Hi Daniel,

I love your patch! Perhaps something to improve:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Daniel-Borkmann/BPF-support-for-global-data/20190301-112203
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: x86_64-randconfig-x017-201908 (attached as .config)
compiler: gcc-8 (Debian 8.2.0-21) 8.2.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   kernel//bpf/arraymap.c: In function 'array_map_direct_value_offset':
>> kernel//bpf/arraymap.c:182:24: warning: initialization of 'long unsigned int' from 'char *' makes integer from pointer without a cast [-Wint-conversion]
     unsigned long base  = array->value;
                           ^~~~~

vim +182 kernel//bpf/arraymap.c

   176	
   177	static int array_map_direct_value_offset(const struct bpf_map *map, u64 imm,
   178						 u32 *off)
   179	{
   180		struct bpf_array *array = container_of(map, struct bpf_array, map);
   181		unsigned long range = map->value_size;
 > 182		unsigned long base  = array->value;
   183		unsigned long addr  = imm;
   184	
   185		if (map->max_entries != 1)
   186			return -ENOENT;
   187		if (addr < base || addr >= base + range)
   188			return -ENOENT;
   189	
   190		*off = addr - base;
   191		return 0;
   192	}
   193	

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