arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression

From: kernel test robot <lkp@intel.com>
To: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Sudeep Holla <sudeep.holla@arm.com>
Subject: arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression
Date: Wed, 6 Jan 2021 13:50:41 +0800	[thread overview]
Message-ID: <202101061337.X7esYQdD-lkp@intel.com> (raw)

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62
commit: 68c5debcc06d6d24f15dbf978780fc5efc147d5e arm64: implement CPPC FFH support using AMUs
date:   8 weeks ago
config: arm64-randconfig-s032-20210106 (attached as .config)
compiler: aarch64-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: v0.6.3-208-g46a52ca4-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=68c5debcc06d6d24f15dbf978780fc5efc147d5e
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 68c5debcc06d6d24f15dbf978780fc5efc147d5e
        # 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=arm64 

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 >>)"
>> arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression

vim +367 arch/arm64/kernel/topology.c

   362	
   363	int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val)
   364	{
   365		int ret = -EOPNOTSUPP;
   366	
 > 367		switch ((u64)reg->address) {
   368		case 0x0:
   369			ret = counters_read_on_cpu(cpu, cpu_read_corecnt, val);
   370			break;
   371		case 0x1:
   372			ret = counters_read_on_cpu(cpu, cpu_read_constcnt, val);
   373			break;
   374		}
   375	
   376		if (!ret) {
   377			*val &= GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
   378					    reg->bit_offset);
   379			*val >>= reg->bit_offset;
   380		}
   381	
   382		return ret;
   383	}
   384	

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

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