[linux-next:master 1141/1176] include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false

[linux-next:master 1141/1176] include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   696206280c5e5c028caf9fd259999cb72b1f6127
commit: 241608fc4d70999563abc1ad52e5114f0021af88 [1141/1176] Kbuild: add Rust support
config: riscv-randconfig-c006-20220404 (https://download.01.org/0day-ci/archive/20220404/202204042148.V5rM3bkT-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project c4a1b07d0979e7ff20d7d541af666d822d66b566)
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=241608fc4d70999563abc1ad52e5114f0021af88
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout 241608fc4d70999563abc1ad52e5114f0021af88
        # save the config file to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:1024:55: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
>> include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   include/asm-generic/io.h:1024:55: warning: performing pointer arithmetic on a null pointer has undefined behavior err: false
   cannot find function `iounmap` in module `bindings`
   --> rust/kernel/io_mem.rs:235:28
   |
   235 | unsafe { bindings::iounmap(self.ptr as _) };
   | ^^^^^^^ help: a function with a similar name exists: `ioremap`
   |
   ::: rust/bindings_helpers_generated.rs:40:5
   |
   40 | / pub fn ioremap(
   41 | | offset: resource_size_t,
   42 | | size: c_types::c_ulong,
   43 | | ) -> c_types::c_void;
   | |______________________________- similarly named function `ioremap` defined here


vim +464 include/asm-generic/io.h

3f7e212df82ca0 Arnd Bergmann  2009-05-13  450  
9216efafc52ff9 Thierry Reding 2014-10-01  451  /*
9216efafc52ff9 Thierry Reding 2014-10-01  452   * {in,out}{b,w,l}() access little endian I/O. {in,out}{b,w,l}_p() can be
9216efafc52ff9 Thierry Reding 2014-10-01  453   * implemented on hardware that needs an additional delay for I/O accesses to
9216efafc52ff9 Thierry Reding 2014-10-01  454   * take effect.
9216efafc52ff9 Thierry Reding 2014-10-01  455   */
9216efafc52ff9 Thierry Reding 2014-10-01  456  
f009c89df79abe John Garry     2020-03-28  457  #if !defined(inb) && !defined(_inb)
f009c89df79abe John Garry     2020-03-28  458  #define _inb _inb
214ba3584b2e2c Stafford Horne 2020-07-26  459  static inline u8 _inb(unsigned long addr)
9216efafc52ff9 Thierry Reding 2014-10-01  460  {
87fe2d543f8173 Sinan Kaya     2018-04-05  461  	u8 val;
87fe2d543f8173 Sinan Kaya     2018-04-05  462  
87fe2d543f8173 Sinan Kaya     2018-04-05  463  	__io_pbr();
87fe2d543f8173 Sinan Kaya     2018-04-05 @464  	val = __raw_readb(PCI_IOBASE + addr);
abbbbc83a210e9 Will Deacon    2019-02-22  465  	__io_par(val);
87fe2d543f8173 Sinan Kaya     2018-04-05  466  	return val;
9216efafc52ff9 Thierry Reding 2014-10-01  467  }
9216efafc52ff9 Thierry Reding 2014-10-01  468  #endif
9216efafc52ff9 Thierry Reding 2014-10-01  469  

:::::: The code at line 464 was first introduced by commit
:::::: 87fe2d543f817300e13f0ea683f38c122737856e io: change inX() to have their own IO barrier overrides

:::::: TO: Sinan Kaya <okaya@codeaurora.org>
:::::: CC: Arnd Bergmann <arnd@arndb.de>

-- 
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