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