linux-yocto/arch/powerpc/Makefile
Nathan Chancellor c062bba162 powerpc: Adjust adding stack protector flags to KBUILD_CLAGS for clang
commit bee08a9e6a upstream.

After fixing the HAVE_STACKPROTECTER checks for clang's in-progress
per-task stack protector support [1], the build fails during prepare0
because '-mstack-protector-guard-offset' has not been added to
KBUILD_CFLAGS yet but the other '-mstack-protector-guard' flags have.

  clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default
  clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default
  make[4]: *** [scripts/Makefile.build:229: scripts/mod/empty.o] Error 1
  make[4]: *** [scripts/Makefile.build:102: scripts/mod/devicetable-offsets.s] Error 1

Mirror other architectures and add all '-mstack-protector-guard' flags
to KBUILD_CFLAGS atomically during stack_protector_prepare, which
resolves the issue and allows clang's implementation to fully work with
the kernel.

Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/llvm/llvm-project/pull/110928 [1]
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-2-12fb86b31857@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:33:09 +01:00

14 KiB

This file is included by the global makefile so that you can add your own

architecture-specific flags and dependencies.

This file is subject to the terms and conditions of the GNU General Public

License. See the file "COPYING" in the main directory of this archive

for more details.

Copyright (C) 1994 by Linus Torvalds

Changes for PPC by Gary Thomas

Rewritten by Cort Dougan and Paul Mackerras

HAS_BIARCH := $(call cc-option-yn, -m32)

Set default 32 bits cross compilers for vdso and boot wrapper

CROSS32_COMPILE ?=

If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use

ppc64_defconfig because we have nothing better to go on.

uname := $(shell uname -m) KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig

new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' > /dev/null; then echo y; else echo n; fi)

ifeq ($(new_nm),y) NM := $(NM) --synthetic endif

BITS is used as extension for files which are available in a 32 bit

and a 64 bit version to simplify shared Makefiles.

e.g.: obj-y += foo_$(BITS).o

export BITS

ifdef CONFIG_PPC64 BITS := 64 else BITS := 32 endif

machine-y = ppc machine-$(CONFIG_PPC64) += 64 machine-$(CONFIG_CPU_LITTLE_ENDIAN) += le UTS_MACHINE := $(subst $(space),,$(machine-y))

ifeq ($(CONFIG_PPC64)$(CONFIG_LD_IS_BFD),yy)

Have the linker provide sfpr if possible.

There is a corresponding test in arch/powerpc/lib/Makefile

KBUILD_LDFLAGS_MODULE += --save-restore-funcs else KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o endif

ifdef CONFIG_CPU_LITTLE_ENDIAN KBUILD_CFLAGS += -mlittle-endian KBUILD_LDFLAGS += -EL LDEMULATION := lppc GNUTARGET := powerpcle MULTIPLEWORD := -mno-multiple KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-save-toc-indirect) else KBUILD_CFLAGS += $(call cc-option,-mbig-endian) KBUILD_LDFLAGS += -EB LDEMULATION := ppc GNUTARGET := powerpc MULTIPLEWORD := -mmultiple endif

ifdef CONFIG_PPC64 ifndef CONFIG_CC_IS_CLANG cflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mabi=elfv1) cflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mcall-aixdesc) aflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mabi=elfv1) aflags-$(CONFIG_PPC64_ELF_ABI_V2) += -mabi=elfv2 endif endif

ifndef CONFIG_CC_IS_CLANG cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align endif

cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian) cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian) aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian

ifeq ($(HAS_BIARCH),y) KBUILD_CFLAGS += -m$(BITS) KBUILD_AFLAGS += -m$(BITS) KBUILD_LDFLAGS += -m elf$(BITS)$(LDEMULATION) endif

LDFLAGS_vmlinux-y := -Bstatic LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) += -z notext LDFLAGS_vmlinux := $(LDFLAGS_vmlinux-y)

ifdef CONFIG_PPC64 ifndef CONFIG_PPC_KERNEL_PCREL ifeq ($(call cc-option-yn,-mcmodel=medium),y) # -mcmodel=medium breaks modules because it uses 32bit offsets from # the TOC pointer to create pointers where possible. Pointers into the # percpu data area are created by this method. # # The kernel module loader relocates the percpu data section from the # original location (starting with 0xd...) to somewhere in the base # kernel percpu data space (starting with 0xc...). We need a full # 64bit relocation for this to work, hence -mcmodel=large. KBUILD_CFLAGS_MODULE += -mcmodel=large else export NO_MINIMAL_TOC := -mno-minimal-toc endif endif endif

CFLAGS-$(CONFIG_PPC64) := $(call cc-option,-mtraceback=no) ifdef CONFIG_PPC64_ELF_ABI_V2 CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2,$(call cc-option,-mcall-aixdesc)) else ifndef CONFIG_CC_IS_CLANG CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcall-aixdesc) endif endif CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc)) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mlong-double-128)

