[Buildroot] [PATCH v2, 1/1] board/qemu/s390x: disable SSP when needed

[Alexander Egorenkov <egorenar@linux.ibm.com>]

Fabrice Fontaine <fontaine.fabrice@gmail.com> writes:

> Fix build failure raised since commit
> 810ba387bec3c5b6904e8893fb4cb6f9d3717466 by disabling SSP when needed
>
> Fixes:
>  - https://gitlab.com/kubu93/buildroot/-/jobs/1247043361
>
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
> ---
> Changes v1 -> v2 (after review of Romain Naour):
>  - Move patch from linux to board/qemu/s390x
>
>  ...01-arch-s390-disable-SSP-when-needed.patch | 47 +++++++++++++++++++
>  configs/qemu_s390x_defconfig                  |  1 +
>  2 files changed, 48 insertions(+)
>  create mode 100644 board/qemu/s390x/patches/linux/0001-arch-s390-disable-SSP-when-needed.patch
>
> diff --git a/board/qemu/s390x/patches/linux/0001-arch-s390-disable-SSP-when-needed.patch b/board/qemu/s390x/patches/linux/0001-arch-s390-disable-SSP-when-needed.patch
> new file mode 100644
> index 0000000000..c8199d4fd6
> --- /dev/null
> +++ b/board/qemu/s390x/patches/linux/0001-arch-s390-disable-SSP-when-needed.patch
> @@ -0,0 +1,47 @@
> +From 8a054081678ed0b0e56f829bac0a4656e3a198b9 Mon Sep 17 00:00:00 2001
> +From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
> +Date: Sat, 8 May 2021 22:03:11 +0200
> +Subject: [PATCH] arch/s390: disable SSP when needed
> +
> +Though -nostdlib is passed in PURGATORY_LDFLAGS and -ffreestanding in
> +KBUILD_CFLAGS_DECOMPRESSOR, -fno-stack-protector must also be passed to
> +avoid linking errors related to undefined references to
> +'__stack_chk_guard' and '__stack_chk_fail' if toolchain enforces
> +-fstack-protector.
> +
> +Fixes:
> + - https://gitlab.com/kubu93/buildroot/-/jobs/1247043361
> +
> +Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
> +---
> + arch/s390/Makefile           | 1 +
> + arch/s390/purgatory/Makefile | 1 +
> + 2 files changed, 2 insertions(+)
> +
> +diff --git a/arch/s390/Makefile b/arch/s390/Makefile
> +index e443ed9947bd..098abe3a56f3 100644
> +--- a/arch/s390/Makefile
> ++++ b/arch/s390/Makefile
> +@@ -28,6 +28,7 @@ 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,))
> +diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
> +index c57f8c40e992..21c4ebe29b9a 100644
> +--- a/arch/s390/purgatory/Makefile
> ++++ b/arch/s390/purgatory/Makefile
> +@@ -24,6 +24,7 @@ KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
> + KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
> + KBUILD_CFLAGS += -fno-zero-initialized-in-bss -fno-builtin -ffreestanding
> + KBUILD_CFLAGS += -c -MD -Os -m64 -msoft-float -fno-common
> ++KBUILD_CFLAGS += -fno-stack-protector
> + KBUILD_CFLAGS += $(CLANG_FLAGS)
> + KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
> + KBUILD_AFLAGS := $(filter-out -DCC_USING_EXPOLINE,$(KBUILD_AFLAGS))
> +-- 
> +2.30.2
> +
> diff --git a/configs/qemu_s390x_defconfig b/configs/qemu_s390x_defconfig
> index 9b3821f043..4aed9d9ae5 100644
> --- a/configs/qemu_s390x_defconfig
> +++ b/configs/qemu_s390x_defconfig
> @@ -20,6 +20,7 @@ BR2_LINUX_KERNEL_CUSTOM_VERSION=y
>  BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.10.7"
>  BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
>  BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
> +BR2_GLOBAL_PATCH_DIR="board/qemu/s390x/patches"
>  
>  # host-qemu for gitlab testing
>  BR2_PACKAGE_HOST_QEMU=y
> -- 
> 2.30.2

Thank you for the fix. Looks good to me.

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>

Regards
Alex