Re: [PATCH v2 net] net: Fix sk->sk_stamp race in sock_recv_cmsgs().

[kernel test robot <lkp@intel.com>]

Hi Kuniyuki,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Kuniyuki-Iwashima/net-Fix-sk-sk_stamp-race-in-sock_recv_cmsgs/20230509-005901
base:   net/main
patch link:    https://lore.kernel.org/r/20230508165815.45602-1-kuniyu%40amazon.com
patch subject: [PATCH v2 net] net: Fix sk->sk_stamp race in sock_recv_cmsgs().
config: arm64-randconfig-s032-20230507 (https://download.01.org/0day-ci/archive/20230509/202305091519.TLuWISjA-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
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: v0.6.4-39-gce1a6720-dirty
        # https://github.com/intel-lab-lkp/linux/commit/7755d082501de4c89033aed3be404114fcba1c44
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Kuniyuki-Iwashima/net-Fix-sk-sk_stamp-race-in-sock_recv_cmsgs/20230509-005901
        git checkout 7755d082501de4c89033aed3be404114fcba1c44
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/firmware/tegra/ net/mctp/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305091519.TLuWISjA-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   net/mctp/af_mctp.c: note: in included file (through arch/arm64/include/asm/atomic.h, include/linux/atomic.h, include/asm-generic/bitops/atomic.h, ...):
>> arch/arm64/include/asm/cmpxchg.h:174:1: sparse: sparse: cast truncates bits from constant value (ffffffffc4653600 becomes 0)
   arch/arm64/include/asm/cmpxchg.h:174:1: sparse: sparse: cast truncates bits from constant value (ffffffffc4653600 becomes 3600)

vim +174 arch/arm64/include/asm/cmpxchg.h

10b663aef1c247 Catalin Marinas 2012-03-05  170  
305d454aaa292b Will Deacon     2015-10-08  171  __CMPXCHG_GEN()
305d454aaa292b Will Deacon     2015-10-08  172  __CMPXCHG_GEN(_acq)
305d454aaa292b Will Deacon     2015-10-08  173  __CMPXCHG_GEN(_rel)
305d454aaa292b Will Deacon     2015-10-08 @174  __CMPXCHG_GEN(_mb)
10b663aef1c247 Catalin Marinas 2012-03-05  175  

-- 
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https://github.com/intel/lkp-tests