xref: /openbmc/linux/arch/x86/entry/vdso/Makefile (revision a9d85efb) 
1# SPDX-License-Identifier: GPL-2.0
2#
3# Building vDSO images for x86.
4#
5
6# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
7# the inclusion of generic Makefile.
8ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
9ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
10include $(srctree)/lib/vdso/Makefile
11
12# Sanitizer runtimes are unavailable and cannot be linked here.
13KASAN_SANITIZE			:= n
14UBSAN_SANITIZE			:= n
15KCSAN_SANITIZE			:= n
16OBJECT_FILES_NON_STANDARD	:= y
17
18# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
19KCOV_INSTRUMENT		:= n
20
21VDSO64-$(CONFIG_X86_64)		:= y
22VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
23VDSO32-$(CONFIG_X86_32)		:= y
24VDSO32-$(CONFIG_IA32_EMULATION)	:= y
25
26# files to link into the vdso
27vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
28vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
29vobjs32-y += vdso32/vclock_gettime.o
30vobjs-$(CONFIG_X86_SGX)	+= vsgx.o
31
32# files to link into kernel
33obj-y				+= vma.o extable.o
34KASAN_SANITIZE_vma.o		:= y
35UBSAN_SANITIZE_vma.o		:= y
36KCSAN_SANITIZE_vma.o		:= y
37OBJECT_FILES_NON_STANDARD_vma.o	:= n
38
39# vDSO images to build
40vdso_img-$(VDSO64-y)		+= 64
41vdso_img-$(VDSOX32-y)		+= x32
42vdso_img-$(VDSO32-y)		+= 32
43
44obj-$(VDSO32-y)			+= vdso32-setup.o
45
46vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
47vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
48
49$(obj)/vdso.o: $(obj)/vdso.so
50
51targets += vdso.lds $(vobjs-y)
52targets += vdso32/vdso32.lds $(vobjs32-y)
53
54# Build the vDSO image C files and link them in.
55vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
56vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
57vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
58obj-y += $(vdso_img_objs)
59targets += $(vdso_img_cfiles)
60targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
61
62CPPFLAGS_vdso.lds += -P -C
63
64VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
65			-z max-page-size=4096
66
67$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
68	$(call if_changed,vdso_and_check)
69
70HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
71hostprogs += vdso2c
72
73quiet_cmd_vdso2c = VDSO2C  $@
74      cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
75
76$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
77	$(call if_changed,vdso2c)
78
79#
80# Don't omit frame pointers for ease of userspace debugging, but do
81# optimize sibling calls.
82#
83CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
84       $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
85       -fno-omit-frame-pointer -foptimize-sibling-calls \
86       -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
87
88ifdef CONFIG_RETPOLINE
89ifneq ($(RETPOLINE_VDSO_CFLAGS),)
90  CFL += $(RETPOLINE_VDSO_CFLAGS)
91endif
92endif
93
94$(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
95
96#
97# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
98#
99CFLAGS_REMOVE_vclock_gettime.o = -pg
100CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
101CFLAGS_REMOVE_vgetcpu.o = -pg
102CFLAGS_REMOVE_vsgx.o = -pg
103
104#
105# X32 processes use x32 vDSO to access 64bit kernel data.
106#
107# Build x32 vDSO image:
108# 1. Compile x32 vDSO as 64bit.
109# 2. Convert object files to x32.
110# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
111# so that it can reach 64bit address space with 64bit pointers.
112#
113
114CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
115VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
116			   -z max-page-size=4096
117
118# x32-rebranded versions
119vobjx32s-y := $(vobjs-y:.o=-x32.o)
120
121# same thing, but in the output directory
122vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
123
124# Convert 64bit object file to x32 for x32 vDSO.
125quiet_cmd_x32 = X32     $@
126      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
127
128$(obj)/%-x32.o: $(obj)/%.o FORCE
129	$(call if_changed,x32)
130
131targets += vdsox32.lds $(vobjx32s-y)
132
133$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
134$(obj)/%.so: $(obj)/%.so.dbg FORCE
135	$(call if_changed,objcopy)
136
137$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
138	$(call if_changed,vdso_and_check)
139
140CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
141VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
142
143KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
144$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
145$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
146
147KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
148KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
149KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
150KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
151KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
152KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
153KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
154KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
155KBUILD_CFLAGS_32 += -fno-stack-protector
156KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
157KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
158KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
159
160ifdef CONFIG_RETPOLINE
161ifneq ($(RETPOLINE_VDSO_CFLAGS),)
162  KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
163endif
164endif
165
166$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
167
168$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
169	$(call if_changed,vdso_and_check)
170
171#
172# The DSO images are built using a special linker script.
173#
174quiet_cmd_vdso = VDSO    $@
175      cmd_vdso = $(LD) -nostdlib -o $@ \
176		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
177		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
178		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
179
180VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
181	$(call ld-option, --eh-frame-hdr) -Bsymbolic
182GCOV_PROFILE := n
183
184quiet_cmd_vdso_and_check = VDSO    $@
185      cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
186
187#
188# Install the unstripped copies of vdso*.so.  If our toolchain supports
189# build-id, install .build-id links as well.
190#
191quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
192define cmd_vdso_install
193	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
194	if readelf -n $< |grep -q 'Build ID'; then \
195	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
196	  first=`echo $$buildid | cut -b-2`; \
197	  last=`echo $$buildid | cut -b3-`; \
198	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
199	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
200	fi
201endef
202
203vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
204
205$(MODLIB)/vdso: FORCE
206	@mkdir -p $(MODLIB)/vdso
207
208$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
209	$(call cmd,vdso_install)
210
211PHONY += vdso_install $(vdso_img_insttargets)
212vdso_install: $(vdso_img_insttargets)
213
214clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*
215