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-y                           += vma.o
  27 obj-$(VDSO64-y)                 += vdso.o
  28 obj-$(VDSOX32-y)                += vdsox32.o
  29 obj-$(VDSO32-y)                 += vdso32.o vdso32-setup.o
  30
  31 vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
  32
  33 $(obj)/vdso.o: $(obj)/vdso.so
  34
  35 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  36
  37 export CPPFLAGS_vdso.lds += -P -C
  38
  39 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  40                         -Wl,--no-undefined \
  41                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  42                         $(DISABLE_LTO)
  43
  44 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  45
  46 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  47         $(call if_changed,vdso)
  48
  49 $(obj)/%.so: OBJCOPYFLAGS := -S
  50 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  51         $(call if_changed,objcopy)
  52
  53 #
  54 # Don't omit frame pointers for ease of userspace debugging, but do
  55 # optimize sibling calls.
  56 #
  57 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  58        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  59        -fno-omit-frame-pointer -foptimize-sibling-calls
  60
  61 $(vobjs): KBUILD_CFLAGS += $(CFL)
  62
  63 #
  64 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  65 #
  66 CFLAGS_REMOVE_vdso-note.o = -pg
  67 CFLAGS_REMOVE_vclock_gettime.o = -pg
  68 CFLAGS_REMOVE_vgetcpu.o = -pg
  69 CFLAGS_REMOVE_vvar.o = -pg
  70
  71 targets += vdso-syms.lds
  72 obj-$(VDSO64-y)                 += vdso-syms.lds
  73
  74 #
  75 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  76 #
  77 sed-vdsosym := -e 's/^00*/0/' \
  78         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  79 quiet_cmd_vdsosym = VDSOSYM $@
  80 define cmd_vdsosym
  81         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  82 endef
  83
  84 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  85         $(call if_changed,vdsosym)
  86
  87 #
  88 # X32 processes use x32 vDSO to access 64bit kernel data.
  89 #
  90 # Build x32 vDSO image:
  91 # 1. Compile x32 vDSO as 64bit.
  92 # 2. Convert object files to x32.
  93 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  94 # so that it can reach 64bit address space with 64bit pointers.
  95 #
  96
  97 targets += vdsox32-syms.lds
  98 obj-$(VDSOX32-y)                += vdsox32-syms.lds
  99
 100 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 101 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
 102                            -Wl,-soname=linux-vdso.so.1 \
 103                            -Wl,-z,max-page-size=4096 \
 104                            -Wl,-z,common-page-size=4096
 105
 106 vobjx32s-y := $(vobj64s:.o=-x32.o)
 107 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 108
 109 # Convert 64bit object file to x32 for x32 vDSO.
 110 quiet_cmd_x32 = X32     $@
 111       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 112
 113 $(obj)/%-x32.o: $(obj)/%.o FORCE
 114         $(call if_changed,x32)
 115
 116 targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
 117
 118 $(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
 119
 120 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 121         $(call if_changed,vdso)
 122
 123 #
 124 # Build multiple 32-bit vDSO images to choose from at boot time.
 125 #
 126 obj-$(VDSO32-y)                 += vdso32-syms.lds
 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-images) $(vdso32-images:=.dbg)
 142 targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
 143
 144 extra-y += $(vdso32-images)
 145
 146 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 147
 148 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 149 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 150 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 151
 152 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 153 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 154 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 155 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 156 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 157 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 158 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 159 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 160 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 161
 162 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 163                                  $(obj)/vdso32/vdso32.lds \
 164                                  $(obj)/vdso32/vclock_gettime.o \
 165                                  $(obj)/vdso32/note.o \
 166                                  $(obj)/vdso32/%.o
 167         $(call if_changed,vdso)
 168
 169 # Make vdso32-*-syms.lds from each image, and then make sure they match.
 170 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
 171
 172 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
 173
 174 quiet_cmd_vdso32sym = VDSOSYM $@
 175 define cmd_vdso32sym
 176         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 177            $(foreach H,$(filter-out FORCE,$^),\
 178                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 179                      then diff -u $(@D)/.tmp_$(@F) $H; \
 180                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 181                           diff -u - $H; fi &&) : ;\
 182         then mv -f $(@D)/.tmp_$(@F) $@; \
 183         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 184         fi
 185 endef
 186
 187 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 188         $(call if_changed,vdso32sym)
 189
 190 #
 191 # The DSO images are built using a special linker script.
 192 #
 193 quiet_cmd_vdso = VDSO    $@
 194       cmd_vdso = $(CC) -nostdlib -o $@ \
 195                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 196                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 197                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 198
 199 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 200                 $(LTO_CFLAGS)
 201 GCOV_PROFILE := n
 202
 203 #
 204 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 205 #
 206 quiet_cmd_vdso_install = INSTALL $@
 207       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 208 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 209         @mkdir -p $(MODLIB)/vdso
 210         $(call cmd,vdso_install)
 211
 212 PHONY += vdso_install $(vdso-install-y)
 213 vdso_install: $(vdso-install-y)
 214
 215 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*