2 # Building vDSO images for x86.
5 KBUILD_CFLAGS
+= $(DISABLE_LTO
)
9 VDSO64-
$(CONFIG_X86_64
) := y
10 VDSOX32-
$(CONFIG_X86_X32_ABI
) := y
11 VDSO32-
$(CONFIG_X86_32
) := y
12 VDSO32-
$(CONFIG_IA32_EMULATION
) := y
14 # files to link into the vdso
15 vobjs-y
:= vdso-note.o vclock_gettime.o vgetcpu.o
17 # files to link into kernel
20 # vDSO images to build
21 vdso_img-
$(VDSO64-y
) += 64
22 vdso_img-
$(VDSOX32-y
) += x32
23 vdso_img-
$(VDSO32-y
) += 32
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
) \
41 $(vdso_img-y
:%=$(obj
)/vdso
%.so
)
43 export CPPFLAGS_vdso.lds
+= -P
-C
45 VDSO_LDFLAGS_vdso.lds
= -m64
-Wl
,-soname
=linux-vdso.so
.1 \
47 -Wl
,-z
,max-page-size
=4096 -Wl
,-z
,common-page-size
=4096 \
50 $(obj
)/vdso64.so.dbg
: $(src
)/vdso.lds
$(vobjs
) FORCE
51 $(call if_changed
,vdso
)
53 HOST_EXTRACFLAGS
+= -I
$(srctree
)/tools
/include -I
$(srctree
)/include/uapi
-I
$(srctree
)/arch
/x86
/include/uapi
56 quiet_cmd_vdso2c
= VDSO2C
$@
58 $(obj
)/vdso2c
$< $(<:%.dbg
=%) $@
61 $(obj
)/vdso-image-
%.c
: $(obj
)/vdso
%.so.dbg
$(obj
)/vdso
%.so
$(obj
)/vdso2c FORCE
62 $(call if_changed
,vdso2c
)
65 # Don't omit frame pointers for ease of userspace debugging, but do
66 # optimize sibling calls.
68 CFL
:= $(PROFILING
) -mcmodel
=small
-fPIC
-O2
-fasynchronous-unwind-tables
-m64 \
69 $(filter -g
%,$(KBUILD_CFLAGS
)) $(call cc-option
, -fno-stack-protector
) \
70 -fno-omit-frame-pointer
-foptimize-sibling-calls \
71 -DDISABLE_BRANCH_PROFILING
-DBUILD_VDSO
73 $(vobjs
): KBUILD_CFLAGS
+= $(CFL
)
76 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
78 CFLAGS_REMOVE_vdso-note.o
= -pg
79 CFLAGS_REMOVE_vclock_gettime.o
= -pg
80 CFLAGS_REMOVE_vgetcpu.o
= -pg
81 CFLAGS_REMOVE_vvar.o
= -pg
84 # X32 processes use x32 vDSO to access 64bit kernel data.
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.
93 CPPFLAGS_vdsox32.lds
= $(CPPFLAGS_vdso.lds
)
94 VDSO_LDFLAGS_vdsox32.lds
= -Wl
,-m
,elf32_x86_64 \
95 -Wl
,-soname
=linux-vdso.so
.1 \
96 -Wl
,-z
,max-page-size
=4096 \
97 -Wl
,-z
,common-page-size
=4096
99 # 64-bit objects to re-brand as x32
100 vobjs64-for-x32
:= $(filter-out $(vobjs-nox32
),$(vobjs-y
))
102 # x32-rebranded versions
103 vobjx32s-y
:= $(vobjs64-for-x32
:.o
=-x32.o
)
105 # same thing, but in the output directory
106 vobjx32s
:= $(foreach F
,$(vobjx32s-y
),$(obj
)/$F)
108 # Convert 64bit object file to x32 for x32 vDSO.
109 quiet_cmd_x32
= X32
$@
110 cmd_x32
= $(OBJCOPY
) -O elf32-x86-64
$< $@
112 $(obj
)/%-x32.o
: $(obj
)/%.o FORCE
113 $(call if_changed
,x32
)
115 targets
+= vdsox32.lds
$(vobjx32s-y
)
117 $(obj
)/%.so
: OBJCOPYFLAGS
:= -S
118 $(obj
)/%.so
: $(obj
)/%.so.dbg
119 $(call if_changed
,objcopy
)
121 $(obj
)/vdsox32.so.dbg
: $(src
)/vdsox32.lds
$(vobjx32s
) FORCE
122 $(call if_changed
,vdso
)
124 CPPFLAGS_vdso32.lds
= $(CPPFLAGS_vdso.lds
)
125 VDSO_LDFLAGS_vdso32.lds
= -m32
-Wl
,-m
,elf_i386
-Wl
,-soname
=linux-gate.so
.1
127 # This makes sure the $(obj) subdirectory exists even though vdso32/
128 # is not a kbuild sub-make subdirectory.
