1# SPDX-License-Identifier: GPL-2.0 2# 3# Makefile for vdso32 4# 5 6include $(srctree)/lib/vdso/Makefile.include 7 8# Same as cc-*option, but using CC_COMPAT instead of CC 9ifeq ($(CONFIG_CC_IS_CLANG), y) 10CC_COMPAT ?= $(CC) 11CC_COMPAT += --target=arm-linux-gnueabi 12else 13CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc 14endif 15 16ifeq ($(CONFIG_LD_IS_LLD), y) 17LD_COMPAT ?= $(LD) 18else 19LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld 20endif 21 22cc32-option = $(call try-run,\ 23 $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 24 25# We cannot use the global flags to compile the vDSO files, the main reason 26# being that the 32-bit compiler may be older than the main (64-bit) compiler 27# and therefore may not understand flags set using $(cc-option ...). Besides, 28# arch-specific options should be taken from the arm Makefile instead of the 29# arm64 one. 30# As a result we set our own flags here. 31 32# KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile 33VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc 34VDSO_CPPFLAGS += -isystem $(shell $(CC_COMPAT) -print-file-name=include 2>/dev/null) 35VDSO_CPPFLAGS += $(LINUXINCLUDE) 36 37# Common C and assembly flags 38# From top-level Makefile 39VDSO_CAFLAGS := $(VDSO_CPPFLAGS) 40VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) 41ifdef CONFIG_DEBUG_INFO 42VDSO_CAFLAGS += -g 43endif 44 45# From arm Makefile 46VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm) 47VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft 48ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) 49VDSO_CAFLAGS += -mbig-endian 50else 51VDSO_CAFLAGS += -mlittle-endian 52endif 53 54# From arm vDSO Makefile 55VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector 56VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING 57VDSO_CAFLAGS += -march=armv8-a 58 59VDSO_CFLAGS := $(VDSO_CAFLAGS) 60# KBUILD_CFLAGS from top-level Makefile 61VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ 62 -fno-strict-aliasing -fno-common \ 63 $(filter -Werror,$(KBUILD_CPPFLAGS)) \ 64 -Werror-implicit-function-declaration \ 65 -Wno-format-security \ 66 -std=gnu11 -fms-extensions 67VDSO_CFLAGS += -O2 68# Some useful compiler-dependent flags from top-level Makefile 69VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) 70VDSO_CFLAGS += -fno-strict-overflow 71VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) 72VDSO_CFLAGS += -Werror=date-time 73VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types) 74VDSO_CFLAGS += $(if $(CONFIG_CC_IS_CLANG),-Wno-microsoft-anon-tag) 75 76# Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is 77# unreliable. 78ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y) 79VDSO_CFLAGS += -mthumb -fomit-frame-pointer 80else 81VDSO_CFLAGS += -marm 82endif 83 84VDSO_AFLAGS := $(VDSO_CAFLAGS) 85VDSO_AFLAGS += -D__ASSEMBLY__ 86 87# From arm vDSO Makefile 88VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 89VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096 90VDSO_LDFLAGS += -shared --build-id=sha1 91VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) 92 93 94# Borrow vdsomunge.c from the arm vDSO 95# We have to use a relative path because scripts/Makefile.host prefixes 96# $(hostprogs) with $(obj) 97munge := ../../../arm/vdso/vdsomunge 98hostprogs := $(munge) 99 100c-obj-vdso := note.o 101c-obj-vdso-gettimeofday := vgettimeofday.o 102 103ifneq ($(c-gettimeofday-y),) 104VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) 105endif 106 107VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os 108 109# Build rules 110targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso32.so.dbg vdso.so.raw 111c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) 112c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) 113asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) 114obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) 115 116targets += vdso.lds 117CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 118 119# Strip rule for vdso.so 120$(obj)/vdso.so: OBJCOPYFLAGS := -S 121$(obj)/vdso.so: $(obj)/vdso32.so.dbg FORCE 122 $(call if_changed,objcopy) 123 124$(obj)/vdso32.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE 125 $(call if_changed,vdsomunge) 126 127# Link rule for the .so file, .lds has to be first 128$(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE 129 $(call if_changed,vdsold_and_vdso_check) 130 131# Compilation rules for the vDSO sources 132$(c-obj-vdso): %.o: %.c FORCE 133 $(call if_changed_dep,vdsocc) 134$(c-obj-vdso-gettimeofday): %.o: %.c FORCE 135 $(call if_changed_dep,vdsocc_gettimeofday) 136$(asm-obj-vdso): %.o: %.S FORCE 137 $(call if_changed_dep,vdsoas) 138 139# Actual build commands 140quiet_cmd_vdsold_and_vdso_check = LD32 $@ 141 cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check) 142 143quiet_cmd_vdsold = LD32 $@ 144 cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \ 145 -T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 146quiet_cmd_vdsocc = CC32 $@ 147 cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< 148quiet_cmd_vdsocc_gettimeofday = CC32 $@ 149 cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< 150quiet_cmd_vdsoas = AS32 $@ 151 cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< 152 153quiet_cmd_vdsomunge = MUNGE $@ 154 cmd_vdsomunge = $(obj)/$(munge) $< $@ 155