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