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
  28 # vDSO images to build
  29 vdso_img-$(VDSO64-y)            += 64
  30 vdso_img-$(VDSOX32-y)           += x32
  31 vdso_img-$(VDSO32-y)            += 32-int80
  32 vdso_img-$(CONFIG_COMPAT)       += 32-syscall
  33 vdso_img-$(VDSO32-y)            += 32-sysenter
  34
  35 obj-$(VDSO32-y)                 += vdso32-setup.o
  36
  37 vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
  38
  39 $(obj)/vdso.o: $(obj)/vdso.so
  40
  41 targets += vdso.lds $(vobjs-y)
  42
  43 # Build the vDSO image C files and link them in.
  44 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  45 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  46 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  47 obj-y += $(vdso_img_objs)
  48 targets += $(vdso_img_cfiles)
  49 targets += $(vdso_img_sodbg)
  50 .SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
  51
  52 export CPPFLAGS_vdso.lds += -P -C
  53
  54 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  55                         -Wl,--no-undefined \
  56                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  57                         $(DISABLE_LTO)
  58
  59 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  60         $(call if_changed,vdso)
  61
  62 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
  63 hostprogs-y                     += vdso2c
  64
  65 quiet_cmd_vdso2c = VDSO2C  $@
  66 define cmd_vdso2c
  67         $(obj)/vdso2c $< $@
  68 endef
  69
  70 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
  71         $(call if_changed,vdso2c)
  72
  73 #
  74 # Don't omit frame pointers for ease of userspace debugging, but do
  75 # optimize sibling calls.
  76 #
  77 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  78        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  79        -fno-omit-frame-pointer -foptimize-sibling-calls
  80
  81 $(vobjs): KBUILD_CFLAGS += $(CFL)
  82
  83 #
  84 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  85 #
  86 CFLAGS_REMOVE_vdso-note.o = -pg
  87 CFLAGS_REMOVE_vclock_gettime.o = -pg
  88 CFLAGS_REMOVE_vgetcpu.o = -pg
  89 CFLAGS_REMOVE_vvar.o = -pg
  90
  91 #
  92 # X32 processes use x32 vDSO to access 64bit kernel data.
  93 #
  94 # Build x32 vDSO image:
  95 # 1. Compile x32 vDSO as 64bit.
  96 # 2. Convert object files to x32.
  97 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  98 # so that it can reach 64bit address space with 64bit pointers.
  99 #
 100
 101 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 102 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
 103                            -Wl,-soname=linux-vdso.so.1 \
 104                            -Wl,-z,max-page-size=4096 \
 105                            -Wl,-z,common-page-size=4096
 106
 107 vobjx32s-y := $(vobj64s:.o=-x32.o)
 108 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 109
 110 # Convert 64bit object file to x32 for x32 vDSO.
 111 quiet_cmd_x32 = X32     $@
 112       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 113
 114 $(obj)/%-x32.o: $(obj)/%.o FORCE
 115         $(call if_changed,x32)
 116
 117 targets += vdsox32.lds $(vobjx32s-y)
 118
 119 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 120         $(call if_changed,vdso)
 121
 122 #
 123 # Build multiple 32-bit vDSO images to choose from at boot time.
 124 #
 125 vdso32.so-$(VDSO32-y)           += int80
 126 vdso32.so-$(CONFIG_COMPAT)      += syscall
 127 vdso32.so-$(VDSO32-y)           += sysenter
 128
 129 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
 130
 131 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 132 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
 133
 134 # This makes sure the $(obj) subdirectory exists even though vdso32/
 135 # is not a kbuild sub-make subdirectory.
 136 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 137
 138 targets += vdso32/vdso32.lds
 139 targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
 140 targets += vdso32/vclock_gettime.o
 141
 142 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 143
 144 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 145 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 146 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
 147
 148 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 149 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 150 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 151 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 152 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 153 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 154 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 155 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 156 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 157
 158 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 159                                  $(obj)/vdso32/vdso32.lds \
 160                                  $(obj)/vdso32/vclock_gettime.o \
 161                                  $(obj)/vdso32/note.o \
 162                                  $(obj)/vdso32/%.o
 163         $(call if_changed,vdso)
 164
 165 #
 166 # The DSO images are built using a special linker script.
 167 #
 168 quiet_cmd_vdso = VDSO    $@
 169       cmd_vdso = $(CC) -nostdlib -o $@ \
 170                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 171                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 172                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 173
 174 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 175         -Wl,-Bsymbolic $(LTO_CFLAGS)
 176 GCOV_PROFILE := n
 177
 178 #
 179 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
 180 #
 181 quiet_cmd_vdso_install = INSTALL $@
 182       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
 183 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
 184         @mkdir -p $(MODLIB)/vdso
 185         $(call cmd,vdso_install)
 186
 187 PHONY += vdso_install $(vdso-install-y)
 188 vdso_install: $(vdso-install-y)
 189
 190 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*