arch/x86/entry/vdso/Makefile

   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.
   7 include $(srctree)/lib/vdso/Makefile
   8
   9 # Sanitizer runtimes are unavailable and cannot be linked here.
  10 KASAN_SANITIZE                  := n
  11 KMSAN_SANITIZE_vclock_gettime.o := n
  12 KMSAN_SANITIZE_vgetcpu.o        := n
  13
  14 UBSAN_SANITIZE                  := n
  15 KCSAN_SANITIZE                  := n
  16 OBJECT_FILES_NON_STANDARD       := y
  17
  18 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
  19 KCOV_INSTRUMENT         := n
  20
  21 VDSO64-$(CONFIG_X86_64)         := y
  22 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
  23 VDSO32-$(CONFIG_X86_32)         := y
  24 VDSO32-$(CONFIG_IA32_EMULATION) := y
  25
  26 # files to link into the vdso
  27 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  28 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
  29 vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o
  30 vobjs-$(CONFIG_X86_SGX) += vsgx.o
  31
  32 # files to link into kernel
  33 obj-y                                   += vma.o extable.o
  34 KASAN_SANITIZE_vma.o                    := y
  35 UBSAN_SANITIZE_vma.o                    := y
  36 KCSAN_SANITIZE_vma.o                    := y
  37 OBJECT_FILES_NON_STANDARD_vma.o         := n
  38 OBJECT_FILES_NON_STANDARD_extable.o     := n
  39
  40 # vDSO images to build
  41 vdso_img-$(VDSO64-y)            += 64
  42 vdso_img-$(VDSOX32-y)           += x32
  43 vdso_img-$(VDSO32-y)            += 32
  44
  45 obj-$(VDSO32-y)                          += vdso32-setup.o
  46 OBJECT_FILES_NON_STANDARD_vdso32-setup.o := n
  47
  48 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  49 vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
  50
  51 $(obj)/vdso.o: $(obj)/vdso.so
  52
  53 targets += vdso.lds $(vobjs-y)
  54 targets += vdso32/vdso32.lds $(vobjs32-y)
  55
  56 # Build the vDSO image C files and link them in.
  57 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  58 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  59 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  60 obj-y += $(vdso_img_objs)
  61 targets += $(vdso_img_cfiles)
  62 targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
  63
  64 CPPFLAGS_vdso.lds += -P -C
  65
  66 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
  67                         -z max-page-size=4096
  68
  69 $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
  70         $(call if_changed,vdso_and_check)
  71
  72 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
  73 hostprogs += vdso2c
  74
  75 quiet_cmd_vdso2c = VDSO2C  $@
  76       cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
  77
  78 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
  79         $(call if_changed,vdso2c)
  80
  81 #
  82 # Don't omit frame pointers for ease of userspace debugging, but do
  83 # optimize sibling calls.
  84 #
  85 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  86        $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
  87        -fno-omit-frame-pointer -foptimize-sibling-calls \
  88        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
  89
  90 ifdef CONFIG_RETPOLINE
  91 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
  92   CFL += $(RETPOLINE_VDSO_CFLAGS)
  93 endif
  94 endif
  95
  96 $(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
  97 $(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
  98
  99 #
 100 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
 101 #
 102 CFLAGS_REMOVE_vclock_gettime.o = -pg
 103 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
 104 CFLAGS_REMOVE_vgetcpu.o = -pg
 105 CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg
 106 CFLAGS_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
 118 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 119 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
 120                            -z max-page-size=4096
 121
 122 # x32-rebranded versions
 123 vobjx32s-y := $(vobjs-y:.o=-x32.o)
 124
 125 # same thing, but in the output directory
 126 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 127
 128 # Convert 64bit object file to x32 for x32 vDSO.
 129 quiet_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
 135 targets += 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
 144 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 145 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 146
 147 KBUILD_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
 151 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 152 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 153 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 154 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 155 KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 156 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 157 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 158 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
 159 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
 160 KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32))
 161 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 162 KBUILD_CFLAGS_32 += -fno-stack-protector
 163 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 164 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 165 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 166
 167 ifdef CONFIG_RETPOLINE
 168 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 169   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 170 endif
 171 endif
 172
 173 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 174
 175 $(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
 176         $(call if_changed,vdso_and_check)
 177
 178 #
 179 # The DSO images are built using a special linker script.
 180 #
 181 quiet_cmd_vdso = VDSO    $@
 182       cmd_vdso = $(LD) -o $@ \
 183                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 184                        -T $(filter %.lds,$^) $(filter %.o,$^) && \
 185                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 186
 187 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 188         $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
 189 GCOV_PROFILE := n
 190
 191 quiet_cmd_vdso_and_check = VDSO    $@
 192       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
 193
 194 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*