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)/, $(obj-vdso)) 19 20btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti 21 22# -Bsymbolic has been added for consistency with arm, the compat vDSO and 23# potential future proofing if we end up with internal calls to the exported 24# routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so 25# preparation in build-time C")). 26ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ 27 -Bsymbolic --build-id=sha1 -n $(btildflags-y) -T 28 29ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 30ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO 31 32CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) \ 33 $(CC_FLAGS_LTO) 34KASAN_SANITIZE := n 35UBSAN_SANITIZE := n 36OBJECT_FILES_NON_STANDARD := y 37KCOV_INSTRUMENT := n 38 39CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables 40 41ifneq ($(c-gettimeofday-y),) 42 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) 43endif 44 45# Disable gcov profiling for VDSO code 46GCOV_PROFILE := n 47 48targets += vdso.lds 49CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 50 51# Force dependency (incbin is bad) 52$(obj)/vdso.o : $(obj)/vdso.so 53 54# Link rule for the .so file, .lds has to be first 55$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE 56 $(call if_changed,vdsold_and_vdso_check) 57 58# Strip rule for the .so file 59$(obj)/%.so: OBJCOPYFLAGS := -S 60$(obj)/%.so: $(obj)/%.so.dbg FORCE 61 $(call if_changed,objcopy) 62 63# Generate VDSO offsets using helper script 64gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh 65quiet_cmd_vdsosym = VDSOSYM $@ 66 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 67 68include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 69 $(call if_changed,vdsosym) 70 71# Actual build commands 72quiet_cmd_vdsold_and_vdso_check = LD $@ 73 cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) 74 75# Install commands for the unstripped file 76quiet_cmd_vdso_install = INSTALL $@ 77 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ 78 79vdso.so: $(obj)/vdso.so.dbg 80 @mkdir -p $(MODLIB)/vdso 81 $(call cmd,vdso_install) 82 83vdso_install: vdso.so 84