Commit b8321ed4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 

Pull Kbuild updates from Masahiro Yamada:

 - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
   additional flags to be passed to user-space programs.

 - Fix missing fflush() bugs in Kconfig and fixdep

 - Fix a minor bug in the comment format of the .config file

 - Make kallsyms ignore llvm's local labels, .L*

 - Fix UAPI compile-test for cross-compiling with Clang

 - Extend the LLVM= syntax to support LLVM=<suffix> form for using a
   particular version of LLVm, and LLVM=<prefix> form for using custom
   LLVM in a particular directory path.

 - Clean up Makefiles

* tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: Make $(LLVM) more flexible
  kbuild: add --target to correctly cross-compile UAPI headers with Clang
  fixdep: use fflush() and ferror() to ensure successful write to files
  arch: syscalls: simplify uapi/kapi directory creation
  usr/include: replace extra-y with always-y
  certs: simplify empty certs creation in certs/Makefile
  certs: include certs/signing_key.x509 unconditionally
  kallsyms: ignore all local labels prefixed by '.L'
  kconfig: fix missing '# end of' for empty menu
  kconfig: add fflush() before ferror() check
  kbuild: replace $(if A,A,B) with $(or A,B)
  kbuild: Add environment variables for userprogs flags
  kbuild: unify cmd_copy and cmd_shipped
parents f87cbd05 e9c28192

Documentation/kbuild/kbuild.rst

+11 −0
Original line number Diff line number Diff line
@@ -77,6 +77,17 @@ HOSTLDLIBS 
----------

Additional libraries to link against when building host programs.



.. _userkbuildflags:



USERCFLAGS

----------

Additional options used for $(CC) when compiling userprogs.



USERLDFLAGS

-----------

Additional options used for $(LD) when linking userprogs. userprogs are linked

with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable.



KBUILD_KCONFIG

--------------

Set the top-level Kconfig file to the value of this environment

Documentation/kbuild/llvm.rst

+25 −6
Original line number Diff line number Diff line
@@ -49,17 +49,36 @@ example: :: 
LLVM Utilities

--------------



LLVM has substitutes for GNU binutils utilities. Kbuild supports ``LLVM=1``

to enable them. ::



	make LLVM=1



They can be enabled individually. The full list of the parameters: ::

LLVM has substitutes for GNU binutils utilities. They can be enabled individually.

The full list of supported make variables::



	make CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \

	  OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump READELF=llvm-readelf \

	  HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar HOSTLD=ld.lld



To simplify the above command, Kbuild supports the ``LLVM`` variable::



	make LLVM=1



If your LLVM tools are not available in your PATH, you can supply their

location using the LLVM variable with a trailing slash::



	make LLVM=/path/to/llvm/



which will use ``/path/to/llvm/clang``, ``/path/to/llvm/ld.lld``, etc.



If your LLVM tools have a version suffix and you want to test with that

explicit version rather than the unsuffixed executables like ``LLVM=1``, you

can pass the suffix using the ``LLVM`` variable::



	make LLVM=-14



which will use ``clang-14``, ``ld.lld-14``, etc.



``LLVM=0`` is not the same as omitting ``LLVM`` altogether, it will behave like

``LLVM=1``. If you only wish to use certain LLVM utilities, use their respective

make variables.



The integrated assembler is enabled by default. You can pass ``LLVM_IAS=0`` to

disable it.

Documentation/kbuild/makefiles.rst

+2 −0
Original line number Diff line number Diff line
@@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of 


	When linking bpfilter_umh, it will be passed the extra option -static.



	From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.



5.4 When userspace programs are actually built

----------------------------------------------

Makefile

+27 −19
Original line number Diff line number Diff line
@@ -424,19 +424,26 @@ HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null) 
HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)



ifneq ($(LLVM),)

HOSTCC	= clang

HOSTCXX	= clang++

ifneq ($(filter %/,$(LLVM)),)

LLVM_PREFIX := $(LLVM)

else ifneq ($(filter -%,$(LLVM)),)

LLVM_SUFFIX := $(LLVM)

endif



HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)

HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)

else

HOSTCC	= gcc

HOSTCXX	= g++

endif



export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \

KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \

			 -O2 -fomit-frame-pointer -std=gnu11 \

			 -Wdeclaration-after-statement

export KBUILD_USERLDFLAGS :=

KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)

KBUILD_USERLDFLAGS := $(USERLDFLAGS)



KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)

KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)

KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)

KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)

KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
@@ -444,14 +451,14 @@ KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) 
# Make variables (CC, etc...)

CPP		= $(CC) -E

ifneq ($(LLVM),)

CC		= clang

LD		= ld.lld

AR		= llvm-ar

NM		= llvm-nm

OBJCOPY		= llvm-objcopy

OBJDUMP		= llvm-objdump

READELF		= llvm-readelf

STRIP		= llvm-strip

CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)

LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)

AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)

NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)

OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)

OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)

READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)

STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)

else

CC		= $(CROSS_COMPILE)gcc

LD		= $(CROSS_COMPILE)ld
@@ -531,6 +538,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW 
export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX

export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD

export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE

export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS



export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS

export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
@@ -1237,8 +1245,8 @@ define filechk_version.h 
	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)

endef



$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)

$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)

$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)

$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)

$(version_h): FORCE

	$(call filechk,version.h)
@@ -1621,7 +1629,7 @@ help: 
	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp

	@echo  ''

	@echo  'Architecture specific targets ($(SRCARCH)):'

	@$(if $(archhelp),$(archhelp),\

	@$(or $(archhelp),\

		echo '  No architecture specific help defined for $(SRCARCH)')

	@echo  ''

	@$(if $(boards), \
@@ -1838,7 +1846,7 @@ $(clean-dirs): 


clean: $(clean-dirs)

	$(call cmd,rmfiles)

	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \

	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \

		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \

		-o -name '*.ko.*' \

		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \

arch/alpha/kernel/syscalls/Makefile

+1 −2
Original line number Diff line number Diff line
@@ -2,8 +2,7 @@ 
kapi := arch/$(SRCARCH)/include/generated/asm

uapi := arch/$(SRCARCH)/include/generated/uapi/asm



_dummy := $(shell [ -d '$(uapi)' ] || mkdir -p '$(uapi)')	\

	  $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)')

$(shell mkdir -p $(uapi) $(kapi))



syscall := $(src)/syscall.tbl

syshdr := $(srctree)/scripts/syscallhdr.sh