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 $(filter -m32,$(KBUILD_CFLAGS)) \ 16 $(filter -m64,$(KBUILD_CFLAGS)) \ 17 $(filter -march=%,$(KBUILD_CFLAGS)) \ 18 $(filter -m%-float,$(KBUILD_CFLAGS)) \ 19 $(CLANG_FLAGS) \ 20 -D__VDSO__ 21 22ifdef CONFIG_32BIT 23ccflags-vdso += -DBUILD_VDSO32 24endif 25 26cflags-vdso := $(ccflags-vdso) \ 27 -isystem $(shell $(CC) -print-file-name=include) \ 28 $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ 29 $(CC_FLAGS_DIALECT) -O2 -g -fno-strict-aliasing -fno-common -fno-builtin \ 30 -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ 31 $(call cc-option, -fasynchronous-unwind-tables) \ 32 $(call cc-option, -fno-stack-protector) 33aflags-vdso := $(ccflags-vdso) \ 34 -D__ASSEMBLY__ -Wa,-gdwarf-2 35 36ifneq ($(c-gettimeofday-y),) 37 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) 38endif 39 40ifneq ($(c-getrandom-y),) 41 CFLAGS_vgetrandom.o += -include $(c-getrandom-y) 42endif 43 44# VDSO linker flags. 45ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \ 46 $(filter -E%,$(KBUILD_CFLAGS)) -shared --build-id --eh-frame-hdr -T 47 48# 49# Shared build commands. 50# 51 52quiet_cmd_vdsold_and_vdso_check = LD $@ 53 cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) 54 55quiet_cmd_vdsoas_o_S = AS $@ 56 cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $< 57 58# Generate VDSO offsets using helper script 59gen-vdsosym := $(src)/gen_vdso_offsets.sh 60quiet_cmd_vdsosym = VDSOSYM $@ 61 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 62 63include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 64 $(call if_changed,vdsosym) 65 66# 67# Build native VDSO. 68# 69 70native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS)) 71 72targets += $(obj-vdso-y) 73targets += vdso.lds vdso.so.dbg vdso.so 74 75obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o) 76 77$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi) 78$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi) 79 80$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi) 81 82$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE 83 $(call if_changed,vdsold_and_vdso_check) 84 85$(obj)/vdso.so: OBJCOPYFLAGS := -S 86$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE 87 $(call if_changed,objcopy) 88 89obj-y += vdso.o 90 91$(obj)/vdso.o : $(obj)/vdso.so 92