Clang unconditionally reserves r2 on ppc32 and does not support the flag

https://bugs.llvm.org/show_bug.cgi?id=39555

CFLAGS-$(CONFIG_PPC32) := $(call cc-option, -ffixed-r2)

Clang doesn't support -mmultiple / -mno-multiple

https://bugs.llvm.org/show_bug.cgi?id=39556

CFLAGS-$(CONFIG_PPC32) += $(call cc-option, $(MULTIPLEWORD))

CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata)

ifdef CONFIG_FUNCTION_TRACER ifdef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY CC_FLAGS_FTRACE := -fpatchable-function-entry=2 else CC_FLAGS_FTRACE := -pg ifdef CONFIG_MPROFILE_KERNEL CC_FLAGS_FTRACE += -mprofile-kernel endif endif endif

CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU) AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU)

CFLAGS-y += $(CONFIG_TUNE_CPU)

asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)

KBUILD_CPPFLAGS += -I $(srctree)/arch/$(ARCH) $(asinstr) KBUILD_AFLAGS += $(AFLAGS-y) KBUILD_CFLAGS += $(call cc-option,-msoft-float) KBUILD_CFLAGS += $(CFLAGS-y) CPP = $(CC) -E $(KBUILD_CFLAGS)

CHECKFLAGS += -m$(BITS) -D__powerpc__ -D__powerpc$(BITS)__ ifdef CONFIG_CPU_BIG_ENDIAN CHECKFLAGS += -D__BIG_ENDIAN__ else CHECKFLAGS += -D__LITTLE_ENDIAN__ endif

ifdef CONFIG_476FPE_ERR46 KBUILD_LDFLAGS_MODULE += --ppc476-workaround
-T $(srctree)/arch/powerpc/platforms/44x/ppc476_modules.lds endif

No prefix or pcrel

ifdef CONFIG_PPC_KERNEL_PREFIXED KBUILD_CFLAGS += $(call cc-option,-mprefixed) else KBUILD_CFLAGS += $(call cc-option,-mno-prefixed) endif ifdef CONFIG_PPC_KERNEL_PCREL KBUILD_CFLAGS += $(call cc-option,-mpcrel) else KBUILD_CFLAGS += $(call cc-option,-mno-pcrel) endif

No AltiVec or VSX or MMA instructions when building kernel

KBUILD_CFLAGS += $(call cc-option,-mno-altivec) KBUILD_CFLAGS += $(call cc-option,-mno-vsx) KBUILD_CFLAGS += $(call cc-option,-mno-mma)

No SPE instruction when building kernel

(We use all available options to help semi-broken compilers)

KBUILD_CFLAGS += $(call cc-option,-mno-spe) KBUILD_CFLAGS += $(call cc-option,-mspe=no)

Don't emit .eh_frame since we have no use for it

KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

Never use string load/store instructions as they are

often slow when they are implemented at all

KBUILD_CFLAGS += $(call cc-option,-mno-string)

cpu-as-$(CONFIG_ALTIVEC) += $(call as-option,-Wa$(comma)-maltivec)

When using '-many -mpower4' gas will first try and find a matching power4

mnemonic and failing that it will allow any valid mnemonic that GAS knows

about. GCC will pass -many to GAS when assembling, clang does not.

LLVM IAS doesn't understand either flag: https://github.com/ClangBuiltLinux/linux/issues/675

but LLVM IAS only supports ISA >= 2.06 for Book3S 64 anyway...

cpu-as-$(CONFIG_PPC_BOOK3S_64) += $(call as-option,-Wa$(comma)-mpower4) $(call as-option,-Wa$(comma)-many)

KBUILD_AFLAGS += $(cpu-as-y) KBUILD_CFLAGS += $(cpu-as-y)

KBUILD_AFLAGS += $(aflags-y) KBUILD_CFLAGS += $(cflags-y)

Default to zImage, override when needed

all: zImage

With make 3.82 we cannot mix normal and wildcard targets

BOOT_TARGETS1 := zImage zImage.initrd uImage BOOT_TARGETS2 := zImage% dtbImage% treeImage.% cuImage.% simpleImage.% uImage.%

PHONY += $(BOOT_TARGETS1) $(BOOT_TARGETS2)

boot := arch/$(ARCH)/boot

$(BOOT_TARGETS1): vmlinux $(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@) $(BOOT_TARGETS2): vmlinux $(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)

