1#
2# Building vDSO images for x86.
3#
4
5VDSO64-$(CONFIG_X86_64)		:= y
6VDSO32-$(CONFIG_X86_32)		:= y
7VDSO32-$(CONFIG_COMPAT)		:= y
8
9vdso-install-$(VDSO64-y)	+= vdso.so
10vdso-install-$(VDSO32-y)	+= $(vdso32-images)
11
12
13# files to link into the vdso
14vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
15
16# files to link into kernel
17obj-$(VDSO64-y)			+= vma.o vdso.o
18obj-$(VDSO32-y)			+= vdso32.o vdso32-setup.o
19
20vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
21
22$(obj)/vdso.o: $(obj)/vdso.so
23
24targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
25
26export CPPFLAGS_vdso.lds += -P -C
27
28VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
29			-Wl,--no-undefined \
30		      	-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
31
32$(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#
45CFL := $(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 += $(CFL)
50
51#
52# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
53#
54CFLAGS_REMOVE_vdso-note.o = -pg
55CFLAGS_REMOVE_vclock_gettime.o = -pg
56CFLAGS_REMOVE_vgetcpu.o = -pg
57CFLAGS_REMOVE_vvar.o = -pg
58
59targets += vdso-syms.lds
60obj-$(VDSO64-y)			+= vdso-syms.lds
61
62#
63# Match symbols in the DSO that look like VDSO*; produce a file of constants.
64#
65sed-vdsosym := -e 's/^00*/0/' \
66	-e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
67quiet_cmd_vdsosym = VDSOSYM $@
68define cmd_vdsosym
69	$(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
70endef
71
72$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
73	$(call if_changed,vdsosym)
74
75#
76# Build multiple 32-bit vDSO images to choose from at boot time.
77#
78obj-$(VDSO32-y)			+= vdso32-syms.lds
79vdso32.so-$(VDSO32-y)		+= int80
80vdso32.so-$(CONFIG_COMPAT)	+= syscall
81vdso32.so-$(VDSO32-y)		+= sysenter
82
83vdso32-images			= $(vdso32.so-y:%=vdso32-%.so)
84
85CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
86VDSO_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.
90override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
91
92targets += vdso32/vdso32.lds
93targets += $(vdso32-images) $(vdso32-images:=.dbg)
94targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
95
96extra-y	+= $(vdso32-images)
97
98$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
99
100KBUILD_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
113targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
114
115quiet_cmd_vdso32sym = VDSOSYM $@
116define 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
126endef
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#
134quiet_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
140VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
141GCOV_PROFILE := n
142
143#
144# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
145#
146quiet_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
152PHONY += vdso_install $(vdso-install-y)
153vdso_install: $(vdso-install-y)
154
155clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*
156