arch/x86/entry/vdso/Makefile

   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.
   8 ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
   9 ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
  10 include $(srctree)/lib/vdso/Makefile
  11
  12 KBUILD_CFLAGS += $(DISABLE_LTO)
  13 KASAN_SANITIZE                  := n
  14 UBSAN_SANITIZE                  := n
  15 OBJECT_FILES_NON_STANDARD       := y
  16
  17 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
  18 KCOV_INSTRUMENT         := n
  19
  20 VDSO64-$(CONFIG_X86_64)         := y
  21 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
  22 VDSO32-$(CONFIG_X86_32)         := y
  23 VDSO32-$(CONFIG_IA32_EMULATION) := y
  24
  25 # files to link into the vdso
  26 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  27
  28 # files to link into kernel
  29 obj-y                           += vma.o
  30 OBJECT_FILES_NON_STANDARD_vma.o := n
  31
  32 # vDSO images to build
  33 vdso_img-$(VDSO64-y)            += 64
  34 vdso_img-$(VDSOX32-y)           += x32
  35 vdso_img-$(VDSO32-y)            += 32
  36
  37 obj-$(VDSO32-y)                 += vdso32-setup.o
  38
  39 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  40
  41 $(obj)/vdso.o: $(obj)/vdso.so
  42
  43 targets += vdso.lds $(vobjs-y)
  44
  45 # Build the vDSO image C files and link them in.
  46 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  47 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  48 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  49 obj-y += $(vdso_img_objs)
  50 targets += $(vdso_img_cfiles)
  51 targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
  52
  53 CPPFLAGS_vdso.lds += -P -C
  54
  55 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
  56                         -z max-page-size=4096
  57
  58 $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
  59         $(call if_changed,vdso_and_check)
  60
  61 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
  62 hostprogs-y                     += vdso2c
  63
  64 quiet_cmd_vdso2c = VDSO2C  $@
  65       cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
  66
  67 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
  68         $(call if_changed,vdso2c)
  69
  70 #
  71 # Don't omit frame pointers for ease of userspace debugging, but do
  72 # optimize sibling calls.
  73 #
  74 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  75        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  76        -fno-omit-frame-pointer -foptimize-sibling-calls \
  77        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
  78
  79 ifdef CONFIG_RETPOLINE
  80 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
  81   CFL += $(RETPOLINE_VDSO_CFLAGS)
  82 endif
  83 endif
  84
  85 $(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
  86
  87 #
  88 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  89 #
  90 CFLAGS_REMOVE_vdso-note.o = -pg
  91 CFLAGS_REMOVE_vclock_gettime.o = -pg
  92 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
  93 CFLAGS_REMOVE_vgetcpu.o = -pg
  94 CFLAGS_REMOVE_vvar.o = -pg
  95
  96 #
  97 # X32 processes use x32 vDSO to access 64bit kernel data.
  98 #
  99 # Build x32 vDSO image:
 100 # 1. Compile x32 vDSO as 64bit.
 101 # 2. Convert object files to x32.
 102 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
 103 # so that it can reach 64bit address space with 64bit pointers.
 104 #
 105
 106 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 107 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
 108                            -z max-page-size=4096
 109
 110 # x32-rebranded versions
 111 vobjx32s-y := $(vobjs-y:.o=-x32.o)
 112
 113 # same thing, but in the output directory
 114 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 115
 116 # Convert 64bit object file to x32 for x32 vDSO.
 117 quiet_cmd_x32 = X32     $@
 118       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 119
 120 $(obj)/%-x32.o: $(obj)/%.o FORCE
 121         $(call if_changed,x32)
 122
 123 targets += vdsox32.lds $(vobjx32s-y)
 124
 125 $(obj)/%.so: OBJCOPYFLAGS := -S
 126 $(obj)/%.so: $(obj)/%.so.dbg FORCE
 127         $(call if_changed,objcopy)
 128
 129 $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
 130         $(call if_changed,vdso_and_check)
 131
 132 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 133 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 134
 135 targets += vdso32/vdso32.lds
 136 targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
 137 targets += vdso32/vclock_gettime.o
 138
 139 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
 140 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 141 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
 142
 143 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 144 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 145 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 146 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 147 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 148 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 149 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 150 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 151 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 152 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 153 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 154
 155 ifdef CONFIG_RETPOLINE
 156 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 157   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 158 endif
 159 endif
 160
 161 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 162
 163 $(obj)/vdso32.so.dbg: FORCE \
 164                       $(obj)/vdso32/vdso32.lds \
 165                       $(obj)/vdso32/vclock_gettime.o \
 166                       $(obj)/vdso32/note.o \
 167                       $(obj)/vdso32/system_call.o \
 168                       $(obj)/vdso32/sigreturn.o
 169         $(call if_changed,vdso_and_check)
 170
 171 #
 172 # The DSO images are built using a special linker script.
 173 #
 174 quiet_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
 180 VDSO_LDFLAGS = -shared --hash-style=both --build-id \
 181         $(call ld-option, --eh-frame-hdr) -Bsymbolic
 182 GCOV_PROFILE := n
 183
 184 quiet_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 #
 191 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
 192 define 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
 201 endef
 202
 203 vdso_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
 211 PHONY += vdso_install $(vdso_img_insttargets)
 212 vdso_install: $(vdso_img_insttargets)
 213
 214 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*