kernel.git/arch/s390/Makefile, branch linux-5.4.y

s390: Add '-std=gnu11' to decompressor and purgatory CFLAGS

2025-07-17T16:24:55Z

commit 3b8b80e993766dc96d1a1c01c62f5d15fafc79b9 upstream. GCC changed the default C standard dialect from gnu17 to gnu23, which should not have impacted the kernel because it explicitly requests the gnu11 standard in the main Makefile. However, there are certain places in the s390 code that use their own CFLAGS without a '-std=' value, which break with this dialect change because of the kernel's own definitions of bool, false, and true conflicting with the C23 reserved keywords. include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant 11 | false = 0, | ^~~~~ include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards include/linux/types.h:35:33: error: 'bool' cannot be defined via 'typedef' 35 | typedef _Bool bool; | ^~~~ include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards Add '-std=gnu11' to the decompressor and purgatory CFLAGS to eliminate these errors and make the C standard version of these areas match the rest of the kernel. Cc: stable@vger.kernel.org Signed-off-by: Nathan Chancellor Tested-by: Heiko Carstens Link: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390: disable -Warray-bounds

2022-05-18T07:47:26Z

[ Upstream commit 8b202ee218395319aec1ef44f72043e1fbaccdd6 ] gcc-12 shows a lot of array bound warnings on s390. This is caused by the S390_lowcore macro which uses a hardcoded address of 0. Wrapping that with absolute_pointer() works, but gcc no longer knows that a 12 bit displacement is sufficient to access lowcore. So it emits instructions like 'lghi %r1,0; l %rx,xxx(%r1)' instead of a single load/store instruction. As s390 stores variables often read/written in lowcore, this is considered problematic. Therefore disable -Warray-bounds on s390 for gcc-12 for the time being, until there is a better solution. Signed-off-by: Sven Schnelle Link: https://lore.kernel.org/r/yt9dzgkelelc.fsf@linux.ibm.com Link: https://lore.kernel.org/r/20220422134308.1613610-1-svens@linux.ibm.com Link: https://lore.kernel.org/r/20220425121742.3222133-1-svens@linux.ibm.com Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390: make 'install' not depend on vmlinux

2020-03-12T12:00:13Z

[ Upstream commit 94e90f727f7424d827256023cace829cad6896f4 ] For the same reason as commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"), the install targets should never trigger the rebuild of the kernel. The variable, CONFIGURE, is not set by anyone. Remove it as well. Link: https://lkml.kernel.org/r/20200216144829.27023-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390: adjust -mpacked-stack support check for clang 10

2020-02-24T07:36:55Z

[ Upstream commit 253b3c4b2920e07ce9e2b18800b9b65245e2fafa ] clang 10 introduces -mpacked-stack compiler option implementation. At the same time currently it does not support a combination of -mpacked-stack and -mbackchain. This leads to the following build error: clang: error: unsupported option '-mpacked-stack with -mbackchain' for target 's390x-ibm-linux' If/when clang adds support for a combination of -mpacked-stack and -mbackchain it would also require -msoft-float (like gcc does). According to Ulrich Weigand "stack slot assigned to the kernel backchain overlaps the stack slot assigned to the FPR varargs (both are required to be placed immediately after the saved r15 slot if present)." Extend -mpacked-stack compiler option support check to include all 3 options -mpacked-stack -mbackchain -msoft-float which must present to support -mpacked-stack with -mbackchain. Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390: add support for IBM z15 machines

2019-09-13T10:19:14Z

Add detection for machine types 0x8562 and 8x8561 and set the ELF platform name to z15. Add the miscellaneous-instruction-extension 3 facility to the list of facilities for z15. And allow to generate code that only runs on a z15 machine. Reviewed-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens

Merge tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-07-12T23:06:27Z

Pull Kconfig updates from Masahiro Yamada: - always require argument for --defconfig and remove the hard-coded arch/$(ARCH)/defconfig path - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig - some code cleanups * tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove meaningless if-conditional in conf_read() kconfig: Fix spelling of sym_is_changable unicore32: rename unicore32_defconfig to defconfig kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG kconfig: add static qualifier to expand_string() kconfig: require the argument of --defconfig kconfig: remove always false ifeq ($(KBUILD_DEFCONFIG,) conditional

s390/boot: disable address-of-packed-member warning

2019-06-11T07:46:43Z

Get rid of gcc9 warnings like this: arch/s390/boot/ipl_report.c: In function 'find_bootdata_space': arch/s390/boot/ipl_report.c:42:26: warning: taking address of packed member of 'struct ipl_rb_components' may result in an unaligned pointer value [-Waddress-of-packed-member] 42 | for_each_rb_entry(comp, comps) | ^~~~~ This is effectively the s390 variant of commit 20c6c1890455 ("x86/boot: Disable the address-of-packed-member compiler warning"). Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG

2019-06-09T06:08:18Z

Until recently, if KBUILD_DEFCONFIG was not set by the arch Makefile, the default path arch/*/defconfig was used. The last users of the default are gone by the following commits: - Commit f3e20ad67b4c ("s390: move arch/s390/defconfig to arch/s390/configs/defconfig") - Commit 986a13769c4b ("alpha: move arch/alpha/defconfig to arch/alpha/configs/defconfig") Let's set arch/*/configs/defconfig as a new default. This saves KBUILD_DEFCONFIG for some architectures. Signed-off-by: Masahiro Yamada Acked-by: Catalin Marinas

s390: move arch/s390/defconfig to arch/s390/configs/defconfig

2019-05-14T15:54:48Z

As of Linux 5.1, alpha and s390 are the last architectures that have defconfig in arch/*/ instead of arch/*/configs/. $ find arch -name defconfig | sort arch/alpha/defconfig arch/arm64/configs/defconfig arch/csky/configs/defconfig arch/nds32/configs/defconfig arch/riscv/configs/defconfig arch/s390/defconfig The arch/$(ARCH)/defconfig is the hard-coded default in Kconfig, and I want to deprecate it after evacuating the remaining defconfig into the standard location, arch/*/configs/. Define KBUILD_DEFCONFIG like other architectures, and move defconfig into the configs/ subdirectory. Signed-off-by: Masahiro Yamada Signed-off-by: Martin Schwidefsky

s390: boot, purgatory: pass $(CLANG_FLAGS) where needed

2019-05-03T15:17:58Z

The purgatory and boot Makefiles do not inherit the original cflags, so clang falls back to the default target architecture when building it, typically this would be x86 when cross-compiling. Add $(CLANG_FLAGS) everywhere so we pass the correct --target=s390x-linux option when cross-compiling. Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky