Hi "Jason,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20220211]
[cannot apply to char-misc/char-misc-testing linux/master linus/master v5.17-rc3 v5.17-rc2 v5.17-rc1 v5.17-rc3]
[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]

url:    https://github.com/0day-ci/linux/commits/Jason-A-Donenfeld/random-do-not-take-pool-spinlock-at-boot/20220212-083131
base:    6d9bd4ad4ca08b1114e814c2c42383b8b13be631
config: um-x86_64_defconfig (https://download.01.org/0day-ci/archive/20220212/202202121318.QSBkUcwP-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/cac377f6ab22a8bfe966643ebe19812e8187de3b
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jason-A-Donenfeld/random-do-not-take-pool-spinlock-at-boot/20220212-083131
        git checkout cac377f6ab22a8bfe966643ebe19812e8187de3b
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=um SUBARCH=x86_64 SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   drivers/char/random.c: In function 'rand_initialize':
>> drivers/char/random.c:162:3: error: implicit declaration of function '_mix_pool_bytes'; did you mean 'mix_pool_bytes'? [-Werror=implicit-function-declaration]
     162 |   _mix_pool_bytes(&rv, sizeof(rv));
         |   ^~~~~~~~~~~~~~~
         |   mix_pool_bytes
   drivers/char/random.c: At top level:
   drivers/char/random.c:822:13: warning: conflicting types for '_mix_pool_bytes'
     822 | static void _mix_pool_bytes(const void *in, size_t nbytes)
         |             ^~~~~~~~~~~~~~~
>> drivers/char/random.c:822:13: error: static declaration of '_mix_pool_bytes' follows non-static declaration
   drivers/char/random.c:162:3: note: previous implicit declaration of '_mix_pool_bytes' was here
     162 |   _mix_pool_bytes(&rv, sizeof(rv));
         |   ^~~~~~~~~~~~~~~
   drivers/char/random.c:1109:6: warning: no previous prototype for 'add_hwgenerator_randomness' [-Wmissing-prototypes]
    1109 | void add_hwgenerator_randomness(const void *buffer, size_t count,
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +162 drivers/char/random.c

   138 
   139  /*
   140   * Note that setup_arch() may call add_device_randomness()
   141   * long before we get here. This allows seeding of the pools
   142   * with some platform dependent data very early in the boot
   143   * process. But it limits our options here. We must use
   144   * statically allocated structures that already have all
   145   * initializations complete at compile time. We should also
   146   * take care not to overwrite the precious per platform data
   147   * we were given.
   148   */
   149  int __init rand_initialize(void)
   150  {
   151          size_t i;
   152          ktime_t now = ktime_get_real();
   153          bool arch_init = true;
   154          unsigned long rv;
   155 
   156          for (i = BLAKE2S_BLOCK_SIZE; i > 0; i -= sizeof(rv)) {
   157                  if (!arch_get_random_seed_long_early(&rv) &&
   158                      !arch_get_random_long_early(&rv)) {
   159                          rv = random_get_entropy();
   160                          arch_init = false;
   161                  }
 > 162                  _mix_pool_bytes(&rv, sizeof(rv));
   163          }
   164          _mix_pool_bytes(&now, sizeof(now));
   165          _mix_pool_bytes(utsname(), sizeof(*(utsname())));
   166 
   167          extract_entropy(base_crng.key, sizeof(base_crng.key));
   168          ++base_crng.generation;
   169 
   170          if (arch_init && trust_cpu && crng_init < 2) {
   171                  crng_init = 2;
   172                  pr_notice("crng init done (trusting CPU's manufacturer)\n");
   173          }
   174 
   175          if (ratelimit_disable) {
   176                  urandom_warning.interval = 0;
   177                  unseeded_warning.interval = 0;
   178          }
   179          return 0;
   180  }
   181 

---
0-DAY CI Kernel Test Service, Intel Corporation
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