linux/scripts/Makefile.vdsoinst
Masahiro Yamada 56769ba4b2 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 19514fc665 ("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>
2023-10-28 21:09:02 +09:00

46 lines
1.1 KiB
Makefile

# 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)