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 $(srctree)/lib/vdso/Makefile
   8
   9 # Sanitizer runtimes are unavailable and cannot be linked here.
  10 KASAN_SANITIZE                  := n
  11 KMSAN_SANITIZE_vclock_gettime.o := n
  12 KMSAN_SANITIZE_vgetcpu.o        := n
  13
  14 UBSAN_SANITIZE                  := n
  15 KCSAN_SANITIZE                  := n
  16 OBJECT_FILES_NON_STANDARD       := y
  17
  18 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
  19 KCOV_INSTRUMENT         := n
  20
  21 # Files to link into the vDSO:
  22 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  23 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
  24 vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o
  25 vobjs-$(CONFIG_X86_SGX) += vsgx.o
  26
  27 # Files to link into the kernel:
  28 obj-y                                           += vma.o extable.o
  29 KASAN_SANITIZE_vma.o                            := y
  30 UBSAN_SANITIZE_vma.o                            := y
  31 KCSAN_SANITIZE_vma.o                            := y
  32
  33 OBJECT_FILES_NON_STANDARD_vma.o                 := n
  34 OBJECT_FILES_NON_STANDARD_extable.o             := n
  35
  36 # vDSO images to build:
  37 obj-$(CONFIG_X86_64)                            += vdso-image-64.o
  38 obj-$(CONFIG_X86_X32_ABI)                       += vdso-image-x32.o
  39 obj-$(CONFIG_COMPAT_32)                         += vdso-image-32.o vdso32-setup.o
  40
  41 OBJECT_FILES_NON_STANDARD_vdso-image-32.o       := n
  42 OBJECT_FILES_NON_STANDARD_vdso-image-64.o       := n
  43 OBJECT_FILES_NON_STANDARD_vdso32-setup.o        := n
  44
  45 vobjs := $(addprefix $(obj)/, $(vobjs-y))
  46 vobjs32 := $(addprefix $(obj)/, $(vobjs32-y))
  47
  48 $(obj)/vdso.o: $(obj)/vdso.so
  49
  50 targets += vdso.lds $(vobjs-y)
  51 targets += vdso32/vdso32.lds $(vobjs32-y)
  52
  53 targets += $(foreach x, 64 x32 32, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg)
  54
  55 CPPFLAGS_vdso.lds += -P -C
  56
  57 VDSO_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         $(call if_changed,vdso_and_check)
  62
  63 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
  64 hostprogs += vdso2c
  65
  66 quiet_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 #
  76 CFL := $(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
  81 ifdef CONFIG_MITIGATION_RETPOLINE
  82 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
  83   CFL += $(RETPOLINE_VDSO_CFLAGS)
  84 endif
  85 endif
  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 #
  93 CFLAGS_REMOVE_vclock_gettime.o = -pg
  94 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
  95 CFLAGS_REMOVE_vgetcpu.o = -pg
  96 CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg
  97 CFLAGS_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
 109 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 110 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
 111                            -z max-page-size=4096
 112
 113 # x32-rebranded versions
 114 vobjx32s-y := $(vobjs-y:.o=-x32.o)
 115
 116 # same thing, but in the output directory
 117 vobjx32s := $(addprefix $(obj)/, $(vobjx32s-y))
 118
 119 # Convert 64bit object file to x32 for x32 vDSO.
 120 quiet_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
 126 targets += 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
 135 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 136 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 137
 138 KBUILD_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
 142 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 143 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 144 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 145 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 146 KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 147 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 148 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 149 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
 150 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
 151 KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32))
 152 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 153 KBUILD_CFLAGS_32 += -fno-stack-protector
 154 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 155 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 156 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 157
 158 ifdef CONFIG_MITIGATION_RETPOLINE
 159 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 160   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 161 endif
 162 endif
 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 #
 172 quiet_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
 178 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 179         $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
 180 GCOV_PROFILE := n
 181
 182 quiet_cmd_vdso_and_check = VDSO    $@
 183       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)