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: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Makefile

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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

arch/arm64/kernel/vdso32/Makefile

@@ -172,13 +172,3 @@ gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh
 quiet_cmd_vdsosym = VDSOSYM $@
 # The AArch64 nm should be able to read an AArch32 binary
       cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
-
-# Install commands for the unstripped file
-quiet_cmd_vdso_install = INSTALL32 $@
-      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so
-
-vdso.so: $(obj)/vdso.so.dbg
-	@mkdir -p $(MODLIB)/vdso
-	$(call cmd,vdso_install)
-
-vdso_install: vdso.so

arch/loongarch/Makefile

@@ -136,9 +136,7 @@ vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/loongarch/vdso include/generated/vdso-offsets.h
 endif
 
-PHONY += vdso_install
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/loongarch/vdso $@
+vdso-install-y += arch/loongarch/vdso/vdso.so.dbg
 
 all:	$(notdir $(KBUILD_IMAGE))
 

arch/loongarch/vdso/Makefile

@@ -83,13 +83,3 @@ $(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
 obj-y += vdso.o
 
 $(obj)/vdso.o : $(obj)/vdso.so
-
-# 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

arch/parisc/Makefile

@@ -177,12 +177,8 @@ vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/parisc/kernel/vdso32 include/generated/vdso32-offsets.h
 endif
 
-PHONY += vdso_install
-
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/parisc/kernel/vdso $@
-	$(if $(CONFIG_COMPAT_VDSO), \
-		$(Q)$(MAKE) $(build)=arch/parisc/kernel/vdso32 $@)
+vdso-install-y			+= arch/parisc/kernel/vdso32/vdso32.so
+vdso-install-$(CONFIG_64BIT)	+= arch/parisc/kernel/vdso64/vdso64.so
 
 install: KBUILD_IMAGE := vmlinux
 zinstall: KBUILD_IMAGE := vmlinuz

arch/riscv/Makefile

@@ -131,12 +131,6 @@ endif
 libs-y += arch/riscv/lib/
 libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 
-PHONY += vdso_install
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@
-	$(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
-		$(build)=arch/riscv/kernel/compat_vdso compat_$@)
-
 ifeq ($(KBUILD_EXTMOD),)
 ifeq ($(CONFIG_MMU),y)
 prepare: vdso_prepare
@@ -148,6 +142,9 @@ vdso_prepare: prepare0
 endif
 endif
 
+vdso-install-y			+= arch/riscv/kernel/vdso/vdso.so.dbg
+vdso-install-$(CONFIG_COMPAT)	+= arch/riscv/kernel/compat_vdso/compat_vdso.so.dbg:../compat_vdso/compat_vdso.so
+
 ifneq ($(CONFIG_XIP_KERNEL),y)
 ifeq ($(CONFIG_RISCV_M_MODE)$(CONFIG_ARCH_CANAAN),yy)
 KBUILD_IMAGE := $(boot)/loader.bin

arch/riscv/kernel/compat_vdso/Makefile

@@ -76,13 +76,3 @@ quiet_cmd_compat_vdsold = VDSOLD  $@
 # actual build commands
 quiet_cmd_compat_vdsoas = VDSOAS $@
       cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $<
-
-# install commands for the unstripped file
-quiet_cmd_compat_vdso_install = INSTALL $@
-      cmd_compat_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/compat_vdso/$@
-
-compat_vdso.so: $(obj)/compat_vdso.so.dbg
-	@mkdir -p $(MODLIB)/compat_vdso
-	$(call cmd,compat_vdso_install)
-
-compat_vdso_install: compat_vdso.so

arch/riscv/kernel/vdso/Makefile

@@ -73,13 +73,3 @@ quiet_cmd_vdsold = VDSOLD  $@
       cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
                    $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
                    rm $@.tmp
-
-# 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

arch/s390/Makefile

@@ -138,9 +138,6 @@ bzImage: vmlinux
 zfcpdump:
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/$(ARCH)/kernel/vdso64 $@
-
 archheaders:
 	$(Q)$(MAKE) $(build)=$(syscalls) uapi
 
@@ -160,6 +157,9 @@ vdso_prepare: prepare0
 	$(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
 		$(build)=arch/s390/kernel/vdso32 include/generated/vdso32-offsets.h)
 
+vdso-install-y			+= arch/s390/kernel/vdso64/vdso64.so.dbg
+vdso-install-$(CONFIG_COMPAT)	+= arch/s390/kernel/vdso32/vdso32.so.dbg
+
 ifdef CONFIG_EXPOLINE_EXTERN
 modules_prepare: expoline_prepare
 expoline_prepare: scripts

arch/s390/kernel/vdso32/Makefile

@@ -61,16 +61,6 @@ quiet_cmd_vdso32as = VDSO32A $@
 quiet_cmd_vdso32cc = VDSO32C $@
       cmd_vdso32cc = $(CC) $(c_flags) -c -o $@ $<
 
