Makefile 6.3 KB

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  1. #
  2. # Building vDSO images for x86.
  3. #
  4. KBUILD_CFLAGS += $(DISABLE_LTO)
  5. VDSO64-$(CONFIG_X86_64) := y
  6. VDSOX32-$(CONFIG_X86_X32_ABI) := y
  7. VDSO32-$(CONFIG_X86_32) := y
  8. VDSO32-$(CONFIG_COMPAT) := y
  9. # files to link into the vdso
  10. vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  11. # files to link into kernel
  12. obj-y += vma.o
  13. # vDSO images to build
  14. vdso_img-$(VDSO64-y) += 64
  15. vdso_img-$(VDSOX32-y) += x32
  16. vdso_img-$(VDSO32-y) += 32-int80
  17. vdso_img-$(CONFIG_COMPAT) += 32-syscall
  18. vdso_img-$(VDSO32-y) += 32-sysenter
  19. obj-$(VDSO32-y) += vdso32-setup.o
  20. vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  21. $(obj)/vdso.o: $(obj)/vdso.so
  22. targets += vdso.lds $(vobjs-y)
  23. # Build the vDSO image C files and link them in.
  24. vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  25. vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  26. vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  27. obj-y += $(vdso_img_objs)
  28. targets += $(vdso_img_cfiles)
  29. targets += $(vdso_img_sodbg)
  30. .SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
  31. $(vdso_img-y:%=$(obj)/vdso%.so)
  32. export CPPFLAGS_vdso.lds += -P -C
  33. VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  34. -Wl,--no-undefined \
  35. -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
  36. $(DISABLE_LTO)
  37. $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  38. $(call if_changed,vdso)
  39. HOST_EXTRACFLAGS += -I$(srctree)/tools/include
  40. hostprogs-y += vdso2c
  41. quiet_cmd_vdso2c = VDSO2C $@
  42. define cmd_vdso2c
  43. $(obj)/vdso2c $< $(<:%.dbg=%) $@
  44. endef
  45. $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
  46. $(call if_changed,vdso2c)
  47. #
  48. # Don't omit frame pointers for ease of userspace debugging, but do
  49. # optimize sibling calls.
  50. #
  51. CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  52. $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  53. -fno-omit-frame-pointer -foptimize-sibling-calls \
  54. -DDISABLE_BRANCH_PROFILING
  55. $(vobjs): KBUILD_CFLAGS += $(CFL)
  56. #
  57. # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  58. #
  59. CFLAGS_REMOVE_vdso-note.o = -pg
  60. CFLAGS_REMOVE_vclock_gettime.o = -pg
  61. CFLAGS_REMOVE_vgetcpu.o = -pg
  62. CFLAGS_REMOVE_vvar.o = -pg
  63. #
  64. # X32 processes use x32 vDSO to access 64bit kernel data.
  65. #
  66. # Build x32 vDSO image:
  67. # 1. Compile x32 vDSO as 64bit.
  68. # 2. Convert object files to x32.
  69. # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
  70. # so that it can reach 64bit address space with 64bit pointers.
  71. #
  72. CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
  73. VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
  74. -Wl,-soname=linux-vdso.so.1 \
  75. -Wl,-z,max-page-size=4096 \
  76. -Wl,-z,common-page-size=4096
  77. # 64-bit objects to re-brand as x32
  78. vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
  79. # x32-rebranded versions
  80. vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
  81. # same thing, but in the output directory
  82. vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
  83. # Convert 64bit object file to x32 for x32 vDSO.
  84. quiet_cmd_x32 = X32 $@
  85. cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
  86. $(obj)/%-x32.o: $(obj)/%.o FORCE
  87. $(call if_changed,x32)
  88. targets += vdsox32.lds $(vobjx32s-y)
  89. $(obj)/%.so: OBJCOPYFLAGS := -S
  90. $(obj)/%.so: $(obj)/%.so.dbg
  91. $(call if_changed,objcopy)
  92. $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
  93. $(call if_changed,vdso)
  94. #
  95. # Build multiple 32-bit vDSO images to choose from at boot time.
  96. #
  97. vdso32.so-$(VDSO32-y) += int80
  98. vdso32.so-$(CONFIG_COMPAT) += syscall
  99. vdso32.so-$(VDSO32-y) += sysenter
  100. vdso32-images = $(vdso32.so-y:%=vdso32-%.so)
  101. CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
  102. VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
  103. # This makes sure the $(obj) subdirectory exists even though vdso32/
  104. # is not a kbuild sub-make subdirectory.
  105. override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
  106. targets += vdso32/vdso32.lds
  107. targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
  108. targets += vdso32/vclock_gettime.o
  109. $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
  110. KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
  111. $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
  112. $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32
  113. KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
  114. KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
  115. KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
  116. KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
  117. KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
  118. KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
  119. KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
  120. KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
  121. KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
  122. $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
  123. $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
  124. $(obj)/vdso32/vdso32.lds \
  125. $(obj)/vdso32/vclock_gettime.o \
  126. $(obj)/vdso32/note.o \
  127. $(obj)/vdso32/%.o
  128. $(call if_changed,vdso)
  129. #
  130. # The DSO images are built using a special linker script.
  131. #
  132. quiet_cmd_vdso = VDSO $@
  133. cmd_vdso = $(CC) -nostdlib -o $@ \
  134. $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
  135. -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
  136. sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
  137. VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
  138. $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
  139. GCOV_PROFILE := n
  140. #
  141. # Install the unstripped copies of vdso*.so. If our toolchain supports
  142. # build-id, install .build-id links as well.
  143. #
  144. quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
  145. define cmd_vdso_install
  146. cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
  147. if readelf -n $< |grep -q 'Build ID'; then \
  148. buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
  149. first=`echo $$buildid | cut -b-2`; \
  150. last=`echo $$buildid | cut -b3-`; \
  151. mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
  152. ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
  153. fi
  154. endef
  155. vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
  156. $(MODLIB)/vdso: FORCE
  157. @mkdir -p $(MODLIB)/vdso
  158. $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
  159. $(call cmd,vdso_install)
  160. PHONY += vdso_install $(vdso_img_insttargets)
  161. vdso_install: $(vdso_img_insttargets) FORCE
  162. clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*