arch/arm64/kernel/vdso32/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 #
   3 # Makefile for vdso32
   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_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32
   9 include $(srctree)/lib/vdso/Makefile
  10
  11 # Same as cc-*option, but using CC_COMPAT instead of CC
  12 ifeq ($(CONFIG_CC_IS_CLANG), y)
  13 COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
  14 COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
  15
  16 CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
  17 CC_COMPAT_CLANG_FLAGS += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE_COMPAT))
  18 CC_COMPAT_CLANG_FLAGS += -no-integrated-as -Qunused-arguments
  19 ifneq ($(COMPAT_GCC_TOOLCHAIN),)
  20 CC_COMPAT_CLANG_FLAGS += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
  21 endif
  22
  23 CC_COMPAT ?= $(CC)
  24 CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS)
  25
  26 ifneq ($(LLVM),)
  27 LD_COMPAT ?= $(LD)
  28 else
  29 LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
  30 endif
  31 else
  32 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
  33 LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
  34 endif
  35
  36 cc32-option = $(call try-run,\
  37         $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
  38 cc32-disable-warning = $(call try-run,\
  39         $(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
  40 cc32-as-instr = $(call try-run,\
  41         printf "%b\n" "$(1)" | $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
  42
  43 # We cannot use the global flags to compile the vDSO files, the main reason
  44 # being that the 32-bit compiler may be older than the main (64-bit) compiler
  45 # and therefore may not understand flags set using $(cc-option ...). Besides,
  46 # arch-specific options should be taken from the arm Makefile instead of the
  47 # arm64 one.
  48 # As a result we set our own flags here.
  49
  50 # KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
  51 VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc -isystem $(shell $(CC_COMPAT) -print-file-name=include)
  52 VDSO_CPPFLAGS += $(LINUXINCLUDE)
  53
  54 # Common C and assembly flags
  55 # From top-level Makefile
  56 VDSO_CAFLAGS := $(VDSO_CPPFLAGS)
  57 ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),)
  58 VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
  59 endif
  60
  61 VDSO_CAFLAGS += $(call cc32-option,-fno-PIE)
  62 ifdef CONFIG_DEBUG_INFO
  63 VDSO_CAFLAGS += -g
  64 endif
  65
  66 # From arm Makefile
  67 VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm)
  68 VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft
  69 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
  70 VDSO_CAFLAGS += -mbig-endian
  71 else
  72 VDSO_CAFLAGS += -mlittle-endian
  73 endif
  74
  75 # From arm vDSO Makefile
  76 VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
  77 VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING
  78
  79
  80 # Try to compile for ARMv8. If the compiler is too old and doesn't support it,
  81 # fall back to v7. There is no easy way to check for what architecture the code
  82 # is being compiled, so define a macro specifying that (see arch/arm/Makefile).
  83 VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
  84                                    -march=armv7-a -D__LINUX_ARM_ARCH__=7)
  85
  86 VDSO_CFLAGS := $(VDSO_CAFLAGS)
  87 VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
  88 # KBUILD_CFLAGS from top-level Makefile
  89 VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
  90                -fno-strict-aliasing -fno-common \
  91                -Werror-implicit-function-declaration \
  92                -Wno-format-security \
  93                -std=gnu89
  94 VDSO_CFLAGS  += -O2
  95 # Some useful compiler-dependent flags from top-level Makefile
  96 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
  97 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
  98 VDSO_CFLAGS += -fno-strict-overflow
  99 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
 100 VDSO_CFLAGS += -Werror=date-time
 101 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
 102
 103 # The 32-bit compiler does not provide 128-bit integers, which are used in
 104 # some headers that are indirectly included from the vDSO code.
 105 # This hack makes the compiler happy and should trigger a warning/error if
 106 # variables of such type are referenced.
