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 $(srctree)/lib/vdso/Makefile 8 9# Sanitizer runtimes are unavailable and cannot be linked here. 10KASAN_SANITIZE := n 11KMSAN_SANITIZE_vclock_gettime.o := n 12KMSAN_SANITIZE_vdso32/vclock_gettime.o := n 13KMSAN_SANITIZE_vgetcpu.o := n 14KMSAN_SANITIZE_vdso32/vgetcpu.o := n 15 16UBSAN_SANITIZE := n 17KCSAN_SANITIZE := n 18OBJECT_FILES_NON_STANDARD := y 19 20# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 21KCOV_INSTRUMENT := n 22 23# Files to link into the vDSO: 24vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o 25vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o 26vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o 27vobjs-$(CONFIG_X86_SGX) += vsgx.o 28 29# Files to link into the kernel: 30obj-y += vma.o extable.o 31KASAN_SANITIZE_vma.o := y 32UBSAN_SANITIZE_vma.o := y 33KCSAN_SANITIZE_vma.o := y 34 35OBJECT_FILES_NON_STANDARD_vma.o := n 36OBJECT_FILES_NON_STANDARD_extable.o := n 37 38# vDSO images to build: 39obj-$(CONFIG_X86_64) += vdso-image-64.o 40obj-$(CONFIG_X86_X32_ABI) += vdso-image-x32.o 41obj-$(CONFIG_COMPAT_32) += vdso-image-32.o vdso32-setup.o 42 43OBJECT_FILES_NON_STANDARD_vdso-image-32.o := n 44OBJECT_FILES_NON_STANDARD_vdso-image-64.o := n 45OBJECT_FILES_NON_STANDARD_vdso32-setup.o := n 46 47vobjs := $(addprefix $(obj)/, $(vobjs-y)) 48vobjs32 := $(addprefix $(obj)/, $(vobjs32-y)) 49 50$(obj)/vdso.o: $(obj)/vdso.so 51 52targets += vdso.lds $(vobjs-y) 53targets += vdso32/vdso32.lds $(vobjs32-y) 54 55targets += $(foreach x, 64 x32 32, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg) 56 57CPPFLAGS_vdso.lds += -P -C 58 59VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ 60 -z max-page-size=4096 61 62$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 63 $(call if_changed,vdso_and_check) 64 65HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi 66hostprogs += vdso2c 67 68quiet_cmd_vdso2c = VDSO2C $@ 69 cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@ 70 71$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE 72 $(call if_changed,vdso2c) 73 74# 75# Don't omit frame pointers for ease of userspace debugging, but do 76# optimize sibling calls. 77# 78CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 79 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 80 -fno-omit-frame-pointer -foptimize-sibling-calls \ 81 -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO 82 83ifdef CONFIG_MITIGATION_RETPOLINE 84ifneq ($(RETPOLINE_VDSO_CFLAGS),) 85 CFL += $(RETPOLINE_VDSO_CFLAGS) 86endif 87endif 88 89$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL) 90$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO 91 92# 93# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 94# 95CFLAGS_REMOVE_vclock_gettime.o = -pg 96CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg 97CFLAGS_REMOVE_vgetcpu.o = -pg 98CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg 99CFLAGS_REMOVE_vsgx.o = -pg 100 101# 102# X32 processes use x32 vDSO to access 64bit kernel data. 103# 104# Build x32 vDSO image: 105# 1. Compile x32 vDSO as 64bit. 106# 2. Convert object files to x32. 107# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes 108# so that it can reach 64bit address space with 64bit pointers. 109# 110 111CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) 112VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \ 113 -z max-page-size=4096 114 115# x32-rebranded versions 116vobjx32s-y := $(vobjs-y:.o=-x32.o) 117 118# same thing, but in the output directory 119vobjx32s := $(addprefix $(obj)/, $(vobjx32s-y)) 120 121# Convert 64bit object file to x32 for x32 vDSO. 122quiet_cmd_x32 = X32 $@ 123 cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@ 124 125$(obj)/%-x32.o: $(obj)/%.o FORCE 126 $(call if_changed,x32) 127 128targets += vdsox32.lds $(vobjx32s-y) 129 130$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table 131$(obj)/%.so: $(obj)/%.so.dbg FORCE 132 $(call if_changed,objcopy) 133 134$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE 135 $(call if_changed,vdso_and_check) 136 137CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds) 138VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 139 140KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO 141$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32) 142$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32 143 144KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS)) 145KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32)) 146KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) 147KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) 148KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32)) 149KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) 150KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32)) 151KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32)) 152KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32)) 153KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32)) 154KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic 155KBUILD_CFLAGS_32 += -fno-stack-protector 156KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) 157KBUILD_CFLAGS_32 += -fno-omit-frame-pointer 158KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING 159 160ifdef CONFIG_MITIGATION_RETPOLINE 161ifneq ($(RETPOLINE_VDSO_CFLAGS),) 162 KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS) 163endif 164endif 165 166$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32) 167 168$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE 169 $(call if_changed,vdso_and_check) 170 171# 172# The DSO images are built using a special linker script. 173# 174quiet_cmd_vdso = VDSO $@ 175 cmd_vdso = $(LD) -o $@ \ 176 $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 177 -T $(filter %.lds,$^) $(filter %.o,$^) && \ 178 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' 179 180VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \ 181 $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack 182GCOV_PROFILE := n 183 184quiet_cmd_vdso_and_check = VDSO $@ 185 cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check) 186