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       cmd_vdsosym = $(NM) $< | sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  54
  55 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  56         $(call if_changed,vdsosym)
  57
  58 #
  59 # Build multiple 32-bit vDSO images to choose from at boot time.
  60 #
  61 obj-$(VDSO32-y)                 += vdso32-syms.lds
  62 vdso32.so-$(CONFIG_X86_32)      += int80
  63 vdso32.so-$(CONFIG_COMPAT)      += syscall
  64 vdso32.so-$(VDSO32-y)           += sysenter
  65
  66 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
  67
  68 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
  69 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -Wl,-soname=linux-gate.so.1
  70
  71 # This makes sure the $(obj) subdirectory exists even though vdso32/
  72 # is not a kbuild sub-make subdirectory.
  73 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
  74
  75 targets += vdso32/vdso32.lds
  76 targets += $(vdso32-images) $(vdso32-images:=.dbg)
  77 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
  78
  79 extra-y += $(vdso32-images)
  80
  81 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
  82
  83 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
  84 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
  85 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
  86
  87 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
  88                                  $(obj)/vdso32/vdso32.lds \
  89                                  $(obj)/vdso32/note.o \
  90                                  $(obj)/vdso32/%.o
  91         $(call if_changed,vdso)
  92
  93 # Make vdso32-*-syms.lds from each image, and then make sure they match.
  94 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
  95
  96 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
  97
  98 quiet_cmd_vdso32sym = VDSOSYM $@
  99 define cmd_vdso32sym
 100         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 101            $(foreach H,$(filter-out FORCE,$^),\
 102                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 103                      then diff -u $(@D)/.tmp_$(@F) $H; \
 104                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 105                           diff -u - $H; fi &&) : ;\
 106         then mv -f $(@D)/.tmp_$(@F) $@; \
 107         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 108         fi
 109 endef
 110
 111 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 112         $(call if_changed,vdso32sym)
 113
 114 #
 115 # The DSO images are built using a special linker script.
 116 #
 117 quiet_cmd_vdso = VDSO    $@
 118       cmd_vdso = $(CC) -nostdlib -o $@ \
 119                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 120                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^)
 121
 122 VDSO_LDFLAGS = -fPIC -shared $(call ld-option, -Wl$(comma)--hash-style=sysv)
 123
 124 #
 125 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 126 #
 127 quiet_cmd_vdso_install = INSTALL $@
 128       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 129 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 130         @mkdir -p $(MODLIB)/vdso
 131         $(call cmd,vdso_install)
 132
 133 PHONY += vdso_install $(vdso-install-y)
 134 vdso_install: $(vdso-install-y)
 135
 136 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*