Work around buggy relocation from gas if requested: ifeq ($(CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11),y) -CFLAGS_MODULE +=-fno-optimize-sibling-calls +KBUILD_CFLAGS_MODULE +=-fno-optimize-sibling-calls endif else CFLAGS_ISA :=$(call cc-option,-marm,) From 265444a008ae4451f69a24efda7b3f542cb30f7d Mon Sep 17 00:00:00 2001 From: Cao jin Date: Mon, 9 Oct 2017 15:11:46 +0800 Subject: [PATCH 10/30] c6x/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE As kbuild document & commit 6588169d51 says: KBUILD_CFLAGS_MODULE is used to add arch-specific options for $(CC). From commandline, CFLAGS_MODULE shall be used. Doesn't have any functional change, but just follow kbuild rules. Signed-off-by: Cao jin CC: Mark Salter CC: Aurelien Jacquiot CC: linux-c6x-dev@linux-c6x.org Signed-off-by: Masahiro Yamada --- arch/c6x/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/c6x/Makefile b/arch/c6x/Makefile index 6b0be670ddfabc..6f6096ff05a462 100644 --- a/arch/c6x/Makefile +++ b/arch/c6x/Makefile @@ -12,7 +12,7 @@ cflags-y += -mno-dsbt -msdata=none -D__linux__ cflags-$(CONFIG_C6X_BIG_KERNEL) += -mlong-calls -CFLAGS_MODULE += -mlong-calls -mno-dsbt -msdata=none +KBUILD_CFLAGS_MODULE += -mlong-calls -mno-dsbt -msdata=none CHECKFLAGS += From 3a5befc146175de8bf6c4eb68866a4f5ad46265a Mon Sep 17 00:00:00 2001 From: Cao jin Date: Mon, 9 Oct 2017 15:11:47 +0800 Subject: [PATCH 11/30] hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE As kbuild document & commit 6588169d51 says: KBUILD_CFLAGS_MODULE is used to add arch-specific options for $(CC). From commandline, CFLAGS_MODULE shall be used. Doesn't have any functional change, but just follow kbuild rules. Signed-off-by: Cao jin CC: linux-hexagon@vger.kernel.org Acked-by: Richard Kuo Signed-off-by: Masahiro Yamada --- arch/hexagon/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/hexagon/Makefile b/arch/hexagon/Makefile index 207711a0fd0c3a..4f5c84c4bbb47b 100644 --- a/arch/hexagon/Makefile +++ b/arch/hexagon/Makefile @@ -11,9 +11,9 @@ KBUILD_CFLAGS += -fno-short-enums # Modules must use either long-calls, or use pic/plt. # Use long-calls for now, it's easier. And faster. -# CFLAGS_MODULE += -fPIC -# LDFLAGS_MODULE += -shared -CFLAGS_MODULE += -mlong-calls +# KBUILD_CFLAGS_MODULE += -fPIC +# KBUILD_LDFLAGS_MODULE += -shared +KBUILD_CFLAGS_MODULE += -mlong-calls cflags-y += $(call cc-option,-mv${CONFIG_HEXAGON_ARCH_VERSION}) aflags-y += $(call cc-option,-mv${CONFIG_HEXAGON_ARCH_VERSION}) From 4e13d47c5806bafb5e524b08a9d759b606b1851c Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 10 Oct 2017 20:43:21 +0900 Subject: [PATCH 12/30] kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS Accumulate subdir-{cc,as}flags-y directly to KBUILD_{A,C}FLAGS. Remove KBUILD_SUBDIR_{AS,CC}FLAGS. Signed-off-by: Masahiro Yamada Reviewed-by: Cao jin --- scripts/Makefile.lib | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 580e605118e493..4d88ad70fd9643 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -5,8 +5,8 @@ cppflags-y += $(EXTRA_CPPFLAGS) ldflags-y += $(EXTRA_LDFLAGS) # flags that take effect in current and sub directories -export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y) -export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y) +KBUILD_AFLAGS += $(subdir-asflags-y) +KBUILD_CFLAGS += $(subdir-ccflags-y) # Figure out what we need to build from the various variables # =========================================================================== @@ -94,10 +94,10 @@ basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) modname_flags = $(if $(filter 1,$(words $(modname))),\ -DKBUILD_MODNAME=$(call name-fix,$(modname))) -orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \ +orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \ $(ccflags-y) $(CFLAGS_$(basetarget).o) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags)) -orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \ +orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \ $(asflags-y) $(AFLAGS_$(basetarget).o) _a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags)) _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F)) From a7d34df3d12c34304638bbe7375d91c63717c453 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 11 Oct 2017 12:52:29 +0900 Subject: [PATCH 13/30] kbuild: add forward declaration of default target to Makefile.asm-generic $(kbuild-file) and Kbuild.include are included before the default target "all". We will add a target into Kbuild.include. In advance, add a forward declaration of the default target. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- scripts/Makefile.asm-generic | 3 +++ 1 file changed, 3 insertions(+) diff --git a/scripts/Makefile.asm-generic b/scripts/Makefile.asm-generic index a6c8c17808551a..9563215a23c69f 100644 --- a/scripts/Makefile.asm-generic +++ b/scripts/Makefile.asm-generic @@ -5,6 +5,9 @@ # and for each file listed in this file with generic-y creates # a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/$(src)) +PHONY := all +all: + kbuild-file := $(srctree)/arch/$(SRCARCH)/include/$(src)/Kbuild -include $(kbuild-file) From 3298b690b21cdbe6b2ae8076d9147027f396f2b1 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 16 Oct 2017 10:12:45 -0700 Subject: [PATCH 14/30] kbuild: Add a cache for generated variables While timing a "no-op" build of the kernel (incrementally building the kernel even though nothing changed) in the Chrome OS build system I found that it was much slower than I expected. Digging into things a bit, I found that quite a bit of the time was spent invoking the C compiler even though we weren't actually building anything. Currently in the Chrome OS build system the C compiler is called through a number of wrappers (one of which is written in python!) and can take upwards of 100 ms to invoke even if we're not doing anything difficult, so these invocations of the compiler were taking a lot of time. Worse the invocations couldn't seem to take advantage of the multiple cores on my system. Certainly it seems like we could make the compiler invocations in the Chrome OS build system faster, but only to a point. Inherently invoking a program as big as a C compiler is a fairly heavy operation. Thus even if we can speed the compiler calls it made sense to track down what was happening. It turned out that all the compiler invocations were coming from usages like this in the kernel's Makefile: KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) Due to the way cc-option and similar statements work the above contains an implicit call to the C compiler. ...and due to the fact that we're storing the result in KBUILD_CFLAGS, a simply expanded variable, the call will happen every time the Makefile is parsed, even if there are no users of KBUILD_CFLAGS. Rather than redoing this computation every time, it makes a lot of sense to cache the result of all of the Makefile's compiler calls just like we do when we compile a ".c" file to a ".o" file. Conceptually this is quite a simple idea. ...and since the calls to invoke the compiler and similar tools are centrally located in the Kbuild.include file this doesn't even need to be super invasive. Implementing the cache in a simple-to-use and efficient way is not quite as simple as it first sounds, though. To get maximum speed we really want the cache in a format that make can natively understand and make doesn't really have an ability to load/parse files. ...but make _can_ import other Makefiles, so the solution is to store the cache in Makefile format. This requires coming up with a valid/unique Makefile variable name for each value to be cached, but that's solvable with some cleverness. After this change, we'll automatically create a ".cache.mk" file that will contain our cached variables. We'll load this on each invocation of make and will avoid recomputing anything that's already in our cache. The cache is stored in a format that it shouldn't need any invalidation since anything that might change should affect the "key" and any old cached value won't be used. Signed-off-by: Douglas Anderson Tested-by: Ingo Molnar Tested-by: Guenter Roeck Signed-off-by: Masahiro Yamada --- Makefile | 1 + scripts/Kbuild.include | 90 +++++++++++++++++++++++++++++++++++------- 2 files changed, 77 insertions(+), 14 deletions(-) diff --git a/Makefile b/Makefile index 1254719958ca70..5be2c8d2ce73cb 100644 --- a/Makefile +++ b/Makefile @@ -1545,6 +1545,7 @@ clean: $(clean-dirs) -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ + -o -name .cache.mk \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ -o -name '*.gcno' \) -type f -print | xargs rm -f diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 9ffd3dda3889c5..dfadb1c94368fb 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -8,6 +8,8 @@ squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ +right_paren := ) +left_paren := ( ### # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o @@ -80,6 +82,60 @@ cc-cross-prefix = \ echo $(c); \ fi))) +# Tools for caching Makefile variables that are "expensive" to compute. +# +# Here we want to help deal with variables that take a long time to compute +# by making it easy to store these variables in a cache. +# +# The canonical example here is testing for compiler flags. On a simple system +# each call to the compiler takes 10 ms, but on a system with a compiler that's +# called through various wrappers it can take upwards of 100 ms. If we have +# 100 calls to the compiler this can take 1 second (on a simple system) or 10 +# seconds (on a complicated system). +# +# The "cache" will be in Makefile syntax and can be directly included. +# Any time we try to reference a variable that's not in the cache we'll +# calculate it and store it in the cache for next time. + +# Include values from last time +make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk +ifeq ($(wildcard $(dir $(make-cache))),) +$(shell mkdir -p '$(dir $(make-cache))') +endif +$(make-cache): ; +-include $(make-cache) + +# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) +# +# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' +__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1))))))))) + +# Usage: $(call shell-cached,shell_command) +# Example: $(call shell-cached,md5sum /usr/bin/gcc) +# +# If we've already seen a call to this exact shell command (even in a +# previous invocation of make!) we'll return the value. If not, we'll +# compute it and store the result for future runs. +# +# This is a bit of voodoo, but basic explanation is that if the variable +# was undefined then we'll evaluate the shell command and store the result +# into the variable. We'll then store that value in the cache and finally +# output the value. +# +# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We +# happen to know that the caller will have their shell command in $(2) so the +# result of "call"ing this will produce a reference to that $(2). The reason +# for this strangeness is to avoid an extra level of eval (and escaping) of +# $(2). +define __run-and-store +ifeq ($(origin $(1)),undefined) + $$(eval $(1) := $$(shell $$(2))) + $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) +endif +endef +__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1)) +shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1)) + # output directory for tests below TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) @@ -87,30 +143,36 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) # Exit code chooses option. "$$TMP" serves as a temporary file and is # automatically cleaned up. -try-run = $(shell set -e; \ +__try-run = set -e; \ TMP="$(TMPOUT).$$$$.tmp"; \ TMPO="$(TMPOUT).$$$$.o"; \ if ($(1)) >/dev/null 2>&1; \ then echo "$(2)"; \ else echo "$(3)"; \ fi; \ - rm -f "$$TMP" "$$TMPO") + rm -f "$$TMP" "$$TMPO" + +try-run = $(shell $(__try-run)) + +# try-run-cached +# This works like try-run, but the result is cached. +try-run-cached = $(call shell-cached,$(__try-run)) # as-option # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) -as-option = $(call try-run,\ +as-option = $(call try-run-cached,\ $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) # as-instr # Usage: cflags-y += $(call as-instr,instr,option1,option2) -as-instr = $(call try-run,\ +as-instr = $(call try-run-cached,\ printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) # __cc-option # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) -__cc-option = $(call try-run,\ +__cc-option = $(call try-run-cached,\ $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) # Do not attempt to build with gcc plugins during cc-option tests. @@ -130,23 +192,23 @@ hostcc-option = $(call __cc-option, $(HOSTCC),\ # cc-option-yn # Usage: flag := $(call cc-option-yn,-march=winchip-c6) -cc-option-yn = $(call try-run,\ +cc-option-yn = $(call try-run-cached,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) # cc-disable-warning # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) -cc-disable-warning = $(call try-run,\ +cc-disable-warning = $(call try-run-cached,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) # cc-name # Expands to either gcc or clang -cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) +cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) # cc-version -cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) +cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) # cc-fullversion -cc-fullversion = $(shell $(CONFIG_SHELL) \ +cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \ $(srctree)/scripts/gcc-version.sh -p $(CC)) # cc-ifversion @@ -159,22 +221,22 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo # cc-ldoption # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) -cc-ldoption = $(call try-run,\ +cc-ldoption = $(call try-run-cached,\ $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) # ld-option # Usage: LDFLAGS += $(call ld-option, -X) -ld-option = $(call try-run,\ +ld-option = $(call try-run-cached,\ $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D) # Important: no spaces around options -ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) +ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2)) # ld-version # Note this is mainly for HJ Lu's 3 number binutil versions -ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) +ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh) # ld-ifversion # Usage: $(call ld-ifversion, -ge, 22252, y) From 4e56207130eda9a27df116623e2fce7cca2c6764 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 16 Oct 2017 10:12:46 -0700 Subject: [PATCH 15/30] kbuild: Cache a few more calls to the compiler These are a few stragglers that I left out of the original patch to cache calls to the C compiler ("kbuild: Add a cache for generated variables") because they bleed out into the main Makefile and thus uglify things a little bit. The idea is the same here, though. Signed-off-by: Douglas Anderson Tested-by: Ingo Molnar Tested-by: Guenter Roeck Signed-off-by: Masahiro Yamada --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 5be2c8d2ce73cb..d3e6fccfad9bee 100644 --- a/Makefile +++ b/Makefile @@ -638,7 +638,7 @@ KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \ KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) # check