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)        += $(vdso32-y:=.so)
  11
  12
  13 # files to link into the vdso
  14 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o
  15
  16 # files to link into kernel
  17 obj-$(VDSO64-y)                 += vma.o vdso.o
  18 obj-$(CONFIG_X86_32)            += 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 # The DSO images are built using a special linker script.
  27 quiet_cmd_syscall = SYSCALL $@
  28       cmd_syscall = $(CC) -m elf_x86_64 -nostdlib $(SYSCFLAGS_$(@F)) \
  29                           -Wl,-T,$(filter-out FORCE,$^) -o $@
  30
  31 export CPPFLAGS_vdso.lds += -P -C
  32
  33 vdso-flags = -fPIC -shared -Wl,-soname=linux-vdso.so.1 \
  34                  $(call ld-option, -Wl$(comma)--hash-style=sysv) \
  35                 -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  36 SYSCFLAGS_vdso.so = $(vdso-flags)
  37 SYSCFLAGS_vdso.so.dbg = $(vdso-flags)
  38
  39 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  40
  41 $(obj)/vdso.so: $(src)/vdso.lds $(vobjs) FORCE
  42
  43 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  44         $(call if_changed,syscall)
  45
  46 $(obj)/%.so: OBJCOPYFLAGS := -S
  47 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  48         $(call if_changed,objcopy)
  49
  50 CFL := $(PROFILING) -mcmodel=small -fPIC -g0 -O2 -fasynchronous-unwind-tables -m64
  51
  52 $(obj)/vclock_gettime.o: KBUILD_CFLAGS = $(CFL)
  53 $(obj)/vgetcpu.o: KBUILD_CFLAGS = $(CFL)
  54
  55 targets += vdso-syms.lds
  56 obj-$(VDSO64-y)                 += vdso-syms.lds
  57
  58 #
  59 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  60 #
  61 sed-vdsosym := -e 's/^00*/0/' \
  62         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  63 quiet_cmd_vdsosym = VDSOSYM $@
  64       cmd_vdsosym = $(NM) $< | sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  65
  66 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  67         $(call if_changed,vdsosym)
  68
  69 #
  70 # Build multiple 32-bit vDSO images to choose from at boot time.
  71 #
  72 obj-$(VDSO32-y)                 += vdso32-syms.lds
  73 vdso32.so-$(CONFIG_X86_32)      += int80
  74 vdso32.so-$(CONFIG_COMPAT)      += syscall
  75 vdso32.so-$(VDSO32-y)           += sysenter
  76
  77 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
  78 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -Wl,-soname=linux-gate.so.1
  79
  80 # This makes sure the $(obj) subdirectory exists even though vdso32/
  81 # is not a kbuild sub-make subdirectory.
  82 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
  83
  84 targets += vdso32/vdso32.lds
  85 targets += $(vdso32.so-y:%=vdso32-%.so.dbg) $(vdso32.so-y:%=vdso32-%.so)
  86 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
  87
  88 extra-y += $(vdso32.so-y:%=vdso32-%.so)
  89
  90 $(obj)/vdso32.o: $(vdso32.so-y:%=$(obj)/vdso32-%.so)
  91
  92 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
  93 $(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
  94 $(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): asflags-$(CONFIG_X86_64) += -m32
  95
  96 $(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
  97                                          $(obj)/vdso32/vdso32.lds \
  98                                          $(obj)/vdso32/note.o \
  99                                          $(obj)/vdso32/%.o
 100         $(call if_changed,vdso)
 101
 102 # Make vdso32-*-syms.lds from each image, and then make sure they match.
 103 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
 104
 105 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
 106
 107 quiet_cmd_vdso32sym = VDSOSYM $@
 108 define cmd_vdso32sym
 109         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 110            $(foreach H,$(filter-out FORCE,$^),\
 111                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 112                      then diff -u $(@D)/.tmp_$(@F) $H; \
 113                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 114                           diff -u - $H; fi &&) : ;\
 115         then mv -f $(@D)/.tmp_$(@F) $@; \
 116         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 117         fi
 118 endef
 119
 120 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 121         $(call if_changed,vdso32sym)
 122
 123 #
 124 # The DSO images are built using a special linker script.
 125 #
 126 quiet_cmd_vdso = VDSO    $@
 127       cmd_vdso = $(CC) -nostdlib -o $@ \
 128                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 129                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^)
 130
 131 VDSO_LDFLAGS = -fPIC -shared $(call ld-option, -Wl$(comma)--hash-style=sysv)
 132
 133 #
 134 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 135 #
 136 quiet_cmd_vdso_install = INSTALL $@
 137       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 138 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 139         @mkdir -p $(MODLIB)/vdso
 140         $(call cmd,vdso_install)
 141
 142 PHONY += vdso_install $(vdso-install-y)
 143 vdso_install: $(vdso-install-y)