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