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# 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.
#
# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
# the inclusion of generic Makefile.
ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64
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)
# 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