1693c819fSH. Peter Anvin# SPDX-License-Identifier: GPL-2.0 2693c819fSH. Peter Anvin# 3693c819fSH. Peter Anvin# Building vDSO images for x86. 4693c819fSH. Peter Anvin# 5693c819fSH. Peter Anvin 6693c819fSH. Peter Anvin# Include the generic Makefile to check the built vDSO: 7693c819fSH. Peter Anvininclude $(srctree)/lib/vdso/Makefile.include 8693c819fSH. Peter Anvin 9693c819fSH. Peter Anvinobj-y += $(foreach x,$(vdsos-y),vdso$(x)-image.o) 10693c819fSH. Peter Anvin 11693c819fSH. Peter Anvintargets += $(foreach x,$(vdsos-y),vdso$(x)-image.c vdso$(x).so vdso$(x).so.dbg vdso$(x).lds) 12693c819fSH. Peter Anvintargets += $(vobjs-y) 13693c819fSH. Peter Anvin 14693c819fSH. Peter Anvin# vobjs-y with $(obj)/ prepended 15693c819fSH. Peter Anvinvobjs := $(addprefix $(obj)/,$(vobjs-y)) 16693c819fSH. Peter Anvin 17693c819fSH. Peter Anvin# Options for vdso*.lds 18693c819fSH. Peter AnvinCPPFLAGS_VDSO_LDS := -P -C -I$(src)/.. 19693c819fSH. Peter Anvin$(obj)/%.lds : KBUILD_CPPFLAGS += $(CPPFLAGS_VDSO_LDS) 20693c819fSH. Peter Anvin 21693c819fSH. Peter Anvin# 22693c819fSH. Peter Anvin# Options from KBUILD_[AC]FLAGS that should *NOT* be kept 23693c819fSH. Peter Anvin# 24693c819fSH. Peter Anvinflags-remove-y += \ 25693c819fSH. Peter Anvin -D__KERNEL__ -mcmodel=kernel -mregparm=3 \ 26*a48acbafSH. Peter Anvin -fno-pic -fno-PIC -fno-pie -fno-PIE \ 27693c819fSH. Peter Anvin -mfentry -pg \ 28*a48acbafSH. Peter Anvin $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(KSTACK_ERASE_CFLAGS) \ 29693c819fSH. Peter Anvin $(RETPOLINE_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ 30693c819fSH. Peter Anvin $(PADDING_CFLAGS) 31693c819fSH. Peter Anvin 32693c819fSH. Peter Anvin# 33693c819fSH. Peter Anvin# Don't omit frame pointers for ease of userspace debugging, but do 34693c819fSH. Peter Anvin# optimize sibling calls. 35693c819fSH. Peter Anvin# 36693c819fSH. Peter Anvinflags-y += -D__DISABLE_EXPORTS 37693c819fSH. Peter Anvinflags-y += -DDISABLE_BRANCH_PROFILING 38693c819fSH. Peter Anvinflags-y += -DBUILD_VDSO 39693c819fSH. Peter Anvinflags-y += -I$(src)/.. -I$(srctree) 40693c819fSH. Peter Anvinflags-y += -O2 -fpic 41693c819fSH. Peter Anvinflags-y += -fno-stack-protector 42693c819fSH. Peter Anvinflags-y += -fno-omit-frame-pointer 43693c819fSH. Peter Anvinflags-y += -foptimize-sibling-calls 44693c819fSH. Peter Anvinflags-y += -fasynchronous-unwind-tables 45693c819fSH. Peter Anvin 46693c819fSH. Peter Anvin# Reset cf protections enabled by compiler default 47693c819fSH. Peter Anvinflags-y += $(call cc-option, -fcf-protection=none) 48693c819fSH. Peter Anvinflags-$(X86_USER_SHADOW_STACK) += $(call cc-option, -fcf-protection=return) 49693c819fSH. Peter Anvin# When user space IBT is supported, enable this. 50693c819fSH. Peter Anvin# flags-$(CONFIG_USER_IBT) += $(call cc-option, -fcf-protection=branch) 51693c819fSH. Peter Anvin 52693c819fSH. Peter Anvinflags-$(CONFIG_MITIGATION_RETPOLINE) += $(RETPOLINE_VDSO_CFLAGS) 53693c819fSH. Peter Anvin 54693c819fSH. Peter Anvin# These need to be conditional on $(vobjs) as they do not apply to 55693c819fSH. Peter Anvin# the output vdso*-image.o files which are standard kernel objects. 56693c819fSH. Peter Anvin$(vobjs) : KBUILD_AFLAGS := \ 57693c819fSH. Peter Anvin $(filter-out $(flags-remove-y),$(KBUILD_AFLAGS)) $(flags-y) 58693c819fSH. Peter Anvin$(vobjs) : KBUILD_CFLAGS := \ 59693c819fSH. Peter Anvin $(filter-out $(flags-remove-y),$(KBUILD_CFLAGS)) $(flags-y) 60693c819fSH. Peter Anvin 61693c819fSH. Peter Anvin# 62693c819fSH. Peter Anvin# The VDSO images are built using a special linker script. 63693c819fSH. Peter Anvin# 64693c819fSH. Peter AnvinVDSO_LDFLAGS := -shared --hash-style=both --build-id=sha1 --no-undefined \ 65693c819fSH. Peter Anvin $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack 66693c819fSH. Peter Anvin 67693c819fSH. Peter Anvinquiet_cmd_vdso = VDSO $@ 68693c819fSH. Peter Anvin cmd_vdso = $(LD) -o $@ \ 69693c819fSH. Peter Anvin $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$*) \ 70693c819fSH. Peter Anvin -T $(filter %.lds,$^) $(filter %.o,$^) 71693c819fSH. Peter Anvinquiet_cmd_vdso_and_check = VDSO $@ 72693c819fSH. Peter Anvin cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check) 73693c819fSH. Peter Anvin 74693c819fSH. Peter Anvin$(obj)/vdso%.so.dbg: $(obj)/vdso%.lds FORCE 75693c819fSH. Peter Anvin $(call if_changed,vdso_and_check) 76693c819fSH. Peter Anvin 77693c819fSH. Peter Anvin$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table 78693c819fSH. Peter Anvin$(obj)/%.so: $(obj)/%.so.dbg FORCE 79693c819fSH. Peter Anvin $(call if_changed,objcopy) 80693c819fSH. Peter Anvin 81693c819fSH. Peter AnvinVDSO2C = $(objtree)/arch/x86/tools/vdso2c 82693c819fSH. Peter Anvin 83693c819fSH. Peter Anvinquiet_cmd_vdso2c = VDSO2C $@ 84693c819fSH. Peter Anvin cmd_vdso2c = $(VDSO2C) $< $(<:%.dbg=%) $@ 85693c819fSH. Peter Anvin 86693c819fSH. Peter Anvin$(obj)/%-image.c: $(obj)/%.so.dbg $(obj)/%.so $(VDSO2C) FORCE 87693c819fSH. Peter Anvin $(call if_changed,vdso2c) 88693c819fSH. Peter Anvin 89693c819fSH. Peter Anvin$(obj)/%-image.o: $(obj)/%-image.c 90