[ammarfaizi2-block:dhowells/linux-fs/afs-testing 44/45] arch/sparc/include/asm/cmpxchg_64.h:95:36: sparse: sparse: cast truncates bits from constant value (5e5ee5e5 becomes e5e5)

[ammarfaizi2-block:dhowells/linux-fs/afs-testing 44/45] arch/sparc/include/asm/cmpxchg_64.h:95:36: sparse: sparse: cast truncates bits from constant value (5e5ee5e5 becomes e5e5)

[kernel test robot]

tree:   https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/afs-testing
head:   bd9f21ac2aa3a4b3332c504a89afe0019a56391a
commit: 17b80dadaf0195ee91f7f115d78b0ea93ae3355c [44/45] Check for dead timer
config: sparc-randconfig-s031-20220327 (https://download.01.org/0day-ci/archive/20220327/202203270732.dEGMthw5-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 11.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/ammarfaizi2/linux-block/commit/17b80dadaf0195ee91f7f115d78b0ea93ae3355c
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block dhowells/linux-fs/afs-testing
        git checkout 17b80dadaf0195ee91f7f115d78b0ea93ae3355c
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=sparc SHELL=/bin/bash kernel/time/

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


sparse warnings: (new ones prefixed by >>)
   kernel/time/timer.c: note: in included file (through arch/sparc/include/asm/cmpxchg.h, arch/sparc/include/asm/atomic_64.h, arch/sparc/include/asm/atomic.h, ...):
>> arch/sparc/include/asm/cmpxchg_64.h:95:36: sparse: sparse: cast truncates bits from constant value (5e5ee5e5 becomes e5e5)

vim +95 arch/sparc/include/asm/cmpxchg_64.h

79d39e2bab60d1 Babu Moger    2017-05-24   89  
d550bbd40c0e10 David Howells 2012-03-28   90  static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
d550bbd40c0e10 David Howells 2012-03-28   91  				       int size)
d550bbd40c0e10 David Howells 2012-03-28   92  {
d550bbd40c0e10 David Howells 2012-03-28   93  	switch (size) {
79d39e2bab60d1 Babu Moger    2017-05-24   94  	case 2:
79d39e2bab60d1 Babu Moger    2017-05-24  @95  		return xchg16(ptr, x);
d550bbd40c0e10 David Howells 2012-03-28   96  	case 4:
d550bbd40c0e10 David Howells 2012-03-28   97  		return xchg32(ptr, x);
d550bbd40c0e10 David Howells 2012-03-28   98  	case 8:
d550bbd40c0e10 David Howells 2012-03-28   99  		return xchg64(ptr, x);
d550bbd40c0e10 David Howells 2012-03-28  100  	}
d550bbd40c0e10 David Howells 2012-03-28  101  	__xchg_called_with_bad_pointer();
d550bbd40c0e10 David Howells 2012-03-28  102  	return x;
d550bbd40c0e10 David Howells 2012-03-28  103  }
d550bbd40c0e10 David Howells 2012-03-28  104  

:::::: The code at line 95 was first introduced by commit
:::::: 79d39e2bab60d18a68a5abc00be4506864397efc arch/sparc: Introduce xchg16 for SPARC

:::::: TO: Babu Moger <babu.moger@oracle.com>
:::::: CC: David S. Miller <davem@davemloft.net>

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [ammarfaizi2-block:dhowells/linux-fs/afs-testing 44/45] arch/sparc/include/asm/cmpxchg_64.h:95:36: sparse: sparse: cast truncates bits from constant value (5e5ee5e5 becomes e5e5)

[David Howells]

kernel test robot <lkp@intel.com> wrote:

> >> arch/sparc/include/asm/cmpxchg_64.h:95:36: sparse: sparse: cast truncates bits from constant value (5e5ee5e5 becomes e5e5)

Just ignore this.  The patch that triggered the objection is a debugging patch
designed to track down a specific problem and is not intended for upstreaming.

David