diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-07 14:09:24 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-07 14:09:24 -0700 |
commit | 58f051fc9828709e6c55803510761413d92c4e57 (patch) | |
tree | 8b92cf129f74105d9b17ada2b227aa45f2898d51 | |
parent | ef3ad0898a60d30da7f170032992914998c366e5 (diff) | |
parent | c4e6fff1ae5729c2af159008b13fca39fbbac70e (diff) |
Merge tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Clean up Makefiles and scripts
- Improve clang support
- Remove unneeded genhdr-y syntax
- Remove unneeded cc-option-align macro
- Introduce __cc-option macro and use it to fix x86 boot code compiler
flags
* tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: improve comments on KBUILD_SRC
x86/build: Specify stack alignment for clang
x86/build: Use __cc-option for boot code compiler options
kbuild: Add __cc-option macro
kbuild: remove cc-option-align
kbuild: replace genhdr-y with generated-y
kbuild: clang: Disable 'address-of-packed-member' warning
kbuild: remove duplicated arch/*/include/generated/uapi include path
kbuild: speed up checksyscalls.sh
kbuild: simplify silent build (-s) detection
-rw-r--r-- | Documentation/kbuild/makefiles.txt | 41 | ||||
-rw-r--r-- | Makefile | 24 | ||||
-rw-r--r-- | arch/arm/include/uapi/asm/Kbuild | 6 | ||||
-rw-r--r-- | arch/x86/Makefile | 33 | ||||
-rw-r--r-- | arch/x86/Makefile_32.cpu | 7 | ||||
-rw-r--r-- | arch/x86/include/uapi/asm/Kbuild | 6 | ||||
-rw-r--r-- | scripts/Kbuild.include | 19 | ||||
-rw-r--r-- | scripts/Makefile.asm-generic | 2 | ||||
-rw-r--r-- | scripts/Makefile.host | 6 | ||||
-rwxr-xr-x | scripts/checksyscalls.sh | 11 | ||||
-rw-r--r-- | tools/build/Makefile.build | 8 | ||||
-rw-r--r-- | tools/scripts/Makefile.include | 8 |
12 files changed, 67 insertions, 104 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 659afd56ecdb..7003141a6d4f 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -45,10 +45,9 @@ This document describes the Linux kernel Makefiles. === 7 Kbuild syntax for exported headers --- 7.1 no-export-headers - --- 7.2 genhdr-y - --- 7.3 generic-y - --- 7.4 generated-y - --- 7.5 mandatory-y + --- 7.2 generic-y + --- 7.3 generated-y + --- 7.4 mandatory-y === 8 Kbuild Variables === 9 Makefile language @@ -487,22 +486,6 @@ more details, with real examples. respectively. 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 $(CC) options - cc-disable-warning cc-disable-warning checks if gcc supports a given warning and returns the commandline switch to disable it. This special function is needed, @@ -1277,18 +1260,7 @@ See subsequent chapter for the syntax of the Kbuild file. avoid exporting specific headers (e.g. kvm.h) on architectures that do not support it. It should be avoided as much as possible. - --- 7.2 genhdr-y - - genhdr-y specifies asm files to be generated. - - Example: - #arch/x86/include/uapi/asm/Kbuild - genhdr-y += unistd_32.h - genhdr-y += unistd_64.h - genhdr-y += unistd_x32.h - - - --- 7.3 generic-y + --- 7.2 generic-y If an architecture uses a verbatim copy of a header from include/asm-generic then this is listed in the file @@ -1315,11 +1287,10 @@ See subsequent chapter for the syntax of the Kbuild file. Example: termios.h #include <asm-generic/termios.h> - --- 7.4 generated-y + --- 7.3 generated-y If an architecture generates other header files alongside generic-y - wrappers, and not included in genhdr-y, then generated-y specifies - them. + wrappers, generated-y specifies them. This prevents them being treated as stale asm-generic wrappers and removed. @@ -84,17 +84,10 @@ endif # If the user is running make -s (silent mode), suppress echoing of # commands -ifneq ($(filter 4.%,$(MAKE_VERSION)),) # make-4 -ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),) +ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) quiet=silent_ tools_silent=s endif -else # make-3.8x -ifneq ($(filter s% -s%,$(MAKEFLAGS)),) - quiet=silent_ - tools_silent=-s -endif -endif export quiet Q KBUILD_VERBOSE @@ -113,8 +106,8 @@ export quiet Q KBUILD_VERBOSE # The O= assignment takes precedence over the KBUILD_OUTPUT environment # variable. -# KBUILD_SRC is set on invocation of make in OBJ directory -# KBUILD_SRC is not intended to be used by the regular user (for now) +# KBUILD_SRC is not intended to be used by the regular user (for now), +# it is set on invocation of make with KBUILD_OUTPUT or O= specified. ifeq ($(KBUILD_SRC),) # OK, Make called in directory where kernel src resides @@ -135,7 +128,6 @@ ifneq ($(words $(subst :, ,$(CURDIR))), 1) endif ifneq ($(KBUILD_OUTPUT),) -# Invoke a second make in the output directory, passing relevant variables # check that the output directory actually exists saved-output := $(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 @: +# Invoke a second make in the output directory, passing relevant variables sub-make: $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \ -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS)) @@ -303,7 +296,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \ HOSTCC = gcc 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 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1) @@ -388,12 +381,10 @@ USERINCLUDE := \ # Needed to be compatible with the O= option LINUXINCLUDE := \ -I$(srctree)/arch/$(hdr-arch)/include \ - -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \ -I$(objtree)/arch/$(hdr-arch)/include/generated \ $(if $(KBUILD_SRC), -I$(srctree)/include) \ - -I$(objtree)/include - -LINUXINCLUDE += $(filter-out $(LINUXINCLUDE),$(USERINCLUDE)) + -I$(objtree)/include \ + $(USERINCLUDE) 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, format-invalid-specifier) 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 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare) # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the diff --git a/arch/arm/include/uapi/asm/Kbuild b/arch/arm/include/uapi/asm/Kbuild index e9b098d6b766..5fb3368e70cb 100644 --- a/arch/arm/include/uapi/asm/Kbuild +++ b/arch/arm/include/uapi/asm/Kbuild @@ -1,8 +1,8 @@ # UAPI Header export list include include/uapi/asm-generic/Kbuild.asm -genhdr-y += unistd-common.h -genhdr-y += unistd-oabi.h -genhdr-y += unistd-eabi.h +generated-y += unistd-common.h +generated-y += unistd-oabi.h +generated-y += unistd-eabi.h generic-y += siginfo.h diff --git a/arch/x86/Makefile b/arch/x86/Makefile index ad2db82e9953..1e902f926be3 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -11,6 +11,14 @@ else KBUILD_DEFCONFIG := $(ARCH)_defconfig endif +# For gcc stack alignment is specified with -mpreferred-stack-boundary, +# clang has the option -mstack-alignment for that purpose. +ifneq ($(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; # 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 \ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ - -mno-mmx -mno-sse \ - $(call cc-option, -ffreestanding) \ - $(call cc-option, -fno-stack-protector) \ - $(call cc-option, -mpreferred-stack-boundary=2) + -mno-mmx -mno-sse + +REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding) +REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) +REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align_opt)=2) export REALMODE_CFLAGS # BITS is used as extension for files which are available in a 32 bit @@ -64,8 +73,10 @@ ifeq ($(CONFIG_X86_32),y) # with nonstandard options KBUILD_CFLAGS += -fno-pic - # prevent gcc from keeping the stack 16 byte aligned - KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2) + # Align the stack to the register width instead of using the default + # 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 # 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-fp-ret-in-387) - # Use -mpreferred-stack-boundary=3 if supported. - KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3) + # By default gcc and clang use a stack alignment of 16 bytes for x86. + # 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 *mis*aligned. + # 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. KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu index a45eb15b7cf2..f3717d36718a 100644 --- a/arch/x86/Makefile_32.cpu +++ b/arch/x86/Makefile_32.cpu @@ -9,7 +9,6 @@ else tune = $(call cc-option,-mcpu=$(1),$(2)) endif -align := $(cc-option-align) cflags-$(CONFIG_M486) += -march=i486 cflags-$(CONFIG_M586) += -march=i586 cflags-$(CONFIG_M586TSC) += -march=i586 @@ -24,11 +23,11 @@ cflags-$(CONFIG_MK6) += -march=k6 # They make zero difference whatsosever to performance at this time. cflags-$(CONFIG_MK7) += -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_MEFFICEON) += -march=i686 $(call tune,pentium3) $(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 $(call tune,pentium3) -falign-functions=0 -falign-jumps=0 -falign-loops=0 cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586) cflags-$(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_MVIAC7) += -march=i686 cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2) diff --git a/arch/x86/include/uapi/asm/Kbuild b/arch/x86/include/uapi/asm/Kbuild index 83b6e9a0dce4..da1489cb64dc 100644 --- a/arch/x86/include/uapi/asm/Kbuild +++ b/arch/x86/include/uapi/asm/Kbuild @@ -1,6 +1,6 @@ # UAPI Header export list include include/uapi/asm-generic/Kbuild.asm -genhdr-y += unistd_32.h -genhdr-y += unistd_64.h -genhdr-y += unistd_x32.h +generated-y += unistd_32.h +generated-y += unistd_64.h +generated-y += unistd_x32.h diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 61f87a99bf0a..dd8e2dde0b34 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -108,6 +108,11 @@ as-option = $(call try-run,\ as-instr = $(call try-run,\ printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) +# __cc-option +# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) +__cc-option = $(call try-run,\ + $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) + # Do not attempt to build with gcc plugins during cc-option tests. # (And this uses delayed resolution so the flags will be up to date.) CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) @@ -115,19 +120,19 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) # cc-option # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) -cc-option = $(call try-run,\ - $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) +cc-option = $(call __cc-option, $(CC),\ + $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) + +# hostcc-option +# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) +hostcc-option = $(call __cc-option, $(HOSTCC),\ + $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2)) # cc-option-yn # Usage: flag := $(call cc-option-yn,-march=winchip-c6) cc-option-yn = $(call try-run,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) -# cc-option-align -# Prefix align with either -falign or -malign -cc-option-align = $(subst -functions=0,,\ - $(call cc-option,-falign-functions=0,-malign-functions=0)) - # cc-disable-warning # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) cc-disable-warning = $(call try-run,\ diff --git a/scripts/Makefile.asm-generic b/scripts/Makefile.asm-generic index e4d017d53819..95f7d8090152 100644 --- a/scripts/Makefile.asm-generic +++ b/scripts/Makefile.asm-generic @@ -15,7 +15,7 @@ _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) # Stale wrappers when the corresponding files are removed from generic-y # need removing. -generated-y := $(generic-y) $(genhdr-y) $(generated-y) +generated-y := $(generic-y) $(generated-y) all-files := $(patsubst %, $(obj)/%, $(generated-y)) old-headers := $(wildcard $(obj)/*.h) unwanted := $(filter-out $(all-files),$(old-headers)) diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 45b5b1aaedbd..9cfd5c84d76f 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -20,12 +20,6 @@ # Will compile qconf as a C++ program, and menu as a C program. # They are linked as C++ code to the executable qconf -# hostcc-option -# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) - -hostcc-option = $(call try-run,\ - $(HOSTCC) $(HOSTCFLAGS) $(HOST_EXTRACFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) - __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m)) host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m)) host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m)) diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh index 116b7735ee9f..5a387a264201 100755 --- a/scripts/checksyscalls.sh +++ b/scripts/checksyscalls.sh @@ -202,15 +202,12 @@ EOF } syscall_list() { - grep '^[0-9]' "$1" | sort -n | ( + grep '^[0-9]' "$1" | sort -n | while read nr abi name entry ; do - cat <<EOF -#if !defined(__NR_${name}) && !defined(__IGNORE_${name}) -#warning syscall ${name} not implemented -#endif -EOF + echo "#if !defined(__NR_${name}) && !defined(__IGNORE_${name})" + echo "#warning syscall ${name} not implemented" + echo "#endif" done - ) } (ignore_list && syscall_list $(dirname $0)/../arch/x86/entry/syscalls/syscall_32.tbl) | \ diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build index e279a71c650d..c46b20e4ad87 100644 --- a/tools/build/Makefile.build +++ b/tools/build/Makefile.build @@ -19,15 +19,9 @@ else Q=@ endif -ifneq ($(filter 4.%,$(MAKE_VERSION)),) # make-4 -ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),) +ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) quiet=silent_ endif -else # make-3.8x -ifneq ($(filter s% -s%,$(MAKEFLAGS)),) - quiet=silent_ -endif -endif build-dir := $(srctree)/tools/build diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index fc74db62fef4..ccad8ce925e4 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -58,15 +58,9 @@ else NO_SUBDIR = : endif -ifneq ($(filter 4.%,$(MAKE_VERSION)),) # make-4 -ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),) +ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) silent=1 endif -else # make-3.8x -ifneq ($(filter s% -s%,$(MAKEFLAGS)),) - silent=1 -endif -endif # # Define a callable command for descending to a new directory |