arch/x86/vdso/Makefile

   1 #
   2 # Building vDSO images for x86.
   3 #
   4
   5 VDSO64-$(CONFIG_X86_64)         := y
   6 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
   7 VDSO32-$(CONFIG_X86_32)         := y
   8 VDSO32-$(CONFIG_COMPAT)         := y
   9
  10 vdso-install-$(VDSO64-y)        += vdso.so
  11 vdso-install-$(VDSOX32-y)       += vdsox32.so
  12 vdso-install-$(VDSO32-y)        += $(vdso32-images)
  13
  14
  15 # files to link into the vdso
  16 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  17
  18 vobjs-$(VDSOX32-y) += $(vobjx32s-compat)
  19
  20 # Filter out x32 objects.
  21 vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
  22
  23 # files to link into kernel
  24 obj-$(VDSO64-y)                 += vma.o vdso.o
  25 obj-$(VDSOX32-y)                += vdsox32.o
  26 obj-$(VDSO32-y)                 += vdso32.o vdso32-setup.o
  27
  28 vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
  29
  30 $(obj)/vdso.o: $(obj)/vdso.so
  31
  32 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  33
  34 export CPPFLAGS_vdso.lds += -P -C
  35
  36 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  37                         -Wl,--no-undefined \
  38                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  39
  40 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  41
  42 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  43         $(call if_changed,vdso)
  44
  45 $(obj)/%.so: OBJCOPYFLAGS := -S
  46 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  47         $(call if_changed,objcopy)
  48
  49 #
  50 # Don't omit frame pointers for ease of userspace debugging, but do
  51 # optimize sibling calls.
  52 #
  53 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  54        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  55        -fno-omit-frame-pointer -foptimize-sibling-calls
  56
  57 $(vobjs): KBUILD_CFLAGS += $(CFL)
  58
  59 #
  60 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  61 #
  62 CFLAGS_REMOVE_vdso-note.o = -pg
  63 CFLAGS_REMOVE_vclock_gettime.o = -pg
  64 CFLAGS_REMOVE_vgetcpu.o = -pg
  65 CFLAGS_REMOVE_vvar.o = -pg
  66
  67 targets += vdso-syms.lds
  68 obj-$(VDSO64-y)                 += vdso-syms.lds
  69
  70 #
  71 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  72 #
  73 sed-vdsosym := -e 's/^00*/0/' \
  74         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  75 quiet_cmd_vdsosym = VDSOSYM $@
  76 define cmd_vdsosym
  77         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  78 endef
  79
  80 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  81         $(call if_changed,vdsosym)
  82
  83 #
  84 # X32 processes use x32 vDSO to access 64bit kernel data.
  85 #
  86 # Build x32 vDSO image:
  87 # 1. Compile x32 vDSO as 64bit.
  88 # 2. Convert object files to x32.
  89 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  90 # so that it can reach 64bit address space with 64bit pointers.
  91 #
  92
  93 targets += vdsox32-syms.lds
  94 obj-$(VDSOX32-y)                += vdsox32-syms.lds
  95
  96 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
  97 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
  98                            -Wl,-soname=linux-vdso.so.1 \
  99                            -Wl,-z,max-page-size=4096 \
 100                            -Wl,-z,common-page-size=4096
 101
 102 vobjx32s-y := $(vobj64s:.o=-x32.o)
 103 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 104
 105 # Convert 64bit object file to x32 for x32 vDSO.
 106 quiet_cmd_x32 = X32     $@
 107       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 108
 109 $(obj)/%-x32.o: $(obj)/%.o FORCE
 110         $(call if_changed,x32)
 111
 112 targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
 113
 114 $(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
 115
 116 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 117         $(call if_changed,vdso)
 118
 119 #
 120 # Build multiple 32-bit vDSO images to choose from at boot time.
 121 #
 122 obj-$(VDSO32-y)                 += vdso32-syms.lds
 123 vdso32.so-$(VDSO32-y)           += int80
 124 vdso32.so-$(CONFIG_COMPAT)      += syscall
 125 vdso32.so-$(VDSO32-y)           += sysenter
 126
 127 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
 128
 129 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 130 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-soname=linux-gate.so.1
 131
 132 # This makes sure the $(obj) subdirectory exists even though vdso32/
 133 # is not a kbuild sub-make subdirectory.
 134 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 135
 136 targets += vdso32/vdso32.lds
 137 targets += $(vdso32-images) $(vdso32-images:=.dbg)
 138 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
 139
 140 extra-y += $(vdso32-images)
 141
 142 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 143
 144 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 145 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 146 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 147
 148 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 149                                  $(obj)/vdso32/vdso32.lds \
 150                                  $(obj)/vdso32/note.o \
 151                                  $(obj)/vdso32/%.o
 152         $(call if_changed,vdso)
 153
 154 # Make vdso32-*-syms.lds from each image, and then make sure they match.
 155 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
 156
 157 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
 158
 159 quiet_cmd_vdso32sym = VDSOSYM $@
 160 define cmd_vdso32sym
 161         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 162            $(foreach H,$(filter-out FORCE,$^),\
 163                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 164                      then diff -u $(@D)/.tmp_$(@F) $H; \
 165                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 166                           diff -u - $H; fi &&) : ;\
 167         then mv -f $(@D)/.tmp_$(@F) $@; \
 168         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 169         fi
 170 endef
 171
 172 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 173         $(call if_changed,vdso32sym)
 174
 175 #
 176 # The DSO images are built using a special linker script.
 177 #
 178 quiet_cmd_vdso = VDSO    $@
 179       cmd_vdso = $(CC) -nostdlib -o $@ \
 180                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 181                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 182                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 183
 184 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
 185 GCOV_PROFILE := n
 186
 187 #
 188 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 189 #
 190 quiet_cmd_vdso_install = INSTALL $@
 191       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 192 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 193         @mkdir -p $(MODLIB)/vdso
 194         $(call cmd,vdso_install)
 195
 196 PHONY += vdso_install $(vdso-install-y)
 197 vdso_install: $(vdso-install-y)
 198
 199 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*