[kbuild-all] Re: arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc)

Hi, On Wed, Aug 12, 2020 at 09:49:38AM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: fb893de323e2d39f7a1f6df425703a2edbdf56ea > commit: 47e4937a4a7ca4184fd282791dfee76c6799966a erofs: move erofs out of staging > date: 12 months ago > config: sparc64-randconfig-s032-20200812 (attached as .config) > compiler: sparc64-linux-gcc (GCC) 9.3.0 > 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: v0.6.2-168-g9554805c-dirty > git checkout 47e4937a4a7ca4184fd282791dfee76c6799966a > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=sparc64 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp(a)intel.com&gt; > > > sparse warnings: (new ones prefixed by >>) > > fs/erofs/utils.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:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc) > -- > fs/erofs/zdata.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:161:55: sparse: sparse: cast truncates bits from constant value (ffffffffe0f510cc becomes cc) > arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe) > arch/sparc/include/asm/cmpxchg_64.h:161:50: sparse: sparse: cast truncates bits from constant value (5f0ecafe becomes fe) > arch/sparc/include/asm/cmpxchg_64.h:161:55: sparse: sparse: cast truncates bits from constant value (5f0edead becomes ad) > > vim +161 arch/sparc/include/asm/cmpxchg_64.h > > d550bbd40c0e10 David Howells 2012-03-28 155 > d550bbd40c0e10 David Howells 2012-03-28 156 static inline unsigned long > d550bbd40c0e10 David Howells 2012-03-28 157 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) > d550bbd40c0e10 David Howells 2012-03-28 158 { > d550bbd40c0e10 David Howells 2012-03-28 159 switch (size) { > a12ee2349312d7 Babu Moger 2017-05-24 160 case 1: > a12ee2349312d7 Babu Moger 2017-05-24 @161 return __cmpxchg_u8(ptr, old, new); > d550bbd40c0e10 David Howells 2012-03-28 162 case 4: > d550bbd40c0e10 David Howells 2012-03-28 163 return __cmpxchg_u32(ptr, old, new); > d550bbd40c0e10 David Howells 2012-03-28 164 case 8: > d550bbd40c0e10 David Howells 2012-03-28 165 return __cmpxchg_u64(ptr, old, new); > d550bbd40c0e10 David Howells 2012-03-28 166 } > d550bbd40c0e10 David Howells 2012-03-28 167 __cmpxchg_called_with_bad_pointer(); > d550bbd40c0e10 David Howells 2012-03-28 168 return old; > d550bbd40c0e10 David Howells 2012-03-28 169 } > d550bbd40c0e10 David Howells 2012-03-28 170 Again, I have no idea how to deal with that in my current gatekeeping code. I got these reports, but I cannot help to resolve that. Even I don't know if that's another sparse issue (since I only got such reports on sparc and alpha arch, but no x86 or arm64.) https://lore.kernel.org/r/202007251532.y5A10ZoO%25lkp@intel.com https://lore.kernel.org/r/202007272132.1AgbBO3U%25lkp@intel.com https://lore.kernel.org/r/202008100408.Wc6WGrac%25lkp@intel.com https://lore.kernel.org/r/202008120933.YrVhHyoA%25lkp@intel.com If no one can help that, could you please silence such reports. It really makes me confusing.

Thanks, Gao Xiang > :::::: The code at line 161 was first introduced by commit > :::::: a12ee2349312d7112b9b7c6ac2e70c5ec2ca334e arch/sparc: Introduce cmpxchg_u8 SPARC > > :::::: TO: Babu Moger <babu.moger(a)oracle.com&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 _______________________________________________ kbuild-all mailing list -- kbuild-all(a)lists.01.org To unsubscribe send an email to kbuild-all-leave(a)lists.01.org