1# SPDX-License-Identifier: GPL-2.0 2# 3# Building a vDSO image for AArch64. 4# 5# Author: Will Deacon <will.deacon@arm.com> 6# Heavily based on the vDSO Makefiles for other archs. 7# 8 9# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before 10# the inclusion of generic Makefile. 11ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64 12include $(srctree)/lib/vdso/Makefile 13 14obj-vdso := vgettimeofday.o note.o sigreturn.o 15 16# Build rules 17targets := $(obj-vdso) vdso.so vdso.so.dbg 18obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) 19 20ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ 21 --build-id -n -T 22 23ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 24ccflags-y += -DDISABLE_BRANCH_PROFILING 25 26VDSO_LDFLAGS := -Bsymbolic 27 28CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os 29KBUILD_CFLAGS += $(DISABLE_LTO) 30KASAN_SANITIZE := n 31UBSAN_SANITIZE := n 32OBJECT_FILES_NON_STANDARD := y 33KCOV_INSTRUMENT := n 34 35CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny 36 37ifneq ($(c-gettimeofday-y),) 38 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) 39endif 40 41# Clang versions less than 8 do not support -mcmodel=tiny 42ifeq ($(CONFIG_CC_IS_CLANG), y) 43 ifeq ($(shell test $(CONFIG_CLANG_VERSION) -lt 80000; echo $$?),0) 44 CFLAGS_REMOVE_vgettimeofday.o += -mcmodel=tiny 45 endif 46endif 47 48# Disable gcov profiling for VDSO code 49GCOV_PROFILE := n 50 51obj-y += vdso.o 52extra-y += vdso.lds 53CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 54 55# Force dependency (incbin is bad) 56$(obj)/vdso.o : $(obj)/vdso.so 57 58# Link rule for the .so file, .lds has to be first 59$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE 60 $(call if_changed,vdsold_and_vdso_check) 61 62# Strip rule for the .so file 63$(obj)/%.so: OBJCOPYFLAGS := -S 64$(obj)/%.so: $(obj)/%.so.dbg FORCE 65 $(call if_changed,objcopy) 66 67# Generate VDSO offsets using helper script 68gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh 69quiet_cmd_vdsosym = VDSOSYM $@ 70 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 71 72include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 73 $(call if_changed,vdsosym) 74 75# Actual build commands 76quiet_cmd_vdsold_and_vdso_check = LD $@ 77 cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) 78 79# Install commands for the unstripped file 80quiet_cmd_vdso_install = INSTALL $@ 81 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ 82 83vdso.so: $(obj)/vdso.so.dbg 84 @mkdir -p $(MODLIB)/vdso 85 $(call cmd,vdso_install) 86 87vdso_install: vdso.so 88