1# SPDX-License-Identifier: GPL-2.0 2# Objects to go into the VDSO. 3 4# Include the generic Makefile to check the built vdso. 5include $(srctree)/lib/vdso/Makefile.include 6 7obj-vdso-y := elf.o vgetcpu.o vgetrandom.o \ 8 vgetrandom-chacha.o sigreturn.o 9obj-vdso-$(CONFIG_GENERIC_GETTIMEOFDAY) += vgettimeofday.o 10 11# Common compiler flags between ABIs. 12ccflags-vdso := \ 13 $(filter -I%,$(KBUILD_CFLAGS)) \ 14 $(filter -E%,$(KBUILD_CFLAGS)) \ 15 $(filter -march=%,$(KBUILD_CFLAGS)) \ 16 $(filter -m%-float,$(KBUILD_CFLAGS)) \ 17 $(CLANG_FLAGS) \ 18 -D__VDSO__ 19 20ifdef CONFIG_32BIT 21ccflags-vdso += -DBUILD_VDSO32 22endif 23 24cflags-vdso := $(ccflags-vdso) \ 25 -isystem $(shell $(CC) -print-file-name=include) \ 26 $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ 27 -std=gnu11 -O2 -g -fno-strict-aliasing -fno-common -fno-builtin \ 28 -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ 29 $(call cc-option, -fno-asynchronous-unwind-tables) \ 30 $(call cc-option, -fno-stack-protector) 31aflags-vdso := $(ccflags-vdso) \ 32 -D__ASSEMBLY__ -Wa,-gdwarf-2 33 34ifneq ($(c-gettimeofday-y),) 35 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) 36endif 37 38ifneq ($(c-getrandom-y),) 39 CFLAGS_vgetrandom.o += -include $(c-getrandom-y) 40endif 41 42# VDSO linker flags. 43ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \ 44 $(filter -E%,$(KBUILD_CFLAGS)) -shared --build-id -T 45 46# 47# Shared build commands. 48# 49 50quiet_cmd_vdsold_and_vdso_check = LD $@ 51 cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) 52 53quiet_cmd_vdsoas_o_S = AS $@ 54 cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $< 55 56# Generate VDSO offsets using helper script 57gen-vdsosym := $(src)/gen_vdso_offsets.sh 58quiet_cmd_vdsosym = VDSOSYM $@ 59 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 60 61include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 62 $(call if_changed,vdsosym) 63 64# 65# Build native VDSO. 66# 67 68native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS)) 69 70targets += $(obj-vdso-y) 71targets += vdso.lds vdso.so.dbg vdso.so 72 73obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o) 74 75$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi) 76$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi) 77 78$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi) 79 80$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE 81 $(call if_changed,vdsold_and_vdso_check) 82 83$(obj)/vdso.so: OBJCOPYFLAGS := -S 84$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE 85 $(call if_changed,objcopy) 86 87obj-y += vdso.o 88 89$(obj)/vdso.o : $(obj)/vdso.so 90