1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before 7# the inclusion of generic Makefile. 8ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE| 9ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE 10include $(srctree)/lib/vdso/Makefile 11 12# Sanitizer runtimes are unavailable and cannot be linked here. 13KASAN_SANITIZE := n 14KMSAN_SANITIZE_vclock_gettime.o := n 15KMSAN_SANITIZE_vgetcpu.o := n 16 17UBSAN_SANITIZE := n 18KCSAN_SANITIZE := n 19OBJECT_FILES_NON_STANDARD := y 20 21# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 22KCOV_INSTRUMENT := n 23 24VDSO64-$(CONFIG_X86_64) := y 25VDSOX32-$(CONFIG_X86_X32_ABI) := y 26VDSO32-$(CONFIG_X86_32) := y 27VDSO32-$(CONFIG_IA32_EMULATION) := y 28 29# files to link into the vdso 30vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o 31vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o 32vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o 33vobjs-$(CONFIG_X86_SGX) += vsgx.o 34 35# files to link into kernel 36obj-y += vma.o extable.o 37KASAN_SANITIZE_vma.o := y 38UBSAN_SANITIZE_vma.o := y 39KCSAN_SANITIZE_vma.o := y 40OBJECT_FILES_NON_STANDARD_vma.o := n 41OBJECT_FILES_NON_STANDARD_extable.o := n 42 43# vDSO images to build 44vdso_img-$(VDSO64-y) += 64 45vdso_img-$(VDSOX32-y) += x32 46vdso_img-$(VDSO32-y) += 32 47 48obj-$(VDSO32-y) += vdso32-setup.o 49 50vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 51vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F) 52 53$(obj)/vdso.o: $(obj)/vdso.so 54 55targets += vdso.lds $(vobjs-y) 56targets += vdso32/vdso32.lds $(vobjs32-y) 57 58# Build the vDSO image C files and link them in. 59vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o) 60vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c) 61vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg) 62obj-y += $(vdso_img_objs) 63targets += $(vdso_img_cfiles) 64targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so) 65 66CPPFLAGS_vdso.lds += -P -C 67 68VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ 69 -z max-page-size=4096 70 71$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 72 $(call if_changed,vdso_and_check) 73 74HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi 75hostprogs += vdso2c 76 77quiet_cmd_vdso2c = VDSO2C $@ 78 cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@ 79 80$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE 81 $(call if_changed,vdso2c) 82 83# 84# Don't omit frame pointers for ease of userspace debugging, but do 85# optimize sibling calls. 86# 87CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 88 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 89 -fno-omit-frame-pointer -foptimize-sibling-calls \ 90 -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO 91 92ifdef CONFIG_RETPOLINE 93ifneq ($(RETPOLINE_VDSO_CFLAGS),) 94 CFL += $(RETPOLINE_VDSO_CFLAGS) 95endif 96endif 97 98$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL) 99$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO 100 101# 102# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 103# 104CFLAGS_REMOVE_vclock_gettime.o = -pg 105CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg 106CFLAGS_REMOVE_vgetcpu.o = -pg 107CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg 108CFLAGS_REMOVE_vsgx.o = -pg 109 110# 111# X32 processes use x32 vDSO to access 64bit kernel data. 112# 113# Build x32 vDSO image: 114# 1. Compile x32 vDSO as 64bit. 115# 2. Convert object files to x32. 116# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes 117# so that it can reach 64bit address space with 64bit pointers. 118# 119 120CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) 121VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \ 122 -z max-page-size=4096 123 124# x32-rebranded versions 125vobjx32s-y := $(vobjs-y:.o=-x32.o) 126 127# same thing, but in the output directory 128vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F) 129 130# Convert 64bit object file to x32 for x32 vDSO. 131quiet_cmd_x32 = X32 $@ 132 cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@ 133 134$(obj)/%-x32.o: $(obj)/%.o FORCE 135 $(call if_changed,x32) 136 137targets += vdsox32.lds $(vobjx32s-y) 138 139$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table 140$(obj)/%.so: $(obj)/%.so.dbg FORCE 141 $(call if_changed,objcopy) 142 143$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE 144 $(call if_changed,vdso_and_check) 145 146CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds) 147VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 148 149KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO 150$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32) 151$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32 152 153KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS)) 154KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32)) 155KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) 156KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) 157KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32)) 158KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) 159KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32)) 160KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32)) 161KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32)) 162KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32)) 163KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic 164KBUILD_CFLAGS_32 += -fno-stack-protector 165KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) 166KBUILD_CFLAGS_32 += -fno-omit-frame-pointer 167KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING 168 169ifdef CONFIG_RETPOLINE 170ifneq ($(RETPOLINE_VDSO_CFLAGS),) 171 KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS) 172endif 173endif 174 175$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32) 176 177$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE 178 $(call if_changed,vdso_and_check) 179 180# 181# The DSO images are built using a special linker script. 182# 183quiet_cmd_vdso = VDSO $@ 184 cmd_vdso = $(LD) -o $@ \ 185 $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 186 -T $(filter %.lds,$^) $(filter %.o,$^) && \ 187 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' 188 189VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \ 190 $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack 191GCOV_PROFILE := n 192 193quiet_cmd_vdso_and_check = VDSO $@ 194 cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check) 195 196# 197# Install the unstripped copies of vdso*.so. If our toolchain supports 198# build-id, install .build-id links as well. 199# 200quiet_cmd_vdso_install = INSTALL $(@:install_%=%) 201define cmd_vdso_install 202 cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \ 203 if readelf -n $< |grep -q 'Build ID'; then \ 204 buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \ 205 first=`echo $$buildid | cut -b-2`; \ 206 last=`echo $$buildid | cut -b3-`; \ 207 mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \ 208 ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \ 209 fi 210endef 211 212vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%) 213 214$(MODLIB)/vdso: FORCE 215 @mkdir -p $(MODLIB)/vdso 216 217$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso 218 $(call cmd,vdso_install) 219 220PHONY += vdso_install $(vdso_img_insttargets) 221vdso_install: $(vdso_img_insttargets) 222 223clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so* 224