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