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 11COMPATCC := $(CROSS_COMPILE_COMPAT)gcc 12 13# Same as cc-*option, but using COMPATCC instead of CC 14cc32-option = $(call try-run,\ 15 $(COMPATCC) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 16cc32-disable-warning = $(call try-run,\ 17 $(COMPATCC) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 18cc32-ldoption = $(call try-run,\ 19 $(COMPATCC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 20 21# We cannot use the global flags to compile the vDSO files, the main reason 22# being that the 32-bit compiler may be older than the main (64-bit) compiler 23# and therefore may not understand flags set using $(cc-option ...). Besides, 24# arch-specific options should be taken from the arm Makefile instead of the 25# arm64 one. 26# As a result we set our own flags here. 27 28# From top-level Makefile 29# NOSTDINC_FLAGS 30VDSO_CPPFLAGS := -nostdinc -isystem $(shell $(COMPATCC) -print-file-name=include) 31VDSO_CPPFLAGS += $(LINUXINCLUDE) 32VDSO_CPPFLAGS += $(KBUILD_CPPFLAGS) 33 34# Common C and assembly flags 35# From top-level Makefile 36VDSO_CAFLAGS := $(VDSO_CPPFLAGS) 37VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) 38ifdef CONFIG_DEBUG_INFO 39VDSO_CAFLAGS += -g 40endif 41ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(COMPATCC)), y) 42VDSO_CAFLAGS += -DCC_HAVE_ASM_GOTO 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 57 58# Try to compile for ARMv8. If the compiler is too old and doesn't support it, 59# fall back to v7. There is no easy way to check for what architecture the code 60# is being compiled, so define a macro specifying that (see arch/arm/Makefile). 61VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\ 62 -march=armv7-a -D__LINUX_ARM_ARCH__=7) 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 += $(call cc32-option,-fno-strict-overflow) 77VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) 78VDSO_CFLAGS += $(call cc32-option,-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 91VDSO_AFLAGS := $(VDSO_CAFLAGS) 92VDSO_AFLAGS += -D__ASSEMBLY__ 93 94VDSO_LDFLAGS := $(VDSO_CPPFLAGS) 95# From arm vDSO Makefile 96VDSO_LDFLAGS += -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 97VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 98VDSO_LDFLAGS += -nostdlib -shared -mfloat-abi=soft 99VDSO_LDFLAGS += -Wl,--hash-style=sysv 100VDSO_LDFLAGS += -Wl,--build-id 101VDSO_LDFLAGS += $(call cc32-ldoption,-fuse-ld=bfd) 102 103 104# Borrow vdsomunge.c from the arm vDSO 105# We have to use a relative path because scripts/Makefile.host prefixes 106# $(hostprogs-y) with $(obj) 107munge := ../../../arm/vdso/vdsomunge 108hostprogs-y := $(munge) 109 110c-obj-vdso := note.o 111c-obj-vdso-gettimeofday := vgettimeofday.o 112asm-obj-vdso := sigreturn.o 113 114ifneq ($(c-gettimeofday-y),) 115VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) 116endif 117 118VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os 119 120# Build rules 121targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw 122c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) 123c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) 124asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) 125obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) 126 127obj-y += vdso.o 128extra-y += vdso.lds 129CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 130 131# Force dependency (vdso.s includes vdso.so through incbin) 132$(obj)/vdso.o: $(obj)/vdso.so 133 134include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE 135 $(call if_changed,vdsosym) 136 137# Strip rule for vdso.so 138$(obj)/vdso.so: OBJCOPYFLAGS := -S 139$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE 140 $(call if_changed,objcopy) 141 142$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE 143 $(call if_changed,vdsomunge) 144 145# Link rule for the .so file, .lds has to be first 146$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE 147 $(call if_changed,vdsold) 148 $(call if_changed,vdso_check) 149 150# Compilation rules for the vDSO sources 151$(c-obj-vdso): %.o: %.c FORCE 152 $(call if_changed_dep,vdsocc) 153$(c-obj-vdso-gettimeofday): %.o: %.c FORCE 154 $(call if_changed_dep,vdsocc_gettimeofday) 155$(asm-obj-vdso): %.o: %.S FORCE 156 $(call if_changed_dep,vdsoas) 157 158# Actual build commands 159quiet_cmd_vdsold = VDSOL $@ 160 cmd_vdsold = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_LDFLAGS) \ 161 -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 162quiet_cmd_vdsocc = VDSOC $@ 163 cmd_vdsocc = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< 164quiet_cmd_vdsocc_gettimeofday = VDSOC_GTD $@ 165 cmd_vdsocc_gettimeofday = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< 166quiet_cmd_vdsoas = VDSOA $@ 167 cmd_vdsoas = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< 168 169quiet_cmd_vdsomunge = MUNGE $@ 170 cmd_vdsomunge = $(obj)/$(munge) $< $@ 171 172# Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO) 173gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh 174quiet_cmd_vdsosym = VDSOSYM $@ 175# The AArch64 nm should be able to read an AArch32 binary 176 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 177 178# Install commands for the unstripped file 179quiet_cmd_vdso_install = INSTALL $@ 180 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so 181 182vdso.so: $(obj)/vdso.so.dbg 183 @mkdir -p $(MODLIB)/vdso 184 $(call cmd,vdso_install) 185 186vdso_install: vdso.so 187