linux-stable/arch/s390/Makefile
Linus Torvalds f0be87c42c gcc-12: disable '-Warray-bounds' universally for now
In commit 8b202ee218 ("s390: disable -Warray-bounds") the s390 people
disabled the '-Warray-bounds' warning for gcc-12, because the new logic
in gcc would cause warnings for their use of the S390_lowcore macro,
which accesses absolute pointers.

It turns out gcc-12 has many other issues in this area, so this takes
that s390 warning disable logic, and turns it into a kernel build config
entry instead.

Part of the intent is that we can make this all much more targeted, and
use this conflig flag to disable it in only particular configurations
that cause problems, with the s390 case as an example:

        select GCC12_NO_ARRAY_BOUNDS

and we could do that for other configuration cases that cause issues.

Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more
targeted way, and disable the warning only for particular uses: again
the s390 case as an example:

  KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds)

but this ends up just doing it globally in the top-level Makefile, since
the current issues are spread fairly widely all over:

  KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds

We'll try to limit this later, since the gcc-12 problems are rare enough
that *much* of the kernel can be built with it without disabling this
warning.

Cc: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-09 10:11:12 -07:00

175 lines
5.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# s390/Makefile
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies.
#
# Copyright (C) 1994 by Linus Torvalds
#
LD_BFD := elf64-s390
KBUILD_LDFLAGS := -m elf64_s390
KBUILD_AFLAGS_MODULE += -fPIC
KBUILD_CFLAGS_MODULE += -fPIC
KBUILD_AFLAGS += -m64
KBUILD_CFLAGS += -m64
ifeq ($(CONFIG_RELOCATABLE),y)
KBUILD_CFLAGS += -fPIE
LDFLAGS_vmlinux := -pie
endif
aflags_dwarf := -Wa,-gdwarf-2
KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__
ifndef CONFIG_AS_IS_LLVM
KBUILD_AFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),$(aflags_dwarf))
endif
KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2 -mpacked-stack
KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float -mbackchain
KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables
KBUILD_CFLAGS_DECOMPRESSOR += -ffreestanding
KBUILD_CFLAGS_DECOMPRESSOR += -fno-stack-protector
KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, address-of-packed-member)
KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),-g)
KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO_DWARF4), $(call cc-option, -gdwarf-4,))
KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds)
UTS_MACHINE := s390x
STACK_SIZE := $(if $(CONFIG_KASAN),65536,16384)
CHECKFLAGS += -D__s390__ -D__s390x__
export LD_BFD
mflags-$(CONFIG_MARCH_Z10) := -march=z10
mflags-$(CONFIG_MARCH_Z196) := -march=z196
mflags-$(CONFIG_MARCH_ZEC12) := -march=zEC12
mflags-$(CONFIG_MARCH_Z13) := -march=z13
mflags-$(CONFIG_MARCH_Z14) := -march=z14
mflags-$(CONFIG_MARCH_Z15) := -march=z15
mflags-$(CONFIG_MARCH_Z16) := -march=z16
export CC_FLAGS_MARCH := $(mflags-y)
aflags-y += $(mflags-y)
cflags-y += $(mflags-y)
cflags-$(CONFIG_MARCH_Z10_TUNE) += -mtune=z10
cflags-$(CONFIG_MARCH_Z196_TUNE) += -mtune=z196
cflags-$(CONFIG_MARCH_ZEC12_TUNE) += -mtune=zEC12
cflags-$(CONFIG_MARCH_Z13_TUNE) += -mtune=z13
cflags-$(CONFIG_MARCH_Z14_TUNE) += -mtune=z14