129 override obj-dirs
= $(dir $(obj
)) $(obj
)/vdso32
/
131 targets
+= vdso32
/vdso32.lds
132 targets
+= vdso32
/note.o vdso32
/vclock_gettime.o vdso32
/system_call.o
133 targets
+= vdso32
/vclock_gettime.o
135 KBUILD_AFLAGS_32
:= $(filter-out -m64
,$(KBUILD_AFLAGS
)) -DBUILD_VDSO
136 $(obj
)/vdso32.so.dbg
: KBUILD_AFLAGS
= $(KBUILD_AFLAGS_32
)
137 $(obj
)/vdso32.so.dbg
: asflags-
$(CONFIG_X86_64
) += -m32
139 KBUILD_CFLAGS_32
:= $(filter-out -m64
,$(KBUILD_CFLAGS
))
140 KBUILD_CFLAGS_32
:= $(filter-out -mcmodel
=kernel
,$(KBUILD_CFLAGS_32
))
141 KBUILD_CFLAGS_32
:= $(filter-out -fno-pic
,$(KBUILD_CFLAGS_32
))
142 KBUILD_CFLAGS_32
:= $(filter-out -mfentry
,$(KBUILD_CFLAGS_32
))
143 KBUILD_CFLAGS_32
+= -m32
-msoft-float
-mregparm
=0 -fpic
144 KBUILD_CFLAGS_32
+= $(call cc-option
, -fno-stack-protector
)
145 KBUILD_CFLAGS_32
+= $(call cc-option
, -foptimize-sibling-calls
)
146 KBUILD_CFLAGS_32
+= -fno-omit-frame-pointer
147 KBUILD_CFLAGS_32
+= -DDISABLE_BRANCH_PROFILING
148 $(obj
)/vdso32.so.dbg
: KBUILD_CFLAGS
= $(KBUILD_CFLAGS_32
)
150 $(obj
)/vdso32.so.dbg
: FORCE \
151 $(obj
)/vdso32
/vdso32.lds \
152 $(obj
)/vdso32
/vclock_gettime.o \
153 $(obj
)/vdso32
/note.o \
154 $(obj
)/vdso32
/system_call.o
155 $(call if_changed
,vdso
)
158 # The DSO images are built using a special linker script.
160 quiet_cmd_vdso
= VDSO
$@
161 cmd_vdso
= $(CC
) -nostdlib
-o
$@ \
162 $(VDSO_LDFLAGS
) $(VDSO_LDFLAGS_
$(filter %.lds
,$(^F
))) \
163 -Wl
,-T
,$(filter %.lds
,$^
) $(filter %.o
,$^
) && \
164 sh
$(srctree
)/$(src
)/checkundef.sh
'$(NM)' '$@'
166 VDSO_LDFLAGS
= -fPIC
-shared
$(call cc-ldoption
, -Wl
$(comma
)--hash-style
=both
) \
167 $(call cc-ldoption
, -Wl
$(comma
)--build-id
) -Wl
,-Bsymbolic
$(LTO_CFLAGS
)
171 # Install the unstripped copies of vdso*.so. If our toolchain supports
172 # build-id, install .build-id links as well.
174 quiet_cmd_vdso_install
= INSTALL
$(@
:install_
%=%)
175 define cmd_vdso_install
176 cp
$< "$(MODLIB)/vdso/$(@:install_%=%)"; \
177 if readelf
-n
$< |grep
-q
'Build ID'; then \
178 buildid
=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
179 first
=`echo $$buildid | cut -b-2`; \
180 last
=`echo $$buildid | cut -b3-`; \
181 mkdir
-p
"$(MODLIB)/vdso/.build-id/$$first"; \
182 ln
-sf
"../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
186 vdso_img_insttargets
:= $(vdso_img_sodbg
:%.dbg
=install_
%)
188 $(MODLIB
)/vdso
: FORCE
189 @mkdir
-p
$(MODLIB
)/vdso
191 $(vdso_img_insttargets
): install_
%: $(obj
)/%.dbg
$(MODLIB
)/vdso FORCE
192 $(call cmd
,vdso_install
)
194 PHONY
+= vdso_install
$(vdso_img_insttargets
)
195 vdso_install
: $(vdso_img_insttargets
) FORCE
197 clean-files
:= vdso32.so vdso32.so.dbg vdso64
* vdso-image-
*.c vdsox32.so
*