Re: [PATCH] x86: profiling: Set prof_cpu_mask to NULL after free

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

Hi Chen,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.2 next-20230224]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chen-Zhongjin/x86-profiling-Set-prof_cpu_mask-to-NULL-after-free/20230224-165419
patch link:    https://lore.kernel.org/r/20230224084945.134038-1-chenzhongjin%40huawei.com
patch subject: [PATCH] x86: profiling: Set prof_cpu_mask to NULL after free
config: arm-randconfig-r004-20230222 (https://download.01.org/0day-ci/archive/20230225/202302250609.vmze90DB-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project db89896bbbd2251fff457699635acbbedeead27f)
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 arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/intel-lab-lkp/linux/commit/ed9b4879e816862f4f6210b1c429bcbebac6d317
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chen-Zhongjin/x86-profiling-Set-prof_cpu_mask-to-NULL-after-free/20230224-165419
        git checkout ed9b4879e816862f4f6210b1c429bcbebac6d317
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

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/202302250609.vmze90DB-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/profile.c:136:16: error: array type 'cpumask_var_t' (aka 'struct cpumask[1]') is not assignable
           prof_cpu_mask = NULL;
           ~~~~~~~~~~~~~ ^
   1 error generated.


vim +136 kernel/profile.c

    98	
    99	
   100	int __ref profile_init(void)
   101	{
   102		int buffer_bytes;
   103		if (!prof_on)
   104			return 0;
   105	
   106		/* only text is profiled */
   107		prof_len = (_etext - _stext) >> prof_shift;
   108	
   109		if (!prof_len) {
   110			pr_warn("profiling shift: %u too large\n", prof_shift);
   111			prof_on = 0;
   112			return -EINVAL;
   113		}
   114	
   115		buffer_bytes = prof_len*sizeof(atomic_t);
   116	
   117		if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL))
   118			return -ENOMEM;
   119	
   120		cpumask_copy(prof_cpu_mask, cpu_possible_mask);
   121	
   122		prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN);
   123		if (prof_buffer)
   124			return 0;
   125	
   126		prof_buffer = alloc_pages_exact(buffer_bytes,
   127						GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
   128		if (prof_buffer)
   129			return 0;
   130	
   131		prof_buffer = vzalloc(buffer_bytes);
   132		if (prof_buffer)
   133			return 0;
   134	
   135		free_cpumask_var(prof_cpu_mask);
 > 136		prof_cpu_mask = NULL;
   137		return -ENOMEM;
   138	}
   139	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests