2 # Building vDSO images for x86.
5 KBUILD_CFLAGS
+= $(DISABLE_LTO
)
8 VDSO64-
$(CONFIG_X86_64
) := y
9 VDSOX32-
$(CONFIG_X86_X32_ABI
) := y
10 VDSO32-
$(CONFIG_X86_32
) := y
11 VDSO32-
$(CONFIG_COMPAT
) := y
13 # files to link into the vdso
14 vobjs-y
:= vdso-note.o vclock_gettime.o vgetcpu.o
16 # files to link into kernel
19 # vDSO images to build
20 vdso_img-
$(VDSO64-y
) += 64
21 vdso_img-
$(VDSOX32-y
) += x32
22 vdso_img-
$(VDSO32-y
) += 32-int80
23 vdso_img-
$(CONFIG_COMPAT
) += 32-syscall
24 vdso_img-
$(VDSO32-y
) += 32-sysenter
26 obj-
$(VDSO32-y
) += vdso32-setup.o
28 vobjs
:= $(foreach F
,$(vobjs-y
),$(obj
)/$F)
30 $(obj
)/vdso.o
: $(obj
)/vdso.so
32 targets
+= vdso.lds
$(vobjs-y
)
34 # Build the vDSO image C files and link them in.
35 vdso_img_objs
:= $(vdso_img-y
:%=vdso-image-
%.o
)
36 vdso_img_cfiles
:= $(vdso_img-y
:%=vdso-image-
%.c
)
37 vdso_img_sodbg
:= $(vdso_img-y
:%=vdso
%.so.dbg
)
38 obj-y
+= $(vdso_img_objs
)
39 targets
+= $(vdso_img_cfiles
)
40 targets
+= $(vdso_img_sodbg
)
41 .SECONDARY
: $(vdso_img-y
:%=$(obj
)/vdso-image-
%.c
) \
42 $(vdso_img-y
:%=$(obj
)/vdso
%.so
)
44 export CPPFLAGS_vdso.lds
+= -P
-C
46 VDSO_LDFLAGS_vdso.lds
= -m64
-Wl
,-soname
=linux-vdso.so
.1 \
48 -Wl
,-z
,max-page-size
=4096 -Wl
,-z
,common-page-size
=4096 \
51 $(obj
)/vdso64.so.dbg
: $(src
)/vdso.lds
$(vobjs
) FORCE
52 $(call if_changed
,vdso
)
54 HOST_EXTRACFLAGS
+= -I
$(srctree
)/tools
/include -I
$(srctree
)/include/uapi
57 quiet_cmd_vdso2c
= VDSO2C
$@
59 $(obj
)/vdso2c
$< $(<:%.dbg
=%) $@
62 $(obj
)/vdso-image-
%.c
: $(obj
)/vdso
%.so.dbg
$(obj
)/vdso
%.so
$(obj
)/vdso2c FORCE
63 $(call if_changed
,vdso2c
)
66 # Don't omit frame pointers for ease of userspace debugging, but do
67 # optimize sibling calls.
69 CFL
:= $(PROFILING
) -mcmodel
=small
-fPIC
-O2
-fasynchronous-unwind-tables
-m64 \
70 $(filter -g
%,$(KBUILD_CFLAGS
)) $(call cc-option
, -fno-stack-protector
) \
71 -fno-omit-frame-pointer
-foptimize-sibling-calls \
72 -DDISABLE_BRANCH_PROFILING
74 $(vobjs
): KBUILD_CFLAGS
+= $(CFL
)
77 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
79 CFLAGS_REMOVE_vdso-note.o
= -pg
80 CFLAGS_REMOVE_vclock_gettime.o
= -pg
81 CFLAGS_REMOVE_vgetcpu.o
= -pg
82 CFLAGS_REMOVE_vvar.o
= -pg
85 # X32 processes use x32 vDSO to access 64bit kernel data.
87 # Build x32 vDSO image:
88 # 1. Compile x32 vDSO as 64bit.
89 # 2. Convert object files to x32.
90 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
91 # so that it can reach 64bit address space with 64bit pointers.
94 CPPFLAGS_vdsox32.lds
= $(CPPFLAGS_vdso.lds
)
95 VDSO_LDFLAGS_vdsox32.lds
= -Wl
,-m
,elf32_x86_64 \
96 -Wl
,-soname
=linux-vdso.so
.1 \
97 -Wl
,-z
,max-page-size
=4096 \
98 -Wl
,-z
,common-page-size
=4096
100 # 64-bit objects to re-brand as x32
101 vobjs64-for-x32
:= $(filter-out $(vobjs-nox32
),$(vobjs-y
))
103 # x32-rebranded versions
104 vobjx32s-y
:= $(vobjs64-for-x32
:.o
=-x32.o
)
106 # same thing, but in the output directory
107 vobjx32s
:= $(foreach F
,$(vobjx32s-y
),$(obj
)/$F)
109 # Convert 64bit object file to x32 for x32 vDSO.
110 quiet_cmd_x32
= X32
$@
111 cmd_x32
= $(OBJCOPY
) -O elf32-x86-64
$< $@
113 $(obj
)/%-x32.o
: $(obj
)/%.o FORCE
114 $(call if_changed
,x32
)
116 targets
+= vdsox32.lds
$(vobjx32s-y
)
118 $(obj
)/%.so
: OBJCOPYFLAGS
:= -S
119 $(obj
)/%.so
: $(obj
)/%.so.dbg
120 $(call if_changed
,objcopy
)
122 $(obj
)/vdsox32.so.dbg
: $(src
)/vdsox32.lds
$(vobjx32s
) FORCE
123 $(call if_changed
,vdso
)
126 # Build multiple 32-bit vDSO images to choose from at boot time.
