On Tue, Jan 09, 2024 at 08:28:59AM +0800, kernel test robot wrote: > Hi Thomas, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on tip/x86/core] > [also build test WARNING on efi/next tip/master tip/auto-latest linus/master v6.7 next-20240108] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Zimmermann/arch-x86-Move-UAPI-setup-structures-into-setup_data-h/20240108-180158 > base: tip/x86/core > patch link: https://lore.kernel.org/r/20240108095903.8427-3-tzimmermann%40suse.de > patch subject: [PATCH v4 2/4] arch/x86: Move internal setup_data structures into setup_data.h > config: x86_64-rhel-8.3-bpf (https://download.01.org/0day-ci/archive/20240109/202401090800.UOBEKB3W-lkp@xxxxxxxxx/config) > compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18) > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240109/202401090800.UOBEKB3W-lkp@xxxxxxxxx/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Closes: https://lore.kernel.org/oe-kbuild-all/202401090800.UOBEKB3W-lkp@xxxxxxxxx/ > > All warnings (new ones prefixed by >>): > > In file included from arch/x86/realmode/rm/wakemain.c:3: > In file included from arch/x86/boot/boot.h:24: > In file included from arch/x86/include/asm/setup.h:10: > In file included from arch/x86/include/asm/page_types.h:7: > In file included from include/linux/mem_encrypt.h:17: > In file included from arch/x86/include/asm/mem_encrypt.h:18: > In file included from arch/x86/include/uapi/asm/bootparam.h:5: > >> arch/x86/include/asm/setup_data.h:10:20: warning: field 'data' with variable sized type 'struct setup_data' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] > 10 | struct setup_data data; > | ^ > 1 warning generated. I think this warning is expected. This structure is now included in the realmode part of arch/x86, which has its own set of build flags, including -Wall, which includes -Wgnu on clang. The kernel obviously uses GNU extensions and states this clearly with '-std=gnu11', so -Wno-gnu is unconditionally added to KBUILD_CFLAGS for clang. It seems that same treatment is needed for REALMODE_CFLAGS, which also matches arch/x86/boot/compressed/Makefile, see commit 6c3b56b19730 ("x86/boot: Disable Clang warnings about GNU extensions"): diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 1a068de12a56..24076db59783 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -53,6 +53,9 @@ REALMODE_CFLAGS += -fno-stack-protector REALMODE_CFLAGS += -Wno-address-of-packed-member REALMODE_CFLAGS += $(cc_stack_align4) REALMODE_CFLAGS += $(CLANG_FLAGS) +ifdef CONFIG_CC_IS_CLANG +REALMODE_CFLAGS += -Wno-gnu +endif export REALMODE_CFLAGS # BITS is used as extension for files which are available in a 32 bit
