arch/x86/entry/vdso/Makefile

   1 #
   2 # Building vDSO images for x86.
   3 #
   4
   5 KBUILD_CFLAGS += $(DISABLE_LTO)
   6 KASAN_SANITIZE                  := n
   7 UBSAN_SANITIZE                  := n
   8 OBJECT_FILES_NON_STANDARD       := y
   9
  10 VDSO64-$(CONFIG_X86_64)         := y
  11 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
  12 VDSO32-$(CONFIG_X86_32)         := y
  13 VDSO32-$(CONFIG_IA32_EMULATION) := y
  14
  15 # files to link into the vdso
  16 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  17
  18 # files to link into kernel
  19 obj-y                           += vma.o
  20 OBJECT_FILES_NON_STANDARD_vma.o := n
  21
  22 # vDSO images to build
  23 vdso_img-$(VDSO64-y)            += 64
  24 vdso_img-$(VDSOX32-y)           += x32
  25 vdso_img-$(VDSO32-y)            += 32
  26
  27 obj-$(VDSO32-y)                 += vdso32-setup.o
  28
  29 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  30
  31 $(obj)/vdso.o: $(obj)/vdso.so
  32
  33 targets += vdso.lds $(vobjs-y)
  34
  35 # Build the vDSO image C files and link them in.
  36 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  37 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  38 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  39 obj-y += $(vdso_img_objs)
  40 targets += $(vdso_img_cfiles)
  41 targets += $(vdso_img_sodbg)
  42 .SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
  43         $(vdso_img-y:%=$(obj)/vdso%.so)
  44
  45 export CPPFLAGS_vdso.lds += -P -C
  46
  47 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  48                         -Wl,--no-undefined \
  49                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  50                         $(DISABLE_LTO)
  51
  52 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  53         $(call if_changed,vdso)
  54
  55 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/x86/include/uapi
  56 hostprogs-y                     += vdso2c
  57
  58 quiet_cmd_vdso2c = VDSO2C  $@
  59 define cmd_vdso2c
  60         $(obj)/vdso2c $< $(<:%.dbg=%) $@
  61 endef
  62
  63 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
  64         $(call if_changed,vdso2c)
  65
  66 #
  67 # Don't omit frame pointers for ease of userspace debugging, but do
  68 # optimize sibling calls.
  69 #
  70 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  71        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  72        -fno-omit-frame-pointer -foptimize-sibling-calls \
  73        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
  74
  75 $(vobjs): KBUILD_CFLAGS += $(CFL)
  76
  77 #
  78 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  79 #
  80 CFLAGS_REMOVE_vdso-note.o = -pg
  81 CFLAGS_REMOVE_vclock_gettime.o = -pg
  82 CFLAGS_REMOVE_vgetcpu.o = -pg
  83 CFLAGS_REMOVE_vvar.o = -pg
  84
  85 #
  86 # X32 processes use x32 vDSO to access 64bit kernel data.
  87 #
  88 # Build x32 vDSO image:
  89 # 1. Compile x32 vDSO as 64bit.
  90 # 2. Convert object files to x32.
  91 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  92 # so that it can reach 64bit address space with 64bit pointers.
  93 #
  94
  95 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
  96 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
  97                            -Wl,-soname=linux-vdso.so.1 \
  98                            -Wl,-z,max-page-size=4096 \
  99                            -Wl,-z,common-page-size=4096
 100
 101 # 64-bit objects to re-brand as x32
 102 vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
 103
 104 # x32-rebranded versions
 105 vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
 106
 107 # same thing, but in the output directory
 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)/%.so: OBJCOPYFLAGS := -S
 120 $(obj)/%.so: $(obj)/%.so.dbg
 121         $(call if_changed,objcopy)
 122
 123 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 124         $(call if_changed,vdso)
 125
 126 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 127 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
 128
 129 # This makes sure the $(obj) subdirectory exists even though vdso32/
 130 # is not a kbuild sub-make subdirectory.
 131 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 132
 133 targets += vdso32/vdso32.lds
 134 targets += vdso32/note.o vdso32/vclock_gettime.o vdso32/system_call.o
 135 targets += vdso32/vclock_gettime.o
 136
 137 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
 138 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 139 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
 140
 141 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 142 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 143 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 144 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 145 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 146 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 147 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 148 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 149 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 150 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 151
 152 $(obj)/vdso32.so.dbg: FORCE \
 153                       $(obj)/vdso32/vdso32.lds \
 154                       $(obj)/vdso32/vclock_gettime.o \
 155                       $(obj)/vdso32/note.o \
 156                       $(obj)/vdso32/system_call.o
 157         $(call if_changed,vdso)
 158
 159 #
 160 # The DSO images are built using a special linker script.
 161 #
 162 quiet_cmd_vdso = VDSO    $@
 163       cmd_vdso = $(CC) -nostdlib -o $@ \
 164                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 165                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 166                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 167
 168 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=both) \
 169         $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
 170 GCOV_PROFILE := n
 171
 172 #
 173 # Install the unstripped copies of vdso*.so.  If our toolchain supports
 174 # build-id, install .build-id links as well.
 175 #
 176 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
 177 define cmd_vdso_install
 178         cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
 179         if readelf -n $< |grep -q 'Build ID'; then \
 180           buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
 181           first=`echo $$buildid | cut -b-2`; \
 182           last=`echo $$buildid | cut -b3-`; \
 183           mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
 184           ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
 185         fi
 186 endef
 187
 188 vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
 189
 190 $(MODLIB)/vdso: FORCE
 191         @mkdir -p $(MODLIB)/vdso
 192
 193 $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
 194         $(call cmd,vdso_install)
 195
 196 PHONY += vdso_install $(vdso_img_insttargets)
 197 vdso_install: $(vdso_img_insttargets) FORCE
 198
 199 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*