-# install commands for the unstripped file
-quiet_cmd_vdso_install = INSTALL $@
-      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
-
-vdso32.so: $(obj)/vdso32.so.dbg
-	@mkdir -p $(MODLIB)/vdso
-	$(call cmd,vdso_install)
-
-vdso_install: vdso32.so
-
 # Generate VDSO offsets using helper script
 gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
 quiet_cmd_vdsosym = VDSOSYM $@

arch/s390/kernel/vdso64/Makefile

@@ -70,16 +70,6 @@ quiet_cmd_vdso64as = VDSO64A $@
 quiet_cmd_vdso64cc = VDSO64C $@
       cmd_vdso64cc = $(CC) $(c_flags) -c -o $@ $<
 
-# install commands for the unstripped file
-quiet_cmd_vdso_install = INSTALL $@
-      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
-
-vdso64.so: $(obj)/vdso64.so.dbg
-	@mkdir -p $(MODLIB)/vdso
-	$(call cmd,vdso_install)
-
-vdso_install: vdso64.so
-
 # Generate VDSO offsets using helper script
 gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
 quiet_cmd_vdsosym = VDSOSYM $@

arch/sparc/Makefile

@@ -76,9 +76,8 @@ install:
 archheaders:
 	$(Q)$(MAKE) $(build)=arch/sparc/kernel/syscalls all
 
-PHONY += vdso_install
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/sparc/vdso $@
+vdso-install-$(CONFIG_SPARC64)	+= arch/sparc/vdso/vdso64.so.dbg
+vdso-install-$(CONFIG_COMPAT)	+= arch/sparc/vdso/vdso32.so.dbg
 
 # This is the image used for packaging
 KBUILD_IMAGE := $(boot)/zImage

arch/sparc/vdso/Makefile

@@ -116,30 +116,3 @@ quiet_cmd_vdso = VDSO    $@
 
 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 -Bsymbolic
 GCOV_PROFILE := n
-
-#
-# Install the unstripped copies of vdso*.so.  If our toolchain supports
-# build-id, install .build-id links as well.
-#
-quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
-define cmd_vdso_install
-	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
-	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 "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
-	fi
-endef
-
-vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
-
-$(MODLIB)/vdso: FORCE
-	@mkdir -p $(MODLIB)/vdso
-
-$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
-	$(call cmd,vdso_install)
-
-PHONY += vdso_install $(vdso_img_insttargets)
-vdso_install: $(vdso_img_insttargets) FORCE

arch/x86/Makefile

@@ -291,9 +291,10 @@ PHONY += install
 install:
 	$(call cmd,install)
 
-PHONY += vdso_install
-vdso_install:
-	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
+vdso-install-$(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
 
 archprepare: checkbin
 checkbin:

arch/x86/entry/vdso/Makefile

@@ -190,31 +190,4 @@ GCOV_PROFILE := n
 quiet_cmd_vdso_and_check = VDSO    $@
       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
 
-#
-# Install the unstripped copies of vdso*.so.  If our toolchain supports
-# build-id, install .build-id links as well.
-#
-quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
-define cmd_vdso_install
-	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
-	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 "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
-	fi
-endef
-
-vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
-
-$(MODLIB)/vdso: FORCE
-	@mkdir -p $(MODLIB)/vdso
-
-$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
-	$(call cmd,vdso_install)
-
-PHONY += vdso_install $(vdso_img_insttargets)
-vdso_install: $(vdso_img_insttargets)
-
 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*

scripts/Makefile.vdsoinst

+# SPDX-License-Identifier: GPL-2.0-only
+# ==========================================================================
+# Install unstripped copies of vDSO
+# ==========================================================================
+
+PHONY := __default
+__default:
+	@:
+
+include $(srctree)/scripts/Kbuild.include
+
+install-dir := $(MODLIB)/vdso
+
+define gen_install_rules
+
+src := $$(firstword $$(subst :,$(space),$(1)))
+dest := $(install-dir)/$$(or $$(word 2,$$(subst :,$(space),$(1))),$$(patsubst %.dbg,%,$$(notdir $(1))))
+
+__default: $$(dest)
+$$(dest): $$(src) FORCE
+	$$(call cmd,install)
+
+# Some architectures create .build-id symlinks
+ifneq ($(filter arm sparc x86, $(SRCARCH)),)
+link := $(install-dir)/.build-id/$$(shell $(READELF) -n $$(src) | sed -n 's@^.*Build ID: \(..\)\(.*\)@\1/\2@p')
+
+__default: $$(link)
+$$(link): $$(dest) FORCE
+	$$(call cmd,symlink)
+endif
+
+endef
+
+$(foreach x, $(sort $(INSTALL_FILES)), $(eval $(call gen_install_rules,$(x))))
+
+quiet_cmd_install = INSTALL $@
+      cmd_install = mkdir -p $(dir $@); cp $< $@
+
+quiet_cmd_symlink = SYMLINK $@
+      cmd_symlink = mkdir -p $(dir $@); ln -sf --relative $< $@
+
+PHONY += FORCE
+FORCE:
+
+.PHONY: $(PHONY)