[crng-random:jd/preempt-rt 4/9] drivers/char/random.o: warning: objtool: urandom_read_nowarn()+0x1b2: unreachable instruction

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

CC: zx2c4@kernel.org
CC: linux-kernel@vger.kernel.org
TO: "Jason A. Donenfeld" <zx2c4@kernel.org>
CC: "Jean-Philippe Aumasson" <jeanphilippe.aumasson@gmail.com>

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git jd/preempt-rt
head:   e32d7768f472ed279c1c4a82bf8ba611d67db8e2
commit: 17e19ef79dd0e0ad4b7ec2831088282ddd7674cd [4/9] random: use linear min-entropy accumulation crediting
config: x86_64-buildonly-randconfig-r002-20220207 (https://download.01.org/0day-ci/archive/20220209/202202091149.sGYokEQM-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project e8bff9ae54a55b4dbfeb6ba55f723abbd81bf494)
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git/commit/?id=17e19ef79dd0e0ad4b7ec2831088282ddd7674cd
        git remote add crng-random git://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git
        git fetch --no-tags crng-random jd/preempt-rt
        git checkout 17e19ef79dd0e0ad4b7ec2831088282ddd7674cd
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/

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

All warnings (new ones prefixed by >>):

   drivers/char/random.c:1882:6: warning: no previous prototype for function 'add_hwgenerator_randomness' [-Wmissing-prototypes]
   void add_hwgenerator_randomness(const char *buffer, size_t count,
        ^
   drivers/char/random.c:1882:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void add_hwgenerator_randomness(const char *buffer, size_t count,
   ^
   static 
   1 warning generated.
>> drivers/char/random.o: warning: objtool: urandom_read_nowarn()+0x1b2: unreachable instruction

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