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 48VDSO_CAFLAGS += -mlittle-endian 49 50# From arm vDSO Makefile 51VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector 52VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING 53VDSO_CAFLAGS += -march=armv8-a 54 55VDSO_CFLAGS := $(VDSO_CAFLAGS) 56# KBUILD_CFLAGS from top-level Makefile 57VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ 58 -fno-strict-aliasing -fno-common \ 59 $(filter -Werror,$(KBUILD_CPPFLAGS)) \ 60 -Werror-implicit-function-declaration \ 61 -Wno-format-security \ 62 $(CC_FLAGS_DIALECT) 63VDSO_CFLAGS += -O2 64# Some useful compiler-dependent flags from top-level Makefile 65VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) 66VDSO_CFLAGS += -fno-strict-overflow 67VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) 68VDSO_CFLAGS += -Werror=date-time 69VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types) 70 71# Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is 72# unreliable. 73ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y) 74VDSO_CFLAGS += -mthumb -fomit-frame-pointer 75else 76VDSO_CFLAGS += -marm 77endif 78 79VDSO_AFLAGS := $(VDSO_CAFLAGS) 80VDSO_AFLAGS += -D__ASSEMBLY__ 81 82# From arm vDSO Makefile 83VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 84VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096 85VDSO_LDFLAGS += -shared --build-id=sha1 86VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) 87 88 89# Borrow vdsomunge.c from the arm vDSO 90# We have to use a relative path because scripts/Makefile.host prefixes 91# $(hostprogs) with $(obj) 92munge := ../../../arm/vdso/vdsomunge 93hostprogs := $(munge) 94 95c-obj-vdso := note.o 96c-obj-vdso-gettimeofday := vgettimeofday.o 97 98ifneq ($(c-gettimeofday-y),) 99VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) 100endif 101 102VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os 103 104# Build rules 105targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso32.so.dbg vdso.so.raw 106c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) 107c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) 108asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) 109obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) 110 111targets += vdso.lds 112CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 113 114# Strip rule for vdso.so 115$(obj)/vdso.so: OBJCOPYFLAGS := -S 116$(obj)/vdso.so: $(obj)/vdso32.so.dbg FORCE 117 $(call if_changed,objcopy) 118 119$(obj)/vdso32.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE 120 $(call if_changed,vdsomunge) 121 122# Link rule for the .so file, .lds has to be first 123$(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE 124 $(call if_changed,vdsold_and_vdso_check) 125 126# Compilation rules for the vDSO sources 127$(c-obj-vdso): %.o: %.c FORCE 128 $(call if_changed_dep,vdsocc) 129$(c-obj-vdso-gettimeofday): %.o: %.c FORCE 130 $(call if_changed_dep,vdsocc_gettimeofday) 131$(asm-obj-vdso): %.o: %.S FORCE 132 $(call if_changed_dep,vdsoas) 133 134# Actual build commands 135quiet_cmd_vdsold_and_vdso_check = LD32 $@ 136 cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check) 137 138quiet_cmd_vdsold = LD32 $@ 139 cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \ 140 -T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 141quiet_cmd_vdsocc = CC32 $@ 142 cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< 143quiet_cmd_vdsocc_gettimeofday = CC32 $@ 144 cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< 145quiet_cmd_vdsoas = AS32 $@ 146 cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< 147 148quiet_cmd_vdsomunge = MUNGE $@ 149 cmd_vdsomunge = $(obj)/$(munge) $< $@ 150