[kbuild-all] drivers/net/dsa/ocelot/seville_vsc9953.c:1255:34: warning: unused variable 'seville_of_match'

Sunday, 11 July 2021

Hi Alexander,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   af4cf6a5689a9ecc21722cb2bb6220dcaee89c6e
commit: 227d72063fccb2d19b30fb4197fba478514f7d83 dsa: simplify Kconfig symbols and
dependencies
date:   4 months ago
config: s390-randconfig-r035-20210711 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
8d69635ed9ecf36fd0ca85906bfde17949671cbe)
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...
        git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 227d72063fccb2d19b30fb4197fba478514f7d83
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 

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 drivers/net/dsa/ocelot/seville_vsc9953.c:6:
   In file included from include/soc/mscc/ocelot_vcap.h:9:
   In file included from include/soc/mscc/ocelot.h:10:
   In file included from include/linux/if_vlan.h:10:
   In file included from include/linux/netdevice.h:37:
   In file included from include/net/net_namespace.h:39:
   In file included from include/linux/skbuff.h:31:
   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:80:
   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:34:59: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
           ___constant_swab32(x) :                 \
                              ^
   include/uapi/linux/swab.h:21:12: note: expanded from macro
'___constant_swab32'
           (((__u32)(x) & (__u32)0x00ff0000UL) >>  8) |            \
                     ^
   In file included from drivers/net/dsa/ocelot/seville_vsc9953.c:6:
   In file included from include/soc/mscc/ocelot_vcap.h:9:
   In file included from include/soc/mscc/ocelot.h:10:
   In file included from include/linux/if_vlan.h:10:
   In file included from include/linux/netdevice.h:37:
   In file included from include/net/net_namespace.h:39:
   In file included from include/linux/skbuff.h:31:
   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:80:
   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:34:59: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
           ___constant_swab32(x) :                 \
                              ^
   include/uapi/linux/swab.h:22:12: note: expanded from macro
'___constant_swab32'
           (((__u32)(x) & (__u32)0xff000000UL) >> 24)))
                     ^
   In file included from drivers/net/dsa/ocelot/seville_vsc9953.c:6:
   In file included from include/soc/mscc/ocelot_vcap.h:9:
   In file included from include/soc/mscc/ocelot.h:10:
   In file included from include/linux/if_vlan.h:10:
   In file included from include/linux/netdevice.h:37:
   In file included from include/net/net_namespace.h:39:
   In file included from include/linux/skbuff.h:31:
   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:80:
   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:34:59: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
           __fswab32(x))
                     ^
   In file included from drivers/net/dsa/ocelot/seville_vsc9953.c:6:
   In file included from include/soc/mscc/ocelot_vcap.h:9:
   In file included from include/soc/mscc/ocelot.h:10:
   In file included from include/linux/if_vlan.h:10:
   In file included from include/linux/netdevice.h:37:
   In file included from include/net/net_namespace.h:39:
   In file included from include/linux/skbuff.h:31:
   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:80:
   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/net/dsa/ocelot/seville_vsc9953.c:1255:34: warning: unused
variable 'seville_of_match' [-Wunused-const-variable]    static const struct
of_device_id seville_of_match[] = {
                                    ^
   21 warnings generated.

vim +/seville_of_match +1255 drivers/net/dsa/ocelot/seville_vsc9953.c

84705fc165526e Maxim Kochetkov 2020-07-13  1254  
84705fc165526e Maxim Kochetkov 2020-07-13 @1255  static const struct of_device_id
seville_of_match[] = {
84705fc165526e Maxim Kochetkov 2020-07-13  1256  	{ .compatible =
"mscc,vsc9953-switch" },
84705fc165526e Maxim Kochetkov 2020-07-13  1257  	{ },
84705fc165526e Maxim Kochetkov 2020-07-13  1258  };
84705fc165526e Maxim Kochetkov 2020-07-13  1259  MODULE_DEVICE_TABLE(of,
seville_of_match);
84705fc165526e Maxim Kochetkov 2020-07-13  1260  

:::::: The code at line 1255 was first introduced by commit
:::::: 84705fc165526e8e55d208b2b10a48cc720a106a net: dsa: felix: introduce support for
Seville VSC9953 switch

:::::: TO: Maxim Kochetkov <fido_max(a)inbox.ru&gt;
:::::: CC: David S. Miller <davem(a)davemloft.net&gt;

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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[kbuild-all] drivers/net/dsa/ocelot/seville_vsc9953.c:1255:34: warning: unused variable 'seville_of_match'