PHONY += bootwrapper_install bootwrapper_install: $(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)

include $(srctree)/scripts/Makefile.defconf

generated_configs += ppc64le_defconfig ppc64le_defconfig: $(call merge_into_defconfig,ppc64_defconfig,le)

generated_configs += ppc64le_guest_defconfig ppc64le_guest_defconfig: $(call merge_into_defconfig,ppc64_defconfig,le guest kvm_guest)

generated_configs += ppc64_guest_defconfig ppc64_guest_defconfig: $(call merge_into_defconfig,ppc64_defconfig,be guest kvm_guest)

generated_configs += pseries_le_defconfig pseries_le_defconfig: ppc64le_guest_defconfig

generated_configs += pseries_defconfig pseries_defconfig: ppc64le_guest_defconfig

generated_configs += powernv_be_defconfig powernv_be_defconfig: $(call merge_into_defconfig,powernv_defconfig,be)

generated_configs += mpc85xx_defconfig mpc85xx_defconfig: $(call merge_into_defconfig,mpc85xx_base.config,
85xx-32bit 85xx-hw fsl-emb-nonhw)

generated_configs += mpc85xx_smp_defconfig mpc85xx_smp_defconfig: $(call merge_into_defconfig,mpc85xx_base.config,
85xx-32bit 85xx-smp 85xx-hw fsl-emb-nonhw)

generated_configs += corenet32_smp_defconfig corenet32_smp_defconfig: $(call merge_into_defconfig,corenet_base.config,
85xx-32bit 85xx-smp 85xx-hw fsl-emb-nonhw dpaa)

generated_configs += corenet64_smp_defconfig corenet64_smp_defconfig: $(call merge_into_defconfig,corenet_base.config,
85xx-64bit 85xx-smp altivec 85xx-hw fsl-emb-nonhw dpaa)

generated_configs += mpc86xx_defconfig mpc86xx_defconfig: $(call merge_into_defconfig,mpc86xx_base.config,
86xx-hw fsl-emb-nonhw)

generated_configs += mpc86xx_smp_defconfig mpc86xx_smp_defconfig: $(call merge_into_defconfig,mpc86xx_base.config,
86xx-smp 86xx-hw fsl-emb-nonhw)

generated_configs += ppc32_allmodconfig ppc32_allmodconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/book3s_32.config
-f $(srctree)/Makefile allmodconfig

generated_configs += ppc_defconfig ppc_defconfig: $(call merge_into_defconfig,book3s_32.config,)

generated_configs += ppc64le_allmodconfig ppc64le_allmodconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/le.config
-f $(srctree)/Makefile allmodconfig

generated_configs += ppc64le_allnoconfig ppc64le_allnoconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/ppc64le.config
-f $(srctree)/Makefile allnoconfig

generated_configs += ppc64_book3e_allmodconfig ppc64_book3e_allmodconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/85xx-64bit.config
-f $(srctree)/Makefile allmodconfig

generated_configs += ppc32_randconfig ppc32_randconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/32-bit.config
-f $(srctree)/Makefile randconfig

generated_configs += ppc64_randconfig ppc64_randconfig: $(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/64-bit.config
-f $(srctree)/Makefile randconfig

PHONY += $(generated_configs)

define archhelp echo '* zImage - Build default images selected by kernel config' echo ' zImage.* - Compressed kernel image (arch/$(ARCH)/boot/zImage.*)' echo ' uImage - U-Boot native image format' echo ' cuImage.

- Backwards compatible U-Boot image for older' echo ' versions which do not support device trees' echo ' dtbImage.
- zImage with an embedded device tree blob' echo ' simpleImage.
- Firmware independent image.' echo ' treeImage.
- Support for older IBM 4xx firmware (not U-Boot)' echo ' install - Install kernel using' echo ' (your) ~/bin/$(INSTALLKERNEL) or' echo ' (distribution) /sbin/$(INSTALLKERNEL) or' echo ' install to $$(INSTALL_PATH) and run lilo' echo ' *_defconfig - Select default config from arch/$(ARCH)/configs' echo '' echo ' Targets with
embed a device tree blob inside the image' echo ' These targets support board with firmware that does not' echo ' support passing a device tree directly. Replace
with the' echo ' name of a dts file from the arch/$(ARCH)/boot/dts/ directory' echo ' (minus the .dts extension).' echo $(foreach cfg,$(generated_configs), printf " %-27s - Build for %s\n" $(cfg) $(subst _defconfig,,$(cfg));) endef

PHONY += install install: $(call cmd,install)

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 $(if $(CONFIG_VDSO32),$(Q)$(MAKE)
$(build)=arch/powerpc/kernel/vdso include/generated/vdso32-offsets.h) $(if $(CONFIG_PPC64),$(Q)$(MAKE)
$(build)=arch/powerpc/kernel/vdso include/generated/vdso64-offsets.h) endif

archprepare: checkbin

archheaders: $(Q)$(MAKE) $(build)=arch/powerpc/kernel/syscalls all

ifdef CONFIG_STACKPROTECTOR prepare: stack_protector_prepare

PHONY += stack_protector_prepare stack_protector_prepare: prepare0 ifdef CONFIG_PPC64 $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls -mstack-protector-guard-reg=r13
-mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) else $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls -mstack-protector-guard-reg=r2
-mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) endif endif

PHONY += checkbin checkbin: @if test "x${CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT}" = "xy" -a
"x${CONFIG_LD_IS_BFD}" = "xy" -a
"${CONFIG_LD_VERSION}" = "23700" ; then
echo -n '*** binutils 2.37 drops unused section symbols, which recordmcount ' ;
echo 'is unable to handle.' ;
echo '*** Please use a different binutils version.' ;
false ;
fi