Commit 56769ba4 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: unify vdso_install rules 



Currently, there is no standard implementation for vdso_install,
leading to various issues:

 1. Code duplication

    Many architectures duplicate similar code just for copying files
    to the install destination.

    Some architectures (arm, sparc, x86) create build-id symlinks,
    introducing more code duplication.

 2. Unintended updates of in-tree build artifacts

    The vdso_install rule depends on the vdso files to install.
    It may update in-tree build artifacts. This can be problematic,
    as explained in commit 19514fc6 ("arm, kbuild: make
    "make install" not depend on vmlinux").

 3. Broken code in some architectures

    Makefile code is often copied from one architecture to another
    without proper adaptation.

    'make vdso_install' for parisc does not work.

    'make vdso_install' for s390 installs vdso64, but not vdso32.

To address these problems, this commit introduces a generic vdso_install
rule.

Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.

For example, arch/x86/Makefile looks like this:

  vdso-install-$(CONFIG_X86_64)           += arch/x86/entry/vdso/vdso64.so.dbg
  vdso-install-$(CONFIG_X86_X32_ABI)      += arch/x86/entry/vdso/vdsox32.so.dbg
  vdso-install-$(CONFIG_X86_32)           += arch/x86/entry/vdso/vdso32.so.dbg
  vdso-install-$(CONFIG_IA32_EMULATION)   += arch/x86/entry/vdso/vdso32.so.dbg

These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.

vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.

The following is a snippet from arch/arm64/Makefile.

  vdso-install-$(CONFIG_COMPAT_VDSO)      += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so

This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
Reviewed-by: default avatarGuo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
parent 1b627289

Makefile

+9 −0
Original line number Diff line number Diff line
@@ -1317,6 +1317,14 @@ scripts_unifdef: scripts_basic 
quiet_cmd_install = INSTALL $(INSTALL_PATH)

      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh



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

# vDSO install



PHONY += vdso_install

vdso_install: export INSTALL_FILES = $(vdso-install-y)

vdso_install:

	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst



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

# Tools
@@ -1560,6 +1568,7 @@ help: 
	@echo  '* vmlinux	  - Build the bare kernel'

	@echo  '* modules	  - Build all modules'

	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'

	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'

	@echo  '  dir/            - Build all files in dir and below'

	@echo  '  dir/file.[ois]  - Build specified target only'

	@echo  '  dir/file.ll     - Build the LLVM assembly file'

arch/arm/Makefile

+1 −6
Original line number Diff line number Diff line
@@ -304,11 +304,7 @@ $(INSTALL_TARGETS): KBUILD_IMAGE = $(boot)/$(patsubst %install,%Image,$@) 
$(INSTALL_TARGETS):

	$(call cmd,install)



PHONY += vdso_install

vdso_install:

ifeq ($(CONFIG_VDSO),y)

	$(Q)$(MAKE) $(build)=arch/arm/vdso $@

endif

vdso-install-$(CONFIG_VDSO) += arch/arm/vdso/vdso.so.dbg



# My testing targets (bypasses dependencies)

bp:;	$(Q)$(MAKE) $(build)=$(boot) $(boot)/bootpImage
@@ -331,7 +327,6 @@ define archhelp 
  echo  '                  Install using (your) ~/bin/$(INSTALLKERNEL) or'

  echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'

  echo  '                  install to $$(INSTALL_PATH) and run lilo'

  echo  '  vdso_install  - Install unstripped vdso.so to $$(INSTALL_MOD_PATH)/vdso'

  echo

  echo  '  multi_v7_lpae_defconfig     - multi_v7_defconfig with CONFIG_ARM_LPAE enabled'

endef

arch/arm/vdso/Makefile

+0 −25
Original line number Diff line number Diff line
@@ -63,28 +63,3 @@ quiet_cmd_vdsold_and_vdso_check = LD $@ 


quiet_cmd_vdsomunge = MUNGE   $@

      cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
 


#

# Install the unstripped copy of vdso.so.dbg.  If our toolchain

# supports build-id, install .build-id links as well.

#

# Cribbed from arch/x86/vdso/Makefile.

#

quiet_cmd_vdso_install = INSTALL $<

define cmd_vdso_install

	cp $< "$(MODLIB)/vdso/vdso.so"; \

	if readelf -n $< | grep -q 'Build ID'; then \

	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \

	  first=`echo $$buildid | cut -b-2`; \

	  last=`echo $$buildid | cut -b3-`; \

	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \

	  ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \

	fi

endef



$(MODLIB)/vdso: FORCE

	@mkdir -p $(MODLIB)/vdso



PHONY += vdso_install

vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso

	$(call cmd,vdso_install)

arch/arm64/Makefile

+3 −6
Original line number Diff line number Diff line
@@ -169,12 +169,6 @@ install: KBUILD_IMAGE := $(boot)/Image 
install zinstall:

	$(call cmd,install)



PHONY += vdso_install

vdso_install:

	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@

	$(if $(CONFIG_COMPAT_VDSO), \

		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)



archprepare:

	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi

ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
@@ -205,6 +199,9 @@ ifdef CONFIG_COMPAT_VDSO 
endif

endif



vdso-install-y				+= arch/arm64/kernel/vdso/vdso.so.dbg

vdso-install-$(CONFIG_COMPAT_VDSO)	+= arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so



include $(srctree)/scripts/Makefile.defconf



PHONY += virtconfig

arch/arm64/kernel/vdso/Makefile

+0 −10
Original line number Diff line number Diff line
@@ -78,13 +78,3 @@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 
# Actual build commands

quiet_cmd_vdsold_and_vdso_check = LD      $@

      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
 


# Install commands for the unstripped file

quiet_cmd_vdso_install = INSTALL $@

      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@



vdso.so: $(obj)/vdso.so.dbg

	@mkdir -p $(MODLIB)/vdso

	$(call cmd,vdso_install)



vdso_install: vdso.so