2 # Building vDSO images for x86.
5 KBUILD_CFLAGS
+= $(DISABLE_LTO
)
7 VDSO64-
$(CONFIG_X86_64
) := y
8 VDSOX32-
$(CONFIG_X86_X32_ABI
) := y
9 VDSO32-
$(CONFIG_X86_32
) := y
10 VDSO32-
$(CONFIG_COMPAT
) := y
12 # files to link into the vdso
13 vobjs-y
:= vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o
15 # files to link into kernel
18 # vDSO images to build
19 vdso_img-
$(VDSO64-y
) += 64
20 vdso_img-
$(VDSOX32-y
) += x32
21 vdso_img-
$(VDSO32-y
) += 32-int80
22 vdso_img-
$(CONFIG_COMPAT
) += 32-syscall
23 vdso_img-
$(VDSO32-y
) += 32-sysenter
25 obj-
$(VDSO32-y
) += vdso32-setup.o
27 vobjs
:= $(foreach F
,$(vobjs-y
),$(obj
)/$F)
29 $(obj
)/vdso.o
: $(obj
)/vdso.so
31 targets
+= vdso.lds
$(vobjs-y
)
33 # Build the vDSO image C files and link them in.
34 vdso_img_objs
:= $(vdso_img-y
:%=vdso-image-
%.o
)
35 vdso_img_cfiles
:= $(vdso_img-y
:%=vdso-image-
%.c
)
36 vdso_img_sodbg
:= $(vdso_img-y
:%=vdso
%.so.dbg
)
37 obj-y
+= $(vdso_img_objs
)
38 targets
+= $(vdso_img_cfiles
)
39 targets
+= $(vdso_img_sodbg
)
40 .SECONDARY
: $(vdso_img-y
:%=$(obj
)/vdso-image-
%.c
)
42 export CPPFLAGS_vdso.lds
+= -P
-C
44 VDSO_LDFLAGS_vdso.lds
= -m64
-Wl
,-soname
=linux-vdso.so
.1 \
46 -Wl
,-z
,max-page-size
=4096 -Wl
,-z
,common-page-size
=4096 \
49 $(obj
)/vdso64.so.dbg
: $(src
)/vdso.lds
$(vobjs
) FORCE
50 $(call if_changed
,vdso
)
52 HOST_EXTRACFLAGS
+= -I
$(srctree
)/tools
/include
55 quiet_cmd_vdso2c
= VDSO2C
$@
60 $(obj
)/vdso-image-
%.c
: $(obj
)/vdso
%.so.dbg
$(obj
)/vdso2c FORCE
61 $(call if_changed
,vdso2c
)
64 # Don't omit frame pointers for ease of userspace debugging, but do
65 # optimize sibling calls.
67 CFL
:= $(PROFILING
) -mcmodel
=small
-fPIC
-O2
-fasynchronous-unwind-tables
-m64 \
68 $(filter -g
%,$(KBUILD_CFLAGS
)) $(call cc-option
, -fno-stack-protector
) \
69 -fno-omit-frame-pointer
-foptimize-sibling-calls \
70 -DDISABLE_BRANCH_PROFILING
72 $(vobjs
): KBUILD_CFLAGS
+= $(CFL
)
75 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
77 CFLAGS_REMOVE_vdso-note.o
= -pg
78 CFLAGS_REMOVE_vclock_gettime.o
= -pg
79 CFLAGS_REMOVE_vgetcpu.o
= -pg
80 CFLAGS_REMOVE_vvar.o
= -pg
83 # X32 processes use x32 vDSO to access 64bit kernel data.
85 # Build x32 vDSO image:
86 # 1. Compile x32 vDSO as 64bit.
87 # 2. Convert object files to x32.
88 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
89 # so that it can reach 64bit address space with 64bit pointers.
92 CPPFLAGS_vdsox32.lds
= $(CPPFLAGS_vdso.lds
)
93 VDSO_LDFLAGS_vdsox32.lds
= -Wl
,-m
,elf32_x86_64 \
94 -Wl
,-soname
=linux-vdso.so
.1 \
95 -Wl
,-z
,max-page-size
=4096 \
96 -Wl
,-z
,common-page-size
=4096
98 # 64-bit objects to re-brand as x32
99 vobjs64-for-x32
:= $(filter-out $(vobjs-nox32
),$(vobjs-y
))
101 # x32-rebranded versions
102 vobjx32s-y
:= $(vobjs64-for-x32
:.o
=-x32.o
)
104 # same thing, but in the output directory
105 vobjx32s
:= $(foreach F
,$(vobjx32s-y
),$(obj
)/$F)
107 # Convert 64bit object file to x32 for x32 vDSO.
108 quiet_cmd_x32
= X32
$@
109 cmd_x32
= $(OBJCOPY
) -O elf32-x86-64
$< $@
111 $(obj
)/%-x32.o
: $(obj
)/%.o FORCE
112 $(call if_changed
,x32
)
114 targets
+= vdsox32.lds
$(vobjx32s-y
)
116 $(obj
)/vdsox32.so.dbg
: $(src
)/vdsox32.lds
$(vobjx32s
) FORCE
117 $(call if_changed
,vdso
)
120 # Build multiple 32-bit vDSO images to choose from at boot time.
