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 $(srctree)/lib/vdso/Makefile
   8
   9 # Sanitizer runtimes are unavailable and cannot be linked here.
  10 KASAN_SANITIZE                  := n
  11 KMSAN_SANITIZE_vclock_gettime.o := n
  12 KMSAN_SANITIZE_vdso32/vclock_gettime.o  := n
  13 KMSAN_SANITIZE_vgetcpu.o        := n
  14 KMSAN_SANITIZE_vdso32/vgetcpu.o := n
  15
  16 UBSAN_SANITIZE                  := n
  17 KCSAN_SANITIZE                  := n
  18 OBJECT_FILES_NON_STANDARD       := y
  19
  20 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
  21 KCOV_INSTRUMENT         := n
  22
  23 # Files to link into the vDSO:
  24 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  25 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
  26 vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o
  27 vobjs-$(CONFIG_X86_SGX) += vsgx.o
  28
  29 # Files to link into the kernel:
  30 obj-y                                           += vma.o extable.o
  31 KASAN_SANITIZE_vma.o                            := y
  32 UBSAN_SANITIZE_vma.o                            := y
  33 KCSAN_SANITIZE_vma.o                            := y
  34
  35 OBJECT_FILES_NON_STANDARD_vma.o                 := n
  36 OBJECT_FILES_NON_STANDARD_extable.o             := n
  37
  38 # vDSO images to build:
  39 obj-$(CONFIG_X86_64)                            += vdso-image-64.o
  40 obj-$(CONFIG_X86_X32_ABI)                       += vdso-image-x32.o
  41 obj-$(CONFIG_COMPAT_32)                         += vdso-image-32.o vdso32-setup.o
  42
  43 OBJECT_FILES_NON_STANDARD_vdso-image-32.o       := n
  44 OBJECT_FILES_NON_STANDARD_vdso-image-64.o       := n
  45 OBJECT_FILES_NON_STANDARD_vdso32-setup.o        := n
  46
  47 vobjs := $(addprefix $(obj)/, $(vobjs-y))
  48 vobjs32 := $(addprefix $(obj)/, $(vobjs32-y))
  49
  50 $(obj)/vdso.o: $(obj)/vdso.so
  51
  52 targets += vdso.lds $(vobjs-y)
  53 targets += vdso32/vdso32.lds $(vobjs32-y)
  54
  55 targets += $(foreach x, 64 x32 32, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg)
  56
  57 CPPFLAGS_vdso.lds += -P -C
  58
  59 VDSO_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         $(call if_changed,vdso_and_check)
  64
  65 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
  66 hostprogs += vdso2c
  67
  68 quiet_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 #
  78 CFL := $(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
  83 ifdef CONFIG_MITIGATION_RETPOLINE
  84 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
  85   CFL += $(RETPOLINE_VDSO_CFLAGS)
  86 endif
  87 endif
  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 #
  95 CFLAGS_REMOVE_vclock_gettime.o = -pg
  96 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
  97 CFLAGS_REMOVE_vgetcpu.o = -pg
  98 CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg
  99 CFLAGS_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
 111 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 112 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
 113                            -z max-page-size=4096
 114
 115 # x32-rebranded versions
 116 vobjx32s-y := $(vobjs-y:.o=-x32.o)
 117
 118 # same thing, but in the output directory
 119 vobjx32s := $(addprefix $(obj)/, $(vobjx32s-y))
 120
 121 # Convert 64bit object file to x32 for x32 vDSO.
 122 quiet_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
 128 targets += 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
 137 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 138 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 139
 140 KBUILD_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
 144 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 145 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 146 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 147 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 148 KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 149 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 150 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 151 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
 152 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
 153 KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32))
 154 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 155 KBUILD_CFLAGS_32 += -fno-stack-protector
 156 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 157 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 158 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 159
 160 ifdef CONFIG_MITIGATION_RETPOLINE
 161 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 162   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 163 endif
 164 endif
 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 #
 174 quiet_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
 180 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 181         $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
 182 GCOV_PROFILE := n
 183
 184 quiet_cmd_vdso_and_check = VDSO    $@
 185       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)