cflags-$(CONFIG_MARCH_Z15_TUNE) += -mtune=z15
cflags-$(CONFIG_MARCH_Z16_TUNE) += -mtune=z16
cflags-y += -Wa,-I$(srctree)/arch/$(ARCH)/include
#
# Prevent tail-call optimizations, to get clearer backtraces:
#
cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
KBUILD_AFLAGS_DECOMPRESSOR += $(aflags-y)
KBUILD_CFLAGS_DECOMPRESSOR += $(cflags-y)
ifneq ($(call cc-option,-mstack-size=8192 -mstack-guard=128),)
CC_FLAGS_CHECK_STACK := -mstack-size=$(STACK_SIZE)
ifeq ($(call cc-option,-mstack-size=8192),)
CC_FLAGS_CHECK_STACK += -mstack-guard=$(CONFIG_STACK_GUARD)
endif
export CC_FLAGS_CHECK_STACK
cflags-$(CONFIG_CHECK_STACK) += $(CC_FLAGS_CHECK_STACK)
endif
ifdef CONFIG_EXPOLINE
ifdef CONFIG_EXPOLINE_EXTERN
KBUILD_LDFLAGS_MODULE += arch/s390/lib/expoline.o
CC_FLAGS_EXPOLINE := -mindirect-branch=thunk-extern
CC_FLAGS_EXPOLINE += -mfunction-return=thunk-extern
else
CC_FLAGS_EXPOLINE := -mindirect-branch=thunk
CC_FLAGS_EXPOLINE += -mfunction-return=thunk
endif
CC_FLAGS_EXPOLINE += -mindirect-branch-table
export CC_FLAGS_EXPOLINE
cflags-y += $(CC_FLAGS_EXPOLINE) -DCC_USING_EXPOLINE
aflags-y += -DCC_USING_EXPOLINE
endif
ifdef CONFIG_FUNCTION_TRACER
ifeq ($(call cc-option,-mfentry -mnop-mcount),)
# make use of hotpatch feature if the compiler supports it
cc_hotpatch := -mhotpatch=0,3
ifneq ($(call cc-option,$(cc_hotpatch)),)
CC_FLAGS_FTRACE := $(cc_hotpatch)
KBUILD_AFLAGS += -DCC_USING_HOTPATCH
KBUILD_CFLAGS += -DCC_USING_HOTPATCH
endif
endif
endif
# Test CFI features of binutils
cfi := $(call as-instr,.cfi_startproc\n.cfi_val_offset 15$(comma)-160\n.cfi_endproc,-DCONFIG_AS_CFI_VAL_OFFSET=1)
KBUILD_CFLAGS += -mpacked-stack -mbackchain -msoft-float $(cflags-y)
KBUILD_CFLAGS += -pipe -Wno-sign-compare
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables $(cfi)
KBUILD_AFLAGS += $(aflags-y) $(cfi)
export KBUILD_AFLAGS_DECOMPRESSOR
export KBUILD_CFLAGS_DECOMPRESSOR
OBJCOPYFLAGS := -O binary
head-y := arch/s390/kernel/head64.o
libs-y += arch/s390/lib/
drivers-y += drivers/s390/
boot := arch/s390/boot
syscalls := arch/s390/kernel/syscalls
tools := arch/s390/tools
all: bzImage
#KBUILD_IMAGE is necessary for packaging targets like rpm-pkg, deb-pkg...
KBUILD_IMAGE := $(boot)/bzImage
install:
$(call cmd,install)
bzImage: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
zfcpdump:
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
vdso_install:
$(Q)$(MAKE) $(build)=arch/$(ARCH)/kernel/vdso64 $@
archheaders:
$(Q)$(MAKE) $(build)=$(syscalls) uapi
archprepare:
$(Q)$(MAKE) $(build)=$(syscalls) kapi
$(Q)$(MAKE) $(build)=$(tools) kapi
ifeq ($(KBUILD_EXTMOD),)
# We need to generate vdso-offsets.h before compiling certain files in kernel/.
# In order to do that, we should use the archprepare target, but we can't since
# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
# Therefore we need to generate the header after prepare0 has been made, hence
# this hack.
prepare: vdso_prepare
vdso_prepare: prepare0
$(Q)$(MAKE) $(build)=arch/s390/kernel/vdso64 include/generated/vdso64-offsets.h
$(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
$(build)=arch/s390/kernel/vdso32 include/generated/vdso32-offsets.h)
endif
# Don't use tabs in echo arguments
define archhelp
echo '* bzImage - Kernel image for IPL ($(boot)/bzImage)'
echo ' install - Install kernel using'
echo ' (your) ~/bin/$(INSTALLKERNEL) or'
echo ' (distribution) /sbin/$(INSTALLKERNEL) or'
echo ' install to $$(INSTALL_PATH)'
endef