 107 VDSO_CFLAGS += -D__uint128_t='void*'
 108 # Silence some warnings coming from headers that operate on long's
 109 # (on GCC 4.8 or older, there is unfortunately no way to silence this warning)
 110 VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow)
 111 VDSO_CFLAGS += -Wno-int-to-pointer-cast
 112
 113 # Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is
 114 # unreliable.
 115 ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y)
 116 VDSO_CFLAGS += -mthumb -fomit-frame-pointer
 117 else
 118 VDSO_CFLAGS += -marm
 119 endif
 120
 121 VDSO_AFLAGS := $(VDSO_CAFLAGS)
 122 VDSO_AFLAGS += -D__ASSEMBLY__
 123
 124 # Check for binutils support for dmb ishld
 125 dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)
 126
 127 VDSO_CFLAGS += $(dmbinstr)
 128 VDSO_AFLAGS += $(dmbinstr)
 129
 130 # From arm vDSO Makefile
 131 VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
 132 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
 133 VDSO_LDFLAGS += -nostdlib -shared --hash-style=sysv --build-id=sha1
 134
 135
 136 # Borrow vdsomunge.c from the arm vDSO
 137 # We have to use a relative path because scripts/Makefile.host prefixes
 138 # $(hostprogs) with $(obj)
 139 munge := ../../../arm/vdso/vdsomunge
 140 hostprogs := $(munge)
 141
 142 c-obj-vdso := note.o
 143 c-obj-vdso-gettimeofday := vgettimeofday.o
 144
 145 ifneq ($(c-gettimeofday-y),)
 146 VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y)
 147 endif
 148
 149 VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
 150
 151 # Build rules
 152 targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw
 153 c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso))
 154 c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday))
 155 asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
 156 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
 157
 158 obj-y += vdso.o
 159 targets += vdso.lds
 160 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 161
 162 # Force dependency (vdso.s includes vdso.so through incbin)
 163 $(obj)/vdso.o: $(obj)/vdso.so
 164
 165 include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE
 166         $(call if_changed,vdsosym)
 167
 168 # Strip rule for vdso.so
 169 $(obj)/vdso.so: OBJCOPYFLAGS := -S
 170 $(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
 171         $(call if_changed,objcopy)
 172
 173 $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE
 174         $(call if_changed,vdsomunge)
 175
 176 # Link rule for the .so file, .lds has to be first
 177 $(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
 178         $(call if_changed,vdsold_and_vdso_check)
 179
 180 # Compilation rules for the vDSO sources
 181 $(c-obj-vdso): %.o: %.c FORCE
 182         $(call if_changed_dep,vdsocc)
 183 $(c-obj-vdso-gettimeofday): %.o: %.c FORCE
 184         $(call if_changed_dep,vdsocc_gettimeofday)
 185 $(asm-obj-vdso): %.o: %.S FORCE
 186         $(call if_changed_dep,vdsoas)
 187
 188 # Actual build commands
 189 quiet_cmd_vdsold_and_vdso_check = LD32    $@
 190       cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)
 191
 192 quiet_cmd_vdsold = LD32    $@
 193       cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \
 194                    -T $(filter %.lds,$^) $(filter %.o,$^) -o $@
 195 quiet_cmd_vdsocc = CC32    $@
 196       cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $<
 197 quiet_cmd_vdsocc_gettimeofday = CC32    $@
 198       cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $<
 199 quiet_cmd_vdsoas = AS32    $@
 200       cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $<
 201
 202 quiet_cmd_vdsomunge = MUNGE   $@
 203       cmd_vdsomunge = $(obj)/$(munge) $< $@
 204
 205 # Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO)
 206 gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh
 207 quiet_cmd_vdsosym = VDSOSYM $@
 208 # The AArch64 nm should be able to read an AArch32 binary
 209       cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
 210
 211 # Install commands for the unstripped file
 212 quiet_cmd_vdso_install = INSTALL32 $@
 213       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so
 214
 215 vdso.so: $(obj)/vdso.so.dbg
 216         @mkdir -p $(MODLIB)/vdso
 217         $(call cmd,vdso_install)
 218
 219 vdso_install: vdso.so