Hi Jonathan, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on song-md/md-next] [also build test WARNING on linus/master v6.2 next-20230224] [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/Jonathan-Derrick/md-Move-sb-writer-loop-to-its-own-function/20230224-035451 base: git://git.kernel.org/pub/scm/linux/kernel/git/song/md.git md-next patch link: https://lore.kernel.org/r/20230223195225.534-2-jonathan.derrick%40linux.dev patch subject: [PATCH v4 1/3] md: Move sb writer loop to its own function config: s390-randconfig-r036-20230223 (https://download.01.org/0day-ci/archive/20230224/202302241507.7JQRJLLW-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project db89896bbbd2251fff457699635acbbedeead27f) 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://github.com/intel-lab-lkp/linux/commit/93818e631c76938f9a3ad87d1baf681645d02ba7 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Jonathan-Derrick/md-Move-sb-writer-loop-to-its-own-function/20230224-035451 git checkout 93818e631c76938f9a3ad87d1baf681645d02ba7 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202302241507.7JQRJLLW-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from drivers/md/md-bitmap.c:31: In file included from include/trace/events/block.h:8: In file included from include/linux/blktrace_api.h:5: In file included from include/linux/blk-mq.h:8: 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:547:31: 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:560:61: 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/md/md-bitmap.c:31: In file included from include/trace/events/block.h:8: In file included from include/linux/blktrace_api.h:5: In file included from include/linux/blk-mq.h:8: 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:573:61: 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/md/md-bitmap.c:31: In file included from include/trace/events/block.h:8: In file included from include/linux/blktrace_api.h:5: In file included from include/linux/blk-mq.h:8: 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:584:33: 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:594:59: 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:604:59: 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:692:20: 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:700:20: 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:708:20: 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:717:21: 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:726:21: 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:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> drivers/md/md-bitmap.c:273:18: warning: variable 'rdev' is used uninitialized whenever function 'write_sb_page' is called [-Wsometimes-uninitialized] struct md_rdev *rdev; ~~~~~~~~~~~~~~~~^~~~ drivers/md/md-bitmap.c:278:35: note: uninitialized use occurs here while ((rdev = next_active_rdev(rdev, mddev)) != NULL) { ^~~~ drivers/md/md-bitmap.c:273:22: note: initialize the variable 'rdev' to silence this warning struct md_rdev *rdev; ^ = NULL 13 warnings generated. vim +273 drivers/md/md-bitmap.c 270 271 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait) 272 { > 273 struct md_rdev *rdev; 274 struct mddev *mddev = bitmap->mddev; 275 int ret; 276 277 do { 278 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) { 279 ret = __write_sb_page(rdev, bitmap, page); 280 if (ret) 281 return ret; 282 } 283 } while (wait && md_super_wait(mddev) < 0); 284 285 return 0; 286 } 287 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