128 vdso32.so-
$(VDSO32-y
) += int80
129 vdso32.so-
$(CONFIG_COMPAT
) += syscall
130 vdso32.so-
$(VDSO32-y
) += sysenter
132 vdso32-images
= $(vdso32.so-y
:%=vdso32-
%.so
)
134 CPPFLAGS_vdso32.lds
= $(CPPFLAGS_vdso.lds
)
135 VDSO_LDFLAGS_vdso32.lds
= -m32
-Wl
,-m
,elf_i386
-Wl
,-soname
=linux-gate.so
.1
137 # This makes sure the $(obj) subdirectory exists even though vdso32/
138 # is not a kbuild sub-make subdirectory.
139 override obj-dirs
= $(dir $(obj
)) $(obj
)/vdso32
/
141 targets
+= vdso32
/vdso32.lds
142 targets
+= vdso32
/note.o vdso32
/vclock_gettime.o
$(vdso32.so-y
:%=vdso32
/%.o
)
143 targets
+= vdso32
/vclock_gettime.o
145 $(obj
)/vdso32.o
: $(vdso32-images
:%=$(obj
)/%)
147 KBUILD_AFLAGS_32
:= $(filter-out -m64
,$(KBUILD_AFLAGS
))
148 $(vdso32-images
:%=$(obj
)/%.dbg
): KBUILD_AFLAGS
= $(KBUILD_AFLAGS_32
)
149 $(vdso32-images
:%=$(obj
)/%.dbg
): asflags-
$(CONFIG_X86_64
) += -m32
151 KBUILD_CFLAGS_32
:= $(filter-out -m64
,$(KBUILD_CFLAGS
))
152 KBUILD_CFLAGS_32
:= $(filter-out -mcmodel
=kernel
,$(KBUILD_CFLAGS_32
))
153 KBUILD_CFLAGS_32
:= $(filter-out -fno-pic
,$(KBUILD_CFLAGS_32
))
154 KBUILD_CFLAGS_32
:= $(filter-out -mfentry
,$(KBUILD_CFLAGS_32
))
155 KBUILD_CFLAGS_32
+= -m32
-msoft-float
-mregparm
=0 -fpic
156 KBUILD_CFLAGS_32
+= $(call cc-option
, -fno-stack-protector
)
157 KBUILD_CFLAGS_32
+= $(call cc-option
, -foptimize-sibling-calls
)
158 KBUILD_CFLAGS_32
+= -fno-omit-frame-pointer
159 KBUILD_CFLAGS_32
+= -DDISABLE_BRANCH_PROFILING
160 $(vdso32-images
:%=$(obj
)/%.dbg
): KBUILD_CFLAGS
= $(KBUILD_CFLAGS_32
)
162 $(vdso32-images
:%=$(obj
)/%.dbg
): $(obj
)/vdso32-
%.so.dbg
: FORCE \
163 $(obj
)/vdso32
/vdso32.lds \
164 $(obj
)/vdso32
/vclock_gettime.o \
165 $(obj
)/vdso32
/note.o \
167 $(call if_changed
,vdso
)
170 # The DSO images are built using a special linker script.
172 quiet_cmd_vdso
= VDSO
$@
173 cmd_vdso
= $(CC
) -nostdlib
-o
$@ \
174 $(VDSO_LDFLAGS
) $(VDSO_LDFLAGS_
$(filter %.lds
,$(^F
))) \
175 -Wl
,-T
,$(filter %.lds
,$^
) $(filter %.o
,$^
) && \
176 sh
$(srctree
)/$(src
)/checkundef.sh
'$(NM)' '$@'
178 VDSO_LDFLAGS
= -fPIC
-shared
$(call cc-ldoption
, -Wl
$(comma
)--hash-style
=sysv
) \
179 $(call cc-ldoption
, -Wl
$(comma
)--build-id
) -Wl
,-Bsymbolic
$(LTO_CFLAGS
)
183 # Install the unstripped copies of vdso*.so. If our toolchain supports
184 # build-id, install .build-id links as well.
186 quiet_cmd_vdso_install
= INSTALL
$(@
:install_
%=%)
187 define cmd_vdso_install
188 cp
$< "$(MODLIB)/vdso/$(@:install_%=%)"; \
189 if readelf
-n
$< |grep
-q
'Build ID'; then \
190 buildid
=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
191 first
=`echo $$buildid | cut -b-2`; \
192 last
=`echo $$buildid | cut -b3-`; \
193 mkdir
-p
"$(MODLIB)/vdso/.build-id/$$first"; \
194 ln
-sf
"../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
198 vdso_img_insttargets
:= $(vdso_img_sodbg
:%.dbg
=install_
%)
200 $(MODLIB
)/vdso
: FORCE
201 @mkdir
-p
$(MODLIB
)/vdso
203 $(vdso_img_insttargets
): install_
%: $(obj
)/%.dbg
$(MODLIB
)/vdso FORCE
204 $(call cmd
,vdso_install
)
206 PHONY
+= vdso_install
$(vdso_img_insttargets
)
207 vdso_install
: $(vdso_img_insttargets
) FORCE
209 clean-files
:= vdso32-syscall
* vdso32-sysenter
* vdso32-int80
* vdso64
* vdso-image-
*.c vdsox32.so
*