for 'asm goto' -ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) +ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO endif @@ -774,7 +774,7 @@ KBUILD_CFLAGS += $(call cc-option,-fdata-sections,) endif # arch Makefile may override CC so keep this after arch Makefile is included -NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) +NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include) CHECKFLAGS += $(NOSTDINC_FLAGS) # warn about C99 declaration after statement From 433dc2ebe7d17dd21cba7ad5c362d37323592236 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 12 Oct 2017 18:22:25 +0900 Subject: [PATCH 16/30] kbuild: do not call cc-option before KBUILD_CFLAGS initialization Some $(call cc-option,...) are invoked very early, even before KBUILD_CFLAGS, etc. are initialized. The returned string from $(call cc-option,...) depends on KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS. Since they are exported, they are not empty when the top Makefile is recursively invoked. The recursion occurs in several places. For example, the top Makefile invokes itself for silentoldconfig. "make tinyconfig", "make rpm-pkg" are the cases, too. In those cases, the second call of cc-option from the same line runs a different shell command due to non-pristine KBUILD_CFLAGS. To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS must be initialized before any call of cc-option. This avoids garbage data in the .cache.mk file. Move all calls of cc-option below the config targets because target compiler flags are unnecessary for Kconfig. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/Makefile b/Makefile index d3e6fccfad9bee..a7476e6934f19a 100644 --- a/Makefile +++ b/Makefile @@ -392,9 +392,6 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) - # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ @@ -413,21 +410,19 @@ LINUXINCLUDE := \ -I$(objtree)/include \ $(USERINCLUDE) -KBUILD_CPPFLAGS := -D__KERNEL__ - +KBUILD_AFLAGS := -D__ASSEMBLY__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar \ -Werror-implicit-function-declaration \ -Wno-format-security \ - -std=gnu89 $(call cc-option,-fno-PIE) - - + -std=gnu89 +KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := -KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE) KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds +GCC_PLUGINS_CFLAGS := export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES @@ -435,7 +430,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS -export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN +export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_KASAN CFLAGS_UBSAN export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -607,6 +602,12 @@ endif # Defaults to vmlinux, but the arch makefile usually adds further targets all: vmlinux +KBUILD_CFLAGS += $(call cc-option,-fno-PIE) +KBUILD_AFLAGS += $(call cc-option,-fno-PIE) +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) +CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) +export CFLAGS_GCOV CFLAGS_KCOV + # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default # values of the respective KBUILD_* variables ARCH_CPPFLAGS := From e17c400ae194945eef9d9cae38a321c92c1986fb Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 13 Oct 2017 20:25:29 +0900 Subject: [PATCH 17/30] kbuild: shrink .cache.mk when it exceeds 1000 lines The cache files are only cleaned away by "make clean". If you continue incremental builds, the cache files will grow up little by little. It is not a big deal in general use cases because compiler flags do not change quite often. However, if you do build-test for various architectures, compilers, and kernel configurations, you will end up with huge cache files soon. When the cache file exceeds 1000 lines, shrink it down to 500 by "tail". The Least Recently Added lines are cut. (not Least Recently Used) I hope it will work well enough. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- scripts/Kbuild.include | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index dfadb1c94368fb..064f477dfdca02 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -105,6 +105,12 @@ endif $(make-cache): ; -include $(make-cache) +# If cache exceeds 1000 lines, shrink it down to 500. +ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),) +$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ + mv $(make-cache).tmp $(make-cache)) +endif + # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) # # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' From 86a9df597cdd564d2d29c65897bcad42519e3678 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Mon, 6 Nov 2017 10:47:54 -0800 Subject: [PATCH 18/30] kbuild: fix linker feature test macros when cross compiling with Clang I was not seeing my linker flags getting added when using ld-option when cross compiling with Clang. Upon investigation, this seems to be due to a difference in how GCC vs Clang handle cross compilation. GCC is configured at build time to support one backend, that is implicit when compiling. Clang is explicit via the use of `-target ` and ships with all supported backends by default. GNU Make feature test macros that compile then link will always fail when cross compiling with Clang unless Clang's triple is passed along to the compiler. For example: $ clang -x c /dev/null -c -o temp.o $ aarch64-linux-android/bin/ld -E temp.o aarch64-linux-android/bin/ld: unknown architecture of input file `temp.o' is incompatible with aarch64 output aarch64-linux-android/bin/ld: warning: cannot find entry symbol _start; defaulting to 0000000000400078 $ echo $? 1 $ clang -target aarch64-linux-android- -x c /dev/null -c -o temp.o $ aarch64-linux-android/bin/ld -E temp.o aarch64-linux-android/bin/ld: warning: cannot find entry symbol _start; defaulting to 00000000004002e4 $ echo $? 0 This causes conditional checks that invoke $(CC) without the target triple, then $(LD) on the result, to always fail. Suggested-by: Masahiro Yamada Signed-off-by: Nick Desaulniers Reviewed-by: Matthias Kaehlcke Signed-off-by: Masahiro Yamada --- scripts/Kbuild.include | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 064f477dfdca02..be1c9d65eaf406 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -228,12 +228,13 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo # cc-ldoption # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) cc-ldoption = $(call try-run-cached,\ - $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) + $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) # ld-option # Usage: LDFLAGS += $(call ld-option, -X) ld-option = $(call try-run-cached,\ - $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) + $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \ + $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D) From 859fd5860cd1bbbd0370ba4f20725999681b66c8 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 3 Nov 2017 02:40:32 +0900 Subject: [PATCH 19/30] sh: select KBUILD_DEFCONFIG depending on ARCH You can not select KBUILD_DEFCONFIG depending on any CONFIG option because include/config/auto.conf is not included when building config targets. So, CONFIG_SUPERH32 is never set during the configuration, then cayman_defconfig is always chosen. This commit provides a sensible way to choose shx3/cayman_defconfig. arch/sh/Kconfig sets either SUPERH32 or SUPERH64 depending on ARCH environment, like follows: config SUPERH32 def_bool ARCH = "sh" ... config SUPERH64 def_bool ARCH = "sh64" It should make sense to choose the default defconfig by ARCH, like arch/sparc/Makefile. Signed-off-by: Masahiro Yamada --- arch/sh/Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/sh/Makefile b/arch/sh/Makefile index 280bbff121020e..65300193b99f31 100644 --- a/arch/sh/Makefile +++ b/arch/sh/Makefile @@ -15,6 +15,12 @@ ifneq ($(SUBARCH),$(ARCH)) endif endif +ifeq ($(ARCH),sh) +KBUILD_DEFCONFIG := shx3_defconfig +else +KBUILD_DEFCONFIG := cayman_defconfig +endif + isa-y := any isa-$(CONFIG_SH_DSP) := sh isa-$(CONFIG_CPU_SH2) := sh2 @@ -105,14 +111,12 @@ ifdef CONFIG_SUPERH32 UTS_MACHINE := sh BITS := 32 LDFLAGS_vmlinux += -e _stext -KBUILD_DEFCONFIG := shx3_defconfig else UTS_MACHINE := sh64 BITS := 64 LDFLAGS_vmlinux += --defsym phys_stext=_stext-$(CONFIG_PAGE_OFFSET) \ --defsym phys_stext_shmedia=phys_stext+1 \ -e phys_stext_shmedia -KBUILD_DEFCONFIG := cayman_defconfig endif ifdef CONFIG_CPU_LITTLE_ENDIAN From 9a234a2e384349f21afac8d718aa294a668ad4fa Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:34 +0900 Subject: [PATCH 20/30] kbuild: create directory for make cache only when necessary Currently, the existence of $(dir $(make-cache)) is always checked, and created if it is missing. We can avoid unnecessary system calls by some tricks. [1] If KBUILD_SRC is unset, we are building in the source tree. The output directory checks can be entirely skipped. [2] If at least one cache data is found, it means the cache file was included. Obviously its directory exists. Skip "mkdir -p". [3] If Makefile does not contain any call of __run-and-store, it will not create a cache file. No need to create its directory. [4] The "mkdir -p" should be only invoked by the first call of __run-and-store Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- scripts/Kbuild.include | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index be1c9d65eaf406..065324a8046ff8 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -99,18 +99,19 @@ cc-cross-prefix = \ # Include values from last time make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk -ifeq ($(wildcard $(dir $(make-cache))),) -$(shell mkdir -p '$(dir $(make-cache))') -endif $(make-cache): ; -include $(make-cache) +cached-data := $(filter __cached_%, $(.VARIABLES)) + # If cache exceeds 1000 lines, shrink it down to 500. -ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),) +ifneq ($(word 1000,$(cached-data)),) $(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ mv $(make-cache).tmp $(make-cache)) endif +create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1)) + # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) # # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' @@ -136,6 +137,10 @@ __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$ define __run-and-store ifeq ($(origin $(1)),undefined) $$(eval $(1) := $$(shell $$(2))) +ifeq ($(create-cache-dir),1) + $$(shell mkdir -p $(dir $(make-cache))) + $$(eval create-cache-dir :=) +endif $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) endif endef From 2982c953570b2bced858613d70443c2c6a90587b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:35 +0900 Subject: [PATCH 21/30] kbuild: remove redundant $(wildcard ...) for cmd_files calculation I do not see any reason why $(wildcard ...) needs to be called twice for computing cmd_files. Remove the first one. Signed-off-by: Masahiro Yamada --- Makefile | 3 +-- scripts/Makefile.build | 3 +-- scripts/Makefile.headersinst | 3 +-- scripts/Makefile.modpost | 3 +-- 4 files changed, 4 insertions(+), 8 deletions(-) diff --git a/Makefile b/Makefile index a7476e6934f19a..58dd24520c9ef2 100644 --- a/Makefile +++ b/Makefile @@ -1693,8 +1693,7 @@ cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \ # read all saved command lines -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) $(cmd_files): ; # Do not try to update included dependency files diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 061d0c3a420ad5..62d5314c3b7192 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -583,8 +583,7 @@ FORCE: # optimization, we don't need to read them if the target does not # exist, we will rebuild anyway in that case. -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst index 5692d7a6616325..c6fb2b75d81308 100644 --- a/scripts/Makefile.headersinst +++ b/scripts/Makefile.headersinst @@ -114,9 +114,8 @@ $(check-file): scripts/headers_check.pl $(output-files) FORCE endif -targets := $(wildcard $(sort $(targets))) cmd_files := $(wildcard \ - $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) + $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 16923ba4b5b100..cf125c11ca41da 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -143,8 +143,7 @@ FORCE: # optimization, we don't need to read them if the target does not # exist, we will rebuild anyway in that case. -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) From 591f66899784ae0afa13ff9a3eb5ce0a4358e48b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:36 +0900 Subject: [PATCH 22/30] kbuild: filter-out PHONY targets from "targets" The variable "targets" contains object paths for which existing .*.cmd files should be included. scripts/Makefile.build automatically adds $(MAKECMDGOALS) to "targets" as follows: targets += $(extra-y) $(MAKECMDGOALS) $(always) The $(MAKECMDGOALS) is a PHONY target in several places. PHONY targets never create .*.cmd files. Signed-off-by: Masahiro Yamada --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 62d5314c3b7192..6f603770b08eec 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -562,7 +562,7 @@ $(multi-used-m): FORCE $(call multi_depend, $(multi-used-m), .o, -objs -y -m) targets += $(multi-used-y) $(multi-used-m) - +targets := $(filter-out $(PHONY), $(targets)) # Descending # --------------------------------------------------------------------------- From 8a78756eb545a6fb8007fa154a626ca2bc208027 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:37 +0900 Subject: [PATCH 23/30] kbuild: create object directories simpler and faster For the out-of-tree build, scripts/Makefile.build creates output directories, but this operation is not efficient. scripts/Makefile.lib calculates obj-dirs as follows: obj-dirs := $(dir $(multi-objs) $(obj-y)) Please notice $(sort ...) is not used here. Usually the result is as many "./" as objects here. For a lot of duplicated paths, the following command is invoked. _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) Then, the costly shell command is run over and over again. I see many points for optimization: [1] Use $(sort ...) to cut down duplicated paths before passing them to system call [2] Use single $(shell ...) instead of repeating it with $(foreach ...) This will reduce forking. [3] We can calculate obj-dirs more simply. Most of objects are already accumulated in $(targets). So, $(dir $(targets)) is fine and more comprehensive. I also removed ugly code in arch/x86/entry/vdso/Makefile. This is now really unnecessary. Signed-off-by: Masahiro Yamada Acked-by: Ingo Molnar Tested-by: Douglas Anderson --- arch/x86/entry/vdso/Makefile | 4 ---- scripts/Makefile.build | 15 ++++++--------- scripts/Makefile.host | 12 ------------ scripts/Makefile.lib | 5 ----- 4 files changed, 6 insertions(+), 30 deletions(-) diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index d5409660f5de6f..f8e3d85256ad8a 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -129,10 +129,6 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds) VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1 -# This makes sure the $(obj) subdirectory exists even though vdso32/ -# is not a kbuild sub-make subdirectory. -override obj-dirs = $(dir $(obj)) $(obj)/vdso32/ - targets += vdso32/vdso32.lds targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o