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