1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6# Include the generic Makefile to check the built vdso. 7include $(srctree)/lib/vdso/Makefile 8 9# Sanitizer runtimes are unavailable and cannot be linked here. 10KASAN_SANITIZE := n 11KMSAN_SANITIZE_vclock_gettime.o := n 12KMSAN_SANITIZE_vgetcpu.o := n 13 14UBSAN_SANITIZE := n 15KCSAN_SANITIZE := n 16OBJECT_FILES_NON_STANDARD := y 17 18# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 19KCOV_INSTRUMENT := n 20 21VDSO64-$(CONFIG_X86_64) := y 22VDSOX32-$(CONFIG_X86_X32_ABI) := y 23VDSO32-$(CONFIG_X86_32) := y 24VDSO32-$(CONFIG_IA32_EMULATION) := y 25 26# files to link into the vdso 27vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o 28vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o 29vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o 30vobjs-$(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 38OBJECT_FILES_NON_STANDARD_extable.o := n 39 40# vDSO images to build 41vdso_img-$(VDSO64-y) += 64 42vdso_img-$(VDSOX32-y) += x32 43vdso_img-$(VDSO32-y) += 32 44 45obj-$(VDSO32-y) += vdso32-setup.o 46 47vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 48vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F) 49 50$(obj)/vdso.o: $(obj)/vdso.so 51 52targets += vdso.lds $(vobjs-y) 53targets += vdso32/vdso32.lds $(vobjs32-y) 54 55# Build the vDSO image C files and link them in. 56vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o) 57vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c) 58vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg) 59obj-y += $(vdso_img_objs) 60targets += $(vdso_img_cfiles) 61targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so) 62 63CPPFLAGS_vdso.lds += -P -C 64 65VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ 66 -z max-page-size=4096 67 68$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 69 $(call if_changed,vdso_and_check) 70 71HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi 72hostprogs += vdso2c 73 74quiet_cmd_vdso2c = VDSO2C $@ 75 cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@ 76 77$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE 78 $(call if_changed,vdso2c) 79 80# 81# Don't omit frame pointers for ease of userspace debugging, but do 82# optimize sibling calls. 83# 84CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 85 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 86 -fno-omit-frame-pointer -foptimize-sibling-calls \ 87 -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO 88 89ifdef CONFIG_RETPOLINE 90ifneq ($(RETPOLINE_VDSO_CFLAGS),) 91 CFL += $(RETPOLINE_VDSO_CFLAGS) 92endif 93endif 94 95$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL) 96$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO 97 98# 99# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 100# 101CFLAGS_REMOVE_vclock_gettime.o = -pg 102CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg 103CFLAGS_REMOVE_vgetcpu.o = -pg 104CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg 105CFLAGS_REMOVE_vsgx.o = -pg 106 107# 108# X32 processes use x32 vDSO to access 64bit kernel data. 109# 110# Build x32 vDSO image: 111# 1. Compile x32 vDSO as 64bit. 112# 2. Convert object files to x32. 113# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes 114# so that it can reach 64bit address space with 64bit pointers. 115# 116 117CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) 118VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \ 119 -z max-page-size=4096 120 121# x32-rebranded versions 122vobjx32s-y := $(vobjs-y:.o=-x32.o) 123 124# same thing, but in the output directory 125vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F) 126 127# Convert 64bit object file to x32 for x32 vDSO. 128quiet_cmd_x32 = X32 $@ 129 cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@ 130 131$(obj)/%-x32.o: $(obj)/%.o FORCE 132 $(call if_changed,x32) 133 134targets += vdsox32.lds $(vobjx32s-y) 135 136$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table 137$(obj)/%.so: $(obj)/%.so.dbg FORCE 138 $(call if_changed,objcopy) 139 140$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE 141 $(call if_changed,vdso_and_check) 142 143CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds) 144VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 145 146KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO 147$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32) 148$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32 149 150KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS)) 151KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32)) 152KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) 153KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) 154KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32)) 155KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) 156KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32)) 157KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32)) 158KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32)) 159KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(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 193clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so* 194