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 $(srctree)/lib/vdso/Makefile
  11
  12 # Sanitizer runtimes are unavailable and cannot be linked here.
  13 KASAN_SANITIZE                  := n
  14 KMSAN_SANITIZE_vclock_gettime.o := n
  15 KMSAN_SANITIZE_vgetcpu.o        := n
  16
  17 UBSAN_SANITIZE                  := n
  18 KCSAN_SANITIZE                  := n
  19 OBJECT_FILES_NON_STANDARD       := y
  20
  21 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
  22 KCOV_INSTRUMENT         := n
  23
  24 VDSO64-$(CONFIG_X86_64)         := y
  25 VDSOX32-$(CONFIG_X86_X32_ABI)   := y
  26 VDSO32-$(CONFIG_X86_32)         := y
  27 VDSO32-$(CONFIG_IA32_EMULATION) := y
  28
  29 # files to link into the vdso
  30 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
  31 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
  32 vobjs32-y += vdso32/vclock_gettime.o
  33 vobjs-$(CONFIG_X86_SGX) += vsgx.o
  34
  35 # files to link into kernel
  36 obj-y                           += vma.o extable.o
  37 KASAN_SANITIZE_vma.o            := y
  38 UBSAN_SANITIZE_vma.o            := y
  39 KCSAN_SANITIZE_vma.o            := y
  40 OBJECT_FILES_NON_STANDARD_vma.o := n
  41
  42 # vDSO images to build
  43 vdso_img-$(VDSO64-y)            += 64
  44 vdso_img-$(VDSOX32-y)           += x32
  45 vdso_img-$(VDSO32-y)            += 32
  46
  47 obj-$(VDSO32-y)                 += vdso32-setup.o
  48
  49 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  50 vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
  51
  52 $(obj)/vdso.o: $(obj)/vdso.so
  53
  54 targets += vdso.lds $(vobjs-y)
  55 targets += vdso32/vdso32.lds $(vobjs32-y)
  56
  57 # Build the vDSO image C files and link them in.
  58 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
  59 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
  60 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
  61 obj-y += $(vdso_img_objs)
  62 targets += $(vdso_img_cfiles)
  63 targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
  64
  65 CPPFLAGS_vdso.lds += -P -C
  66
  67 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
  68                         -z max-page-size=4096
  69
  70 $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
  71         $(call if_changed,vdso_and_check)
  72
  73 HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
  74 hostprogs += vdso2c
  75
  76 quiet_cmd_vdso2c = VDSO2C  $@
  77       cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
  78
  79 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
  80         $(call if_changed,vdso2c)
  81
  82 #
  83 # Don't omit frame pointers for ease of userspace debugging, but do
  84 # optimize sibling calls.
  85 #
  86 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  87        $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
  88        -fno-omit-frame-pointer -foptimize-sibling-calls \
  89        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
  90
  91 ifdef CONFIG_RETPOLINE
  92 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
  93   CFL += $(RETPOLINE_VDSO_CFLAGS)
  94 endif
  95 endif
  96
  97 $(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
  98 $(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
  99
 100 #
 101 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
 102 #
 103 CFLAGS_REMOVE_vclock_gettime.o = -pg
 104 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
 105 CFLAGS_REMOVE_vgetcpu.o = -pg
 106 CFLAGS_REMOVE_vsgx.o = -pg
 107
 108 #
 109 # X32 processes use x32 vDSO to access 64bit kernel data.
 110 #
 111 # Build x32 vDSO image:
 112 # 1. Compile x32 vDSO as 64bit.
 113 # 2. Convert object files to x32.
 114 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
 115 # so that it can reach 64bit address space with 64bit pointers.
 116 #
 117
 118 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 119 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
 120                            -z max-page-size=4096
 121
 122 # x32-rebranded versions
 123 vobjx32s-y := $(vobjs-y:.o=-x32.o)
 124
 125 # same thing, but in the output directory
 126 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
 127
 128 # Convert 64bit object file to x32 for x32 vDSO.
 129 quiet_cmd_x32 = X32     $@
 130       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
 131
 132 $(obj)/%-x32.o: $(obj)/%.o FORCE
 133         $(call if_changed,x32)
 134
 135 targets += vdsox32.lds $(vobjx32s-y)
 136
 137 $(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
 138 $(obj)/%.so: $(obj)/%.so.dbg FORCE
 139         $(call if_changed,objcopy)
 140
 141 $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
 142         $(call if_changed,vdso_and_check)
 143
 144 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 145 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 146
 147 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
 148 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 149 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
 150
 151 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 152 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 153 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 154 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 155 KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 156 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 157 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 158 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
 159 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
 160 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 161 KBUILD_CFLAGS_32 += -fno-stack-protector
 162 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 163 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 164 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 165
 166 ifdef CONFIG_RETPOLINE
 167 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 168   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 169 endif
 170 endif
 171
 172 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 173
 174 $(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
 175         $(call if_changed,vdso_and_check)
 176
 177 #
 178 # The DSO images are built using a special linker script.
 179 #
 180 quiet_cmd_vdso = VDSO    $@
 181       cmd_vdso = $(LD) -o $@ \
 182                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 183                        -T $(filter %.lds,$^) $(filter %.o,$^) && \
 184                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 185
 186 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 187         $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
 188 GCOV_PROFILE := n
 189
 190 quiet_cmd_vdso_and_check = VDSO    $@
 191       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
 192
 193 #
 194 # Install the unstripped copies of vdso*.so.  If our toolchain supports
 195 # build-id, install .build-id links as well.
 196 #
 197 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
 198 define cmd_vdso_install
 199         cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
 200         if readelf -n $< |grep -q 'Build ID'; then \
 201           buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
 202           first=`echo $$buildid | cut -b-2`; \
 203           last=`echo $$buildid | cut -b3-`; \
 204           mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
 205           ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
 206         fi
 207 endef
 208
 209 vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
 210
 211 $(MODLIB)/vdso: FORCE
 212         @mkdir -p $(MODLIB)/vdso
 213
 214 $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
 215         $(call cmd,vdso_install)
 216
 217 PHONY += vdso_install $(vdso_img_insttargets)
 218 vdso_install: $(vdso_img_insttargets)
 219
 220 clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*