1#
  2# Building vDSO images for x86.
  3#
  4
  5VDSO64-$(CONFIG_X86_64)		:= y
  6VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
  7VDSO32-$(CONFIG_X86_32)		:= y
  8VDSO32-$(CONFIG_COMPAT)		:= y
  9
 10vdso-install-$(VDSO64-y)	+= vdso.so
 11vdso-install-$(VDSOX32-y)	+= vdsox32.so
 12vdso-install-$(VDSO32-y)	+= $(vdso32-images)
 13
 14
 15# files to link into the vdso
 16vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
 17
 18vobjs-$(VDSOX32-y) += $(vobjx32s-compat)
 19
 20# Filter out x32 objects.
 21vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
 22
 23# files to link into kernel
 24obj-$(VDSO64-y)			+= vma.o vdso.o
 25obj-$(VDSOX32-y)		+= vdsox32.o
 26obj-$(VDSO32-y)			+= vdso32.o vdso32-setup.o
 27
 28vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
 29
 30$(obj)/vdso.o: $(obj)/vdso.so
 31
 32targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
 33
 34export CPPFLAGS_vdso.lds += -P -C
 35
 36VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
 37			-Wl,--no-undefined \
 38		      	-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
 39
 40$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
 41
 42$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
 43	$(call if_changed,vdso)
 44
 45$(obj)/%.so: OBJCOPYFLAGS := -S
 46$(obj)/%.so: $(obj)/%.so.dbg FORCE
 47	$(call if_changed,objcopy)
 48
 49#
 50# Don't omit frame pointers for ease of userspace debugging, but do
 51# optimize sibling calls.
 52#
 53CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
 54       $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
 55       -fno-omit-frame-pointer -foptimize-sibling-calls
 56
 57$(vobjs): KBUILD_CFLAGS += $(CFL)
 58
 59#
 60# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
 61#
 62CFLAGS_REMOVE_vdso-note.o = -pg
 63CFLAGS_REMOVE_vclock_gettime.o = -pg
 64CFLAGS_REMOVE_vgetcpu.o = -pg
 65CFLAGS_REMOVE_vvar.o = -pg
 66
 67targets += vdso-syms.lds
 68obj-$(VDSO64-y)			+= vdso-syms.lds
 69
 70#
 71# Match symbols in the DSO that look like VDSO*; produce a file of constants.
 72#
 73sed-vdsosym := -e 's/^00*/0/' \
 74	-e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
 75quiet_cmd_vdsosym = VDSOSYM $@
 76define cmd_vdsosym
 77	$(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
 78endef
 79
 80$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
 81	$(call if_changed,vdsosym)
 82
 83#
 84# X32 processes use x32 vDSO to access 64bit kernel data.
 85#
 86# Build x32 vDSO image:
 87# 1. Compile x32 vDSO as 64bit.
 88# 2. Convert object files to x32.
 89# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
 90# so that it can reach 64bit address space with 64bit pointers.
 91#
 92
 93targets += vdsox32-syms.lds
 94obj-$(VDSOX32-y)		+= vdsox32-syms.lds
 95
 96CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 97VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
 98			   -Wl,-soname=linux-vdso.so.1 \
 99			   -Wl,-z,max-page-size=4096 \
100			   -Wl,-z,common-page-size=4096
101
102vobjx32s-y := $(vobj64s:.o=-x32.o)
103vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
104
105# Convert 64bit object file to x32 for x32 vDSO.
106quiet_cmd_x32 = X32     $@
107      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
108
109$(obj)/%-x32.o: $(obj)/%.o FORCE
110	$(call if_changed,x32)
111
112targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
113
114$(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
115
116$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
117	$(call if_changed,vdso)
118
119#
120# Build multiple 32-bit vDSO images to choose from at boot time.
121#
122obj-$(VDSO32-y)			+= vdso32-syms.lds
123vdso32.so-$(VDSO32-y)		+= int80
124vdso32.so-$(CONFIG_COMPAT)	+= syscall
125vdso32.so-$(VDSO32-y)		+= sysenter
126
127vdso32-images			= $(vdso32.so-y:%=vdso32-%.so)
128
129CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
130VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-soname=linux-gate.so.1
131
132# This makes sure the $(obj) subdirectory exists even though vdso32
133# is not a kbuild sub-make subdirectory.
134override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
135
136targets += vdso32/vdso32.lds
137targets += $(vdso32-images) $(vdso32-images:=.dbg)
138targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
139
140extra-y	+= $(vdso32-images)
141
142$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
143
144KBUILD_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$(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
149				 $(obj)/vdso32/vdso32.lds \
150				 $(obj)/vdso32/note.o \
151				 $(obj)/vdso32/%.o
152	$(call if_changed,vdso)
153
154# Make vdso32-*-syms.lds from each image, and then make sure they match.
155# The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
156
157targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
158
159quiet_cmd_vdso32sym = VDSOSYM $@
160define cmd_vdso32sym
161	if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
162	   $(foreach H,$(filter-out FORCE,$^),\
163		     if grep -q VDSO32_SYSENTER_RETURN $H; \
164		     then diff -u $(@D)/.tmp_$(@F) $H; \
165		     else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
166			  diff -u - $H; fi &&) : ;\
167	then mv -f $(@D)/.tmp_$(@F) $@; \
168	else rm -f $(@D)/.tmp_$(@F); exit 1; \
169	fi
170endef
171
172$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
173	$(call if_changed,vdso32sym)
174
175#
176# The DSO images are built using a special linker script.
177#
178quiet_cmd_vdso = VDSO    $@
179      cmd_vdso = $(CC) -nostdlib -o $@ \
180		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
181		       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
182		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
183
184VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
185GCOV_PROFILE := n
186
187#
188# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
189#
190quiet_cmd_vdso_install = INSTALL $@
191      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
192$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
193	@mkdir -p $(MODLIB)/vdso
194	$(call cmd,vdso_install)
195
196PHONY += vdso_install $(vdso-install-y)
197vdso_install: $(vdso-install-y)
198
199clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*