xref: /openbmc/linux/arch/x86/entry/vdso/Makefile (revision b96fc2f3) 
1#
2# Building vDSO images for x86.
3#
4
5KBUILD_CFLAGS += $(DISABLE_LTO)
6KASAN_SANITIZE := n
7
8VDSO64-$(CONFIG_X86_64)		:= y
9VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
10VDSO32-$(CONFIG_X86_32)		:= y
11VDSO32-$(CONFIG_IA32_EMULATION)	:= y
12
13# files to link into the vdso
14vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
15
16# files to link into kernel
17obj-y				+= vma.o
18
19# vDSO images to build
20vdso_img-$(VDSO64-y)		+= 64
21vdso_img-$(VDSOX32-y)		+= x32
22vdso_img-$(VDSO32-y)		+= 32-int80
23vdso_img-$(CONFIG_IA32_EMULATION)	+= 32-syscall
24vdso_img-$(VDSO32-y)		+= 32-sysenter
25
26obj-$(VDSO32-y)			+= vdso32-setup.o
27
28vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
29
30$(obj)/vdso.o: $(obj)/vdso.so
31
32targets += vdso.lds $(vobjs-y)
33
34# Build the vDSO image C files and link them in.
35vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
36vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
37vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
38obj-y += $(vdso_img_objs)
39targets += $(vdso_img_cfiles)
40targets += $(vdso_img_sodbg)
41.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
42	$(vdso_img-y:%=$(obj)/vdso%.so)
43
44export CPPFLAGS_vdso.lds += -P -C
45
46VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
47			-Wl,--no-undefined \
48			-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
49			$(DISABLE_LTO)
50
51$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
52	$(call if_changed,vdso)
53
54HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/x86/include/uapi
55hostprogs-y			+= vdso2c
56
57quiet_cmd_vdso2c = VDSO2C  $@
58define cmd_vdso2c
59	$(obj)/vdso2c $< $(<:%.dbg=%) $@
60endef
61
62$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
63	$(call if_changed,vdso2c)
64
65#
66# Don't omit frame pointers for ease of userspace debugging, but do
67# optimize sibling calls.
68#
69CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
70       $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
71       -fno-omit-frame-pointer -foptimize-sibling-calls \
72       -DDISABLE_BRANCH_PROFILING
73
74$(vobjs): KBUILD_CFLAGS += $(CFL)
75
76#
77# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
78#
79CFLAGS_REMOVE_vdso-note.o = -pg
80CFLAGS_REMOVE_vclock_gettime.o = -pg
81CFLAGS_REMOVE_vgetcpu.o = -pg
82CFLAGS_REMOVE_vvar.o = -pg
83
84#
85# X32 processes use x32 vDSO to access 64bit kernel data.
86#
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.
92#
93
94CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
95VDSO_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
99
100# 64-bit objects to re-brand as x32
101vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
102
103# x32-rebranded versions
104vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
105
106# same thing, but in the output directory
107vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
108
109# Convert 64bit object file to x32 for x32 vDSO.
110quiet_cmd_x32 = X32     $@
111      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
112
113$(obj)/%-x32.o: $(obj)/%.o FORCE
114	$(call if_changed,x32)
115
116targets += vdsox32.lds $(vobjx32s-y)
117
118$(obj)/%.so: OBJCOPYFLAGS := -S
119$(obj)/%.so: $(obj)/%.so.dbg
120	$(call if_changed,objcopy)
121
122$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
123	$(call if_changed,vdso)
124
125#
126# Build multiple 32-bit vDSO images to choose from at boot time.
127#
128vdso32.so-$(VDSO32-y)		+= int80
129vdso32.so-$(CONFIG_IA32_EMULATION)	+= syscall
130vdso32.so-$(VDSO32-y)		+= sysenter
131
132vdso32-images			= $(vdso32.so-y:%=vdso32-%.so)
133
134CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
135VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
136
137# This makes sure the $(obj) subdirectory exists even though vdso32/
138# is not a kbuild sub-make subdirectory.
139override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
140
141targets += vdso32/vdso32.lds
142targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
143targets += vdso32/vclock_gettime.o
144
145$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
146
147KBUILD_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
150
151KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
152KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
153KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
154KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
155KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
156KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
157KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
158KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
159KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
160$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
161
162$(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 \
166				 $(obj)/vdso32/%.o
167	$(call if_changed,vdso)
168
169#
170# The DSO images are built using a special linker script.
171#
172quiet_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 '$(NM)' '$@'
177
178VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=both) \
179	$(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
180GCOV_PROFILE := n
181
182#
183# Install the unstripped copies of vdso*.so.  If our toolchain supports
184# build-id, install .build-id links as well.
185#
186quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
187define 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"; \
195	fi
196endef
197
198vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
199
200$(MODLIB)/vdso: FORCE
201	@mkdir -p $(MODLIB)/vdso
202
203$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
204	$(call cmd,vdso_install)
205
206PHONY += vdso_install $(vdso_img_insttargets)
207vdso_install: $(vdso_img_insttargets) FORCE
208
209clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80* vdso64* vdso-image-*.c vdsox32.so*
210