targets += vdso32/vclock_gettime.o diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 6f603770b08eec..496ecd825c71be 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -64,15 +64,6 @@ ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(h include scripts/Makefile.host endif -ifneq ($(KBUILD_SRC),) -# Create output directory if not already present -_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) - -# Create directories for object files if directory does not exist -# Needed when obj-y := dir/file.o syntax is used -_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) -endif - ifndef obj $(warning kbuild: Makefile.build is included improperly) endif @@ -589,6 +580,12 @@ ifneq ($(cmd_files),) include $(cmd_files) endif +ifneq ($(KBUILD_SRC),) +# Create directories for object files if they do not exist +obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets)))) +$(shell mkdir -p $(obj-dirs)) +endif + # Declare the contents of the .PHONY variable as phony. We keep that # information in a variable se we can use it in if_changed and friends. diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 9cfd5c84d76f55..a5e03838eca8b3 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -48,15 +48,6 @@ host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs))) host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs)))) host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs)))) -# output directory for programs/.o files -# hostprogs-y := tools/build may have been specified. -# Retrieve also directory of .o files from prog-objs or prog-cxxobjs notation -host-objdirs := $(dir $(__hostprogs) $(host-cobjs) $(host-cxxobjs)) - -host-objdirs := $(strip $(sort $(filter-out ./,$(host-objdirs)))) - - -__hostprogs := $(addprefix $(obj)/,$(__hostprogs)) host-csingle := $(addprefix $(obj)/,$(host-csingle)) host-cmulti := $(addprefix $(obj)/,$(host-cmulti)) host-cobjs := $(addprefix $(obj)/,$(host-cobjs)) @@ -66,9 +57,6 @@ host-cshlib := $(addprefix $(obj)/,$(host-cshlib)) host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib)) host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs)) host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs)) -host-objdirs := $(addprefix $(obj)/,$(host-objdirs)) - -obj-dirs += $(host-objdirs) ##### # Handle options to gcc. Support building with separate output directory diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 4d88ad70fd9643..5fbc46daa0f815 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -50,15 +50,11 @@ single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m))) # objects depend on those (obviously) multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y))) multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y))) -multi-objs := $(multi-objs-y) $(multi-objs-m) # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to # tell kbuild to descend subdir-obj-y := $(filter %/built-in.o, $(obj-y)) -# $(obj-dirs) is a list of directories that contain object files -obj-dirs := $(dir $(multi-objs) $(obj-y)) - # Replace multi-part objects by their individual parts, look at local dir only real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y) real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m))) @@ -81,7 +77,6 @@ multi-used-m := $(addprefix $(obj)/,$(multi-used-m)) multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y)) multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m)) subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) -obj-dirs := $(addprefix $(obj)/,$(obj-dirs)) # These flags are needed for modversions and compiling, so we define them here # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will From c4da7ed0e7d715b159b11efd10408510ffed1aa3 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:38 +0900 Subject: [PATCH 24/30] kbuild: optimize object directory creation for incremental build The previous commit largely optimized the object directory creation. We can optimize it more for incremental build. There are already *.cmd files in the output directory. The existing *.cmd files have been picked up by $(wildcard ...). Obviously, directories containing them exist too, so we can skip "mkdir -p". With this, Kbuild runs almost zero "mkdir -p" in incremental building. Signed-off-by: Masahiro Yamada --- scripts/Makefile.build | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 496ecd825c71be..8624924a2991fe 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -583,8 +583,13 @@ endif ifneq ($(KBUILD_SRC),) # Create directories for object files if they do not exist obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets)))) +# If cmd_files exist, their directories apparently exist. Skip mkdir. +exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files)))) +obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs))) +ifneq ($(obj-dirs),) $(shell mkdir -p $(obj-dirs)) endif +endif # Declare the contents of the .PHONY variable as phony. We keep that # information in a variable se we can use it in if_changed and friends. From 4173cbac80faa22a8e2de40bcc7c156b675652b3 