x86: vdso: Use $LD instead of $CC to link
[muen/linux.git] / arch / x86 / entry / vdso / Makefile
1 # SPDX-License-Identifier: GPL-2.0
2 #
3 # Building vDSO images for x86.
4 #
5
6 KBUILD_CFLAGS += $(DISABLE_LTO)
7 KASAN_SANITIZE                  := n
8 UBSAN_SANITIZE                  := n
9 OBJECT_FILES_NON_STANDARD       := y
10
11 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
12 KCOV_INSTRUMENT         := n
13
14 VDSO64-$(CONFIG_X86_64)         := y
15 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
16 VDSO32-$(CONFIG_X86_32)         := y
17 VDSO32-$(CONFIG_IA32_EMULATION) := y
18
19 # files to link into the vdso
20 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
21
22 # files to link into kernel
23 obj-y                           += vma.o
24 OBJECT_FILES_NON_STANDARD_vma.o := n
25
26 # vDSO images to build
27 vdso_img-$(VDSO64-y)            += 64
28 vdso_img-$(VDSOX32-y)           += x32
29 vdso_img-$(VDSO32-y)            += 32
30
31 obj-$(VDSO32-y)                 += vdso32-setup.o
32
33 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
34
35 $(obj)/vdso.o: $(obj)/vdso.so
36
37 targets += vdso.lds $(vobjs-y)
38
39 # Build the vDSO image C files and link them in.
40 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
41 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
42 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
43 obj-y += $(vdso_img_objs)
44 targets += $(vdso_img_cfiles)
45 targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
46
47 CPPFLAGS_vdso.lds += -P -C
48
49 VDSO_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         $(call if_changed,vdso)
54
55 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
56 hostprogs-y                     += vdso2c
57
58 quiet_cmd_vdso2c = VDSO2C  $@
59 define cmd_vdso2c
60         $(obj)/vdso2c $< $(<:%.dbg=%) $@
61 endef
62
63 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
64         $(call if_changed,vdso2c)
65
66 #
67 # Don't omit frame pointers for ease of userspace debugging, but do
68 # optimize sibling calls.
69 #
70 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
71        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
72        -fno-omit-frame-pointer -foptimize-sibling-calls \
73        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
74
75 $(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
76
77 #
78 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
79 #
80 CFLAGS_REMOVE_vdso-note.o = -pg
81 CFLAGS_REMOVE_vclock_gettime.o = -pg
82 CFLAGS_REMOVE_vgetcpu.o = -pg
83 CFLAGS_REMOVE_vvar.o = -pg
84
85 #
86 # X32 processes use x32 vDSO to access 64bit kernel data.
87 #
88 # Build x32 vDSO image:
89 # 1. Compile x32 vDSO as 64bit.
90 # 2. Convert object files to x32.
91 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
92 # so that it can reach 64bit address space with 64bit pointers.
93 #
94
95 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
96 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
97                            -z max-page-size=4096 -z common-page-size=4096
98
99 # x32-rebranded versions
100 vobjx32s-y := $(vobjs-y:.o=-x32.o)
101
102 # same thing, but in the output directory
103 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
104
105 # Convert 64bit object file to x32 for x32 vDSO.
106 quiet_cmd_x32 = X32     $@
107       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
108
109 $(obj)/%-x32.o: $(obj)/%.o FORCE
110         $(call if_changed,x32)
111
112 targets += vdsox32.lds $(vobjx32s-y)
113
114 $(obj)/%.so: OBJCOPYFLAGS := -S
115 $(obj)/%.so: $(obj)/%.so.dbg
116         $(call if_changed,objcopy)
117
118 $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
119         $(call if_changed,vdso)
120
121 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
122 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
123
124 targets += vdso32/vdso32.lds
125 targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
126 targets += vdso32/vclock_gettime.o
127
128 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
129 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
130 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
131
132 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
133 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
134 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
135 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
136 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
137 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
138 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
139 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
140 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
141 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
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 #
155 quiet_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
161 VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \
162         $(call ld-option, --build-id) -Bsymbolic
163 GCOV_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 #
169 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
170 define 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
179 endef
180
181 vdso_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
189 PHONY += vdso_install $(vdso_img_insttargets)
190 vdso_install: $(vdso_img_insttargets)
191
192 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*