Hi Mauro, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 4cee37b3a4e68c42b867c87a6218e11bc571ba66 commit: e7b8153e2a4f0c9c8d1450aa7328d54ea64fe8b2 media: platform: place stm32/ and sti/ under st/ dir date: 9 months ago config: s390-randconfig-r011-20221211 compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6e4cea55f0d1104408b26ac574566a0e4de48036) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e7b8153e2a4f0c9c8d1450aa7328d54ea64fe8b2 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout e7b8153e2a4f0c9c8d1450aa7328d54ea64fe8b2 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/media/platform/st/sti/c8sectpfe/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): In file included from drivers/media/platform/st/sti/c8sectpfe/c8sectpfe-core.c:16: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from drivers/media/platform/st/sti/c8sectpfe/c8sectpfe-core.c:16: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from drivers/media/platform/st/sti/c8sectpfe/c8sectpfe-core.c:16: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> drivers/media/platform/st/sti/c8sectpfe/c8sectpfe-core.c:1175:34: warning: unused variable 'c8sectpfe_match' [-Wunused-const-variable] static const struct of_device_id c8sectpfe_match[] = { ^ 13 warnings generated. vim +/c8sectpfe_match +1175 drivers/media/platform/st/sti/c8sectpfe/c8sectpfe-core.c c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1174 c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 @1175 static const struct of_device_id c8sectpfe_match[] = { c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1176 { .compatible = "st,stih407-c8sectpfe" }, c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1177 { /* sentinel */ }, c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1178 }; c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1179 MODULE_DEVICE_TABLE(of, c8sectpfe_match); c5f5d0f99794cf drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c Peter Griffin 2015-07-30 1180 :::::: The code at line 1175 was first introduced by commit :::::: c5f5d0f99794cfb675ecacfe37a1b33b352b9752 [media] c8sectpfe: STiH407/10 Linux DVB demux support :::::: TO: Peter Griffin :::::: CC: Mauro Carvalho Chehab -- 0-DAY CI Kernel Test Service https://01.org/lkp