xref: /openbmc/linux/arch/x86/entry/vdso/Makefile (revision 63f59b73e80a0f7431f6f91383fcc3f5fac49bb8) 
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) $(vdso_img-y:%=vdso%.so)
46
47CPPFLAGS_vdso.lds += -P -C
48
49VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
50			-z max-page-size=4096 -z common-page-size=4096
51
52$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
53	$(call if_changed,vdso)
54
55HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
56hostprogs-y			+= vdso2c
57
58quiet_cmd_vdso2c = VDSO2C  $@
59      cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
60
61$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
62	$(call if_changed,vdso2c)
63
64#
65# Don't omit frame pointers for ease of userspace debugging, but do
66# optimize sibling calls.
67#
68CFL := $(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 $(RETPOLINE_VDSO_CFLAGS)
72
73$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
74
75#
76# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
77#
78CFLAGS_REMOVE_vdso-note.o = -pg
79CFLAGS_REMOVE_vclock_gettime.o = -pg
80CFLAGS_REMOVE_vgetcpu.o = -pg
81CFLAGS_REMOVE_vvar.o = -pg
82
83#
84# X32 processes use x32 vDSO to access 64bit kernel data.
85#
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.
91#
92
93CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
94VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
95			   -z max-page-size=4096 -z common-page-size=4096
96
97# x32-rebranded versions
98vobjx32s-y := $(vobjs-y:.o=-x32.o)
99
100# same thing, but in the output directory
101vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
102
103# Convert 64bit object file to x32 for x32 vDSO.
104quiet_cmd_x32 = X32     $@
105      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
106
107$(obj)/%-x32.o: $(obj)/%.o FORCE
108	$(call if_changed,x32)
109
110targets += vdsox32.lds $(vobjx32s-y)
111
112$(obj)/%.so: OBJCOPYFLAGS := -S
113$(obj)/%.so: $(obj)/%.so.dbg
114	$(call if_changed,objcopy)
115
116$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
117	$(call if_changed,vdso)
118
119CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
120VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
121
122targets += vdso32/vdso32.lds
123targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
124targets += vdso32/vclock_gettime.o
125
126KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
127$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
128$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
129
130KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
131KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
132KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
133KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
134KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
135KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
136KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
137KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
138KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
139KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
140KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
141KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
142$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
143
144$(obj)/vdso32.so.dbg: FORCE \
145		      $(obj)/vdso32/vdso32.lds \
146		      $(obj)/vdso32/vclock_gettime.o \
147		      $(obj)/vdso32/note.o \
148		      $(obj)/vdso32/system_call.o \
149		      $(obj)/vdso32/sigreturn.o
150	$(call if_changed,vdso)
151
152#
153# The DSO images are built using a special linker script.
154#
155quiet_cmd_vdso = VDSO    $@
156      cmd_vdso = $(LD) -nostdlib -o $@ \
157		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
158		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
159		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
160
161VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \
162	$(call ld-option, --build-id) -Bsymbolic
163GCOV_PROFILE := n
164
165#
166# Install the unstripped copies of vdso*.so.  If our toolchain supports
167# build-id, install .build-id links as well.
168#
169quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
170define cmd_vdso_install
171	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
172	if readelf -n $< |grep -q 'Build ID'; then \
173	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
174	  first=`echo $$buildid | cut -b-2`; \
175	  last=`echo $$buildid | cut -b3-`; \
176	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
177	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
178	fi
179endef
180
181vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
182
183$(MODLIB)/vdso: FORCE
184	@mkdir -p $(MODLIB)/vdso
185
186$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
187	$(call cmd,vdso_install)
188
189PHONY += vdso_install $(vdso_img_insttargets)
190vdso_install: $(vdso_img_insttargets)
191
192clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*
193