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)        += $(vdso32-images)
  11
  12
  13 # files to link into the vdso
  14 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  15
  16 # files to link into kernel
  17 obj-$(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 = -m64 -Wl,-soname=linux-vdso.so.1 \
  29                         -Wl,--no-undefined \
  30                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  31
  32 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  33
  34 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  35         $(call if_changed,vdso)
  36
  37 $(obj)/%.so: OBJCOPYFLAGS := -S
  38 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  39         $(call if_changed,objcopy)
  40
  41 #
  42 # Don't omit frame pointers for ease of userspace debugging, but do
  43 # optimize sibling calls.
  44 #
  45 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  46        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  47        -fno-omit-frame-pointer -foptimize-sibling-calls
  48
  49 $(vobjs): KBUILD_CFLAGS += $(CFL)
  50
  51 #
  52 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  53 #
  54 CFLAGS_REMOVE_vdso-note.o = -pg
  55 CFLAGS_REMOVE_vclock_gettime.o = -pg
  56 CFLAGS_REMOVE_vgetcpu.o = -pg
  57 CFLAGS_REMOVE_vvar.o = -pg
  58
  59 targets += vdso-syms.lds
  60 obj-$(VDSO64-y)                 += vdso-syms.lds
  61
  62 #
  63 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  64 #
  65 sed-vdsosym := -e 's/^00*/0/' \
  66         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  67 quiet_cmd_vdsosym = VDSOSYM $@
  68 define cmd_vdsosym
  69         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  70 endef
  71
  72 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  73         $(call if_changed,vdsosym)
  74
  75 #
  76 # Build multiple 32-bit vDSO images to choose from at boot time.
  77 #
  78 obj-$(VDSO32-y)                 += vdso32-syms.lds
  79 vdso32.so-$(VDSO32-y)           += int80
  80 vdso32.so-$(CONFIG_COMPAT)      += syscall
  81 vdso32.so-$(VDSO32-y)           += sysenter
  82
  83 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
  84
  85 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
  86 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-soname=linux-gate.so.1
  87
  88 # This makes sure the $(obj) subdirectory exists even though vdso32/
  89 # is not a kbuild sub-make subdirectory.
  90 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
  91
  92 targets += vdso32/vdso32.lds
  93 targets += $(vdso32-images) $(vdso32-images:=.dbg)
  94 targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
  95
  96 extra-y += $(vdso32-images)
  97
  98 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
  99
 100 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 101 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 102 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 103
 104 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 105                                  $(obj)/vdso32/vdso32.lds \
 106                                  $(obj)/vdso32/note.o \
 107                                  $(obj)/vdso32/%.o
 108         $(call if_changed,vdso)
 109
 110 # Make vdso32-*-syms.lds from each image, and then make sure they match.
 111 # The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
 112
 113 targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
 114
 115 quiet_cmd_vdso32sym = VDSOSYM $@
 116 define cmd_vdso32sym
 117         if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
 118            $(foreach H,$(filter-out FORCE,$^),\
 119                      if grep -q VDSO32_SYSENTER_RETURN $H; \
 120                      then diff -u $(@D)/.tmp_$(@F) $H; \
 121                      else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
 122                           diff -u - $H; fi &&) : ;\
 123         then mv -f $(@D)/.tmp_$(@F) $@; \
 124         else rm -f $(@D)/.tmp_$(@F); exit 1; \
 125         fi
 126 endef
 127
 128 $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 129         $(call if_changed,vdso32sym)
 130
 131 #
 132 # The DSO images are built using a special linker script.
 133 #
 134 quiet_cmd_vdso = VDSO    $@
 135       cmd_vdso = $(CC) -nostdlib -o $@ \
 136                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 137                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 138                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 139
 140 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
 141 GCOV_PROFILE := n
 142
 143 #
 144 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 145 #
 146 quiet_cmd_vdso_install = INSTALL $@
 147       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 148 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 149         @mkdir -p $(MODLIB)/vdso
 150         $(call cmd,vdso_install)
 151
 152 PHONY += vdso_install $(vdso-install-y)
 153 vdso_install: $(vdso-install-y)
 154
 155 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*