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