mirror of
https://github.com/torvalds/linux
synced 2024-09-20 02:57:25 +00:00
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>
81 lines
2.5 KiB
Makefile
81 lines
2.5 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
#
|
|
# Building a vDSO image for AArch64.
|
|
#
|
|
# Author: Will Deacon <will.deacon@arm.com>
|
|
# Heavily based on the vDSO Makefiles for other archs.
|
|
#
|
|
|
|
# Include the generic Makefile to check the built vdso.
|
|
include $(srctree)/lib/vdso/Makefile
|
|
|
|
obj-vdso := vgettimeofday.o note.o sigreturn.o
|
|
|
|
# Build rules
|
|
targets := $(obj-vdso) vdso.so vdso.so.dbg
|
|
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
|
|
|
|
btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti
|
|
|
|
# -Bsymbolic has been added for consistency with arm, the compat vDSO and
|
|
# potential future proofing if we end up with internal calls to the exported
|
|
# routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
|
|
# preparation in build-time C")).
|
|
ldflags-y := -shared -soname=linux-vdso.so.1 --hash-style=sysv \
|
|
-Bsymbolic --build-id=sha1 -n $(btildflags-y)
|
|
|
|
ifdef CONFIG_LD_ORPHAN_WARN
|
|
ldflags-y += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
|
|
endif
|
|
|
|
ldflags-y += -T
|
|
|
|
ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
|
|
ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
|
|
|
|
# -Wmissing-prototypes and -Wmissing-declarations are removed from
|
|
# the CFLAGS of vgettimeofday.c to make possible to build the
|
|
# kernel with CONFIG_WERROR enabled.
|
|
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \
|
|
$(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) \
|
|
$(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \
|
|
-Wmissing-prototypes -Wmissing-declarations
|
|
KASAN_SANITIZE := n
|
|
KCSAN_SANITIZE := n
|
|
UBSAN_SANITIZE := n
|
|
OBJECT_FILES_NON_STANDARD := y
|
|
KCOV_INSTRUMENT := n
|
|
|
|
CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables
|
|
|
|
ifneq ($(c-gettimeofday-y),)
|
|
CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
|
|
endif
|
|
|
|
# Disable gcov profiling for VDSO code
|
|
GCOV_PROFILE := n
|
|
|
|
targets += vdso.lds
|
|
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
|
|
|
|
# Link rule for the .so file, .lds has to be first
|
|
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
|
|
$(call if_changed,vdsold_and_vdso_check)
|
|
|
|
# Strip rule for the .so file
|
|
$(obj)/%.so: OBJCOPYFLAGS := -S
|
|
$(obj)/%.so: $(obj)/%.so.dbg FORCE
|
|
$(call if_changed,objcopy)
|
|
|
|
# Generate VDSO offsets using helper script
|
|
gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
|
|
quiet_cmd_vdsosym = VDSOSYM $@
|
|
cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
|
|
|
|
include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
|
|
$(call if_changed,vdsosym)
|
|
|
|
# Actual build commands
|
|
quiet_cmd_vdsold_and_vdso_check = LD $@
|
|
cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
|