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:39 +0900 Subject: [PATCH 25/30] kbuild: remove redundant mkdir from ./Kbuild These two targets are added to "targets". Their directories are automatically created. Signed-off-by: Masahiro Yamada --- Kbuild | 2 -- 1 file changed, 2 deletions(-) diff --git a/Kbuild b/Kbuild index 94c752762bc265..f1997d8744a738 100644 --- a/Kbuild +++ b/Kbuild @@ -17,7 +17,6 @@ targets := kernel/bounds.s # We use internal kbuild rules to avoid the "is up to date" message from make kernel/bounds.s: kernel/bounds.c FORCE - $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c) $(obj)/$(bounds-file): kernel/bounds.s FORCE @@ -53,7 +52,6 @@ targets += arch/$(SRCARCH)/kernel/asm-offsets.s # We use internal kbuild rules to avoid the "is up to date" message from make arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \ $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE - $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c) $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE From e474ed45777bc230648186c0db990bd290383ada Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:33:19 +0900 Subject: [PATCH 26/30] kbuild: specify FORCE in Makefile.headersinst as .PHONY target Swap the order of ".PHONY: $(PHONY)" and "PHONY += FORCE" so that FORCE is correctly specified as a .PHONY target. Use a preferred way for specifying $(subdirs) as .PHONY targets. Signed-off-by: Masahiro Yamada --- scripts/Makefile.headersinst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst index c6fb2b75d81308..086a821ba8f54e 100644 --- a/scripts/Makefile.headersinst +++ b/scripts/Makefile.headersinst @@ -26,7 +26,7 @@ subdirs := $(patsubst $(srcdir)/%/,%,\ # Recursion __headers: $(subdirs) -.PHONY: $(subdirs) +PHONY += $(subdirs) $(subdirs): $(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(dst)/$@ @@ -123,6 +123,7 @@ endif endif # skip-inst -.PHONY: $(PHONY) PHONY += FORCE FORCE: ; + +.PHONY: $(PHONY) From 2f3b55ac0e15857f46a3696e964bb244305223bf Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:40:40 +0900 Subject: [PATCH 27/30] selinux: remove unnecessary assignment to subdir- Makefile.clean descends into $(subdir-y). Dummy assignment to subdir- is meaningless. Signed-off-by: Masahiro Yamada Acked-by: Paul Moore --- scripts/selinux/Makefile | 1 - 1 file changed, 1 deletion(-) diff --git a/scripts/selinux/Makefile b/scripts/selinux/Makefile index e8049da1831fa9..b3048b894a3976 100644 --- a/scripts/selinux/Makefile +++ b/scripts/selinux/Makefile @@ -1,2 +1 @@ subdir-y := mdp genheaders -subdir- += mdp genheaders From 380a1edbcb66c91bd2aadac1496203f70c266997 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:43:00 +0900 Subject: [PATCH 28/30] frv: .gitignore: ignore vmlinux.lds Signed-off-by: Masahiro Yamada --- arch/frv/kernel/.gitignore | 1 + 1 file changed, 1 insertion(+) create mode 100644 arch/frv/kernel/.gitignore diff --git a/arch/frv/kernel/.gitignore b/arch/frv/kernel/.gitignore new file mode 100644 index 00000000000000..c5f676c3c224b6 --- /dev/null +++ b/arch/frv/kernel/.gitignore @@ -0,0 +1 @@ +vmlinux.lds From 52c291a36cdc639321584de9de0a47ec62c6ffa1 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:58:09 +0900 Subject: [PATCH 29/30] sh: decompressor: add shipped files to .gitignore These files are copied from arch/sh/lib, so should be ignored by git. Signed-off-by: Masahiro Yamada --- arch/sh/boot/compressed/.gitignore | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/sh/boot/compressed/.gitignore b/arch/sh/boot/compressed/.gitignore index 2374a83d87b26f..edff113f1b85f7 100644 --- a/arch/sh/boot/compressed/.gitignore +++ b/arch/sh/boot/compressed/.gitignore @@ -1 +1,6 @@ +ashiftrt.S +ashldi3.c +ashlsi3.S +ashrsi3.S +lshrsi3.S vmlinux.bin.* From 7f855fc805cd9c29867aed56cc20f818b36a7b7b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 14 Nov 2017 18:47:20 +0900 Subject: [PATCH 30/30] kbuild: move coccicheck help from scripts/Makefile.help to top Makefile In my view, it is not helpful to have a separate file just for the coccicheck help message. Merge scripts/Makefile.help into the top-level Makefile. Signed-off-by: Masahiro Yamada Acked-by: Julia Lawall --- Makefile | 2 +- scripts/Makefile.help | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) delete mode 100644 scripts/Makefile.help diff --git a/Makefile b/Makefile index 58dd24520c9ef2..06a5798335fcdb 100644 --- a/Makefile +++ b/Makefile @@ -1384,7 +1384,7 @@ help: @echo ' export_report - List the usages of all exported symbols' @echo ' headers_check - Sanity check on exported headers' @echo ' headerdep - Detect inclusion cycles in headers' - @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help + @echo ' coccicheck - Check with Coccinelle' @echo '' @echo 'Kernel selftest:' @echo ' kselftest - Build and run kernel selftest (run as root)' diff --git a/scripts/Makefile.help b/scripts/Makefile.help deleted file mode 100644 index d03608f5db04b8..00000000000000 --- a/scripts/Makefile.help +++ /dev/null @@ -1,3 +0,0 @@ - -checker-help: - @echo ' coccicheck - Check with Coccinelle.'