Commit 5750121a authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: list sub-directories in ./Kbuild 

Use the ordinary obj-y syntax to list subdirectories.

Note1:
Previously, the link order of lib-y depended on CONFIG_MODULES; lib-y
was linked before drivers-y when CONFIG_MODULES=y, otherwise after
drivers-y. This was a bug of commit 7273ad2b ("kbuild: link lib-y
objects to vmlinux forcibly when CONFIG_MODULES=y"), but it was not a
big deal after all. Now, all objects listed in lib-y are linked last,
irrespective of CONFIG_MODULES.

Note2:
Finally, the single target build in arch/*/lib/ works correctly. There was
a bug report about this. [1]

  $ make ARCH=arm arch/arm/lib/findbit.o
    CALL    scripts/checksyscalls.sh
    AS      arch/arm/lib/findbit.o

[1]: https://lore.kernel.org/linux-kbuild/YvUQOwL6lD4%2F5%2FU6@shell.armlinux.org.uk/



Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Tested-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
parent 88b61e3b

Kbuild

+24 −0
Original line number Diff line number Diff line
@@ -72,3 +72,27 @@ $(atomic-checks): $(obj)/.checked-%: include/linux/atomic/% FORCE 
PHONY += prepare

prepare: $(offsets-file) missing-syscalls $(atomic-checks)

	@:



# Ordinary directory descending

# ---------------------------------------------------------------------------



obj-y			+= init/

obj-y			+= usr/

obj-y			+= arch/$(SRCARCH)/

obj-y			+= $(ARCH_CORE)

obj-y			+= kernel/

obj-y			+= certs/

obj-y			+= mm/

obj-y			+= fs/

obj-y			+= ipc/

obj-y			+= security/

obj-y			+= crypto/

obj-$(CONFIG_BLOCK)	+= block/

obj-$(CONFIG_IO_URING)	+= io_uring/

obj-y			+= $(ARCH_LIB)

obj-y			+= drivers/

obj-y			+= sound/

obj-$(CONFIG_SAMPLES)	+= samples/

obj-$(CONFIG_NET)	+= net/

obj-y			+= virt/

obj-y			+= $(ARCH_DRIVERS)

Makefile

+20 −43
Original line number Diff line number Diff line
@@ -676,11 +676,8 @@ endif 


ifeq ($(KBUILD_EXTMOD),)

# Objects we will link into vmlinux / subdirs we need to visit

core-y		:= init/ usr/ arch/$(SRCARCH)/

drivers-y	:= drivers/ sound/

drivers-$(CONFIG_SAMPLES) += samples/

drivers-$(CONFIG_NET) += net/

drivers-y	+= virt/

core-y		:=

drivers-y	:=

libs-y		:= lib/

endif # KBUILD_EXTMOD
@@ -1099,31 +1096,24 @@ export MODORDER := $(extmod_prefix)modules.order 
export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps



ifeq ($(KBUILD_EXTMOD),)

core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/

core-$(CONFIG_BLOCK)	+= block/

core-$(CONFIG_IO_URING)	+= io_uring/



vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \

		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \

		     $(libs-y) $(libs-m)))



build-dirs	:= $(vmlinux-dirs)

clean-dirs	:= $(sort $(vmlinux-dirs) Documentation . \

build-dir	:= .

clean-dirs	:= $(sort . Documentation \

		     $(patsubst %/,%,$(filter %/, $(core-) \

			$(drivers-) $(libs-))))



subdir-modorder := $(addsuffix /modules.order, $(build-dirs))



export ARCH_CORE	:= $(core-y)

export ARCH_LIB		:= $(filter %/, $(libs-y))

export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)

# Externally visible symbols (used by link-vmlinux.sh)

KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))

KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))



KBUILD_VMLINUX_OBJS := $(head-y) ./built-in.a

ifdef CONFIG_MODULES

KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))

KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))

else

KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))

endif

KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))



export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS

export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
@@ -1138,7 +1128,7 @@ ifdef CONFIG_TRIM_UNUSED_KSYMS 
# (this can be evaluated only once include/config/auto.conf has been included)

KBUILD_MODULES := 1



autoksyms_recursive: descend modules.order

autoksyms_recursive: $(build-dir) modules.order

	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \

	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"

endif
@@ -1166,7 +1156,7 @@ targets := vmlinux 


# The actual objects are generated when descending,

# make sure no implicit rule kicks in

$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;

$(sort $(vmlinux-deps)): . ;



filechk_kernel.release = \

	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
@@ -1437,13 +1427,6 @@ endif 


modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_prepare



cmd_modules_order = cat $(real-prereqs) > $@



modules.order: $(subdir-modorder) FORCE

	$(call if_changed,modules_order)



targets += modules.order



# Target to prepare building external modules

modules_prepare: prepare

	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
@@ -1714,9 +1697,7 @@ else # KBUILD_EXTMOD 
KBUILD_BUILTIN :=

KBUILD_MODULES := 1



build-dirs := $(KBUILD_EXTMOD)

$(MODORDER): descend

	@:

build-dir := $(KBUILD_EXTMOD)



compile_commands.json: $(extmod_prefix)compile_commands.json

PHONY += compile_commands.json
@@ -1754,6 +1735,9 @@ PHONY += modules modules_install modules_prepare 


ifdef CONFIG_MODULES



$(MODORDER): $(build-dir)

	@:



modules: modules_check

	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
@@ -1807,7 +1791,7 @@ single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \ 


$(single-ko): single_modpost

	@:

$(single-no-ko): descend

$(single-no-ko): $(build-dir)

	@:



# Remove MODORDER when done because it is not the real one.
@@ -1817,24 +1801,17 @@ single_modpost: $(single-no-ko) modules_prepare 
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

	$(Q)rm -f $(MODORDER)



single-goals := $(addprefix $(extmod_prefix), $(single-no-ko))



# trim unrelated directories

build-dirs := $(foreach d, $(build-dirs), \

			$(if $(filter $d/%, $(single-goals)), $d))

single-goals := $(addprefix $(build-dir)/, $(single-no-ko))



endif



# Handle descending into subdirectories listed in $(build-dirs)

# Preset locale variables to speed up the build process. Limit locale

# tweaks to this spot to avoid wrong language settings when running

# make menuconfig etc.

# Error messages still appears in the original language

PHONY += descend $(build-dirs)

descend: $(build-dirs)

$(build-dirs): prepare

	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 \

	$(filter $@/%, $(single-goals))

PHONY += $(build-dir)

$(build-dir): prepare

	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)



clean-dirs := $(addprefix _clean_, $(clean-dirs))

PHONY += $(clean-dirs) clean

scripts/Makefile.lib

+2 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ always-y += $(dtb-y) 


# Add subdir path



ifneq ($(obj),.)

extra-y		:= $(addprefix $(obj)/,$(extra-y))

always-y	:= $(addprefix $(obj)/,$(always-y))

targets		:= $(addprefix $(obj)/,$(targets))
@@ -100,6 +101,7 @@ multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m)) 
multi-dtb-y	:= $(addprefix $(obj)/, $(multi-dtb-y))

real-dtb-y	:= $(addprefix $(obj)/, $(real-dtb-y))

subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))

endif



# Finds the multi-part object the current object will be linked into.

# If the object belongs to two or more multi-part objects, list them all.