xref: /openbmc/linux/arch/x86/entry/vdso/Makefile (revision 82df5b73) 
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
12KBUILD_CFLAGS += $(DISABLE_LTO)
13
14# Sanitizer runtimes are unavailable and cannot be linked here.
15KASAN_SANITIZE			:= n
16UBSAN_SANITIZE			:= n
17KCSAN_SANITIZE			:= n
18OBJECT_FILES_NON_STANDARD	:= y
19
20# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
21KCOV_INSTRUMENT		:= n
22
23VDSO64-$(CONFIG_X86_64)		:= y
24VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
25VDSO32-$(CONFIG_X86_32)		:= y
26VDSO32-$(CONFIG_IA32_EMULATION)	:= y
27
28# files to link into the vdso
29vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
30vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
31vobjs32-y += vdso32/vclock_gettime.o
32
33# files to link into kernel
34obj-y				+= vma.o
35KASAN_SANITIZE_vma.o		:= y
36UBSAN_SANITIZE_vma.o		:= y
37KCSAN_SANITIZE_vma.o		:= y
38OBJECT_FILES_NON_STANDARD_vma.o	:= n
39
40# vDSO images to build
41vdso_img-$(VDSO64-y)		+= 64
42vdso_img-$(VDSOX32-y)		+= x32
43vdso_img-$(VDSO32-y)		+= 32
44
45obj-$(VDSO32-y)			+= vdso32-setup.o
46
47vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
48vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
49
50$(obj)/vdso.o: $(obj)/vdso.so
51
52targets += vdso.lds $(vobjs-y)
53targets += vdso32/vdso32.lds $(vobjs32-y)
54
55# Build the vDSO image C files and link them in.
56vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
57vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
58vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
59obj-y += $(vdso_img_objs)
60targets += $(vdso_img_cfiles)
61targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
62
63CPPFLAGS_vdso.lds += -P -C
64
65VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
66			-z max-page-size=4096
67
68$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
69	$(call if_changed,vdso_and_check)
70
71HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
72hostprogs += vdso2c
73
74quiet_cmd_vdso2c = VDSO2C  $@
75      cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
76
77$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
78	$(call if_changed,vdso2c)
79
80#
81# Don't omit frame pointers for ease of userspace debugging, but do
82# optimize sibling calls.
83#
84CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
85       $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
86       -fno-omit-frame-pointer -foptimize-sibling-calls \
87       -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
88
89ifdef CONFIG_RETPOLINE
90ifneq ($(RETPOLINE_VDSO_CFLAGS),)
91  CFL += $(RETPOLINE_VDSO_CFLAGS)
92endif
93endif
94
95$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
96
97#
98# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
99#
100CFLAGS_REMOVE_vclock_gettime.o = -pg
101CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
102CFLAGS_REMOVE_vgetcpu.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
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 += -m32 -msoft-float -mregparm=0 -fpic
154KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
155KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
156KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
157KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
158
159ifdef CONFIG_RETPOLINE
160ifneq ($(RETPOLINE_VDSO_CFLAGS),)
161  KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
162endif
163endif
164
165$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
166
167$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
168	$(call if_changed,vdso_and_check)
169
170#
171# The DSO images are built using a special linker script.
172#
173quiet_cmd_vdso = VDSO    $@
174      cmd_vdso = $(LD) -nostdlib -o $@ \
175		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
176		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
177		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
178
179VDSO_LDFLAGS = -shared --hash-style=both --build-id \
180	$(call ld-option, --eh-frame-hdr) -Bsymbolic
181GCOV_PROFILE := n
182
183quiet_cmd_vdso_and_check = VDSO    $@
184      cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
185
186#
187# Install the unstripped copies of vdso*.so.  If our toolchain supports
188# build-id, install .build-id links as well.
189#
190quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
191define cmd_vdso_install
192	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
193	if readelf -n $< |grep -q 'Build ID'; then \
194	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
195	  first=`echo $$buildid | cut -b-2`; \
196	  last=`echo $$buildid | cut -b3-`; \
197	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
198	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
199	fi
200endef
201
202vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
203
204$(MODLIB)/vdso: FORCE
205	@mkdir -p $(MODLIB)/vdso
206
207$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
208	$(call cmd,vdso_install)
209
210PHONY += vdso_install $(vdso_img_insttargets)
211vdso_install: $(vdso_img_insttargets)
212
213clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*
214