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) 13CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) 14 15CC_COMPAT ?= $(CC) 16CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS) 17 18ifneq ($(LLVM),) 19LD_COMPAT ?= $(LD) 20else 21LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld 22endif 23else 24CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc 25LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld 26endif 27 28cc32-option = $(call try-run,\ 29 $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 30cc32-disable-warning = $(call try-run,\ 31 $(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 32 33# We cannot use the global flags to compile the vDSO files, the main reason 34# being that the 32-bit compiler may be older than the main (64-bit) compiler 35# and therefore may not understand flags set using $(cc-option ...). Besides, 36# arch-specific options should be taken from the arm Makefile instead of the 37# arm64 one. 38# As a result we set our own flags here. 39 40# KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile 41VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc -isystem $(shell $(CC_COMPAT) -print-file-name=include) 42VDSO_CPPFLAGS += $(LINUXINCLUDE) 43 44# Common C and assembly flags 45# From top-level Makefile 46VDSO_CAFLAGS := $(VDSO_CPPFLAGS) 47ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),) 48VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) 49endif 50 51VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) 52ifdef CONFIG_DEBUG_INFO 53VDSO_CAFLAGS += -g 54endif 55 56# From arm Makefile 57VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm) 58VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft 59ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) 60VDSO_CAFLAGS += -mbig-endian 61else 62VDSO_CAFLAGS += -mlittle-endian 63endif 64 65# From arm vDSO Makefile 66VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector 67VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING 68VDSO_CAFLAGS += -march=armv8-a 69 70VDSO_CFLAGS := $(VDSO_CAFLAGS) 71VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1 72# KBUILD_CFLAGS from top-level Makefile 73VDSO_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 78VDSO_CFLAGS += -O2 79# Some useful compiler-dependent flags from top-level Makefile 80VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,) 81VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) 82VDSO_CFLAGS += -fno-strict-overflow 83VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) 84VDSO_CFLAGS += -Werror=date-time 85VDSO_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. 91VDSO_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) 94VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow) 95VDSO_CFLAGS += -Wno-int-to-pointer-cast 96 97# Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is 98# unreliable. 99ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y) 100VDSO_CFLAGS += -mthumb -fomit-frame-pointer 101else 102VDSO_CFLAGS += -marm 103endif 104 105VDSO_AFLAGS := $(VDSO_CAFLAGS) 106VDSO_AFLAGS += -D__ASSEMBLY__ 107 108# From arm vDSO Makefile 109VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 110VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096 111VDSO_LDFLAGS += -nostdlib -shared --hash-style=sysv --build-id=sha1 112 113 114# Borrow vdsomunge.c from the arm vDSO 115# We have to use a relative path because scripts/Makefile.host prefixes 116# $(hostprogs) with $(obj) 117munge := ../../../arm/vdso/vdsomunge 118hostprogs := $(munge) 119 120c-obj-vdso := note.o 121c-obj-vdso-gettimeofday := vgettimeofday.o 122 123ifneq ($(c-gettimeofday-y),) 124VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) 125endif 126 127VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os 128 129# Build rules 130targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw 131c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) 132c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) 133asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) 134obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) 135 136targets += vdso.lds 137CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 138 139# Force dependency (vdso.s includes vdso.so through incbin) 140$(obj)/vdso.o: $(obj)/vdso.so 141 142include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE 143 $(call if_changed,vdsosym) 144 145# Strip rule for vdso.so 146$(obj)/vdso.so: OBJCOPYFLAGS := -S 147$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE 148 $(call if_changed,objcopy) 149 150$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE 151 $(call if_changed,vdsomunge) 152 153# Link rule for the .so file, .lds has to be first 154$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE 155 $(call if_changed,vdsold_and_vdso_check) 156 157# Compilation rules for the vDSO sources 158$(c-obj-vdso): %.o: %.c FORCE 159 $(call if_changed_dep,vdsocc) 160$(c-obj-vdso-gettimeofday): %.o: %.c FORCE 161 $(call if_changed_dep,vdsocc_gettimeofday) 162$(asm-obj-vdso): %.o: %.S FORCE 163 $(call if_changed_dep,vdsoas) 164 165# Actual build commands 166quiet_cmd_vdsold_and_vdso_check = LD32 $@ 167 cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check) 168 169quiet_cmd_vdsold = LD32 $@ 170 cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \ 171 -T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 172quiet_cmd_vdsocc = CC32 $@ 173 cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< 174quiet_cmd_vdsocc_gettimeofday = CC32 $@ 175 cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< 176quiet_cmd_vdsoas = AS32 $@ 177 cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< 178 179quiet_cmd_vdsomunge = MUNGE $@ 180 cmd_vdsomunge = $(obj)/$(munge) $< $@ 181 182# Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO) 183gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh 184quiet_cmd_vdsosym = VDSOSYM $@ 185# The AArch64 nm should be able to read an AArch32 binary 186 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 187 188# Install commands for the unstripped file 189quiet_cmd_vdso_install = INSTALL32 $@ 190 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so 191 192vdso.so: $(obj)/vdso.so.dbg 193 @mkdir -p $(MODLIB)/vdso 194 $(call cmd,vdso_install) 195 196vdso_install: vdso.so 197