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56769ba4b2
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>
66 lines
1.8 KiB
Makefile
66 lines
1.8 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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# Include the generic Makefile to check the built vdso.
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include $(srctree)/lib/vdso/Makefile
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hostprogs := vdsomunge
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obj-vdso := vgettimeofday.o datapage.o note.o
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# Build rules
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targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
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obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
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ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector
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ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO32
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ldflags-$(CONFIG_CPU_ENDIAN_BE8) := --be8
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ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
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-z max-page-size=4096 -shared $(ldflags-y) \
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--hash-style=sysv --build-id=sha1 \
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-T
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obj-$(CONFIG_VDSO) += vdso.o
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CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
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CFLAGS_REMOVE_vdso.o = -pg
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# Force -O2 to avoid libgcc dependencies
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CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS)
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ifeq ($(c-gettimeofday-y),)
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CFLAGS_vgettimeofday.o = -O2
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else
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CFLAGS_vgettimeofday.o = -O2 -include $(c-gettimeofday-y)
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endif
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# Disable gcov profiling for VDSO code
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GCOV_PROFILE := n
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UBSAN_SANITIZE := n
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# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
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KCOV_INSTRUMENT := n
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KASAN_SANITIZE := n
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# Force dependency
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$(obj)/vdso.o : $(obj)/vdso.so
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# Link rule for the .so file
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$(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
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$(call if_changed,vdsold_and_vdso_check)
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$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
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$(call if_changed,vdsomunge)
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# Strip rule for the .so file
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$(obj)/%.so: OBJCOPYFLAGS := -S
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$(obj)/%.so: $(obj)/%.so.dbg FORCE
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$(call if_changed,objcopy)
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# Actual build commands
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quiet_cmd_vdsold_and_vdso_check = LD $@
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cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
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quiet_cmd_vdsomunge = MUNGE $@
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cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
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