arch/x86/vdso/Makefile

   1 #
   2 # Building vDSO images for x86.
   3 #
   4
   5 KBUILD_CFLAGS += $(DISABLE_LTO)
   6
   7 VDSO64-$(CONFIG_X86_64)         := y
   8 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
   9 VDSO32-$(CONFIG_X86_32)         := y
  10 VDSO32-$(CONFIG_COMPAT)         := y
  11
  12 # files to link into the vdso
  13 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o
  14 vobjs-nox32 := vdso-fakesections.o
  15
  16 # files to link into kernel
  17 obj-y                           += vma.o
  18
  19 # vDSO images to build
  20 vdso_img-$(VDSO64-y)            += 64
  21 vdso_img-$(VDSOX32-y)           += x32
  22 vdso_img-$(VDSO32-y)            += 32-int80
  23 vdso_img-$(CONFIG_COMPAT)       += 32-syscall
  24 vdso_img-$(VDSO32-y)            += 32-sysenter
  25
  26 obj-$(VDSO32-y)                 += vdso32-setup.o
  27
  28 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  29
  30 $(obj)/vdso.o: $(obj)/vdso.so
  31
  32 targets += vdso.lds $(vobjs-y)
  33
  34 # Build the vDSO image C files and link them in.
  35 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  36 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  37 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  38 obj-y += $(vdso_img_objs)
  39 targets += $(vdso_img_cfiles)
  40 targets += $(vdso_img_sodbg)
  41 .SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
  42
  43 export CPPFLAGS_vdso.lds += -P -C
  44
  45 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  46                         -Wl,--no-undefined \
  47                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  48                         $(DISABLE_LTO)
  49
  50 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  51         $(call if_changed,vdso)
  52
  53 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
  54 hostprogs-y                     += vdso2c
  55
  56 quiet_cmd_vdso2c = VDSO2C  $@
  57 define cmd_vdso2c
  58         $(obj)/vdso2c $< $@
  59 endef
  60
  61 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
  62         $(call if_changed,vdso2c)
  63
  64 #
  65 # Don't omit frame pointers for ease of userspace debugging, but do
  66 # optimize sibling calls.
  67 #
  68 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  69        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  70        -fno-omit-frame-pointer -foptimize-sibling-calls
  71
  72 $(vobjs): KBUILD_CFLAGS += $(CFL)
  73
  74 #
  75 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  76 #
  77 CFLAGS_REMOVE_vdso-note.o = -pg
  78 CFLAGS_REMOVE_vclock_gettime.o = -pg
  79 CFLAGS_REMOVE_vgetcpu.o = -pg
  80 CFLAGS_REMOVE_vvar.o = -pg
  81
  82 #
  83 # X32 processes use x32 vDSO to access 64bit kernel data.
  84 #
  85 # Build x32 vDSO image:
  86 # 1. Compile x32 vDSO as 64bit.
  87 # 2. Convert object files to x32.
  88 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  89 # so that it can reach 64bit address space with 64bit pointers.
  90 #
  91
  92 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
  93 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
  94                            -Wl,-soname=linux-vdso.so.1 \
  95                            -Wl,-z,max-page-size=4096 \
  96                            -Wl,-z,common-page-size=4096
  97
  98 # 64-bit objects to re-brand as x32
  99 vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
 100
 101 # x32-rebranded versions
 102 vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
 103
 104 # same thing, but in the output directory
 105 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 106
 107 # Convert 64bit object file to x32 for x32 vDSO.
 108 quiet_cmd_x32 = X32     $@
 109       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 110
 111 $(obj)/%-x32.o: $(obj)/%.o FORCE
 112         $(call if_changed,x32)
 113
 114 targets += vdsox32.lds $(vobjx32s-y)
 115
 116 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 117         $(call if_changed,vdso)
 118
 119 #
 120 # Build multiple 32-bit vDSO images to choose from at boot time.
 121 #
 122 vdso32.so-$(VDSO32-y)           += int80
 123 vdso32.so-$(CONFIG_COMPAT)      += syscall
 124 vdso32.so-$(VDSO32-y)           += sysenter
 125
 126 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
 127
 128 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 129 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
 130
 131 # This makes sure the $(obj) subdirectory exists even though vdso32/
 132 # is not a kbuild sub-make subdirectory.
 133 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 134
 135 targets += vdso32/vdso32.lds
 136 targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
 137 targets += vdso32/vclock_gettime.o
 138
 139 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 140
 141 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 142 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 143 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 144
 145 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 146 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 147 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 148 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 149 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 150 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 151 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 152 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 153 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 154
 155 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 156                                  $(obj)/vdso32/vdso32.lds \
 157                                  $(obj)/vdso32/vclock_gettime.o \
 158                                  $(obj)/vdso32/note.o \
 159                                  $(obj)/vdso32/%.o
 160         $(call if_changed,vdso)
 161
 162 #
 163 # The DSO images are built using a special linker script.
 164 #
 165 quiet_cmd_vdso = VDSO    $@
 166       cmd_vdso = $(CC) -nostdlib -o $@ \
 167                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 168                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 169                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 170
 171 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 172         -Wl,-Bsymbolic $(LTO_CFLAGS)
 173 GCOV_PROFILE := n
 174
 175 #
 176 # Install the unstripped copies of vdso*.so.
 177 #
 178 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
 179       cmd_vdso_install = cp $< $(MODLIB)/vdso/$(@:install_%=%)
 180
 181 vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
 182
 183 $(MODLIB)/vdso: FORCE
 184         @mkdir -p $(MODLIB)/vdso
 185
 186 $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
 187         $(call cmd,vdso_install)
 188
 189 PHONY += vdso_install $(vdso_img_insttargets)
 190 vdso_install: $(vdso_img_insttargets) FORCE
 191
 192 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*