b957df3b85
These are generated files. Prefix them with $(obj)/ instead of $(src)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Helge Deller <deller@gmx.de> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
5.6 KiB
SPDX-License-Identifier: GPL-2.0
Makefile for vdso32
include $(srctree)/lib/vdso/Makefile
Same as cc-*option, but using CC_COMPAT instead of CC
ifeq ($(CONFIG_CC_IS_CLANG), y) CC_COMPAT ?= $(CC) CC_COMPAT += --target=arm-linux-gnueabi else CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc endif
ifeq ($(CONFIG_LD_IS_LLD), y) LD_COMPAT ?= $(LD) else LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld endif
cc32-option = $(call try-run,
$(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
cc32-disable-warning = $(call try-run,
$(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
We cannot use the global flags to compile the vDSO files, the main reason
being that the 32-bit compiler may be older than the main (64-bit) compiler
and therefore may not understand flags set using $(cc-option ...). Besides,
arch-specific options should be taken from the arm Makefile instead of the
arm64 one.
As a result we set our own flags here.
KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc VDSO_CPPFLAGS += -isystem $(shell $(CC_COMPAT) -print-file-name=include 2>/dev/null) VDSO_CPPFLAGS += $(LINUXINCLUDE)
Common C and assembly flags
From top-level Makefile
VDSO_CAFLAGS := $(VDSO_CPPFLAGS) VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) ifdef CONFIG_DEBUG_INFO VDSO_CAFLAGS += -g endif
From arm Makefile
VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm) VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) VDSO_CAFLAGS += -mbig-endian else VDSO_CAFLAGS += -mlittle-endian endif
From arm vDSO Makefile
VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING VDSO_CAFLAGS += -march=armv8-a
VDSO_CFLAGS := $(VDSO_CAFLAGS) VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
KBUILD_CFLAGS from top-level Makefile
VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
-fno-strict-aliasing -fno-common
-Werror-implicit-function-declaration
-Wno-format-security
-std=gnu11
VDSO_CFLAGS += -O2
Some useful compiler-dependent flags from top-level Makefile
VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) VDSO_CFLAGS += -fno-strict-overflow VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) VDSO_CFLAGS += -Werror=date-time VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
The 32-bit compiler does not provide 128-bit integers, which are used in
some headers that are indirectly included from the vDSO code.
This hack makes the compiler happy and should trigger a warning/error if
variables of such type are referenced.
VDSO_CFLAGS += -D__uint128_t='void*'
Silence some warnings coming from headers that operate on long's
(on GCC 4.8 or older, there is unfortunately no way to silence this warning)
VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow) VDSO_CFLAGS += -Wno-int-to-pointer-cast
Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is
unreliable.
ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y) VDSO_CFLAGS += -mthumb -fomit-frame-pointer else VDSO_CFLAGS += -marm endif
VDSO_AFLAGS := $(VDSO_CAFLAGS) VDSO_AFLAGS += -D__ASSEMBLY__
From arm vDSO Makefile
VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096 VDSO_LDFLAGS += -shared --hash-style=sysv --build-id=sha1 VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
Borrow vdsomunge.c from the arm vDSO
We have to use a relative path because scripts/Makefile.host prefixes
$(hostprogs) with $(obj)
munge := ../../../arm/vdso/vdsomunge hostprogs := $(munge)
c-obj-vdso := note.o c-obj-vdso-gettimeofday := vgettimeofday.o
ifneq ($(c-gettimeofday-y),) VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) endif
VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
Build rules
targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso32.so.dbg vdso.so.raw c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
targets += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
Strip rule for vdso.so
$(obj)/vdso.so: OBJCOPYFLAGS := -S $(obj)/vdso.so: $(obj)/vdso32.so.dbg FORCE $(call if_changed,objcopy)
$(obj)/vdso32.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE $(call if_changed,vdsomunge)
Link rule for the .so file, .lds has to be first
$(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE $(call if_changed,vdsold_and_vdso_check)
Compilation rules for the vDSO sources
$(c-obj-vdso): %.o: %.c FORCE $(call if_changed_dep,vdsocc) $(c-obj-vdso-gettimeofday): %.o: %.c FORCE $(call if_changed_dep,vdsocc_gettimeofday) $(asm-obj-vdso): %.o: %.S FORCE $(call if_changed_dep,vdsoas)
Actual build commands
quiet_cmd_vdsold_and_vdso_check = LD32 $@ cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)
quiet_cmd_vdsold = LD32 $@
cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS)
-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
quiet_cmd_vdsocc = CC32 $@
cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $<
quiet_cmd_vdsocc_gettimeofday = CC32 $@
cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $<
quiet_cmd_vdsoas = AS32 $@
cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $<
quiet_cmd_vdsomunge = MUNGE $@ cmd_vdsomunge = $(obj)/$(munge) $< $@