[kbuild-all] [hch-misc:pstore 6/6] fs/pstore/blk.c:199:37: warning: unused variable 'pstore_blk_zone_ops'

tree: git://git.infradead.org/users/hch/misc.git pstore head: e43b52f73d29c36717f1d78600efd2b7fc251c18 commit: e43b52f73d29c36717f1d78600efd2b7fc251c18 [6/6] pstore/blk: use the proper I/O path config: riscv-randconfig-r004-20201014 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project e7b4feea8e1bf520b34ad8c116abab6677344b74) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu git remote add hch-misc git://git.infradead.org/users/hch/misc.git git fetch --no-tags hch-misc pstore git checkout e43b52f73d29c36717f1d78600efd2b7fc251c18 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:556:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inb(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb' #define inb(c) ({ u8 __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:87:48: note: expanded from macro 'readb_cpu' #define readb_cpu(c) ({ u8 __r = __raw_readb(c); __r; }) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inw(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw' #define inw(c) ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:88:76: note: expanded from macro 'readw_cpu' #define readw_cpu(c) ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inl(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inl' #define inl(c) ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:89:76: note: expanded from macro 'readl_cpu' #define readl_cpu(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outb(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:58:68: note: expanded from macro 'outb' #define outb(v,c) ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:91:52: note: expanded from macro 'writeb_cpu' #define writeb_cpu(v, c) ((void)__raw_writeb((v), (c))) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outw(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outw' #define outw(v,c) ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:92:76: note: expanded from macro 'writew_cpu' #define writew_cpu(v, c) ((void)__raw_writew((__force u16)cpu_to_le16(v), (c))) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outl(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outl' #define outl(v,c) ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:93:76: note: expanded from macro 'writel_cpu' #define writel_cpu(v, c) ((void)__raw_writel((__force u32)cpu_to_le32(v), (c))) ^ In file included from fs/pstore/blk.c:13: In file included from include/linux/of_address.h:7: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:148: include/asm-generic/io.h:1017:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; ~~~~~~~~~~ ^ static const struct pstore_zone_ops pstore_blk_zone_ops = { ^ 8 warnings generated. vim +/pstore_blk_zone_ops +199 fs/pstore/blk.c 17639f67c1d61ab WeiXiong Liao 2020-03-25 198 0b670e4409bb317 Christoph Hellwig 2020-10-15 @199 static const struct pstore_zone_ops pstore_blk_zone_ops = { 0b670e4409bb317 Christoph Hellwig 2020-10-15 200 .name = KBUILD_MODNAME, 0b670e4409bb317 Christoph Hellwig 2020-10-15 201 .read = psblk_generic_blk_read, 0b670e4409bb317 Christoph Hellwig 2020-10-15 202 .write = psblk_generic_blk_write, 0b670e4409bb317 Christoph Hellwig 2020-10-15 203 }; 0b670e4409bb317 Christoph Hellwig 2020-10-15 204 :::::: The code at line 199 was first introduced by commit :::::: 0b670e4409bb317166cf859b3bb3af2562d275e7 pstore/zone: split struct pstore_zone_info :::::: TO: Christoph Hellwig <hch(a)lst.de&gt; :::::: CC: Christoph Hellwig <hch(a)lst.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org