xref: /openbmc/linux/arch/x86/entry/vdso/Makefile (revision a5a92abb) 
1# SPDX-License-Identifier: GPL-2.0
2#
3# Building vDSO images for x86.
4#
5
6KBUILD_CFLAGS += $(DISABLE_LTO)
7KASAN_SANITIZE			:= n
8UBSAN_SANITIZE			:= n
9OBJECT_FILES_NON_STANDARD	:= y
10
11# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
12KCOV_INSTRUMENT		:= n
13
14VDSO64-$(CONFIG_X86_64)		:= y
15VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
16VDSO32-$(CONFIG_X86_32)		:= y
17VDSO32-$(CONFIG_IA32_EMULATION)	:= y
18
19# files to link into the vdso
20vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
21
22# files to link into kernel
23obj-y				+= vma.o
24OBJECT_FILES_NON_STANDARD_vma.o	:= n
25
26# vDSO images to build
27vdso_img-$(VDSO64-y)		+= 64
28vdso_img-$(VDSOX32-y)		+= x32
29vdso_img-$(VDSO32-y)		+= 32
30
31obj-$(VDSO32-y)			+= vdso32-setup.o
32
33vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
34
35$(obj)/vdso.o: $(obj)/vdso.so
36
37targets += vdso.lds $(vobjs-y)
38
39# Build the vDSO image C files and link them in.
40vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
41vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
42vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
43obj-y += $(vdso_img_objs)
44targets += $(vdso_img_cfiles)
45targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
46
47export CPPFLAGS_vdso.lds += -P -C
48
49VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
50			-Wl,--no-undefined \
51			-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
52			$(DISABLE_LTO)
53
54$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
55	$(call if_changed,vdso)
56
57HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
58hostprogs-y			+= vdso2c
59
60quiet_cmd_vdso2c = VDSO2C  $@
61define cmd_vdso2c
62	$(obj)/vdso2c $< $(<:%.dbg=%) $@
63endef
64
65$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
66	$(call if_changed,vdso2c)
67
68#
69# Don't omit frame pointers for ease of userspace debugging, but do
70# optimize sibling calls.
71#
72CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
73       $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
74       -fno-omit-frame-pointer -foptimize-sibling-calls \
75       -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
76
77$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
78
79#
80# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
81#
82CFLAGS_REMOVE_vdso-note.o = -pg
83CFLAGS_REMOVE_vclock_gettime.o = -pg
84CFLAGS_REMOVE_vgetcpu.o = -pg
85CFLAGS_REMOVE_vvar.o = -pg
86
87#
88# X32 processes use x32 vDSO to access 64bit kernel data.
89#
90# Build x32 vDSO image:
91# 1. Compile x32 vDSO as 64bit.
92# 2. Convert object files to x32.
93# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
94# so that it can reach 64bit address space with 64bit pointers.
95#
96
97CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
98VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
99			   -Wl,-soname=linux-vdso.so.1 \
100			   -Wl,-z,max-page-size=4096 \
101			   -Wl,-z,common-page-size=4096
102
103# 64-bit objects to re-brand as x32
104vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))
105
106# x32-rebranded versions
107vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)
108
109# same thing, but in the output directory
110vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
111
112# Convert 64bit object file to x32 for x32 vDSO.
113quiet_cmd_x32 = X32     $@
114      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
115
116$(obj)/%-x32.o: $(obj)/%.o FORCE
117	$(call if_changed,x32)
118
119targets += vdsox32.lds $(vobjx32s-y)
120
121$(obj)/%.so: OBJCOPYFLAGS := -S
122$(obj)/%.so: $(obj)/%.so.dbg
123	$(call if_changed,objcopy)
124
125$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
126	$(call if_changed,vdso)
127
128CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
129VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
130
131targets += vdso32/vdso32.lds
132targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
133targets += vdso32/vclock_gettime.o
134
135KBUILD_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
138
139KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
140KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
141KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
142KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
143KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
144KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
145KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
146KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
147KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
148KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
149$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
150
151$(obj)/vdso32.so.dbg: FORCE \
152		      $(obj)/vdso32/vdso32.lds \
153		      $(obj)/vdso32/vclock_gettime.o \
154		      $(obj)/vdso32/note.o \
155		      $(obj)/vdso32/system_call.o \
156		      $(obj)/vdso32/sigreturn.o
157	$(call if_changed,vdso)
158
159#
160# The DSO images are built using a special linker script.
161#
162quiet_cmd_vdso = VDSO    $@
163      cmd_vdso = $(CC) -nostdlib -o $@ \
164		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
165		       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
166		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
167
168VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=both) \
169	$(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
170GCOV_PROFILE := n
171
172#
173# Install the unstripped copies of vdso*.so.  If our toolchain supports
174# build-id, install .build-id links as well.
175#
176quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
177define cmd_vdso_install
178	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
179	if readelf -n $< |grep -q 'Build ID'; then \
180	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
181	  first=`echo $$buildid | cut -b-2`; \
182	  last=`echo $$buildid | cut -b3-`; \
183	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
184	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
185	fi
186endef
187
188vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
189
190$(MODLIB)/vdso: FORCE
191	@mkdir -p $(MODLIB)/vdso
192
193$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
194	$(call cmd,vdso_install)
195
196PHONY += vdso_install $(vdso_img_insttargets)
197vdso_install: $(vdso_img_insttargets)
198
199clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*
200