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)        += $(vdso32-images)
  15
  16
  17 # files to link into the vdso
  18 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  19
  20 vobjs-$(VDSOX32-y) += $(vobjx32s-compat)
  21
  22 # Filter out x32 objects.
  23 vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
  24
  25 # files to link into kernel
  26 obj-$(VDSO64-y)                 += vma.o vdso.o
  27 obj-$(VDSOX32-y)                += vdsox32.o
  28 obj-$(VDSO32-y)                 += vdso32.o vdso32-setup.o
  29
  30 vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
  31
  32 $(obj)/vdso.o: $(obj)/vdso.so
  33
  34 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  35
  36 export CPPFLAGS_vdso.lds += -P -C
  37
  38 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  39                         -Wl,--no-undefined \
  40                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  41                         $(DISABLE_LTO)
  42
  43 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  44
  45 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  46         $(call if_changed,vdso)
  47
  48 $(obj)/%.so: OBJCOPYFLAGS := -S
  49 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  50         $(call if_changed,objcopy)
  51
  52 #
  53 # Don't omit frame pointers for ease of userspace debugging, but do
  54 # optimize sibling calls.
  55 #
  56 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  57        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  58        -fno-omit-frame-pointer -foptimize-sibling-calls
  59
  60 $(vobjs): KBUILD_CFLAGS += $(CFL)
  61
  62 #
  63 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  64 #
  65 CFLAGS_REMOVE_vdso-note.o = -pg
  66 CFLAGS_REMOVE_vclock_gettime.o = -pg
  67 CFLAGS_REMOVE_vgetcpu.o = -pg
  68 CFLAGS_REMOVE_vvar.o = -pg
  69
  70 targets += vdso-syms.lds
  71 obj-$(VDSO64-y)                 += vdso-syms.lds
  72
  73 #
  74 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  75 #
  76 sed-vdsosym := -e 's/^00*/0/' \
  77         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  78 quiet_cmd_vdsosym = VDSOSYM $@
  79 define cmd_vdsosym
  80         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  81 endef
  82
  83 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  84         $(call if_changed,vdsosym)
  85
  86 #
  87 # X32 processes use x32 vDSO to access 64bit kernel data.
  88 #
  89 # Build x32 vDSO image:
  90 # 1. Compile x32 vDSO as 64bit.
  91 # 2. Convert object files to x32.
  92 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  93 # so that it can reach 64bit address space with 64bit pointers.
  94 #
  95
  96 targets += vdsox32-syms.lds
  97 obj-$(VDSOX32-y)                += vdsox32-syms.lds
  98
  99 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 100 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
 101                            -Wl,-soname=linux-vdso.so.1 \
 102                            -Wl,-z,max-page-size=4096 \
 103                            -Wl,-z,common-page-size=4096
 104
 105 vobjx32s-y := $(vobj64s:.o=-x32.o)
 106 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 107
 108 # Convert 64bit object file to x32 for x32 vDSO.
 109 quiet_cmd_x32 = X32     $@
 110       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 111
 112 $(obj)/%-x32.o: $(obj)/%.o FORCE
 113         $(call if_changed,x32)
 114
 115 targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
 116
 117 $(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
 118
 119 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 120         $(call if_changed,vdso)
 121
 122 #
 123 # Build multiple 32-bit vDSO images to choose from at boot time.
 124 #
 125 obj-$(VDSO32-y)                 += vdso32-syms.lds
 126 vdso32.so-$(VDSO32-y)           += int80
 127 vdso32.so-$(CONFIG_COMPAT)      += syscall
 128 vdso32.so-$(VDSO32-y)           += sysenter
 129
 130 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
 131
 132 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 133 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
 134
 135 # This makes sure the $(obj) subdirectory exists even though vdso32/
 136 # is not a kbuild sub-make subdirectory.
 137 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 138
 139 targets += vdso32/vdso32.lds
 140 targets += $(vdso32-images) $(vdso32-images:=.dbg)
 141 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
 142
 143 extra-y += $(vdso32-images)
 144
 145 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 146
 147 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 148 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 149 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 150
 151 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 152                                  $(obj)/vdso32/vdso32.lds \
 153                                  $(obj)/vdso32/note.o \
 154                                  $(obj)/vdso32/%.o
 155         $(call if_changed,vdso)
 156
 157 # Make vdso32-*-syms.lds from each image, and then make sure they match.
 158 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
 159
 160 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
 161
 162 quiet_cmd_vdso32sym = VDSOSYM $@
 163 define cmd_vdso32sym
 164         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 165            $(foreach H,$(filter-out FORCE,$^),\
 166                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 167                      then diff -u $(@D)/.tmp_$(@F) $H; \
 168                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 169                           diff -u - $H; fi &&) : ;\
 170         then mv -f $(@D)/.tmp_$(@F) $@; \
 171         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 172         fi
 173 endef
 174
 175 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 176         $(call if_changed,vdso32sym)
 177
 178 #
 179 # The DSO images are built using a special linker script.
 180 #
 181 quiet_cmd_vdso = VDSO    $@
 182       cmd_vdso = $(CC) -nostdlib -o $@ \
 183                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 184                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 185                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 186
 187 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 188                 $(LTO_CFLAGS)
 189 GCOV_PROFILE := n
 190
 191 #
 192 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 193 #
 194 quiet_cmd_vdso_install = INSTALL $@
 195       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 196 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 197         @mkdir -p $(MODLIB)/vdso
 198         $(call cmd,vdso_install)
 199
 200 PHONY += vdso_install $(vdso-install-y)
 201 vdso_install: $(vdso-install-y)
 202
 203 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*