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