122 vdso32.so-
$(VDSO32-y
) += int80
123 vdso32.so-
$(CONFIG_COMPAT
) += syscall
124 vdso32.so-
$(VDSO32-y
) += sysenter
126 vdso32-images
= $(vdso32.so-y
:%=vdso32-
%.so
)
128 CPPFLAGS_vdso32.lds
= $(CPPFLAGS_vdso.lds
)
129 VDSO_LDFLAGS_vdso32.lds
= -m32
-Wl
,-m
,elf_i386
-Wl
,-soname
=linux-gate.so
.1
131 # This makes sure the $(obj) subdirectory exists even though vdso32/
132 # is not a kbuild sub-make subdirectory.
133 override obj-dirs
= $(dir $(obj
)) $(obj
)/vdso32
/
135 targets
+= vdso32
/vdso32.lds
136 targets
+= vdso32
/note.o vdso32
/vclock_gettime.o
$(vdso32.so-y
:%=vdso32
/%.o
)
137 targets
+= vdso32
/vclock_gettime.o vdso32
/vdso-fakesections.o
139 $(obj
)/vdso32.o
: $(vdso32-images
:%=$(obj
)/%)
141 KBUILD_AFLAGS_32
:= $(filter-out -m64
,$(KBUILD_AFLAGS
))
142 $(vdso32-images
:%=$(obj
)/%.dbg
): KBUILD_AFLAGS
= $(KBUILD_AFLAGS_32
)
143 $(vdso32-images
:%=$(obj
)/%.dbg
): asflags-
$(CONFIG_X86_64
) += -m32
145 KBUILD_CFLAGS_32
:= $(filter-out -m64
,$(KBUILD_CFLAGS
))
146 KBUILD_CFLAGS_32
:= $(filter-out -mcmodel
=kernel
,$(KBUILD_CFLAGS_32
))
147 KBUILD_CFLAGS_32
:= $(filter-out -fno-pic
,$(KBUILD_CFLAGS_32
))
148 KBUILD_CFLAGS_32
:= $(filter-out -mfentry
,$(KBUILD_CFLAGS_32
))
149 KBUILD_CFLAGS_32
+= -m32
-msoft-float
-mregparm
=0 -fpic
150 KBUILD_CFLAGS_32
+= $(call cc-option
, -fno-stack-protector
)
151 KBUILD_CFLAGS_32
+= $(call cc-option
, -foptimize-sibling-calls
)
152 KBUILD_CFLAGS_32
+= -fno-omit-frame-pointer
153 KBUILD_CFLAGS_32
+= -DDISABLE_BRANCH_PROFILING
154 $(vdso32-images
:%=$(obj
)/%.dbg
): KBUILD_CFLAGS
= $(KBUILD_CFLAGS_32
)
156 $(vdso32-images
:%=$(obj
)/%.dbg
): $(obj
)/vdso32-
%.so.dbg
: FORCE \
157 $(obj
)/vdso32
/vdso32.lds \
158 $(obj
)/vdso32
/vclock_gettime.o \
159 $(obj
)/vdso32
/vdso-fakesections.o \
160 $(obj
)/vdso32
/note.o \
162 $(call if_changed
,vdso
)
165 # The DSO images are built using a special linker script.
167 quiet_cmd_vdso
= VDSO
$@
168 cmd_vdso
= $(CC
) -nostdlib
-o
$@ \
169 $(VDSO_LDFLAGS
) $(VDSO_LDFLAGS_
$(filter %.lds
,$(^F
))) \
170 -Wl
,-T
,$(filter %.lds
,$^
) $(filter %.o
,$^
) && \
171 sh
$(srctree
)/$(src
)/checkundef.sh
'$(NM)' '$@'
173 VDSO_LDFLAGS
= -fPIC
-shared
$(call cc-ldoption
, -Wl
$(comma
)--hash-style
=sysv
) \
174 $(call cc-ldoption
, -Wl
$(comma
)--build-id
) -Wl
,-Bsymbolic
$(LTO_CFLAGS
)
178 # Install the unstripped copies of vdso*.so. If our toolchain supports
179 # build-id, install .build-id links as well.
181 quiet_cmd_vdso_install
= INSTALL
$(@
:install_
%=%)
182 define cmd_vdso_install
183 cp
$< "$(MODLIB)/vdso/$(@:install_%=%)"; \
184 if readelf
-n
$< |grep
-q
'Build ID'; then \
185 buildid
=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
186 first
=`echo $$buildid | cut -b-2`; \
187 last
=`echo $$buildid | cut -b3-`; \
188 mkdir
-p
"$(MODLIB)/vdso/.build-id/$$first"; \
189 ln
-sf
"../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
193 vdso_img_insttargets
:= $(vdso_img_sodbg
:%.dbg
=install_
%)
195 $(MODLIB
)/vdso
: FORCE
196 @mkdir
-p
$(MODLIB
)/vdso
198 $(vdso_img_insttargets
): install_
%: $(obj
)/%.dbg
$(MODLIB
)/vdso FORCE
199 $(call cmd
,vdso_install
)
201 PHONY
+= vdso_install
$(vdso_img_insttargets
)
202 vdso_install
: $(vdso_img_insttargets
) FORCE
204 clean-files
:= vdso32-syscall
* vdso32-sysenter
* vdso32-int80
*