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