arch/x86/vdso/Makefile

   1 #
   2 # Building vDSO images for x86.
   3 #
   4
   5 VDSO64-$(CONFIG_X86_64)         := y
   6 VDSO32-$(CONFIG_X86_32)         := y
   7 VDSO32-$(CONFIG_COMPAT)         := y
   8
   9 vdso-install-$(VDSO64-y)        += vdso.so
  10 vdso-install-$(VDSO32-y)        += $(vdso32-images)
  11
  12
  13 # files to link into the vdso
  14 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o
  15
  16 # files to link into kernel
  17 obj-$(VDSO64-y)                 += vma.o vdso.o
  18 obj-$(VDSO32-y)                 += vdso32.o vdso32-setup.o
  19
  20 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  21
  22 $(obj)/vdso.o: $(obj)/vdso.so
  23
  24 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  25
  26 export CPPFLAGS_vdso.lds += -P -C
  27
  28 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -Wl,-soname=linux-vdso.so.1 \
  29                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  30
  31 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  32
  33 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  34         $(call if_changed,vdso)
  35
  36 $(obj)/%.so: OBJCOPYFLAGS := -S
  37 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  38         $(call if_changed,objcopy)
  39
  40 CFL := $(PROFILING) -mcmodel=small -fPIC -g0 -O2 -fasynchronous-unwind-tables -m64
  41
  42 $(vobjs): KBUILD_CFLAGS += $(CFL)
  43
  44 targets += vdso-syms.lds
  45 obj-$(VDSO64-y)                 += vdso-syms.lds
  46
  47 #
  48 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  49 #
  50 sed-vdsosym := -e 's/^00*/0/' \
  51         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  52 quiet_cmd_vdsosym = VDSOSYM $@
  53 define cmd_vdsosym
  54         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  55 endef
  56
  57 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  58         $(call if_changed,vdsosym)
  59
  60 #
  61 # Build multiple 32-bit vDSO images to choose from at boot time.
  62 #
  63 obj-$(VDSO32-y)                 += vdso32-syms.lds
  64 vdso32.so-$(CONFIG_X86_32)      += int80
  65 vdso32.so-$(CONFIG_COMPAT)      += syscall
  66 vdso32.so-$(VDSO32-y)           += sysenter
  67
  68 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
  69
  70 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
  71 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -Wl,-soname=linux-gate.so.1
  72
  73 # This makes sure the $(obj) subdirectory exists even though vdso32/
  74 # is not a kbuild sub-make subdirectory.
  75 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
  76
  77 targets += vdso32/vdso32.lds
  78 targets += $(vdso32-images) $(vdso32-images:=.dbg)
  79 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
  80
  81 extra-y += $(vdso32-images)
  82
  83 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
  84
  85 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
  86 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
  87 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
  88
  89 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
  90                                  $(obj)/vdso32/vdso32.lds \
  91                                  $(obj)/vdso32/note.o \
  92                                  $(obj)/vdso32/%.o
  93         $(call if_changed,vdso)
  94
  95 # Make vdso32-*-syms.lds from each image, and then make sure they match.
  96 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
  97
  98 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
  99
 100 quiet_cmd_vdso32sym = VDSOSYM $@
 101 define cmd_vdso32sym
 102         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 103            $(foreach H,$(filter-out FORCE,$^),\
 104                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 105                      then diff -u $(@D)/.tmp_$(@F) $H; \
 106                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 107                           diff -u - $H; fi &&) : ;\
 108         then mv -f $(@D)/.tmp_$(@F) $@; \
 109         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 110         fi
 111 endef
 112
 113 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 114         $(call if_changed,vdso32sym)
 115
 116 #
 117 # The DSO images are built using a special linker script.
 118 #
 119 quiet_cmd_vdso = VDSO    $@
 120       cmd_vdso = $(CC) -nostdlib -o $@ \
 121                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 122                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^)
 123
 124 VDSO_LDFLAGS = -fPIC -shared $(call ld-option, -Wl$(comma)--hash-style=sysv)
 125
 126 #
 127 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 128 #
 129 quiet_cmd_vdso_install = INSTALL $@
 130       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 131 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 132         @mkdir -p $(MODLIB)/vdso
 133         $(call cmd,vdso_install)
 134
 135 PHONY += vdso_install $(vdso-install-y)
 136 vdso_install: $(vdso-install-y)
 137
 138 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*